Edition - March 2024

Fertilization: the cornerstone of healthy soils

HIGHLIGHTED ARTICLES

SCIENCE AND AGRIBUSINESS

NO-TILL FARMING: What is new

CROPS’ NUTRITION

Fertilization is NOT negotiable

ALTERNATIVE PRODUCTION

The society of the hive: the importance of bees for crops and humanity

INTERNATIONAL

CROPS’ NUTRITION

The soil in times of climate change

Checking the soil's pulse: the challenge of collecting precise data

We can eat sorghum as well

Personal hardships led her toward the countryside and the field where she found a new passion owing to Aapresid.

INSTITUTIONAL

Biostimulants application in grain crops in the Argentine Pampeana region: just a trend or valuable for the producer?

Special fertilization, unparalleled cultivation

Is it possible to produce more by using less?

The society of the hive: the importance of bees for crops and humanity

Fertilization of winter forages: alchemy or agronomy?

EDITORIAL

Fertilization: the cornerstone of healthy soils

Nature is an open system with different levels of organization, self-regulation and adaptation to the environment, providing a certain balance and stability throughout time.

After centuries of conventional agriculture, mankind broke this balance by disturbing the soil with tillage practices and nutrient extraction through the harvesting of plants generated in the area to be consumed as food, energy or fiber. It is important to emphasize that the collected elements are nutrients that are no more part of the natural degradation cycle of residues and their later reinstatement into soils, resulting in a deficit in the original nutrients content of the soil.

If this imbalance is not remedied, it leads to a gradual degradation of the soil's chemical, physical and biological aspects. The reduction of organic matter (OM) content, the depletion and instability of nutrients, among others, change the function of

the soil, such as water-retaining capacity, nutrients cycling and mass sustaining of microorganisms essentially needed for a healthy soil.

For a long time, the main approach on soil fertility was focused on the availability and management of nutrients, employing practices like mineral fertilization to correct specific deficiencies. This led to the development of soil analysis and fertilization programs based on the replenishment of those elements spent by crops.

Lately, it was known that soil fertility was not solely limited to nutrients availability, but also that it was influenced by biological factors, for instance, microbial activity or diversity of life in the soil, and physical factors, such as soil structure or water retention capacity. This led to a more holistic approach that recognizes the importance of maintaining long-term soil health. Said viewpoint includes regenerative agricultural practices in

order to boost biodiversity, conserve organic matter, reduce phytosanitary usage, and promote integrated management systems that minimize environmental impact and maximize resilience. A healthy soil is essential for food security, environmental sustainability and all ecosystems health.

The emergence and high adoption of no tillage systems–which in order to succeed requires the introduction of the terms balanced nutrition, diversity, soil protection and integrated management of adversities–made a percentage of producers to employ fertility practices as one of the foundations for sustainability in the production system.

In a similar course, new management means were developed, such as system intensification, that combines cash crops and service crops. This approach aims at including concepts like "always green", to provide nourishment to all life in the soil throughout the year, among other ecosystemic benefits. The use of service crops is a great tool that enables a long-term vision regarding the improvement of factors affecting the system's fertility.

Moreover, as a response to global demands in reducing environmental impact on production systems due to the use of chemical-based supplies, the development of new products with minor carbon footprints was recently intensified. Nowadays, the market offers new and better formulations known as bioinputs. In the category of fertilizers, we find biofertilizers and/or biostimulants, that provide nutrients or generate certain conditions within the plant for it to absorb and intercept nutrients. Although these developments are producing positive results, there will be necessary more long-term research and studies to determine if the microbiome can compensate and replace mineral fertilizers. Currently, there are no indicators that measure the actual impact of biofertilizers in the system.

Challenges and opportunities

In general terms, when analyzing the situation in our country, Argentina has conducted little intensive fertilization historically, clearly below the requirements of cultivations, resulting in negative nutrient balances. The short-term vision, the rare tendency to conduct analysis of the soil, and the frequent economic crisis–which raise the price and affect fertilizers availability, in addition to compromising the productive system profitability–are some of the reasons that have led to the current situation.

Before these issues, there are several directions in which progress can be made.

Promoting the usage of Good Agricultural Practices (GAP) that include balanced nutrition as a productive foundation. This implies the use of diagnostic tools like soil analysis–a key practice to conduct a well-made nutritional diagnosis at very low costs–mapping, remote sensors, drones, NDVI images, etc. All of this must be integrated along other variables that influence the system, like soil's physical state. This wide range of tools allows to delimit sites for precision agriculture and to be more efficient.

Integrating the use of mineral and biologicalbased fertilizers to diversify sources, which maximizes and enhances the effects on the system, reduces environmental impact and promotes sustainability.

Intensifying and diversifying crop’s management within the plots, employing rotations, new species, new sowing dates and service crops. All of this contributes to the concept of constant regeneration, increases resilience in soils and favors conditions to provide production processes with the entire living machinery in the soil at full potential.

Finally, it is essential to design public policies encouraging the promotion and motivation of GAPs, so as to reach production potential by minimizing environmental impact.

Agr. Engr. María Augusta González

Aapresid Executive Committee

Partner Companies

RESPONSIBLE EDITOR

President of Aapresid

Marcelo Torres

DEPUTY DIRECTOR OF PROSPECTIVA ASSISTANT DEPUTY DIRECTOR

Paola Díaz Carolina Meiller

EXECUTIVE EDITOR

Rodrigo Rosso

WRITING AND EDITING

Antonella Fiore

CONTENT MANAGEMENT

María Eugenia Magnelli

PROOFREADING AND EDITING

Lucía Cuffia

TRANSLATION

Laura Cudugnello

LAYOUT AND DESIGN

Daiana Fiorenza

Chiara Scola

COORDINATING MANAGER

Tomás Coyos

PROSPECTIVE PROGRAM

Rodrigo Rosso

Antonella Fiore

Delfina Petrocelli

Lucía Morasso

RESOURCES GENERATION

Matías Troiano

Alejandro Fresneda

Carla Biasutti

Elisabeth Pereyra

COMMUNICATION

Victoria Cappiello

Matilde Gobbo

Florencia Cappiello

Elina Ribot

Magalí Asencio

Agustina Vacchina

Delfina Sanchez

MARKETING

Lucía Ceccarelli

CHACRAS SYSTEM

Andrés Madías

Suyai Almirón

Magalí Gutiérrez

Lina Bosaz

Ramiro Garfagnoli

Solene Mirá

PEST MANAGEMENT NETWORK

Eugenia Niccia

Juan Cruz Tibaldi

Ignacio Dellagiovanna

AAPRESID REGIONALS

Matías D’Ortona

Virginia Cerantola

Bruno De Marco

INTERNATIONAL PROGRAM

Mailén Saluzzio

Federico Ulrich

AAPRESID CERTIFICATIONS

Juan Pablo Costa

Rocío Belda

Eugenia Moreno

ADMINISTRATION AND FINANCE

Cristián Verna

Vanesa Távara

Dana Camelis

María Laura Torrisi

Mariana López

Daniela Moscatello

Samanta Salleras

Julieta Voltattorni

PERSONNEL MANAGEMENT

Macarena Vallejos

INSTITUTIONAL RELATIONS

Lucía Muñoz

STRATEGIC PROJECTS SECRETARY

María Florencia Accame

María Florencia Moresco

Karen Crumenauers

NO-TILL FARMING: What is new

Latest studies are shedding new light on the issues and achievements of no-till farming in sustainable agriculture. From preserving biodiversity to improving soil quality, this practice is redefining the agricultural future. Moreover, notill farming high yields are reinforcing its economic viability, sowing a promising future.

By Hugo Permingeat

Aapresid’s Technology Prospective Committee

No-till farming, highly adopted in Argentine agriculture, is still a subject of study and research globally. Contrary to conventional methods involving soil disturbance before sowing, no-till farming entails the non-disruption of the soil This approach has the potential to improve agricultural sustainability by reducing erosion, maintaining moisture and promoting ecosystem's health.

By maintaining vegetation covers and crop residues on the surface, no-till farming boosts soil biodiversity and can contribute significantly to climate change mitigation.

This article highlights some of the latest studies that explore the key aspects of no-till farming and analyze its benefits for both the producer and the environment.

At a global scale, the agricultural land area covers around five billion hectares, representing around 38% of the earth's surface. Dry farming covers almost 41% of the world's arable land and it is essential for feeding more than two billion people. However, land degradation and the poor quality of the soil had had a major impact in crop production and food security within those arable lands.

Increasing soil organic carbon (SOC) is a main issue in matters of maintaining soil quality, crops productivity and other ecosystemic services. Conventional methods involving intensive tillage have resulted in important losses of SOC in arable lands. Intensive tillage increases the chances of aggregates alteration, heightening soils’ vulnerability to erosion and water runoff. Moreover, it leads to the loss of important ecosystemic services, such cycling and storing of nutrients, retention and availability of water in soil, and net primary productivity, which threatens soil productivity and expands desertification (Thapa et al., 2023).

Soil's physical structure is essential to indicate soil health and to control numerous processes and edaphic functions, while at the same time serves as a vital means for the development of plant roots. As functional units of physical structure, soil aggregates are key determinants for organic matter stabilization, helping to prevent the loss of carbon and nitrogen in soil due to mineralization. Conventional tillage practices disintegrate soil aggregates both in a direct and indirect manner, exposing organic matter to microbes. By contrast, no-till farming favors a better physical quality of the soil and the sustainability of the farming system.

The adoption of no-till farming has been accepted as an efficient practice to enhance soil health and boost carbon sinks in croplands. Therefore, it is necessary to understand in depth how notill farming affects soil aggregates, SOC and the total nitrogen concentration in aggregate fractions of cropland ecosystems (Li P et al., 2023).

Highlighted below, there are some investigations on the multiple effects of no-till farming, such as

Carbon and Nitrogen stocks

Li P et al., (2023) carried out a meta-analysis to examine the responses of soil aggregates, soil organic carbon (SOC) and total nitrogen (TN) related to no-till farming at a global scale. Their findings indicate that no-till farming increased soil aggregation, especially of macroaggregates, and promoted SOC and TN accumulation in every aggregate fraction of the cropland.

In another article published recently, Breil et al., (2023) proved that conservation practices can enhance SOC sinks. More specifically, they found that the combination of service crops and notill farming raised SOC content significantly, particularly at the upper layers of the soil. Moreover, they observed that service crop practices have influence on soil respiration by boosting root density, specially at the topsoil, promoting SOC accumulation.

Biodiversity conservation

Management strategies typically aimed at biodiversity conservation seek to minimize physical disruptions and create suitable habitats for the soil's microbiota and animals, which are vital for nutrient cycles, ensuring food production and agroecosystem sustainability. No-till farming can enhance microbiota in the soil–and its diversity–by reducing the physical disruption of their habitat, while the use of stubble can increase nutrient availability. Moreover, crop rotation provides soil nutrients balance, as well as a wide range of food resources for the living organisms in the soil.

Long-term no-till farming systems under rotation exhibit similar conditions to that of the natural reference system, promoting a continuous residue cycle, stimulating soil's biological activity and improving crops productivity. Similarly, when analyzing residue decomposition, together with other features of the soil, they become a valuable indicator for the understanding of biological dynamics in long-term conservation systems. These dynamics are closely related with management changes of crop species.

Plant species diversity in no tillage systems increase the abundance of microorganisms in the soil and reduce stubble decomposition rate (Polesso et al., 2024). These authors suggest

the combination of no-till methods with crop rotation, by using multiple plant species as a strategy to employ long-term conservation practices that imitate natural systems, thereby promoting sustainable agriculture and strengthening soil health.

Crops yield

Non-disruption of the soil provides constant porosity and improves efficiency for the better flowing of liquids and gasses.

Latest studies prove that long-term no-till farming enhances soil’s physical quality, resulting in an increase of grain productivity.

To conclude, no-till farming is considered to be an integral agricultural practice that offers substantial benefits for the environment and agricultural productivity. The retention and

increase of carbon and nitrogen sinks in soils help mitigate climate change. The preservation and promotion of biodiversity in no-till farming systems highlights their capability to create balanced and resilient agricultural environments. Furthermore, major crop yields obtained under this system enhance no-till farming economic viability, strengthening its position as the best option for the future of sustainable agriculture.

An Aapresid congress that will be on everyone's lips

This year, the Aapresid congress will take place in Buenos Aires for a new unprecedented edition. Under the motto "Everything is connected", this traditional conference proposes to connect, to bring together and to extend the borders of the institution.

The Aapresid Congress, one of the most important events within the farming sector, is being prepared for a new unprecedented edition in 2024. Within the framework of Expoagro, and with the presence of Aapresid's authorities and officials of the national government and of Buenos Aires city, the institution provided a foretaste of what is to expect from the upcoming meeting, disclosing location, date and motto for this year's event.

Caption. From left to right: Marcelo Torres, President of Aapresid; Paola Díaz, deputy director of Aapresid's Prospective Program; Fernando Vilella, Argentina's Secretary of Bioeconomy; and Jorge Macri, Head of Government of Buenos Aires city.

As it is already known, Aapresid and Exponenciar signed a strategic alliance to carry on the Congress 2024. This synergy promotes excellence in events planning related to agriculture and technology applied to the agro-industry.

Exponenciar, known as one of the primary organizing companies of agro-industrial exhibitions, provides its expertise in the creation of innovative spaces and their capability to attract various actors from the agribusiness sector. Aapresid, with their focus on sustainable agriculture and the adoption of cutting-edge agricultural practices based on the creation of collaborative innovation networks and a producer-centered approach, adds an invaluable technical and scientific element, with a global perspective full of opportunities.

This edition of the XXXII Aapresid Congress, together with the strength of Expoagro, will be carried out at the Predio Ferial La Rural in Buenos Aires city this 7, 8 and 9 of August. Under the motto "Everything is connected", the event will be focused on the interconnection between sustainable production, food security and environmental protection.

The agenda of the Congress will be arranged around four main axes: 1. productiveenvironmental, 2. economic, 3. social, and 4. technological. On every axis, plenary sessions and other exchange modalities will be organized under the following 12 sub-axes: Regenerative agriculture and Agroecology, Soil Health and Climate Change, Crop Management, Public Policies, Bioeconomy, Water Management, Communication & Education, Que Vadis, Integrated Systems, Machinery, Agtech & Digitization, and Biotechnology.

"For some time now, Aapresid has been considering this congress to be an opportunity to connect with a public that may not know how Argentinian agribusiness works, as well as how there are many producers betting on sustainable production models since years ago," claimed

Marcelo Torres, President of the institution. "At this edition, we want to bring to Buenos Aires our 31 years of leading a space that is still renowned in the fields of knowledge and technologies for sustainable agriculture, and where discussions about future food systems take place.”

Similarly, the president of Aapresid also emphasized the numerous strategic alliances that the institution has been promoting to place Argentinian agriculture in the global scenario. "Together with the Inter-American Institute for Cooperation on Agriculture (IICA), we understand that Argentinian–and the Americas–agriculture can be an ally in the fight against climate change at a global extent," Torres pointed out.

Paola Díaz, Deputy Director of the Aapresid's Perspective Program, delve into the motto of the Congress: "Everything is connected", that seeks to reflect the connection between healthy soils and daily food, in addition to show how our agriculture is key in the fight against climate change. "We know that for a more sustainable agribusiness we need to imitate nature, never leaving aside the technological means that help us to be increasingly efficient. That connection states the essence of regenerative agriculture."

Fernando Vilella, Argentina's Secretary of Bioeconomy, highlighted the low environmental footprint of the Argentine productive system and acknowledged the essential role of Aapresid as regards this achievement. "Aapresid has been a primary agent on this matter, with the adoption of the No-till Farming System in the country. This is a competitive sector even with all the political-economic ups and downs, and involves producers, technologies and Aapresid," he commented. Regarding the motto of the Congress, Vilella considered it to be a "clear reflection of the connection there is between business knowledge, science and technology."

“Together with the Inter-American Institute for Cooperation on Agriculture (IICA), we understand that Argentinian–and the Americas–agriculture can be an ally in the fight against climate change at a global extent"

Jorge Macri, Head of Government of Buenos Aires city, celebrated the development of the Aapresid Congress 2024 in the city. "I believe that being able to help to connect is very important; concepts like 'city or countryside' are already anachronistic," he stated. Macri showed excitement at the opportunity to work alongside Aapresid. "It will be an honor to receive the Aapresid Congress in Buenos Aires, and to work conjointly with them in order to learn as a city about what our soils have to say," he concluded.

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Aapresid

at the Global Forum for Food and Agriculture: the spotlight on No-till Farming and Carbon Footprint

Aapresid was present at the Global Forum for Food and Agriculture (GFFA) in Germany, underlining the Argentine model for sustainable agriculture. Isabel Lizaso, associate and executive of the institution, spoke about the No-till Farming model and its impact on climate change mitigation. And also shared her experience in producing with low Carbon Footprint, highlighting the role of service crops.

JOINING US

During the first month of 2024, Germany was the setting for the Global Forum for Food and Agriculture (GFFA), an event organized by the Federal Ministry of Food and Agriculture (BMEL in German) in cooperation with the Senate of Berlin and Messe Berlin GmbH. At this conference, there were around 2,000 international guests debating about future food systems and how to strengthen collaborations to reach Sustainable Development Goals from the 2030 Agenda.

As it is essential that the producer's voice be present in these discussion spaces, Aapresid promotes an active participation on international forums, in order to position Argentinian agriculture as a strategic ally in the development of sustainable productive models capable of contributing to global challenges related to food production.

Together with Isabel Lizaso, Aapresid was present at the GFFA in a panel about South America's challenges and opportunities with regard to establishing resilient supply chains. Participating at the panel were also Ana Carolina Zimmermann, Brazilian cattle farmer, Jorge Sellare, economist from the University of Wageningen, and Hendrik Schulze-Düllo, Market research at CLAAS Group.

As a result of this strategy, the institution was accompanied by Isabel M. Lizaso, Aapresid farmer from Southeast Buenos Aires Province, member of the Executive Committee, and Deputy Spokesperson of the institution. During her lecture in front of a massive audience, Lizaso conveyed the foundations of the No-till Farming System and its implications in Argentine productive models, as well as its contribution to climate change mitigation.

The Aapresid International Program stated that "to participate in this type of events representing Argentinian agribusiness, is crucial to ensure that all discussions take into account the role of agriculture as part of the solution for global issues, and to acknowledge the producer as a key protagonist in the transition toward more sustainable food systems."

Moreover, the expansion of collaborative innovation networks with new countries is a strategic course of action to build alliances among farmers, researchers, technological companies and the community, promoting the adaptation of productive systems to environmental and cultural characteristics of each region; and contributing to the creation of learning societies.

It is important to highlight that the event took place within a context of tension among several farmers from European countries protesting against EU regulations–like the European Green Deal–that impose strong limitations to agricultural activities without considering tools and means to enable the farmer to lead the transition toward a more sustainable agriculture.

More than 1,000 tractors have participated in the demonstration against the government in Berlin.

"I arrived when they were finishing the tractor demonstrations in Berlin. I think there is a biased and critical view of the farming sector in general.

I was shocked by the impetuosity on how laws and regulations difficult to apply are encouraged, even with all available technologies and innovations. Especially, as the global population is firmly increasing and it is our responsibility to produce more and better food to satisfy that demand," Lizaso commented.

"Aapresid has a lot to contribute in regard to sustainable agriculture. In a country with constant changes on the playing field of exchange, legal and tax matters, the producer has become an expert in producing under unfavorable conditions. In addition, Argentina is the country with major adoption of No-till Farming practices,"

Aapresid's associate and executive pointed out. And added: “Regional branches serving as gathering points for all Aapresid farmers, are spaces of constant exchange of information, innovation and technology. This enables us to make management decisions more efficiently. Is a working methodology that we are sure could be successfully replicated in other parts of the world."

Similarly, it is worth underlining all the assumed commitments by numerous countries in continuing the necessary transformation toward sustainable agricultural and food systems and, therefore, resilience. In addition to the support of agricultural practices that enhance sustainable food production, which as a consequence of climate change and biodiversity crisis, have destabilized the world.

Instituciones que nos acompañan Institutions that accompany us

A model management with minimum C footprint

During this panel, Isabel shared with the audience her experience regarding production with low Carbon Footprint, which she leads at her establishment in Guamini city, Southeast Buenos Aires Province. Her field has been under no-till farming for 20 years and, up until 6 years ago, she only employed service crops in certain situations, aiming to cover the surface of the soil and avoid water evaporation.

Isabel knew that there was yet so much to be improved, so she took action: "My first move was to hire an environmental conditioning service and to conduct a georeferencing soil sampling. Later, I incorporated satellite images to study the crops' evolution and made prescriptions on sowing and fertilization according to the site's environment."

However, everything changed when she was invited to join the regional branch GuaniniCarhué. "It was the first time I heard about Service Crops. They were years of listening and reading: podcasts; exchanges with other associates of the regional branch, the magazine, meetings and debates," she added.

This new-found knowledge enabled Isabel to make the most of the tools she had incorporated, enhancing efficiency and decision-making. "I learned that service crops have huge potential, but that it is of paramount importance to previously know what kind of services we will ask from them." These crops were allies in rotation intensification, passing from the sequence wheat/soybean - corn - soybean, to another one of wheat/soybean - Vicia villosa+Feed Barley or Ryegrass - corn - soybean.

Further on came the sowing of service crops by plane over ongoing corn, both early and late ones. In the first years, ryegrass and feed barley were sowed. This year, a study to change grass for Vicia villosa is being conducted, aiming at further balancing C-N relation of stubble.

"Nutrients available in the soil after corn crops finished maturing were captured by the service crop, acting as a savings sink-like process to return them in the following crop. There was still biological activity due to the development of living roots while corn was already harvested," the producer explained.

The results of all of these improvements were noticeable in a few years: better weed control, major nutrient contribution via biological fertilization, efficiency regarding seeds and fertilizers investment, and more stable and resilient cash crops. "A stable soil and a well-nourished crop are the perfect combination to face climate variations that cannot be controlled," she stated.

However, Isabel decided to go further and assess if this management optimization may also have environmental impact. Supported by Carbon Group, she measured greenhouse gas (GHG) emissions and carbon footprint in her cultivations.

The results showed that, in an average of 5 years and for every crop sowed, 50.6kg CO2eq per tonne of harvested grain were emitted, which represents 80% less than the mean obtained in another study conducted by the consultant.

These values are also placed 80% below the national C footprint for crops such as soybean, wheat and corn (measured by institutions like CONICET-INTI-INTA, Maizar and Argentrigo), if it is considered the increments in carbon capture on the producer's soils with her almost constant no-till practices and photosynthetic activity.

Feed barley service crop sowed by plane over ongoing corn.

Fertilization is NOT negotiable

Essential nutrients like nitrogen, phosphorus, potassium and sulfur enhance growth and quality of crops and soil health. Challenge: nutrients replenishment to ensure the sustainability of Argentinian agricultural systems.

By: Esteban Ciarlo, Gustavo Ferramondo and María

Fernanda González Sanjuan

Fertilization is the cornerstone of farming production, it entails the application of nutrients in the soil to replenish those elements extracted in every harvest, enhancing crops' growth and yields. Fertilizers contain a great variety of essential elements–nitrogen, phosphorus, potassium, magnesium and sulfur–vital for plants' development.

As strategic management means, fertilization provides production systems the following benefits:

Increase in productivity is the most direct and straightforward effect to measure. Proper fertilization helps boost crops and fodder production. Nutrients applied via fertilizers contribute to tissue formation and raise general metabolic activity, allowing plants to grow better and faster.

Nutrients are also involved in the quality of formed tissues and obtained harvests. For example, phosphorus is essential for root formation, while potassium improves disease resistance and fruit flavor.

A properly applied fertilization accelerates plant growth by reducing growing periods and allowing early harvests for some species, as well as a faster rotation of crops.

Crops’ health is influenced by fertilization. Nutrients strengthen plants and make them more resistant to diseases and pests.

Besides production systems, fertilization can provide numerous solutions against current threats that the environment is exposed to.

A well-managed fertilization–through the generation of a major biomass and vegetation cover–helps prevent soil erosion.

Balanced fertilization, involving the application of several nutrients in necessary quantities to plants, can limit the contamination of groundwater with many mobile nutrients like nitrogen.

Major productivity of fertilized systems can also reduce the pressure on natural and sensitive environments, such as native forests.

Major productivity as a result of higher nutrient availability, means a return of greater organic matter levels to the soil derived from large residue quantities. This entails improvements in various aspects regarding chemical, physical and biological fertility of soils.

In addition, biomass generation and its subsequent transformation in stable organic matter in the soil can increase atmospheric C sequestration–a crucial element involved in global warming processes–expanding its benefits across the entire society.

Deficiency in nutrients availability in soils is a common problem in several Argentinian regions, affecting agricultural productivity and the soil's usage sustainability. The evidence of soil nutrient deficiency in Argentina is generalized in some cases, while in others, is too noticeable in some particular regions.

Nitrogen deficiency is generalized throughout the country, as it is the primary nutrient affecting plant growth in every soil in the world. Nevertheless, these deficiencies are pronounced

in soils with low organic matter levels (sandy, or with many years of intensive extraction), cold due to a low organic matter decomposition, or when there is a very high demand that cannot be compensated by soils supply, which is the usual case of cereals–like wheat or corn–growing at high speed and generating large quantities of biomass.

In the case of phosphorus, the second most important, soils originally more prone to suffer a deficiency of this element are those in Northeast Argentina (NEA). However, there are many published studies and maps proving almost generalized phosphorus deficiencies in most productive areas of the country.

The case of potassium–a nutrient absorbed in large quantities–is special because even though Argentine soils are usually well-stocked with this element (except, namely those tropical soils in Misiones Province), there are some productive areas that are starting to indicate deficiencies consistently. Said deficiencies were clearly relieved in a study conducted by Fertilizar in the provinces of Entre Ríos and Corrientes.

Sulfur often exhibits specific deficiencies, typical in areas with a long history on agriculture activities and declining organic matter levels, being the first cases found in the south of Santa Fe Province. A similar behavior has been seen in micronutrients such as Zinc and Boron, especially in crops with high production potential.

If nutrients are considered as a group, it can be observed how the appearance of nutrients deficiency is increasingly frequent in various productive areas. Although a part of this phenomenon can be explained by gene materials designed to increase biomass levels and to improve harvest indexes of generated biomass, it is very probable that the cause of this tendency is a low replenishment of extracted nutrients.

In Argentina, the evolution of productive systems has led to a high nutrient extraction rate that was not replenished in equal proportions, originating processes of degradation and run out of said resource and threatening sustainability of productive systems. Fertilizer application is the most direct and operational way to replenish

the nutrients extracted by crops. In the past years, there was around 58% of nutrients replenishment in Argentina, taking into account all nutrients and crops, meaning that for every 100kg of extracted nutrients, only 58kg were replenished.

Beyond global replenishment estimations, which indicate intensive nutrient extractions that should be interpreted as deterioration of the soil–the main raw material for agricultural production–there are important differences regarding fertilization contributions between the various crops and nutrients.

Among the most relevant extensive crops, wheat has usually major replenishment percentages; whereas soybean crop, even without considering the nitrogen assimilated from the air by roots, is the one that least responds, and therefore, presents less replenishment values. Given the cultivated surface with this oleaginous plant,

In the past years, there was around 58% of nutrients replenishment in Argentina, taking into account all nutrients and crops, meaning that for every 100kg of extracted nutrients, only 58kg were replenished.

especially in season 2023-2024, it is evident the importance as regards soil conservation that this low replenishment represents. In this context, secondary soybean crops present an even darker scenario, as they frequently use only those nutrients provided by the soil and those that were not used by the previous cereal.

When it comes to the most important nutrients, phosphorus is commonly the one with the highest replenishment levels recorded, probably owing to general responses noticed by the lack of regional maps of extractable phosphorus, the index used to estimate its availability. At the other end there is potassium, the element that was never considered for fertilization plans in the main areas of Argentina, and whose application is almost exclusively limited to some regional products or under intensive production practices.

One particular case is the estimation of global N replenishment as there are legume species of great commercial significance–soybean, alfalfa–that provide this nutrient through biological fixation, which is not sufficiently measured. Therefore, global balance estimations between what is fixated and extracted remains unclear. The addition of vicia–another legume species used as cover crop of great recent dissemination–will probably alleviate the negative balances of nitrogen in soil, although hydric conditions

during last season could have limited the positive effects of this type of crop that is not harvested. In summary, nutrient replenishment in Argentinian agricultural systems is an issue that requires careful management of all resources in order to achieve real sustainable strategies.

The fertilizers market has been maintaining the same tendencies for several years. During 2022, 4.77 million tons were shipped, of which 55% were Nitrogenous, 38% Phosphate-based, 4% Sulfur-containing, and 1% Potassium-based (micronutrients have a low proportion of the total volume of the market, although they are becoming relevant according to their sales numbers). For 2023, it is estimated a decline of 3.9% in comparison to 2022, with similar proportions in every group. It was the second consecutive fall of the market, bearing in mind that the market's volume in 2022 was 16% lower than 2021.

These variations regarding the shipped volume in the market are explained mainly because of climatic conditions like severe droughts, especially in the second semester of 2022, which were prolonged even to this day in some Argentinian areas. Moreover, the cost of fertilizers registered very high volatility, generating much uncertainty for the industry sector when purchasing, and for the producer when defining the margins of the crops. Last but not least, imports did not have the same fluency as previous years owing to restrictions imposed by the government–SIRA and other bureaucratic aspects–causing a slight decrease in fertilizers availability, mostly phosphate-based ones.

If precipitation conditions improve acrossthe-board, the fertilizers market might exceed the maximum historical volume recorded in 2021, since nutrients replenishment is low in Argentina compared with the region and the rest of the world–applied nutrients versus nutrients extracted by crops. In addition, crop yield breaches remain notably broad. In Argentina, increasing the dose of fertilizer per hectare produces a raise of yields, which, almost every year, results in a major economic margin per hectare for the producer.

In Argentina, increasing the dose of fertilizer per hectare produces a raise of yields, which, almost every year, results in a major economic margin per hectare for the producer.

In FERTILIZAR Asociación Civil we are convinced that it is not feasible to carry out agricultural activities in a productive and sustainable manner if different aspects of soil fertility are not well-conserved, many of which are directly related to the proper nutrition of plants and organisms that grow in the soil.

The soil in times of climate change

Climate projections as regards global dynamics scenarios indicate a tendency toward a more intense hydrological cycle, which might cause an increase in soil degradation at a domestic and global scale.

Authors: Carfagno Patricia¹; Imhoff Silvia²; Duval Matias³, Landriscini María Rosa⁴; Castiglioni Mario⁵

¹ Soil Institute, CIRN INTA Castelar - AACS

² ICiAgro Litoral-UNL-CONICET-FCA - AACS

³ Universidad Nacional del Sur. Center of Renewable Natural Resources of the Semi-arid Zone (CERZOS, CONICET) - AACS

⁴ Argentine Association of Soil Science (AACS in Spanish)

⁵ Cátedra de Manejo y Conservación de Suelos, Faculty of Agronomy, UBA - AACS

E-mail contact: carfagno.patricia@inta.gob.ar

One of the most complex elements in the agroecosystem, and essential for food production, is the soil. Internally in the soil, there is an infinite number of organisms that interact and contribute to global cycles that makes life possible. During the XXI century, the soil regained attention in the world's agenda due to its contribution to climate change mitigation. However, there was an increase in degradation processes of this natural resource–erosion, organic carbon loss, nutrients imbalance, acidification, contamination, floods, compaction, salinization and biodiversity loss.

Erosion causes loss of soil because of the action of external agents–wind or water–resulting in the reduction of the topsoil. The loss of soil by water erosion represents one of the main problems affecting productive systems sustainability, with an estimated economic impact of 30 million dollars annually owing to the drop in yields of soybean, corn and wheat. It is estimated that the total loss could raise up to 1.645 billion dollars within a decade, as stated in the book "Estimación de la pérdida de suelo por erosión hídrica en la República Argentina" (Gaitán et al., 2017).

This domestic, scientific study carried out by INTA is the first one made in the last 30 years, and seeks to contribute to the sustainable development and management of soils. According to this study, nearly 26% of the Argentine territory–equivalent to 72 million hectares–presents water erosion levels over tolerance rates, having a negative impact on ecosystems health. This makes the problem worse as the last study conducted in 1988 estimated that the damaged topsoil caused by this process was 25 million hectares, representing a current increase of 47 million hectares.

Besides economic losses, erosion implies additional non-monetary expenses, such as "environmental costs". These are related with the loss or diminish of ecosystemic services provided by the soil. For instance, during the process of erosion, the water drags particles from the soil along with associated pollutants, affecting the quality of bodies of water.

To estimate water erosion, various models have been developed, the most used is the empirical one known as Universal Soil Loss Equation (USLE). USLE is a method to predict soil loss rate

in whatever combination of soil, topography, climate, service crop and management practices. From the creation of this model–using satellite images, basic climate information, soil characteristics, digital land models and field data collection–it was possible to estimate and map current and potential water erosion in soils at a domestic level (Figure 1).

Figure 1. Distribution of current and potential water erosion in the Argentine Republic (Gaitán et al., 2017).

Since the 1990s, as a consequence of the erosion process in soils and the depletion of nutrients by agricultural crops, as well as little replenishment through fertilization, soils started to exhibit symptoms of nutrient decline and organic matter content reduction. Similarly, at the last Argentine Congress of Soil Science it was highlighted that only 30% of the extracted nutrients are replenished in Argentina. Although fertilizers consumption reached a record in 2020, fertilization is still underutilized in the country, causing a negative balance of nutrients. This imbalance causes a deterioration of the soil and of the ecosystemic services provided by fertilizers, originating, in some cases, irreversible damage.

Livestock farming production intensification, together with the mechanical harvesting of fodder and the moving of animals into corrals, caused the extraction rates of some nutrients in plots to tripled, gradually reducing their chemical fertility and, at the same time, generating effluents accumulation that pollute soil, water and air resources. In Argentina, soil salinization and groundwater contamination with nitrite, nitrates,

At the last Argentine Congress of Soil Science it was highlighted that only 30% of the extracted nutrients are replenished in Argentina. Although fertilizers consumption reached a record in 2020, fertilization is still underutilized in the country, causing a negative balance of nutrients.

Metalfor, la Fertilizadora oficial de Aapresid

Conocé más en www.metalfor.com.ar

and numerous organic and inorganic forms of phosphorus constitute severe issues that require immediate action so as to avoid soil degradation in the most productive soils in the country.

Another soil degradation process that has recently got worse is the damage of physical properties. The significant reduction of organic matter and nutrients content, e.g., calcium, that are the main aggregating agents of soil structure in most Argentine regions, increase compaction susceptibility. Nowadays, compaction is the most important process of soil physical degradation globally, and in Argentina is reaching alarming levels in large areas. The loss of aggregating agents, related to the increased size of agricultural equipment and machinery activity in inappropriate humid conditions, causes compaction. This affects edaphic properties negatively–caption and storage of rainwater, root penetration resistance, air and nutrients availability–leading to more fragile productive systems before extreme weather conditions.

Within these contexts, it is important to emphasize that it is easier to maintain soil health than to recover a damaged soil, which usually affects profitability. The key to counteract degradation's negative impact and, simultaneously contribute to soil health, lies in attaining sustainable

production systems. This represents a great challenge, as it implies to coordinate objectives with different impact levels and not always depend on the producer. However, there are alternatives to accomplish sustainable systems. Therefore, it is essential to respect the capacity for use of the land, by employing cash crops and service crops rotations suitable for every situation in order to generate a positive carbon balance. This entails, among other things, acquiring high yield crops to generate covers and roots that provide enough residues to favor organic matter formation, employing fertilization techniques adjusted to crops necessities, correcting edaphic acidity if necessary, applying proper doses of organic amendments, and conducting erosion monitoring practices. To prevent this, it is important to be efficient regarding applications and to conduct constant monitoring through the analysis of chemical and physical properties of the soil.

Proper management of soils allows, undoubtedly, to improve its quality, meaning less risky and more profitable proposals for the producer to face climate change, in addition to reduce the impact on environmental health, which basically affects all living beings.

The effect of the weather

Both climate and changes on land usage are closely related. Climate change's direct effect regarding intensity, duration and precipitation magnitude, along with changes on land usage–including population expansion, deforestation and other human activities–lead to an increased loss of soils by erosion, hence, loss of carbon and nutrients. The soil, as the second major carbon sink of the planet after the oceans, is essential to stop some of the negative effects of climate change. Nevertheless, for soils to provide this ecosystemic service, it is crucial for them to be healthy and to be sustainably and responsibly managed.

In countries like Argentina, it is necessary to adopt mitigation measures that promote higher carbon sequestration, among other things. Carbon sequestration is the process of capturing atmospheric CO2 by plants and storing it in the soil as organic matter. Therefore, those practices that increase carbon in soils (service crops, rotations, balanced fertilization, reasonable grazing, etc.) or that reduce C loss in soils (no

tillage, agricultural intensification, etc.) are some strategies contributing to soil degradation control and, indirectly, climate change mitigation.

One example of the benefits originated by management practices promoting the presence of living vegetation covers and decompactionrelated rotations, is that they help to dissipate the energy caused by water drops, and at the same time, increase water retention and drainage control. Thus, the relation between infiltration and drainage in the first centimeters of the soil's surface is of significant importance (Figure 2).

Other conservation management practices for controlling water erosion involve sowing by cutting across the slope or following the curves' levels, as well as employing terrace systems to shorten the slope. These measures contribute to control erosion processes, and maintain the structure and health of soils for carbon storing. Many of these practices are "abandoned" during drought periods, as erosion signs or the occurrence of rills and gullies (Figure 3) become less noticeable.

Figure 2. Curves on infiltration for tests conducted with a rain microsimulator at EEA INTA Oliveros-Santa Fe Province. Sequences of soybean monocropping under rotation with cereals in compacted and uncompacted soils (Eiza y Carfagno, 2018).

Figure 3. Rill erosion–left–with stubble dragging in no-till farming (Azul, Buenos Aires Province), gully erosion–right–in soybean cultivation at the headland edge (Arrecifes, Buenos Aires Province).

As a conclusion, according to future projections (Borrelli et al., 2020), an increase in erosion processes related to precipitation intensity is expected, within a climate change context. These studies suggest that, when comparing multiple scenarios, a change toward more aggressive water cycles might be the main driver for the future expansion of soil erosion, which would result in carbon losses. According to the utilized model, it is estimated that water erosion might increase between 30% and 66% by 2070.

Hence, from the Argentine Association of Soil Science (AACS in Spanish) we emphisize the importance of not taking soil protection measures lightly and to keep on employing conservation practices, even during drought periods.

Check the references by entering www.aapresid.org.ar/blog/revista-aapresid-n-217

Checking the soil's pulse: the challenge of collecting precise data

The breach between potential and actual crop yield emphasizes the need of employing precise fertilization. Soil rigorous sampling is presented as a key means for accurate decision-making, as well as to achieve sustainable production systems.

By:

F. Mateos Inchauspe¹, N. Diovisalvi¹, F.O. Garcia²,³ and N.I. Reussi Calvo³,⁴*

¹FERTILAB¹, ² Private consultant, ³Unidad Integrada Balcarce Agricultural Experimental Station (EEA) INTA Balcarce - Faculty of Agricultural Sciences, University of Mar del Plata (UNMdP), ⁴CONICET *e-mail: reussicalvo. nahuel@mdp.edu.ar

In Argentina, the breach between potential yield and the one achieved by producers can reach up to 50% in primary crops such as wheat, corn and soybean. Nutrition plays an essential role in the reduction of this breach. Currently, a major demand is observed owing to the increase in crop yield, whereas the natural supply of nutrients in agricultural plots is diminishing due to the loss of organic matter, and, therefore, fertility.

In the Argentine Pampeana region, where there is most of the land under production, the reduction of the yield breach can be explained by the combined effect between nutrients availability and the improvement of edaphic health. Therefore, a balanced nutrition is vital to achieve not only optimal yield, but also a

sustainable usage of the soil. Studies conducted in several areas of the country showed that a balanced nutrition with nitrogen (N), phosphorus (P) and sulfur (S) can contribute between 15% and 47% to crops yield, such as soybean, wheat and corn.

Despite the raising in fertilizers consumption in the past years (Figure 1), the current level of fertilization is not enough to diminish the yield breach. Partial balance assessments of nutrients in main crops are negative for N-P-S, indicating that nutrient extraction in soil exceeds replenishment. Moreover, only 21% of producers conducted an analysis of the soil during the season 2021/22 (Figure 2). Although up until season 2019/20 there was a positive inclination in the adoption of this practice, in past years there has been a slight decrease (Report by Agricultural Applied Technology Survey–AATS–https://www. bolsadecereales.com/tecnologia-informes).

Meaning that fertilizers are being poorly used, and occasionally, without the necessary information to determine proper doses, that is, "blindly".

A balanced nutrition is vital to achieve not only optimal yield, but also a sustainable usage of the soil.

Figure 1. Evolution of fertilizers consumption (by nutrients) in Argentina. Source: Fertilizar A.C. and the Secretary of Agriculture, Livestock and Fisheries of Argentina (SAGyP).

The diagnosis of soil fertility and the suggestion of crop fertilization entail several phases: 1 Soil sampling, 2 Sample analysis, and 3 Interpretation of results. Soil sampling is the most important step of the whole process. There is no analysis and/or suggestion that can improve the representativeness of the collected sample. In the past years, it has been observed that mistakes during soil sampling are 3 to 6 times greater than those happening during the analysis in the laboratory. To understand the importance of this stage, it is necessary to consider that stratum 0-20cm of a 50ha plot has an approximate weight of 120 thousand tones. It is evident that only a little fraction of the soil can be delivered to the

laboratory, generally 500gr per sample. Hence, a series of guidelines should be taken into account in order to obtain a representative sample of the plot or section.

Figure 2. Evolution of the percentage of producers that conducted the analysis in soil in Argentina (% of producers). Source: Report AAATS from the Buenos Aires Grains Exchange, Argentina.

Soil sampling

The first thing to do is to determine the depth (0-20; 20-40; 40-60cm; etc.) and the time of the sampling (pre-sowing, during cultivation, postharvest, etc.) depending on the nutrient and the objective of the analysis (Table 1). In addition, it is crucial to make sure that an appropriate soil sampler probe is employed. It is not advisable to take the sample with a shovel, because this may complicate, among other things, homogenization of the depth of the sample, as well as the taking of numerous subsamples.

The depth of the sample is important because there are nutrients with little mobility in soil like phosphorus (P), that tend to stratify in the first 20 centimeters of the land. Consequently, the result of the analysis may vary if the sample is taken in areas of land of different depth levels. Also, most of the recommendation models for low mobility nutrients fertilization are based on the determination of the content in samples of 0-20cm, that is why a mistake in the depth of the sample will affect the analysis results and suggestions regarding fertilization.

Table 1. Illustrative determinations of soil samples at different depths and time per crop.

Besides stratification, some nutrients present spatial variability. The most common case is that of P, which tends to concentrate near the furrow of the previous crop in no-till farming (with no removal of the soil) and localized fertilization systems. As a result, it is advisable to avoid taking samples from the sowing lines of the previous crop, as well as from the areas close to water sources, wire fences, animal wastes, corners, etc., as they may have a greater concentration than the overall average.

Moreover, it is recommended the extraction of 25-30 subsamples per sample, regardless of the area that is being tested. Thus, any mistake during the conducted task can dilute the final results. Similarly, the sample will be representative when making sure these subsamples are distributed

in the entire area. Once the sample is taken, it is important to thoroughly homogenize 500gr of soil approximately before taking it to the laboratory.

Another aspect to address is the variability within the plot. If a plot has different areas with productive potential, a site-specific soil sampling can be conducted (Figure 3), provided that each area is large enough so as to justify a differentiated management. Contrarily, if a plot has some sections with different productive levels, namely flood-prone areas with no significant percentage of the total surface, it should be conducted in the most representative area of said plot.

Lastly, a very important aspect is the identification of the sample. It is recommended to identify

Figure 3. Diagram of random stratified or site-specific sampling (Source: Carretero et al., 2016-agricultural technical information-IPNI).

samples externally by using permanent markers, external tags or double bags. The minimum amount of information that should be provided includes the name of the plot, and, if necessary, the specific site, in addition to the depth of the sample taken. Never place the identification tag inside the bag containing the sample. A useful option to avoid mistakes is to include a sequential numbering on the identification tags. It is also possible to identify them solely with numbers and then register detailed information of each sample in a form that should be attached when delivering them to the laboratory.

Sample guidelines checklist:

Establish depth and time depending on the nutrient and the objective of the analysis.

Conduct the sampling with an appropriate soil sampler probe.

Avoid the sowing lines of previous crops and also those areas close to water sources, wire fences, animal wastes, corners, etc.

Extract 25-30 subsamples per sample.

Conduct the sampling in specific sites or in the most representative area of the plot.

Identify the samples externally.

Analysis and interpretation of results.

The analyses result of the samples will provide a significant portion of the necessary information for interpretation and decision-making. The analysis conducted in the laboratory produces reliable results of the received sample, supported by material quality, equipment, patterns and control crops employed. There should be no difference between the results obtained in different laboratories for the same sample; however, should they exist, might be due to 1- sample conditioning (fractioning, mixing, homogenization, drying and milling), 2- analysis methodology or, 3- analytical quality of the laboratory. In relation to the latter, there are interlaboratory comparisons (SAMLA, PROINSA, among others) that contribute to quality improvement of results analysis.

Nitrogen

Nitrogen diagnosis consists in determining how much will the crop demand and how much will the soil supply. The demand can be estimated according to the required amount of N per ton, which varies depending on the cultivated species and targeted yield. Yield estimation must consider genetic potential of the employed material, physical and chemical limitations of specific sites within the plot, climatic conditions like precipitation and temperature patterns, among others.

On the other hand, the main components in the supply of N are the N available for sowing and the N mineralized in soil, which becomes available for

The final stage of interpretation has as an objective the decision-making about crop fertilization management. To accomplish this, besides taking into account the analysis results of soil samples, it is necessary to be familiarized with the area where the plot is located, the environment and its productive potential, nutrient dynamics to be diagnosed, etc. Currently, most diagnosis methodologies quantify inorganic labile fractions or indexes that try to extract a proportional fraction of nutrients similar to that absorbed by plants. Among the nutrients that most frequently limit crops yield are N and P, followed by S and, most recently, zinc and boron.

plants after being part of organic matter, and from previous crop residues during the crop cycle. The difference between demand and supply should be provided through fertilization.

To examine initial N availability, it is advisable the sampling of the soil during sowing, both of surface stratum (0-20cm) and those beneath the surface (20-50 or 20-40 and 40-60cm). In regions, or years, with water excess during pre-sowing and/or with predecessors allowing a short period of fallow land–namely soybean, especially secondary one–it is convenient to conduct a second control of N during vegetative phases before crop demand raises, for instance,

in tillering, 3-4 leaves. There are models that propose a threshold of N when sowing (N soil 0-60cm + N fertilizer), varying depending on area, crop and target yield.

Mineralized N from organic matter during the crop growing cycle can be estimated as of the determination of N anaerobic (Nan). This index reflects the mineralization potential that varies between plots or specific sites within a same plot due to previous management and/or soil characteristics. This Nan sampling can be performed on every season of the year, only in stratum 0-20cm, and it is suggested to monitor it every 3-4 years. However, if the sampling is not correctly conducted by respecting the specific sites within each plot, yearly variations regarding Nan values can be observed. Moreover, in plots with vicia or clover as previous crops, Nan values can change from one year to another.

According to more than five thousand samples analyzed by FERTILAB for southeast Buenos Aires, the average value of Nan was 60ppm, with 25% of the plots with values below 45ppm and over 75ppm. Average values of Nan tend

to be lower toward the north and west of the Pampeana region, with an average of 4045ppm in west and north of Buenos Aires, and south of Santa Fe. Generally, for wheat crops, N contribution by mineralization ranges from 2.0 to 2.4kg N/ha per every ppm of Nan, a value that varies depending on the area, date of sowing and soil texture. For summer crops like corn, the contribution can reach values between 3.2 and 4kg N/ha. There are several studies on this subject available in FERTILAB's website (https:// www.laboratoriofertilab.ar/newsletters.php).

Phosphorus

Suggestions on phosphate fertilization are formulated based on the fertility diagnosis on the analysis of P extractable from the soil (P Bray) at 0-20cm. Although phosphorus is a stable nutrient and can be sampled at whatever period during the year, it is ideal to do it previously to sowing, following the guidelines previously mentioned. P levels in soil vary depending on the balance between extraction by crops and replenishment by fertilizers. In plots with continuous cropping that have been fertilized with a single dose, some differences in P Bray levels can be observed based on the performance of each specific site.

In rotations involving wheat, it is ideal to be above the critical range of 15-20ppm P Bray. Recommendations based on the analysis may be directed toward the satisfaction of crops’ needs, known as sufficiency, or to improve/maintain P Bray levels in soil, known as building and maintaining. In the latter, it must be considered that the average requirement to raise 1ppm P Bray in the Pampeana region’s soils is 3 to 5kg of P/ ppm, in addition to compensating extractions by the crop. If P Bray levels are low, it is advisable to fraction replenishment throughout several years during rotation, applying in every cycle a P dose superior to that of the crop extraction.

Sulfur

S deficiency was widespread in multiple areas, especially in crops like wheat and soybean. The primary reserve of S in soil is organic matter, similar to N and most of P. The analysis of the soil can be conducted by taking samples during presowing at 0-20cm, although it is also interesting to know the distribution of this nutrient in that area of land by analyzing stratum of 20-40 and 40-60cm.

The diagnose for this nutrient is established by identifying deficient plots based on the following observations:

Soils with low organic matter content, sandy soils.

More intensive cultivation systems that may cause a decrease of the original organic matter content.

Analysis of S-sulfate: critical levels below 10ppm (0-20cm).

The presence of groundwater or irrigation usage: groundwater and water for irrigation can contain high levels of sulfate. Something similar was observed in soils with calcium carbonate deposits due to sulfate accumulation.

Similar to N, S application can be conducted when sowing or in advance states of the crop due to delayed absorption of said nutrient.

For the Pampeana region, studies conducted by INTA established a critical threshold when sowing of 45kg S ha-1 (0-60cm), with 79% of diagnose accuracy in those cases studied in the region. Moreover, for southeast Buenos Aires, Nan analysis might contribute to identifying plots with problems regarding S, being the critical level 62ppm.

Finally, the analysis of grain can be used to identify the sulfur status of the crop and to schedule fertilization dates for the following crops during rotation. In any case, S dose seeks to achieve neutral or slightly positive balances.

Similar to N, S application can be conducted when sowing or in advance states of the crop due to delayed absorption of said nutrient Moreover, given its residual effect, all S in a secondary wheat/soybean sequence may be applied when fertilizing wheat.

In summary, to achieve sustainable production systems, it is key to conduct an appropriate management of crop nutrition, starting with a proper sample of the soil and the following interpretation of the outcome.

Biostimulants application in grain crops in the Argentine Pampeana region: just a trend or valuable for the producer?

In the past years, there has been a significant increase in demand for biofertilizers and biostimulants in both global and regional agriculture, being Latin America one of the regions of major adoption. The objective of this article is to describe the main features and benefits of biological products with nutritional impact in Argentina, and to provide a scientific perspective for its sustainable usage in agroecosystems.

By Agr. Engr. Martín Torres Duggan

Tecnoagro; Professor guest at Escuela para Graduados (EPG) from the School of Agriculture of the University of Buenos Aires (FAUBA); Coordinator of Biological Nutrition Network (RNB in Spanish) at Aapresid.

1.

Biostimulants, or development promoters, are characterized by presenting living microorganisms and/or metabolites derived from said microorganisms and/or substances, meaning bioactive compounds, that when applied to crops via seed or foliar treatments, they stimulate the development of roots, aboveground biomass and grain yield. Although these development

Definition of "biofertilizer" and "biostimulant"

promoters are assessed according to several criteria, they are usually defined mostly because of what they do instead of what they have. Thus, for instance, if there are biological products containing certain nitrogen-fixing bacteria (e.g., rhizobia) or nutrient solubilizing microbes (several bacterial species and/or microbial consortia), they can be classified as "biofertilizers" because they contribute and/or help in the assimilation of nutrients. In this regard, biofertilizers are a particular case of biostimulant. However, there are

few bacteria that besides solubilizing nutrients, also stimulate roots development and even act as biological control agents–to combat fungi diseases–, that is why, under a broad criterion, it is possible to define them as plant growth promoting rhizobacteria (PGPR).

Another criterion commonly used to classify or analyze biostimulant markets is to set them as "microbial" biostimulants–those containing primarily living microorganisms–or "non-

microbial", when their effect is caused by the presence of bioactive compounds or substances. In the latter group, there is a very diverse number of formulations that combine one or more substances, like amino acids, peptides, botanical extracts, fulvic acids, phytohormones, etc. Similarly, in the market it can be found every combination possible on microbial and nonmicrobial ingredients, that can contain, or not, added macro or micronutrients.

The great complexity as regards type of formulation, microbial and non-microbial compounds that characterizes biostimulants is a challenge for the development of proper regulatory frameworks. In many cases, there is decoupling between what is known about biostimulants (their effects) based on scientific evidence and the established regulations. Therefore, in most Latin American countries–with some exceptions–biostimulants ended up being incorrectly registered as fertilizers, plant amendments, soil amendments, etc.

2. Prime agricultural and environmental benefits of biological inputs usage.

One of the main differences between "fertilizers per se" and biofertilizers and biostimulants is that the effects of the last two are not associated with nutrient concentration, but with the kind of active ingredient and its impact in crops physiology, meaning biostimulation. Thus, what gains relevance is the functional aspect of biological products and, mostly, the context of their use, as it will be explained later on.

In relation to biopesticides–not discussed in this article–these do not allow pathogens biocontrol like insects, fungi or bacteria. As a result, there emerge terms such as "bio-insecticides", "biobactericide or bio-bacteriostatic", "bio-fungicides or bio-fungistatic", depending on the type of organism to control. One interesting example of a microorganism presenting bio-fungicide properties along with PGPR is Trichoderma sp., of which there is enough scientific evidence about its effects in multiple crops, even when combined with other plant growth-promoting bacteria.

Figure 1 shows in detail the main effects of biological inputs based on an extensive search of bibliographies and experts’ consultation carried out recently by FAO and published in a book, and exhibits that bio-inputs benefits depend on the

type of product. Therefore, major scientific-based evidence benefits of biofertilizers are their capacity to fixate N or solubilizing other nutrients, to stimulate plant growth and to gradually improve yield.

Figure 1. Benefits of bio-inputs depending on the magnitude of impact and their scientific evidence. Source: Bullor et al., (2023).

Biofertilizers can improve soil fertility aspects, as well as reduce environmental contamination (soil, groundwater, etc.) or mitigate greenhouse gasses (GHG), among other effects.

The primary benefits of biostimulants supported by experimental evidence are the abiotic stress tolerance of crops and the improvement in soils’ quality or health. Other effects or benefits present a variable level of impact and scientific evidence (Figure 1)

3. Response to biofertilizers and biostimulants application

When analyzing experimental data about biostimulants application, it is advisable to know the product very well, to know the proper application methods, and to take into account the type of research or tests conducted to generate said data. It is also relevant to consider that the results obtained from monitored settings, like tests in greenhouses or growth chambers, are not always detected on field testing in conditions of extensive production. Lately, there is notable progress in the development of commercial formulations, mostly regarding additives usage and/or microbial protectors.

3.1. Azospirillum brasilense-based inoculation results conducted worldwide and in the Argentine Pampeana region.

In the universe of bacteria-based microbial biostimulants, the genus Azospirillum is the most studied globally. Azospirillum brasilense (strain Az 39-INTA) is the most extensively studied and tested at a regional scale in Brazil, where it was isolated and characterized, in Argentina and other Latin American countries. Figure 2 shows the

mean response to inoculation with Azospirillum sp. in different crops, derived from a review of experimental data that consisted of 47 studies conducted internationally.

Figure 2. Mean raise of yield (%) in tests with applied Azospirillum sp. as inoculant in different crops. The number of experimental sites is indicated between parentheses. Adapted from Diaz Zorita et al., (2015) taken from Cassan et al., (2028).

As regards conditions in the Pampeana region and in wheat crops, Diaz Zorita et al., (2013) reported a mean increase of 22% in dry matter production, 12.9% in aboveground dry matter, and 8% in grain yield, by analyzing 297 experimental sites in which the crop was inoculated with a liquid formulation containing Azospirillum brasilense The responses were independent of practices like genotype selection, fertilization, etc. Similarly, the response frequency was positively related to the site's potential yield, exhibiting that the biological treatment acts in complement to the

agricultural management, improving the crop capability to benefit from available resources–water or nutrients–in the soil. Similar results were observed in corn crops within the same region based on nearly 280 tests conducted throughout a large number of seasons (Figure 3).

Figure 3. Response to inoculation with Azospirillum brasilense in corn crops under extensive production conditions in the Pampeana region.

In this collection of studies, the mean increase of Azospirillum brasilense application was 6%, although the authors observed a greater magnitude of response within contexts of summer drought, and a major frequency of response when water limitations appeared along with early corn sowing.

As an outcome of the international and domestic results previously mentioned, there is solid experimental data on the meaningful and fruitful effect of inoculation with Azospirillum sp. for roots’ biomass, aboveground dry matter and grain yield–expected range between 5-10% for grain biomass.

3.2. Impact of the addition of non-microbial biostimulants

As it was previously mentioned, there is a wide range of commercial formulations of nonmicrobial biostimulants, both for soil application–fertigation, seeds treatment, or localized application in the furrow as liquid igniter, etc.–and foliar application. Among the ingredients, or their combination, present in commercial formulations of non-microbial biostimulants are:

Protein hydrolysates, peptides and/or free amino acids

Botanical extracts, including algae or other plants

Phytohormones

Organic acids, including humic and fulvic ones

Macro and/or micronutrients, present or added ad hoc

Low domestic employment of Azospirillum sp. in wheat and other crops, e.g., soybean, where growth-promoting effects are expected, it is mainly due to the lack of awareness, dissemination and/or disclosure on the productive, economic and environmental impact of inoculation with these bacteria. Similarly, in the case of corn, where hybrid seeds are commercialized, there should be systems that enable corn seeds marketing companies to offer professional services with PGPRs, or that these companies allow the producer to conduct inoculation without losing guarantees for the use of said seeds.

Lately, there has been considerable progress regarding the understanding of mechanisms and modes of action of several of the abovementioned bioactive ingredients, although this aspect will not be detailed in this article.

Rouphael et al., (2023) collected and revised current scientific evidence and knowledge gaps still existing in relation to microbial and nonmicrobial biostimulants modes of action. Beyond the experimental complexity that the studying in isolation of the effect of a certain compound from a certain biostimulant requires, and even more their combination, it is worth to emphasize that there is a general consensus that most non-microbial biostimulant compounds–free amino acids, humic and fulvic acids, botanical extracts, etc.–promote roots growth by sometimes modifying its structure and absorption capability, and other times, by mitigating abiotic limitations like drought or soil salinity, among other effects.

Table 1 shows the result of a meta-analysis conducted by Li et al., (2022) based on experiments performed in different regions of the world. This meta-analysis exhibits the mean response to the application of different nonmicrobial biostimulant compounds, such as chitosan, plant extracts, humic and fulvic acids, phosphites, silicates,etc., and the reliability interval of said response. This type of research provides solid experimental data, collected from scientific articles, that help to understand the magnitude of the responses, ranges, etc.

In general terms, yield increments confirmed by this meta-analysis are placed on superior levels than those that have been reported for microbial biostimulants. However, response variability is usually high in both microbial and non-microbial-based products. The authors observed that most responses to non-microbial biostimulants usage were held under suboptimal growth conditions–drought–associated with poor fertile soils, low cation exchange capacity or OM, and low nutrients availability. Therefore, and in coincidence with most research, it is postulated that the best opportunity to add value through crop biostimulation happens in contexts of high climatic variability and abiotic stress. Nevertheless, it is interesting that these studies detected significant effects in optimal conditions of nutrients availability. This would permit the inference that, in these latter situations, non-microbial biostimulants application would increase water or nutrients utilization, or promote synergies with nutrition, enhancing capturing capacity of these resources.

(*) RI of 95% indicates that it is 95% probable that the true response value (inferred) is found between the indicated values.

Table 1. Response to the addition of non-microbial biostimulants based on a global review of experimental data (source: Li et al., 2022).

4. Perspectives on biostimulants development and their use in extensive agriculture

Personally, I think that the great disruption and innovation regarding plant biostimulation products is about to come, and it should emerge from the conjoint work of scientists and technologists in those fields of study in which teamwork is rare. Some of these fields of study are: plant microbiology and biotechnology, plant genetics, metagenomics, biostatistics, plant physiology, soil fertility, plant nutrition, economy, sociology, artificial intelligence, among others. As science history can attest, disruption appears when someone, or a group of people, combine their knowledge or technologies already available to develop a technological product that "incorporates" decades of generated essential knowledge. That is why, evading the importance of basic research in technological development is usually due to the lack of understanding on how to do valuable science.

It is worth emphasizing that there is also evidence of a tendency to overvalue the role of soil biology in soil fertility matters, ignoring chemical, geochemical and physical principles of which there is decades of research and meaningful corpus-based knowledge. As a result, there is a clear need to reconcile and integrate soil biologists–or soil biology as a discipline–with essential knowledge of the soil's chemistry, geochemistry and physics. In a few words, it would be ideal for soil biologists to acquire a

deeper understanding of pedology, geology, geochemistry, micromorphology, soil physics and chemistry; and for soil fertility and crops fertilization specialists to learn more about soil biology to benefit from the whole body of knowledge and not only from that generated in every field of study separately.

Currently, the main issue regarding biostimulants development is the knowledge gap on mechanisms and modes of action of bioactive ingredients. There is also little understanding about soil microbiome, as only 1% of living microorganisms are known, mainly due to their DNA and not so much for what they do. This situation challenges the possibility to relate biostimulants management based on soil microbiome, at least not for the time being. However, these knowledge gaps can be rapidly

reduced by considering that the generation rate of fresh knowledge has notably increased recently. Moreover, there is a better understanding on frames of reference and modes of action regarding several microbial and non-microbial biostimulants components, mostly concerning nutrient absorption effects, gene expression and changes in roots' morphology and growth, primarily under abiotic and biotic stress conditions.

Many innovations currently being offered are "promising" but not yet real. It is also not clear which would be the valuable proposals for producers. For instance, there are references on the possibility of including sensors in microencapsulation formulations that allow to activate and/or release microorganisms to perform certain functions at some point in the crop cycle. Although "controlled release" of nutrients has been a reality for decades now, and there is global access to "smart fertilizers" presenting morphologies or special additives on the granules

To know more about the soil’s microbiome, mechanisms and modes of action of bioactive ingredients are one of the great current issues.

in charge of regulate dissolution rate in soil, as well as releasing nutrients with major synchrony according to plants demand, nowadays, it does not seem to exist an equivalent development for biofertilizers or biostimulants. Nevertheless, today's progress rate of knowledge is astonishing and many disruptions of this kind may appear in a few years.

Another fascinating field owning commercial formulations are "microbial consortia", which, for example, combines different microorganisms to expand the spectrum of effects on plants (biocontrol+biostimulation) in the same seed treatment. Low-cost equipment employed in microbiology and biotechnology studies grant to "play" by examining different microorganisms in a laboratory or growth chambers, and to detect synergy effects–or antagonist effects–from different microorganisms.

5. Final conceptions

As it was previously discussed, bioinputs in general and biostimulants in particular, broaden the spectrum of means available for the agricultural producer, both for improving crops yield and to add extra benefits related to agroecosystems sustainability. These last features of bioinputs can be, in a way, considered when purchasing a certain biostimulant or biofertilizer within a framework of a company's decision-making. In this regard, there are numerous "sustainability" and "carbon project" programs offered by companies that supply fertilizers and phytosanitary certificates, where sometimes it is possible to monetize part of these benefits going beyond increasing grain yields of crops.

I think that, nowadays, the best an agricultural businessman interested in increasing the productivity, profitability and sustainability of their company, is not to replace "chemical fertilizers" for "biological" ones–except that they employ organic production systems–but to adapt and integrate biostimulation to the management of all available nutrient sources that can add value. Today, we know that through good management of soil fertility and crop nutrition we can improve crops yield between 15% and 30% related to the "regular management" of the producer. Within this framework, microbial and non-microbial biostimulants application

enable us to enhance between 5% and 10% of yield efficiency (as a mean value, or even more), especially within contexts of climatic and abiotic stress variability–which is no longer an unusual context–but the rule for most productive systems in the Chaco Pampeana region.

This is even more important if we consider that soils in this region present frequent physical damage and constant nutritional deficiency. This means that agroecosystems in the Pampeana region are not subjected to an excess of fertilizer applications or contamination phenomena, but, contrarily, a great part of its deterioration is caused by fertilization. Therefore, under this framework, we should consider biostimulants as a complement and not as a substitute of conventional fertilization, i.e., organic or inorganic fertilizers application. Although, as everything in life, there may be exceptions that should be validated by local and reliable scientific examination.

Special fertilization, unparalleled cultivation

From biofertilizers to biostimulants, special fertilizers are optimizing agricultural productivity and reducing environmental impact. With data collected from 290 trials on extensive crops, this article offers a full view on how these technologies are changing agriculture in Argentina.

In the past years, there has been a sustained increase in the supply of especial fertilizers, as well as their commercialization and participation in the market. These products are considered an ecological and sustainable alternative due to their minor environmental impact and their major efficiency regarding the use of supplies.

By: Cesar Quintero¹,², María de los Angeles Zamero¹, Nicolás Rouillet¹ ¹Faculty of Agricultural Sciences of UNER, ²Fertilizar AC–Asociación Civil.

Thus, there has been a broad and varied development of products classified as "especial" fertilizers with technological improvements incorporated in their production. The most noticeable of these improvements are the alternatives aiming at reducing environmental impact, like a major efficiency in the usage of provided nutrients, reduction or limitation of

nutrient fixation in the soil–phosphorus (P)–and prevention of nitrogen (N) losses, a nutrient subjected to great losses.

Another noticeable one is the formulation of chemical mixtures that combine several elements in one product. The advantage of these chemical mixtures is that they provide the same

concentration of elements in every granule of the fertilizer. For instance, the incorporation of sulfur (S) and zinc (Zn) to the conventional sources of (P) and (N) had meaningful outcomes in Argentina.

Liquid and water-soluble formulations are considered special fertilizers as well, which can be applied to the soil, foliage and seeds, or through fertigation.

A different concept within the category of special fertilizers is that of biofertilizers and biostimulants, which do not have considerable amounts of nutrients in their formulation. They are products that prompt plants growth by achieving major efficiency regarding nutrients usage.

Biofertilizer is a substance containing living microorganisms that, when applied to seeds, plants or soils, colonizes the rhizosphere or the interior of a plant, enhancing growth by raising nutrient supplies of the host plant. Moreover, they improve soil fertility by fixing atmospheric nitrogen, solubilizing insoluble phosphates, and producing plant growth promoting substances in soil. Biofertilizers represent an economically appealing and ecologically reasonable option to increase nutrients supply.

Plant biostimulants are substances or materials that, when applied to foliage, seeds or substrates of specific formulations, have the capability to modify plants' physiological processes by providing potential benefits for their growth, development and stress response. Biostimulants stimulate natural processes to enhance nutrients absorption, nutrients usage efficiency, abiotic stress resistance, or crops' quality and yield.

This article will set aside fertilizers of controlled or slow release because of greater availability of scientific information. However, despite all listed benefits about biostimulants, biofertilizers and foliar fertilizers, there is not a clear and objective assessment on their effects on extensive crops productivity.

The aim of this work was to collect available information from numerous trials conducted on extensive crops in Argentina, so as to assess the absolute and relative response regarding various special fertilizers currently available in the market.

Characterization of the studies involved

The committee of specialties at Fertilizar AC carried out a systematic review based on Argentine research works about especial fertilizers. Certain criteria were established in order to include database results, meaning that at least three repetitions were taken into account by following a statistical design to be able to provide enough details so as to interpret all treatments.

In total, 161 studies and reports were collected, with 290 trials, including more than 2300 observations. These trials were conducted by renowned professionals from INTA, universities and private consultant firms, between 2012 and 2023. Analyzed crops and regions are shown in Figure 1.

In each study, or report, particular emphasis was placed on identifying control treatment from those with special fertilizers. In most cases, the control treatment involved conventional fertilization using commodity fertilizers like MAP-DAP plus UREA. Moreover, in each case, the effect of more than one special product applied whenever possible was analyzed. Here are some examples:

A Absolute control crop without fertilizers

B Conventional fertilization

C Conventional fertilization plus Biostimulant

D FConventional fertilization plus Herbicide

E Conventional fertilization plus Herbicide plus Biostimulant

F Conventional fertilization plus Fungicide

G Conventional fertilization plus Fungicide plus Foliar Fertilizer

Response to Commodities = B - A.

Response to Biostimulant = C - B

Response to Herbicide = D - B

Response to Biostimulant = E - D

Response to Fungicide = D - B

Response to Foliar Fertilizer = G - F

It was assumed that the effects of each application were additives and attributed to the added product. For example:

1 Conventional fertilization

2 Conventional fertilization + seeds treatment

3 Conventional fertilization + seeds treatment + Foliar Biostimulant

4 Conventional fertilization + seeds treatment + Foliar Biostimulant + Foliar Fertilizer

Figura 1. Origen de los datos disponibles por provincia y por cultivo.

Response to Seeds treatment = 2-1

Response to Biostimulant = 3-2

Response to Foliar Fertilizer = 4-3

There were registered the time of application (sowing, vegetative, reproductive), manner of application (soil, seed, foliage) and dose.

Fertilizar AC's established classification was utilized, which was adapted according to data of available tests. Those cases involving product mixtures, or when there was not a clear understanding of their composition, were labeled as "No Classification", both for the group and the subgroup accordingly. There is also shown the observed effect on herbicides and fungicides.

Biofertilizers Bradirrizobium/Azospirillum Mycorrhizae

Trichoderma

AA or protein derivatives

Seaweed extracts

Hormones

Biostimulants

Special Mineral Fertilizers

Biostimulants + Special Mineral Fertilizers

Commodities

Elicitors

Humic acids - Fulvic

OTHER (enzymes, polysaccharides, polyphenols)

Applied to Soil

Applied to Seed

Applied to Foliage

Multiple and various combinations

Phosphates and Nitrogenous

Fungicides Various

Results

Figure 2 exhibits all data considered in this article.

A wide yield range for all crops, provinces and products was observed. Moreover, there were considered the results with both negative and positive responses. However, it was observed that the line between control treatments and those treated was of 200kg/ha above the line 1:1, with a slightly positive slope.

Average of absolute response for all examinations was of 226kg/ha, with a standard diversion of 441kg/ha, proving a great variability in the results.

Figure 2. Relation between control groups yield and the treated ones for all available data.

Absolute response for each crop and group of products is shown in Figure 3. Conventional fertilizers and fungicides stand out, with responses above 300kg/ha in different crops, representing an increase of 7% to 15% of response.

On the other hand, special fertilizers exhibited mean responses between 100 to 300kg/ ha, meaning a yield increase of 5% to 10% in comparison with non-treated crops.

The effect of herbicides–mostly Fomesafen or Benazolin in soybean–was negative, with an average yield reduction above 1.5%.

Figure 3. Average of absolute response per crop and group of products.

Means with shared letters are not significantly different (p > 0.05). Test:LSD Fisher Alfa=0.05 DMS=203

Biofertilizers

The response to biofertilizers was very variable, with 126 observations and an average response of 1.5%. The most frequent cases included Trichoderma (n=54) with a response of 1.1% (74 +/-63kg/ha) and Bacillus (n=51) with

a response of 1.9% and 35 +/- 66kg/ha, both for wheat and barley. Some interesting responses were registered regarding Trichoderma plus Azospirillum (5.4%), Trichoderma plus Bacillus (4.9%) and Bradirrizobium (14.2%).

Response to Biostimulants

With a large number of observations of this group (n=1019), an average response of 310kg/ha above control groups was registered (Table 2). These data included a series of tests conducted in sorghum crops with very high yields, where some treatments exhibited significant negative responses. Without considering sorghum, other crops revealed positive and meaningful absolute responses.

The number between parentheses indicates the relative response to the control group.

Table 2. Response of biostimulants in various analyzed crops.

The effect of different biostimulant subgroups can be seen in Table 3. Average responses ranging from 4% to 9% were observed. Seaweed extractbased biostimulants exhibited a mean response of 130kg/ha, whereas the group ‘Others’, mainly composed of polyphenols, registered a response of 156kg/ha. Elicitors had an average response of 155kg/ha. Some products with mixtures of various biostimulant components–labeled as "No Classification"–showed a response of 166kg/ha.

Amino acid or hydrolyzed protein-based products in the subgroup with 533 observations, indicated an average response of 240kg/ha. Whereas Hormone-based biostimulants, with 27 observations, exhibited a response of 429kg/ha, representing an increase of 8.9%.

Biostimulants

Table 3. Effect of the different biostimulant subgroups.

Amino acids and protein derivatives

These products indicated a solid positive response in all crops. Percentage increase was particularly relevant for green peas and sunflowers (Table 4).

Foliar application during the crop's vegetative and reproductive stages, in addition to two extra applications, showed responses ranging from 5% to 8%. However, when they were applied solely on seeds, the response was lower (Table 5).

Table 4. Response to the application of protein derivatives-based Biostimulants

Values between parentheses represent the relative response to the control group.

Table 5. Response to the application of protein derivatives-based Biostimulants

Values between parentheses represent the relative response to the control group.

Seaweed extracts

Four tests conducted on sorghum, with yields of 10.000kg/ha, exhibited a negative mean response to treatments with biostimulants. In barley and wheat, absolute yield response was of small magnitude; whereas in soybean, sunflower and corn, especially, there was a response of 8% to 9% (Table 6)

Seaweed extracts application in seeds and during the reproductive stage, revealed the highest responses (Table 7)

Values between parentheses represent the relative response to the control group.

Table 6. Response to the application of Seaweed Extract-based Biostimulants

Values between parentheses represent the relative response to the control group.

These products, mainly phosphides, were mostly tested in combination with fungicides. Therefore, to a large extent, the observed response is the result of an effect that can be added to fungicides. The case of soybean could be underlined, where it was registered a meaningful response and a considerable number of cases (Table 8)

The most appropriate time for the application of these biostimulants may seem to be during the crop's reproductive stage (Table 9)

Table 7. Response to the application of Seaweed Extract-based Biostimulants

Elicitor-based Biostimulants

Values between parentheses represent the relative response to the control group. Values

Table 8. Response to the application of Elicitors-based Biostimulants

Table 9. Response to the application of Elicitors-based Biostimulants

Special Mineral Fertilizers

Special mineral fertilizers exhibited an average response of 256kg/ha in a total of 314 observations.

The Seed treatment subgroup registered a mean response of 187kg/ha (6.3%), possibly attributed to the contribution of Zn (with a dose of 7 to 300g/ha).

On the other hand, Foliar Fertilizers showed an average response of 242kg/ha (6.8%) based on a mean dose of Zn (225g/ha), B (76g/ha) and N (1.4kg/ ha) and smaller quantities of the other elements.

Fertilizers applied to the soil, mainly microgranulates supplying P (5.5kg/ha) and N (3kg/ha), along with Zn (350g/ha) and S (2kg/ ha)–higher quantities to those applied to seed or foliage–exhibited an average response of 566kg/ ha (16.1%), proving to be considerable meaningful.

Mineral-based Foliar Fertilizers

Foliar fertilizers presented a solid response from 6% to 9% in wheat, sunflower, soybean and corn (Table 10). Applications during vegetative stage had a slightly superior response in comparison to those applications during reproductive stages (Table 11).

Table 10. Response to application of Mineral-based Foliar Fertilizers

Table 11. Response to application of Mineral-based Foliar Fertilizers

Summary and conclusions

This report, or meta-analysis, based on a significant number of recent tests conducted in the Pampeana region, has allowed synthesization and gave value to responses of various special fertilizers and their variability. Their utilization unlocks the possibility of increasing crop yields, complementing conventional fertilization with commodities.

Biostimulants presented a solid and positive mean response of 200 +/-14kg/ha, meaning a general increase of 6%. Corn registered a mean response of nearly 400kg/ha; whereas sunflower, green peas and soybean exhibited a response range of 8% to 20%. Hormone-based biostimulants presented a much solid response of over 400kg/ha. Protein and seaweed-based products also showed a meaningful response in all crops, especially in corn, sunflower and soybean.

Elicitors, with good response in soybean when applied in the reproductive stage, complemented the fungicide effect with yield increase from 7% to 8%.

Mineral-based foliar fertilization in corn, soybean and sunflower during vegetative stages, exhibited solid responses ranging from 7% to 9%.

It is crucial the proper selection of products, time, dose and manner of application in order to attain the best results. The response to the application of these products is mostly explained by growth stimulation and abiotic stress reduction, rather than the contribution of mineral elements.

We want to express our appreciation to the members of the committee of specialties at Fertilizar AC, and also to the following companies for their generous contribution of information: Yara, Stoller, Spraytec, Compo, Amauta, Rizobacter, Fertiglobal, Kioshi Stone, ACA, Fitoquímica and Tropfen.

Fertilization and its sustainability: Metalfor's technological approach

This company located in Córdoba Province is a leader in the industry owing to its constant technological innovation and substantial changes promoting productivity.

By: Metalfor

Metalfor company is characterized for their constant innovations, specially in the field of fertilization, where they stand out as leaders. As a result they not only produce more, but also better. That is why, both the executives and engineers of the company are focused on the soil's sustainability and health.

Juan Pablo Rodríguez, agricultural engineer from the División Fertilización at Metalfor, analyzed the advantages of the pneumatic fertilizer F7040N. This team possesses the highest levels in both technology and reliability of the market, and has sold more than 210 units in the last five years.

"We want to emphasize that when acquiring our products, there is also access to a post-sales solution package that includes end-user training and equipment adjustment, as well as parts replacement and technical support across the country through Red Servicap," Rodríguez commented.

Pneumatic Fertilizer F7040N

Clearly, all modifications and the implementation of technological innovations entail an investment. That is why the agricultural engineer stressed on the decision of the company: "In a significant financial effort for Metalfor, we will be offering optimal benefits in the acquisition of our fertilizers."

Sustainability

Metalfor is greatly and deeply committed to the protection of the soil. Therefore, it makes the most of new technologies like biostimulants or biofertilizers, an area in which the role of Cordoba's machinery stands out.

"Metalfor's responsibility entails developing more precise equipment and working on end-user training for the adjustment and calibration of our machines. Thus, we prevent the emergence of negative side effects on the environment," said Juan Pablo Rodríguez.

José Luis Dassie, Director at Metalfor, commented on the challenges of the company that focus on "provide technologically advanced tools to attain major productivity and help activities to become more sustainable."

At the same time, he claimed: "I have no doubt that we need to develop new abilities for the operators of agricultural machinery, as machines are equipped with ever more relevant technology, both for their usage and data generation for future usage.”

To conclude, Juan Pablo Rodríguez underlined: "Our soils' demand for a more efficient nutrition is increasing. From Metalfor we are strongly insisting on providing the market with notable high-performance equipment intended for quality application."

"Our soils' demand for a more efficient nutrition is increasing. From Metalfor we are strongly insisting on providing the market with notable high-performance equipment intended for quality application."

Is it possible to produce more by using less?

Nicolás Domesi, marketing manager at FieldView Cono Sur, provides details on how a digital agriculture platform can become a big ally when searching for more sustainable production models, without losing productivity.

Producers’ adoption of digital agriculture tools has exponentially grown in the last four years. FieldView, the platform developed by Bayer, was tested by producers in 2019 and was commercially released later in 2020. Currently, it is used in more than 17 million hectares across Argentina, representing nearly 60% of the cultivated area in the ongoing season. Digital agriculture is still

By: FieldView

growing strong in Argentina with FieldView clearly rising as the flag-bearer platform. The usage of FieldView throughout the season allows decisionmaking based on self-produced data, reaching a maximum yield level in every hectare and using resources more efficiently.

"The numbers speak for themselves, and in FieldView we are convinced that they reflect the great value proposition of our platform, which provides a user-friendly functioning and large amounts of information for better decisionmaking," explained Nicolás Domesi, marketing manager of the brand. "Undoubtedly, this was possible due to the change in our business model, where the producer has no limits regarding the usage of the platform in terms of hectares."

Digital Agriculture is here to stay, emphasizing the importance of data collection to turn it into information and power for a more efficient and sustainable decision-making. All historic data the producer uploads in the platform is further developed, improving the quality of the information constantly via algorithms, namely the setting conditions of the field. So, the more information uploaded, the better. "This aspect is key to producing more by using less," claimed Domesi.

Nicolás Domesi, marketing manager at FieldView Cono Sur

Quality and security

Which are the reasons to have data on FieldView?

Complete analysis from sowing to harvesting. Full data registration allows a better quality and deep analysis leading to more accurate conclusions and finer results.

The historical data available for decisionmaking. Every new client enters into a three-year record of satellite images of a particular plot, which combined with FieldViewTM Drive data operation results, provides a complete view of the crop at every phase of the harvesting.

More analysis possibilities. Plot conditions, application rates and the time of labor are registered. During the activity, it offers a real-time view of relevant climatic factors, like wind speed and others.

Better prescriptions. FieldViewTM Diagnostics’ satellite images and harvesting data can be used to establish management areas with different yield potential, so as to get advice regarding seed density for each area of the plot in just a few minutes. Thus, hybrid potential can be optimized in each productive site of the plot, depending on productivity, profitability and seeds price objectives.

Efficiency

This production system attains a more efficient usage of supplies and, at the same time, optimizes the time employed in monitoring. "For instance, platforms detect anomalies in the plot instantly, and allow streamlining the time for the early detection of pests, weeds and/or diseases," Domesi explained.

By using this directed monitoring, both for fallow lands and in-progress crops, the producer can make the decision of delimiting the area that needs more precise and efficient application. The producer acquires this power through the collection and analysis of data by FieldView. Data collection can be made by using FieldViewTM Drive, a device connected to the CAN diagnostic port, which collects information about the field and the machine. The Drive is connected to the IPad® via Bluetooth, generating real-time maps and reports and storing them in the FieldViewTM Cab application.

Compatibility

"Recently, we are focused on further development of the product by incorporating more brands of sprayer machines and fertilizers, so that they are compatible with our platform," he said.

With FieldViewTM Sync, all data about machines on the field can be rapidly and easily transferred via Bluetooth, and uploaded in the cloud. As a result, when the Sync device is connected to the internet, all data can be quickly synchronized. This process can also be conducted by carrying FieldViewTM Cab into a place with internet connection.

The producer can access the information saved in the cloud whenever they need to. With applications for Android/IOS and a web platform, the producer can access their account from whatever location they may be: the field, the office or at home. Data is stored safely and the producer can choose whom to share it with: consultants, employees or associates.

This accomplishment was possible due to strategic alliances with several companies, seeking always to facilitate the producer’s experience when using the platform. Moreover, this facilitates the work in the field as it allows the usage of various brands and machinery platforms connected to FieldView in a simple and enjoyable manner.

FieldView Digital Agriculture platform.

Companionship

"It is crucial for us to be able to accompany the producer in this technology adoption curve, by offering both remote and from-the-field assistance channels, as well as training not only in the use of our platform but also for Digital Agriculture in general. This allows a better employment of our offered solution, FieldView, and a deeper understanding so that users have major

autonomy," Domesi affirmed, who also considers that this is one of the most important values the company owns. "Moreover, we understood that the producer does not work alone, that is why through our brand we launched two programs to train agricultural contractors and consultants, as they are the comrades in arms with the producer during the season."

FieldView, the platform that provides solutions

As there is a need to train the producer and their work team, there are various companies investing and contributing to reduce this technology adoption curve through ever-present companionship. "We understood that we must be a solution instead of something that causes uncertainty by not knowing how to use it," Domesi pointed out.

Every field is unique, every plot is different. Using FieldViewTM throughout the season, decisionmaking based on self-produced data is possible, allowing to maximize yields in every hectare and to make a more efficient usage of resources. Digital Agriculture took the next step, as it grew from an isolated tool and became a solution within those business models seeking to share risks and generate more sustainable productive systems.

It is crucial for us to be able to accompany the producer in this technology adoption curve, by offering assistance and training channels.

We can eat sorghum as well

Advanta promotes human consumption of sorghum, emphasizing its nutritional value and culinary versatility, as well as its usage in the production of gluten-free beer.

Sorghum is one of the five main cereals in the world, a crop expanding its reach and that presents multiple advantages when producing food.

Advanta's proposal involves the suggestion and introduction of sorghum crop as an alternative food option for humans in response to the global tendency toward a more responsible consumption. Millions of people have adopted this tendency, which seeks to understand food traceability to raise awareness on what is being consumed, where it was produced and how sustainable it is for the ecosystem and the planet. This increasing awareness is the driving force putting sustainable and health-beneficial crops as main protagonists, and at the same time, enables the development of a new market and the expansion of the existing ones.

"Climate change demands companies to focus on smart and more efficient crops. Advanta is one of the three most important companies of sorghum globally, and we chose this crop because it is scientifically proven that it produces more biomass, provides greater nutrition, and requires less resources like water and fertilizers compared to other crops," claimed Bhupen Dubey, Advanta's global CEO.

There is a clear objective: to succeed for sorghum to become a part of our daily diet, as it is a sustainable, high-fiber-containing crop rich in antioxidants, and a source of energy and nutrients. Currently, in Argentina, the only way to consume sorghum is through flour, used in the production of several products such as pasta, cookies, bread, among others. Knowing this alternative, the company aims at broadening the opportunities by testing the use of this grain in other dishes, namely hamburgers, pickles, falafel, tacos, tortillas and more.

To expand this knowledge, the company associated with the gastronomic group Nala, located in Rosario city. Advanta provided the team with sorghum grains from their hybrid stocks, and the chef

analyzed the alternatives, studied the textures, took precautions on cleaning processes and, finally, examined the taste. The results overcame expectations widely, allowing the development of more than 9 sorghum-based recipes.

Advanta understands that it is not possible to find sorghum grain as it is at the supermarket, which makes the execution of these recipes somewhat difficult. Therefore, the company intends to disclose the numerous culinary possibilities of sorghum, with the purpose of allowing the consumer to discover its taste and to demand this product to be available in supermarkets. Nevertheless, consumers can purchase sorghum flour, which is ideal for cooking gluten-free meals.

A nutritional crop

Rich in nutrients: sorghum is composed of those proteins necessary for the healthy development of bones, muscles, skin and enzymes. It contains Iron, which contributes to strengthening the immune system and the capacity of oxygen transportation in the blood; Vitamin B6, essential for synthesizing antibodies and improving nerve functions; Niacin, which enhance blood circulation; Magnesium, for calcium absorption and body temperature regulation; and Phosphorus, to form healthy bones.

Digestive health: Its high fiber content promotes digestive health by acting as a regulator for the digestive system.

Blood pressure and circulation: Because of its high levels in potassium and low levels in sodium, sorghum grain contributes to maintaining a healthy blood pressure. Moreover, it contains iron, copper, zinc and magnesium that enhance circulation.

Energy: Sorghum is a complex carbohydrate that provides sustained energy. It also contains niacin or vitamin B3 that supports the transformation of food into energy.

Gluten-free: Sorghum is 100% gluten-free, making it a safe option for celiac or gluten-intolerant people. Sorghum flour and whole-grain sorghum are excellent substitutes for wheat-based recipes.

Beer: a gluten-free toast

Besides focusing on the promotion of sorghum as food, Advanta was also interested in the use of this crop for the production of drinks such as beer. That is why Advanta started to work with Straus, a company devoted to producing sorghum malt-based beer of many varieties: blond, honey, red IPA, dark, among others.

Located in Rosario city, Santa Fe Province, Straus has been a pioneer in the production of sorghum-based beer since 2013. Currently, the company produces between 5,000 and 7,000 liters monthly, equivalent to 15,000-20,000 bottles of 355ml. Straus founders are Jésica Espósito (bromatologist) and Guillermo Lione (accountant and commerce businessman).

The first contact between Advanta and Strauss took place during the launching of Igrowth in 2018. Since then, both companies have been collaborating together occasionally to promote sorghumbased beer in various events. In 2022, they took their collaboration further by launching a co-branding limited edition.

Sorghum-based beer is available in several breweries of the country, as well as through wholesale suppliers and online marketplace. The demand for this product is constantly increasing because it is very tasty.

At the 2024 edition of Expoagro, Advanta presented their gastronomic space at stand 330, with the purpose of reinforcing a message they consider to be essential: "We can eat sorghum as well." In this space, attendees could try a whole-grain menu that included hot, cold and sweet meals, all sorghum-based so as they could enjoy a unique taste.

The company claims that they will keep on working and exploring this field until everyone can incorporate this grain in their daily diet.

A different taste present at Expoagro

The society of the hive: the importance of bees for crops and humanity

Bees enhance crops productivity and contribute to global food security by being vital agents in the process of pollination and plant species diversity. But first let us delve into the essential role of these insects since ancient times.

By: Agr. Engr. Antonella Fiore Prospective Program - Aapresid

"If the bee disappeared off the face of the Earth, man would only have four years left to live.”

This quote is attributed to none other than Albert Einstein, winner of the Nobel Prize in Physics in 1921. Although it may sound fatalistic, the aim of this month's column is not to sow panic but to raise awareness of the vital role of the bee in pollination, agriculture and, therefore, human nutrition.

According to FAO (www.fao.org.ar), nearly 75% of worldwide crops producing fruits and seeds for human consumption depend, at least partially, on pollinators.

Food security, nutrition and the environment's health are aspects closely related to the bee's work and other pollinators. These insects contribute to 35% of global agricultural production, by pollinating around 85 of the main 115 food crops in the world.

Pollination does not only benefit agriculture, but also has a positive impact on the environment in general, as it helps to maintain biodiversity and the vitality of those ecosystems sustaining agriculture and human life. Actually, bees and other pollinators provide an important ecosystemic service by ensuring crosspollination, meaning genes transfer, promoting reproduction of many cultivated and wild plants.

Besides this information, there are other interesting facts about this month's protagonists that stand out. Bees have been the subject of study for decades, as they are a socially notable species and can live grouped in colonies of up to 50,000 individuals. Yes, you read correctly. These groups formed very well-organized hives in which every member performs a specific task and has distinctive physical characteristics.

Bees are known as the only and big producers of honey, a natural food consumed by humans since olden days. Apiculture, meaning the raising and keeping of bees of the Apis genus, has been practiced for centuries, providing not only honey but also products such as royal jelly, propolis, wax and pollen.

Apiculture in Argentina

Argentina is placed among the three primary producers of honey globally, being the second major exporting country with an average volume of over 75,000 tons (t) annually; whereas domestic consumption is around 6,000t, according to data on the official website of the Argentine government (www.argentina.gob.ar).

According to the Registro Nacional de Productores Apícolas (RENAPA online)–a national registry of beekeepers–there are 15,306 apiarists in the country, who manage 33,477 apiaries with more than 3,500,000 beehives. Moreover, the sector has a total of 1,209 authorized rooms by Senasa intended for honey extraction.

Regional Map of Honey's Identities -the outcome of active cooperation- identifies different productive regions and their characteristic honey, according to the flowering types that bees visit to collect nectar and pollen. Credits to: https://magyp.gob.ar/apicultura/mapa.php

Most part of the Argentinian territory is suitable for the development of apiculture activities and presents different productive potentials both for honey and other beehive byproducts. Said activities are conducted in multiple cities across the country.

Climate conditions and technological advances enable the extraction of high-quality honey with various characteristics that distinguish it internationally. Most producers are from Buenos Aires, Entre Ríos and Santa Fe provinces. However, apiculture in Argentina is an activity with a marked federal profile, being developed in 22 provinces: Jujuy, Salta, Catamarca; La Rioja, Tucumán, Santiago del Estero, San Juan Mendoza, Córdoba, Santa Fe, Chaco; Formosa, Misiones, Corrientes, Entre Ríos, Buenos Aires, La Pampa; Río Negro, Neuquén, Chubut and Santa Cruz. This generates an impact in all local economies, as producers usually live near the places where they carry out these activities.

The society of the hive

Scientific name: Apis mellifera

Common name: Western honey bee or European honey bee

Type: Invertebrate

Diet: Herbivorous

Name of the group: Colony, swarm

Size: 1 to 1.5 centimeters (worker honey bees)

Bees are eusocial insects. Eusociality is defined as the highest level of social organization that takes place among animals or insects. According to a study conducted by the University of Florida, there are three features determining the levels of sociability in insects, and bees meet every one of them:

Reproductive division of labor: every colony consists of a queen (reproductive female), workers (non-reproductive females) and drones (males; Figure 1). Each cast plays a well-defined part.

Cooperative brood-care: worker bees take care of the queen's offspring. In most cases, the queen's offspring are sisters to those worker bees breeding them.

Overlap of generations: queen bees can live several years and coexist with their brood in the colony–workers and drones.

There are three types of castes of western honey bees: drones, queens, workers (Figure 1).

A. Drones: male bees. Their head and thorax are larger than the females'. Drones' big eyes reach the high-central part of the head, giving them a fly-like appearance. Their abdomen is thick and round at the end, unlike sharp ones in females. Drones are responsible for transmitting the colony's genes to the next generation by mating with queens from other colonies.

B. Queens: female bees, breeders of western honey bees. The size of their head and thorax are similar to workers', but they have a longer and thicker abdomen. During most of the life cycle of the colony, the queen is the only female breeder, and is responsible for procreating the entire offspring in the hive.

C. Workers: usually non-reproductive females and the smallest individuals of the three castes. Their bodies are specially made for pollen and nectar collection. Worker bees perform all caretaking duties of the offspring, maintenance of the hive and defense of the colony. Instead of specializing in a single task, every worker bee is put through a predictable progression of tasks based on their age. This progression is called temporal, or age, polyethism.

Figure 1. Western honey bee castes: a- drone (male), b- queen (reproductive female), and c- worker (non-reproductive female). Credits to: Mike Bentley, UF/IFAS.

Temporal polyethism is the age-based division of labor happening within western honey bee colonies. At different ages, worker honey bees are more suited to perform different tasks. Throughout their development, every worker performs, predictably, different tasks in the colony rather than specializing in just one.

Generally, young worker bees perform duties in the central area of the hive, where the brood–immature bees–is placed. Their labors include cleaning the cells, feeding and caring for the offspring and also the queen. As they grow older, worker bees start to carry out chores in other parts inside the hive and, eventually, in its external areas. These chores include, progressively, washing and feeding of their sisters, building of cells, airing of the hive, receiving and storing nectar and pollen, and processing nectar into honey. Oldest bees are devoted to tasks on the outside, namely, protecting the hive, eliminating dead bees and searching for food, i.e., foraging (Figure 2).

Figure 2. Simplified representation of the order in which worker bees perform different tasks. Credits to: Ashley Mortensen, University of Florida, generalized data from Seeley (1985).

It is believed that the development of age-related labor is regulated by the Juvenile Hormone (JH). Worker bees' JH levels vary throughout their lives, and these changes cause glands to activatedeactivate, simultaneously changing worker bees' physiological activity to adapt to ongoing duties. For instance, young bees responsible for the caring of the brood have hypopharyngeal glands highly developed to produce food for larvae; whereas oldest bees responsible for building cells have reduced hypopharyngeal glands, but they have other specialized, highly developed glands to produce wax.

In the social system within the hive, it has been observed hormonal variations that can explain why not all bees adhere to the regular duty structure. For instance, if many forager bees die, the younger ones will advance faster toward pollen and nectar collection tasks to compensate for the losses. On the contrary, if a disease affects the brood and drastically reduces the number of developing young bees, some older bees will resume those "duties performed by younger bees" to ensure that every task is fulfilled.

During winter, bees live off storage honey and pollen, and they huddle together in a ball-like manner to maintain the heat. During this season, larvae feed from these reserves, and for spring, the hive is filled with a new generation of bees.

All bees cooperate in the execution of tasks to build and maintain the proper functioning of the hive. Some examples include thermoregulation (regulation of the hive's temperature), respiration (exchange of air from inside and outside of the hive) and reproduction (creation of new colonies of bees).

Thermoregulation: Bees maintain the brood area of the hive at a temperature of around 34°C. When the room temperature is over 34°C, worker bees cool the interior of the hive by fanning the air with water drops. If the temperature drops under 34°C, worker bees grouped around the brood nest and generate heat by vibrating the muscles in their wings.

Respiration: Bees prefer to nest in enclosed cavities–like those in trees–which limits a passive exchange of air. Therefore, worker bees actively ventilate the air inside and outside the colony through the inhalation and exhalation from the entrance of the hive.

Reproduction: Reproduction does not entail one queen laying thousands of eggs. A western honey bee colony breeds through a process known as swarming, and by which a new colony is created. Swarming is initiated when daughter queens are produced. The old queen and even up to two-thirds of worker bees leave the hive in search of a new cavity to nest. As a result, a daughter colony emerges (bees that remain at the original nest site) and a parent colony (bees that left to find a new nest).

Management of the hive and issues to consider

In an interview for Tv Agro conducted by the journalist Juan Gonzalo Angel, the Argentine apiarist, Horacio Usatorre, shared information about management and considerations to take into account regarding beehives keeping in Argentina.

As regards to the installation of beehives, he highlighted two essential aspects: knowing the floral and sanitary characteristics of the area in which beehives will be settled.

Usatorre also suggested to work as bees would, in cooperation with other apiarists: "The first task is to find a group of apiarists, 2 or 3 people with whom to exchange ideas with. Not to isolate yourself. Every day new diseases and technologies emerge, that is why information is of paramount importance. Not always every disease can be found on the internet," he said.

In apiculture, bearing in mind that it is an activity that has been performed for hundreds of years, there are two factors that mankind has not yet been able to change: the weather–which has influence over the amount of food for bees–and the habits or biology of bees.

"In fall, we put beehives into hibernation, that is, we leave them part of what they produce so they have food for the entire winter," the apiarist said.

As regards beehive management during winter, Usatorre pointed out that there is almost no activity and bees are left alone while hibernating. Bees cluster, meaning that they form a type of ball by getting closer together, generating heat and drinking honey. "That is how bees all around the world survive winter, even under snow conditions, as long as they have enough honey reservations."

When spring comes, the beehive begins to develop gradually. Bees live according to their hours of flight, so the more they fly, the less they live. As a consequence, in summer, a bee can live 50 days, while in winter it can live up to 90 days, as they fly less and suffer less exhaustion.

"In spring, it is the time of the renovation process of the old bees passing the winter; they will die and new bees will be born, who will enable the exponential development of the hive. Therefore, the number will slowly grow until covering three parts of the beehive and thus, have a good production of honey," Usatorre commented.

In Argentina, the average annual precipitation rate in the Pampa Húmeda region is between 700 and 800mm. "During drought years, there is less honey. This is because plants depend on water; if there is a long period with no rain, plants release less nectar and, as a result, there is less honey," the producer explained.

During summer, honey extraction is performed. During months of absolute drought, honey production is very low, producing only between 5 and 7kg per beehive instead of the regular 25 or 30kg under good precipitation conditions.

Honey bees can travel nearly 1,000 meters around the beehive for the collection of nectar and pollen.

As regards which is the best bee for the production of honey, Usatorre claimed that "the best bee is the one born in the area, as it is adapted to the climate."

When the interview was over, he shared a few suggestions for those who wanted to initiate this activity, stating that at the beginning it may need a low investment as long as it is properly managed. "My first advice is to read a lot and then, if you are decided, to take a course with a consultant from the area. Apiculture has a great advantage: it is possible to start with just one beehive. Investment costs, in line with some other production activity in a farming system, is minimal, until reaching a profitable number of beehives," Usatorre concluded.

Karl von Frisch and the language of bees

The language of bees is one of the most fascinating behaviors within the animal world. In the past century, the Australian biologist, Karl von Frisch, devoted 30 years of his life to the study of insects, and succeeding to decode the message of their communicative dance. His work led him to receive the Nobel Prize in Physiology or Medicine in 1973 for this discovery.

In his book "Dancing Bees", Von Frisch describes in detail the behaviors of these insects. When a bee dances, the others follow its every movement, capturing both its movements and scent. Thus, they receive indications on the type of food they should search for.

The "Circling dance" indicates that food sources are near the hive, usually at a distance of around 50 and 100 meters. However, this dance does not provide details on the exact location, so bees will have to look around the proximities of the hive.

The "Waggle dance" conveys information about the presence of a food source at a greater distance. For this dance, the dancing bee will outline a figure-eight pattern through straight lines followed by semicircles. At the straight central section, the bee moves its abdomen. The direction of this straight section indicates the food location based on the sun's position. Moreover, the speed and movements of the abdomen provide specific information regarding distance and length of the journey. For example, the more far the food source is, the more time it would take for the honey bee to travel the straight section.

Karl von Frisch, Nobel Prize in Physiology or Medicine (1973), pioneer in decoding the fascinating language of bees and revealing the secrets of their communicative dance.

Circling Dance

Waggle Dance

- Distance < 100 meters

- Quantity

- Type of food (by on scent)

- Distance > 100 meters

- Direction based on the sun's position

- Time and energy needed for the journey

- Quantity

- Type of food (based on scent)

Gentileza: www.daviddelgado.me

What seemed impossible before, today is becoming true. For several years now, a group of German scientists from the University of Berlin, have been carrying out a revolutionary project: the development of "RoboBees", which are bee-simulating nanobots.

These biometric devices are programmed to imitate the characteristic communication dances of these insects, aiming at attracting bees from various regions in order to make them pollinate in certain areas.

Through several tests, researchers have studied Robobee in several scenarios. And, although results are encouraging, scientists acknowledge that the device needs further improvements for major efficiency, especially regarding appearance, as they need to look more like real bees.

Despite these issues, researchers are maintaining a positive attitude toward the potential of their creation to address the much concerning decrease of these insects, vital for the survival of multiple plant species.

RoboBees: Nanobots that imitate bees' behavior to promote pollination. Credits to: Wyss Institute at Harvard University.

May 20: World Bee Day

To raise awareness on the importance of pollinators, the threats they face and their contributions to sustainable development, the United Nations declared May 20 as the World Bee Day.

Check the references by entering www.aapresid.org.ar/blog/revista-aapresid-n-217

Personal hardships led her toward the countryside and the

field

where

she

found a new passion owing to Aapresid

With a professor degree and the heart of a fighter, Lidia Carletto found refuge in her career, the field and her loved ones against the challenges and the losses she had to face. Resilience and love are her banner. An invitation she accepted due to her sense of duty brought her closer to Aapresid, where she found both technical knowledge and a group of people that gave her strength to move on.

By: Lucía Cuffia To: Prospective Program - Aapresid

Profile

Name: Lidia Gladys Carletto

Profession: Retired after 38 years as a professor of Social Sciences.

Place of birth: Caleufú (La Pampa Province, Argentina)

Family: Mother to Mariana and grandmother to Lola, who has "8 new years-old" as she recently celebrated her birthday.

Hobbies: Travelling, playing golf and spending time with Mariana and Lola.

At the core of every organization there are people whose attitude and commitment do not go unnoticed, even more so when you add a generous dose of warmth. Lidia Carletto is one of those people.

Her life story is marked with challenges and meaningful losses, confronting situations that required her resilience to move on. In this path, her family, her loved ones, her colleagues and the students from the school she taught in, as well as the Aapresid community, were and still are a vital support for Lidia.

Roots in Caleufú, her childhood and her passion for teaching

She was born in Caleufú, a small town located in the north of La Pampa Province, almost at the limit with San Luis and Córdoba provinces. Her dad had a harvester and worked providing services to agribusiness. When she was 5 years old her mother died, and the following year, her dad. "I was the youngest of a family of four children, so one of my sisters ended up raising me," Lidia tells us.

She remembers her childhood with much affection. "Apart from losing my parents, they were happy years, I was surrounded by many friends and constantly playing on the streets."

After finishing high school, Lidia wanted to continue studying. Back then Caleufú had no high schools, so one had to move to the city of General Pico. "As I insisted so much on studying, my siblings made a great effort and sent me there." She enrolled in a boarding nun's school in General Pico and studied teaching. "I had never thought of being a teacher, I wanted to go to Colegio Nacional but back then the only option I had was to study to become a teacher or not study at all, and I came to discover that I loved teaching," she confesses.

Lidia worked as a teacher for almost 38 years. She was a professor of Social Sciences at Caleufú high school up until she retired. According to her students, she was quite demanding but also very loved there. "They used to come to my house frequently. I taught them Social Sciences and they taught me how to play card games," she says.

She always tells the story of when she was in a stationery shop and someone covered her eyes and said: "Guess who I am, I was your student." And she answered with a smile on her face and said: "Everyone in this town was a student of mine." It is that with all those years of teaching, today Lidia is known by most people in the area.

Her relation with agribusiness and her arrival to Aapresid happened because of an invitation she accepted as it was her “responsibility”

Lidia married Alberto Illuminati, who was an agricultural producer in General Pico and whom she has two kids with, Pablo and Mariana. They lived for two years in the countryside and later they moved to town. "My relationship with the field was limited to only Sunday trips when I accompanied Alberto. Sometimes I helped him with the tractor, but it was always minor stuff," she says.

Life adversities forced her to take control of the field. The tragic death of her son, who had just obtained his degree in agricultural engineering, and the loss of her husband a short time later, forced her to take the reins of the establishment.

"I was in charge of the field together with my

daughter, who was studying architecture at that time. It was a really hard time."

"A relative helped us to understand more about how everything worked and, all through the pain and already retired, I told myself: I am alone, I do not know anything about managing the land and this is our source of income." It was then when the invitation to join Aapresid came. "A girl from Caleufú invited me. They were carrying out a UPA meeting–"a producer in action"–at a hall in Santa Rosa city, and I accepted partly out of kindness and partly out of responsibility. That was how I entered and never got out," she claims.

To deal with her initial lack of knowledge on land matters, Lidia found in Aapresid a place to learn everything she needed to know so as to take care of it. "I went all in in the group and started to love the field more and more, as well as to develop an interest in its administration." Aapresid not only provided her with knowledge, but also with a group of people that allowed her to have friends all across the country. She quotes as her own a phrase used by Andrés Garciarena: "Puedo salir de 25 de Mayo, provincia de Buenos Aires, y llegar a San Luis, y sé que voy a encontrar un amigo en

cualquier lugar que cruce"–meaning that one can go from one province to another and will be able to find a friend in every place across the way.

Lidia has been part of the regional branch in La Pampa for more than 15 years. She always remembers the night in which Gustavo Herrero, member of the branch and who also did sow and harvest works in Lidia's field, asked her to take over the Treasury Department. "It was a June evening, we were inside the enclosed trailer and it was very, very cold. He suddenly said: 'Come on, take over the Treasury Department', and handed me a greasy notebook with a list of the members of the group." Two years later, she assumed vice president of the branch, then president, and in 2021 she was invited to be part of Aapresid's executive committee during the presidency of David Roggero.

Despite "not knowing much on technical matters and not being an agricultural engineer", Lidia is always willing to cooperate with everything within her reach. Although her period at the executive committee ended in April of last year, her commitment is strong and she still participates actively with the group at the regional branch. "I still ‘bother them’, as they usually say to me as I am constantly underpinning one thing or another."

"I always say that Aapresid gave me more than I gave to them," However, both her journey and

her colleagues in this path are proof that the contribution was mutual.

With everything she learned throughout these years, Lidia now sees the field from another perspective. "Even though it is currently leased, I am in continuous contact with the tenants in order to be informed on what is being done and what needs to be improved. I know now what I am talking about all thanks to Aapresid," she acknowledges.

A day in Lidia's life is everything but predictable. "Routines are not an option to me; there are always people at home, and if there is an issue in the field, I am on my way there immediately."

It has been 8 years now since being Lola's grandmother became one of her most important roles. "Lola is the joy of the family," she says tenderly. "I always tell her: 'You are the best granddaughter I have', and she answers: 'Grandma, I am the only one."

Since Lola was a baby, they have shared many things together, from vacations to entire game days at home or in the countryside. Both Lidia and her daughter, Mariana, wish for Lola to Grandmother to Lola, traveler and golf player

share their love for the field. "We try to spend the weekends there and use that time to tell stories and anecdotes about the uncle and grandfather she could not meet," she says emotionally.

These days, Lola is constantly spinning around in the roller skates she bought with the money the tooth fairy gave her, and until last year she practiced equestrianism. Actually, a cousin got her a horse for her birthday, who she named "Chizito"–the same name her father named his horse when he was a child–and which she later changed to "Luky".

For a couple of years, Lidia played golf, a sport she knew as an adult and one she enjoys very much. "I had to quit for several reasons, among them

the pandemic and my commitments to Aapresid, although I would like to resume it." However, she never stopped traveling. Together with Alicia, a lifelong friend, they try to go on one or two trips a year. "It is something that I love and that I will keep on doing my whole life."

Lidia defines herself as a tireless fighter, who had to face many challenges and hard blows throughout her life. "I always fought hard to overcome adversities and I was always surrounded by love. One friend of mine keeps telling me that I am one resilient person." Although she knows her path has not been a steady one, she constantly seeks to keep a positive attitude, to see the glass half full and to find new goals worth fighting for.

Fertilization of winter forages: alchemy or agronomy?

José Jauregui analyzes some of the reasons limiting fertilization on winter forages–a crucial practice for livestock farming production sustainability–by destroying deep rooted myths and emphasizing their economic and environmental importance.

By: José Jauregui Adjunct Professor- Forages Lecture (FCA - UNL)

Winter forages are essential resources that allow us to sustain animal production during the coldest months of the year. They are noticeable because of their vigorous growth during winter periods, which allows to solve possible issues that may arise because of most evergreen resources.

However, the production of these forages may be conditioned by nutritional factors that are often confused with "drought" effects or other features. The fact is that a well-nourished plant will make a better usage of available resources, especially radiation and water, meaning more kilos of dry matter (DM) per unit of product (Image 1).

The nutrient mostly conditioning winter forage production is usually nitrogen, although phosphorus, and sometimes sulfur, show up occasionally in second place. A fast way to estimate this element's requirements is to multiply the expected yield by 0.03. This value emerges from the premise that a crop is considered to be well nourished on N when it contains 3% of this element in its chemical

composition, assuming that grazing is between 1.5 and 3tn of DM/ha. This premise is based on a concept known as "nitrogen nutrition index (NNI)". This index basically indicates if a crop has negative N levels (below 1 index) or N surplus (above 1 index).

As regards the field, it is mostly common to expect crops to reach between 80% and 90% on the NNI

Image 1. Ryegrass forage crop with nitrogenous fertilization (left)–100kg of urea applied when sowing; another without fertilization (right). The immediate conclusion when analyzing the picture is that, with the same quantity of accumulated water within the same soil, the fertilized crop on the left made better use of this resource than the one on the right.

in order to maximize production. Therefore, to obtain a 10 tonnes of DM/ha yield, it is needed an application of nearly 270kg of N/ha. This application can derive from fertilizers or organic matter mineralization in the soil.

But... Why are winter forages not properly fertilized? What is preventing it? Below, there is a list of some of the reasons that are probably contributing to this situation.

"Fertilization is expensive"

This affirmation usually starts the everlasting debate on fertilization. Within contexts of high prices on fertilizers and relative low prices on milk and meat, this may be true. However, few people are questioning the return of investment when applying fertilizers. Here are some points to put a picture to this statement.

One kilogram of urea currently costs U$S 0.83. The index of bullock in the Cañuelas marketplace is around U$S 2 per kilogram. Assuming that:

Three fertilization occasions per hectare during the entire cycle of forages–100kg of urea in each one–with an application expense of U$S 21 (U$S 7/ha/application).

Usage efficiency of 9.2kg of DM generated per kg of applied urea (usage efficiency of N of 20:1).

A requirement of 10kg of DM to produce 1kg of bullock meat (between 180-300kg).

Harvest efficiency of 75% over the additional generated grass.

Sale expenses of 9% over additional generated kg of bullock meat.

These data show that fertilizing a winter forage with 300kg of urea can generate more than U$S 100 of profits per hectare. Certainly, this will depend on urea and bullock's relative prices. Figure 1 exhibits different scenarios of profit and loss regarding U$S/kg of bullock according to variations in the prices on both bullock and urea. This figure can be used as a reference for model scenarios in which it might be convenient, or not, to fertilize with N. Positive scenarios have been presented to this day.

22

"If it does not rain or if it rains a lot there is a loss of nutrients"

To maximize the response to fertilizers, particularly to nitrogenous ones, it is necessary to divide the dose. Similarly, it is advisable to avoid fertilization with high levels of N when sowing due to the risk of phytotoxicity on seedlings, probably resulting in "burnt" seedlings by an excess of N. To maximize the response to nitrogen, it is ideal to apply no more than 40-50kg when sowing–when possible, employ a phosphoruscontaining starter as Diammonium Phosphate–and then apply 40-50kg of N after every grazing activity. This makes logistics a complex matter, leading to the frequent application of higher doses that the crop is not able to absorb entirely owing to phenomena of lixiviation/washing (excessive rain) and volatilization (lack of rain).

Nevertheless, there are some alternatives to compensate for this situation at least partially. One of the more noticeable is the usage of protected urea. These fertilizers contain an enzyme called "urease" that is added to the urea granule and inhibits urea-ammonium conversion partially, reducing losses by volatilization, which is typical under drought conditions. Losses by lixiviation caused by excessive rain are more complex to resolve, but when dividing applications into 2-3 times during the crop cycle, these losses are significantly reduced.

Figure 1. Profit or loss (expressed in U$S/kg of bullock) according to variations on the price per kilogram of both bullock and urea.

"There is no need to fertilize, previous cultivated alfalfa leaves many nutrients available"

It may be one of the greatest myths in livestock farming. Some people claim that legumes, by fixing nitrogen from the air, leave much nitrate available for the next crop to use. If the next crop is from the grass family (common in rotation), people arguing over this matter assure that it would not be necessary to fertilize with nitrogen because grass would benefit from great amounts of NO3 left by alfalfa.

However, reality is quite different. Generally, alfalfa crops reaching 3-4 years are later changed for oat or ryegrass crops, or other winter forages. Alfalfa crops achieving that last year of life are

usually degraded and their productive levels are often low, reaching between 4 and 6 tonnes of dry matter. This, together with the general damage of the plant stand, reduces alfalfa's symbiotic fixation capacity and increases nitrate consumption in the soil by the crop. Meaning that, assuming alfalfa fixates an average of 70% of required N, this value may drop to zero in its final year.

Therefore, despite a NO3 surplus left in soils by previous alfalfa cultivation, and if that nitrate could be used by the following crop, there would not be large amounts available. This entails the need to properly fertilize winter grasses.

"I perform regenerative livestock farming, there is no need for fertilization"

In the past years, the concept of "regenerative livestock farming" has become very popular. Although there is not a sole definition or a specific "recipe" for this productive model, some may claim that crops under this management system should not be chemically fertilized. Even though it is possible to replace chemical fertilizers for biological ones, it is important to take into account that large amounts of biological amends will be needed to reach the equivalent supply of chemical fertilizers.

Even more complex is the case of those producers that decide to abandon every type of fertilization practice, either biological or chemical, claiming that "the cow restores nutrients through their manure" and "regenerates soils". Livestock farming, as any other farming system, is an open system, meaning that a fraction of nutrients present in the soil leave as meat, milk and byproducts. In spite of the fact that soil health can be enhanced by well-managed grazing, among other practices, the only way to replenish nutrients in

the system is by incorporating these nutrients in either a chemical or biological manner.

Some nutrients can also be provided through atmospheric deposition–wind and rain–even if it is a low supply amount (Berhongaray et al.,

2019). Nitrogen is the only nutrient that may be potentially exported 100% biologically based on atmospheric N fixation conducted by some legumes. In the case of grasses, there are also some free-living nitrogen-fixing bacteria that can provide this nutrient to the system.

"I apply foliar products that provide specific nutrients needed by winter forages"

While foliar products are capable to satisfy certain necessities of the crop and even help endure stress conditions, it should be considered that foliage absorption capacity is very low. Therefore, nutrients doses that can be applied through foliage are usually not enough to meet plants’ macro requirements, and they commonly

act as a "temporary amendment" before the absence of other available macroelements.

When contemplating fertilization, it should be taken into account, firstly, the crop's macro requirements, and then, focus on microelements or accurate applications, such as foliar fertilization.

Winter forage fertilization is the cornerstone to maximize both yield and income of livestock farming systems. This article proves that a proper nutrition of crops, especially through the application of nitrogen, is not only economically viable, but also essential to maximize efficiency in the usage of resources like water and solar radiation.

Regardless of the observed issues, namely initial fertilization expense, concerns on nutrients

volatility and lixiviation, and myths related to alternative management practices of the soil, the tangible benefits clearly exceed these barriers.

A properly managed fertilization, far from being a luxury or an arbitrary choice, is an essential strategy for sustaining animal production during winter, enhancing soil health and, lastly, increasing the profitability of livestock farming activities.