Autumn Pasture and Fertiliser 2023

2023 AUTUMN

Pasture& Fertiliser

Wet weather a headache for Wairarapa farmers and contractors

It’s been a tough season for Wairarapa contractors but even worse further north, says Clinton Carroll (pictured), Wairarapa representative on the board of Rural Contractors New Zealand (RCNZ).

Speaking to the Wairarapa Times-Age two weeks ago, Clinton said “Here in the Wairarapa there’s plenty of grass, but the ongoing rain means few contractors/farmers are able to get in hay and some farmers haven’t managed to get winter crops in yet.

“We contractors are having a bit of nightmare season, whether those cropping or sprayers like us.

“We all need a clear window without rain to spray or bring in hay or plant crops.”

On the plus side, Clinton says he is not hearing any issues with sta˜ shortages.

“Because of the ongoing rain, we’ve asked ours to take the leave they’re owed.

“There’s only so much maintenance you can do – it’s too early to start stripping down machines because those are big jobs.

“Once the grain harvest starts later this month, it’ll get busy again and the machinery will be needed.”

Clinton’s advice to farmers is to

“maintain communication with your contractors.

“Once we get some heat, things will get busy and there will be a backlog of work.

“If we get prior advice from farmers, we can plan better to get there when their crop is ready or the conditions are right for spraying.”

Clinton says it is important to recognise how tough things are in other parts of the country.

“Our Waikato-based president Helen Slattery says her ÿ rm worked far fewer days than usual in December due to wet weather, followed by more rain in January.

“She’s warned if wet weather continues to a˜ ect maize growth – and the ability to harvest it – this could raise farmer costs and consumer prices.

“Our CEO, Andrew Olsen, who’s based here in the Wairarapa, says maize harvesting is currently down about 30% on normal in parts of Waikato, Northland and Bay of Plenty. “He’s advising feed shortages due to wet weather will present a major issue for many farmers up there – creating as big a challenge as the labour shortages of previous years.

“Rural Contractors NZ is working with Federated Farmers and MPI to look at what can be done to ease the looming feed shortage.”

Look out for facial

eczema

Warm summer temperatures and high humidity create the perfect conditions for Facial Eczema, and Beef + Lamb New Zealand is urging farmers to be vigilant.

Will Halliday, B+LNZ’s senior advisor for Biosecurity and Animal Welfare recommends that farmers in high-risk regions undertake weekly monitoring of their own property and when spore counts start to rise, put management strategies in place to prevent stock being a˛ ected by this production-

Warm temperatures and possible heavy rainfall predicted for autumn

limiting disease. These strategies could include avoiding hard grazing, feeding “clean” forage crops such as chicory or plantain, dosing sheep and cattle with zinc oxide boluses or drenches, or adding zinc oxide to cattle water troughs.

Facial Eczema (FE) is caused by the spores of the fungus pithomyces chartarum (which grows on litter at the base of

Temperatures are likely to be average or above average for the Wairarapa from now until April, according to NIWA’s “Seasonal Climate Outlook February - April 2023”.

“Temperatures are about equally likely to be near average (45% chance) or above average (50% chance),” it predicts.

“More frequent onshore winds and above average coastal sea surface temperatures may

pasture) and a˛ ects more than just an animal’s face. The spores release a toxin which can damage the liver resulting in photosensitivity and sunburn which are the clinical signs of the disease.

The fungus is ever-present, but when temperature and moisture levels are high, the fungus grows rapidly, releasing huge numbers of toxic spores.

lead to higher humidity levels, more cloud cover, and warmer overnight temperatures.

“Fewer north-westerly winds will likely continue to limit the number of days above 25°C.

“Rainfall totals are most likely to be above normal (45% chance).

“Sub-tropical low pressure systems and/or atmospheric rivers are forecast to occasionally impact the region, increasing the risk for heavy

When monitoring indicates rising spore counts, he urges farmers to keep a close eye on stock, looking out for signs of discomfort, photosensitivity and skin lesions.

“For every animal with clinical signs of FE – which are obvious skin lesions – there will be many more with sub-clinical disease, which is the invisible on-going liver damage that can cause major productivity losses including reduced liveweight gain especially at mating resulting in lower lambing and calving percentages.”

B+LNZ has a number of resources to help farmers understand and manage FE in both the short and long-term. In sheep, genetics (buying FE-tolerant rams) o˛ ers a longterm solution to limiting the impacts of this disease.

rainfall and ° ooding.

“Soil moisture levels and river ° ows are most likely to be above normal (50% chance).”

La Niña continued during January, but it has gradually weakened, NIWA says.

“It will continue to a˛ ect Aotearoa New Zealand’s atmospheric patterns in coming months, even as neutral conditions are likely reached in early autumn.”

We are 100% New Zealand owned and operated. All of our products are produced from all-natural limestone, quarried right here in Wairarapa. We don’t use unnecessary additives or chemicals and o er both organic and non-organic options.

Soil fertility critical

Correct soil fertility is critical for optimal plant growth, advises DairyNZ. There are 16 nutrients that are essential for pasture plants to grow to their potential - 13 of these are obtained from the soil.

There are ÿ ve nutrients N, P, K, S and Mg (pumice soils) that are added to soils in the form of fertiliser and the remaining nutrients are abundant in most New Zealand soils. Adding elements other than the 16 listed below will not enhance plant growth and some may be toxic to pasture plants and animals.

Assessing nutrient status

Capital fertiliser inputs can be much greater than the maintenance input, especially if a rapid increase in the soil nutrient status is required.

into account fertiliser history is the only way to assess nutrient status.

Soil testing

A robust soil fertility monitoring program is the best way to monitor nutrients in the topsoil of any farm. Fertiliser costs are a major investment and need to be monitored. Even in the maintenance stage, more precise rates can be calculated by establishing trends in soil test levels over time through the use of annual soil testing.

Pasture testing

Pasture testing is a back-up to soil testing. While soil testing determines available soil nutrient status, pasture analysis should be used to assess how much nutrient has been taken up from a fertiliser application and check trace element status.

Clovers have a higher requirement of all nutrients compared to grasses. They are a sensitive indicator of underlying soil fertility.

It is important to measure the current soil nutrient status to assess whether a farm is in the maintenance or development stage. Soil testing and taking

There are two key reasons to test and analyse pasture samples:

1. Concerns about animal health

Insu˙ cient concentrations

of: Mg, Na, Cu, Co and Se. Excessively high concentrations of K, Mo and Mn.

2.Clover Nutrition

Clovers have a higher requirement of all nutrients compared to grasses. They are a sensitive indicator of underlying soil fertility.

Nitrogen

Nitrogen (N) fertiliser can be used to overcome seasonal pasture deÿ cits by increasing pasture supply. Similar to any purchased input, N requires careful use to optimise economic return. Use appropriate applications rates and apply to pasture with some regrowth e.g. 16001800kg DM/ha or better.

Lime Soil Acidity

Liming is carried out to mainly overcome aluminium toxicity and increase molybdenum and phosphorus availability. On pasture, liming generally encourages more productive

pasture species (legumes and ryegrasses) at the expense of low fertility species.

Phosphorus(P)

Phosphorus is a key nutrient for the successful growth of pasture and crops. Soil phosphate (P) moves slowly through soils, reducing opportunity for leaching losses.

Sulphur(S)

Clover has a higher requirement for all nutrients including sulphur, relative to the grasses. Thus, if a soil is S deÿ cient the clover vigour and abundance will be poor.

Potassium(K)

Potassium is lost through animal excretion in dairy sheds and farm tracks. Potassium can be easily leached especially under heavy rainfall. Potassium fertilisers are generally applied in low rates to pasture and the percentage lost by leaching is small.

Source: www.dairynz.co.nz

Pasture & Fertiliser

Podcast sheds light on causes of autumn ill thrift

Autumn rains bring with them the promise of high livestock growth rates, but this not always the case and it can be di˜ cult to know why.

Beef + Lamb New Zealand held an Autumn ill thrift webinar where Charlotte Westwood, a Veterinary Nutritionist with PGG Wrightson Seeds, and Marlborough vet Mary Bowron tackled this multi-faceted issue.

Charlotte says a number of factors can contribute to autumn ill thrift including poor pasture quality, abrupt dietary changes (from poor quality to high quality forage) stock water, feed budgeting challenges, low drymatter pastures, facial eczema, mycotoxins, ryegrass endophytes, internal parasites, subclinical disease, trace element deÿ ciencies and abrupt changes in feed supply and demand.

In the webinar, Charlotte and Mary step through each of these issues, with Charlotte focusing on nutrition and internal parasites while Mary discusses trace elements.

Throughout the webinar, Charlotte stresses the need to allow autumn pastures to build mass before grazing for

both nutritional and animal health (internal parasites, Facial Eczema, mycotoxins) reasons.

She explains that new pasture growth in autumn is typically low in drymatter, so it is easy to over-estimate the pasture mass on o˛ er and therefore easy to inadvertently underfeed stock. After a very dry summer, stock in extensively grazed areas can walk long distances to ÿ nd the green pick after autumn rain. This in itself uses energy. Using sub-divided areas and/ or supplementary feeding for longer, will allow pastures covers to build and will prevent this.

Building more pasture mass after the ÿ rst autumn rains will also favour the survival of perennial pasture species.

Post-rain autumn pastures can be low in drymatter and ÿ bre, yet high in protein and watersoluble carbohydrates. Rumen and other gastrointestinal changes need to be made before an animal can make the best use of this feed.

There is also a degree of harvest ine˜ ciency, because compared with summer pasture, each

mouthful the animal is ingesting is lower in drymatter. Lambs will compensate by taking more bites per day but cattle wont.

Again, pasture mass should be allowed to build before grazing, so at grazing, animals are getting more feed with every mouthful.

If young stock suddenly shift from a low to high protein diet, it can create a sudden burst of rumen ammonia. This makes lambs feel unwell and intakes will be reduced until the rumen adjusts over days or sometimes weeks.

This adjustment will be faster if there is not such a big di˛ erence in the quality of summer and autumn pasture, as will be the case in many regions this year.

Baleage and hay will help with the transition between a low and high protein diet and high pre-grazing pasture covers will have more drymatter and will be lower in protein and will make the transition easier.

Internal parasites can be a big issue in autumn with high populations of L3 larvae in

pastures. Internal parasites should always be considered in cases of ill-thrift.

Marlborough vet Mary Bowron talked about trace elements and minerals, the important ones for sheep being selenium, iodine and cobalt (Vitamin B12) while cattle require copper and selenium, iodine sometimes and cobalt should be kept in the back of the mind.

She says vets are seeing fewer clinical signs of trace element deÿ ciencies. However, farmers are pushing the boundaries of productivity so animals need have su˜ cient trace elements to help them perform at an optimum level.

Adult sheep and hoggets need selenium and iodine premating while retained lambs may need selenium and cobalt at this time of year.

In the webinar, Mary outlines the signs of deÿ ciencies, how to test and methods of supplementation.

The videos and podcasts of the Autumn ill thrift webinar are available on the Beef + Lamb NZ Knowledge Hub at bee˜ ambnz. com/knowledge-hub/

Sechura RPR is Back on the NZ Market

Sechura RPR has been unavailable for a short period owing to di˜ culties at the mine itself and with shipping.

NZ is o° the beaten track at the best of times.

Sechura RPR stocks are now fully available.. Some years ago, a survey of soil samples showed that 90% of arable, orchard and dairy land had ample (or more) phosphate, while 86% of hill country did not have enough.

“Professor Ian Cornforth of Lincoln University commented:

“The gradual dissolution of reactive phosphate rock fertilisers supplies plants with available phosphate at a rate roughly

equal to the rate at which pasture plants absorb phosphate into their roots, so the concentration of phosphate in the soil solution remains reasonably constant. In contrast, phosphate fertilisers that dissolve rapidly produce a very high concentration of phosphate in the soil solution immediately after they have been applied. This encourages a reaction between the fertiliser phosphate and some soil constituents that decreases the availability of the phosphate to plants.”

Sinclair et al., (1997) “It was experimentally shown that yields on plots fertilised for 6 years with RPR (Perrott et al. 1993) were higher than predicted from the Olsen P tests values for those plots. It was found that on average after 6 years annual RPR application, Olsen values needed multiplying by 1.69 if an Olsen P response curve, generated using SSP, was to be used to predict yield.” If an Olsen P was 20; it needed to be multiplied by 1.69 which would equate to an Olsen P of 33.8. The reason for the under prediction

of yield on RPR fertilised plots is that plant roots can access P that that will be released from the undissolved RPR residue, but this P is not extracted in the high pH 8.5 Olsen extract.”

Not all RPRs are equal. There is only one true Sechura RPR. For your own sake take a sample of any RPR you have bought and have it independently analysed. Some operators ne-grind their products before submitting that sample for analysis. That can in ate results.”

In addition to being a superior form of P for the soil and plants, stock health also improves. An example with sheep is that only 25% of hogget’s needed dagging when run on land fertilised with Sechura RPR, while 75% of hogget’s needed dagging when superphosphate was used. This di erence can be further widened by on-farm management practices. On properties using our soil fertility program, animal drenches are not usual or regular and veterinary intervention is rare. Diseases such as facial eczema are almost totally absent.

This is a huge bene t.

A trial was conducted independent fertiliser consultant Robin Boom in 2020 near Taumarunui. To ensure an even playing eld, the amount of fertiliser added was adjusted so each plot had the same amount of P (45 units) and sulphur (30 units) applied.

In order from best to least dry matter, the results were:

1 Sechura RPR with Sulphur 90, 9,907 kg,

2 Superphosphate 9,884 kg,

3 Replenish 9,744 kg,

3 Triple Plus 9,704 kg,

4 DCP18/S90, 9,306 kg,

5 Triple Super/S90, 8,879 kg,

6 Algerian RPR/S90, 8,759 kg,

7 Granular Egyptian RPR/S90, 8,233 kg,

8 Control 7,365 kg. The analysis of Sechura RPR varies as is normal with any mined product. A typical assay is: -

Phosphorus % 11.5-13

Calcium % 25-27 - Liming value 70

Magnesium % 0.65

Potassium % 0.45

Sodium % 1.8%

Sulphate % 2.0

Boron ppm 5-100

Manganese ppm 70-1530

Copper ppm 20-40

Iron* ppm 4700-7550

Zinc 80-220 ppm Liming value 70

Cadmium is very low and citric solubility is around 44-46%.

*Most hill country we test is short of iron.

Sechura RPR works best blended with Elemental Sulphur (and other nutrients if the soil audit shows de ciencies). The product is now in stock and available from our four North Island outlets:

Te Awamutu – Te Teko – Mount View – Havelock North

Ron McLean

Managing Director

Kiwi Fertiliser Company Limited 0272894258

Pasture & Fertiliser 2023 AUTUMN

Keep an eye out for fall armyworm

Wairarapa farmers are being asked to check for fall armyworm.

The fall armyworm is not a worm but a highly invasive moth that can threaten crops in its larvae stage.

The larvae may do the damage, but the adult moths ensure the rapid spread of the pest. If pushed by winds, moths can ° y up to 100km a day.

DairyNZ is supporting the Foundation for Arable Research (FAR) and the Ministry of Primary Industries to keep the community informed about fall armyworm, following recent sightings of the pest that indicate it is spreading and ÿ nding its way into summer crops.

The moth has been found across the North Island and on the South Island’s West Coast.

Moths can ° y long distances, so further spread is likely. Maize and sweet corn crops in the Wairarapa should be checked for fall armyworm

The fall armyworm (Spodoptera frugiperda) arrived in New Zealand around February 2022. It is thought to have come from Australia.

The moth is found around the world and is present in the

Americas, Africa and Asia, and more recently has been found in Papua New Guinea, parts of Australia and now New Zealand.

Strong surveillance will help stop fall armyworm spread, DairyNZ says.

“Early detection and strong surveillance are our best defence against the fall armyworm. It is important to look for signs of the eggs, larvae and moths.

“This pest mainly feeds on sweetcorn and maize but it can survive on a range of plant species across 76 plant families including, potatoes, capsicums, aubergines, and some brassicas.

Autumn management of sub

clover

LEFT: Fall armyworm larvae have four distinctive black spots aligned in square the top the eighth segment near the back, the head section and light stripe down the side. BELOW: The fall armyworm moth measures 3-4cm from wingtip to wingtip. Females and males have white hindwing with dark brown margin.

“There are no negative consequences to growers for reporting, as this pest will not be controlled by removing crops.”

The fall armyworm is resistant to some sprays so farmers and growers should consult with relevant advisers. DairyNZ biosecurity manager Liz Shackleton says farmers are

being asked to actively check their crops for eggs, moths and larvae.

“Larvae have four distinctive

black spots in a square on the top of the eighth segment near their back, a Y on their head section and a light stripe down their side.

“The fall armyworm moth measures 3-4cm from wingtip to wingtip. Females and males have a white hindwing with a dark brown margin.”

Any sightings of adults, larvae or egg masses should be photographed and reported to the Ministry of Primary Industries:

 Through the pest notiÿ cation webpage

 Using the ÿ ndapest.nz app

 Email

FAW@mpi.govt.nz

 By phone 0800 80 99 66.

“Strong surveillance will enable us to quickly identify, act and help limit the spread,” Liz says. For further information, including tips on how to identify fall armyworm at any development stage, visit https://www. mpi.govt.nz/biosecurity/major-pest-anddisease-threats/fall-armyworm/

Pasture & Fertiliser 2023 AUTUMN

critical for spring production

The correct management of subterranean clover in autumn will pay dividends in spring when the seedlings that have emerged after autumn rain grow into a bulk of high-quality feed, says Beef + Lamb NZ.

Subterranean (sub) clover is endemic in many hill-country pastures, but there is a growing appreciation of the value of this early-season clover, particularly for growing high quality feed in late winter and early spring.

Subterranean (sub) clover (Trifolium subterraneum) has the ability to produce high-quality feed in late winter and early spring.

As it thrives on drier sites (sunny hill faces, stony soils), with the correct management, subterranean clover can be a valuable component of east coast, dryland, sheep systems.

Sub clover sets seed in late spring and after su˜ cient rain in autumn (over 20mm), these seeds germinate and seedlings emerge.

It is at this stage that the pastures should be spelled to allow the seedlings to reach the three or four-leaf stage and pass the “pull” test.

Ideally the paddocks or blocks would be grazed by cattle to remove any tag to open up the pasture and allow the sub clover to become well established.

The area can be grazed over winter, but covers should not be grazed below 1200kgDM/ha and ideally, lambing blocks or paddocks should be shut up early to allow the sub to grow a bulk of feed to help drive lactation and preweaning lamb growth rates.

Why is subterranean clover useful on dryland farms?

It grows more in spring

As an annual legume, sub clover produces more drymatter in early spring than perennial legumes such as white clover.

This is because annuals germinate and grow at a lower optimum air temperature (10-15 °C) than perennial legumes (20–25 °C).

Sub clover starts rapid growth at least a month earlier than lucerne, white and Caucasian clovers.

Well-managed dryland pastures can get 50% clover on o˝ er in September and October.

Higher feed value than grasses

Grazing animals, when given the choice, prefer a diet that is 70% clover and 30% grass.

Providing quality herbage from August to November helps lactating ewes milk well, ensuring rapid lamb growth rates. This allows lambs to be ÿ nished earlier, before summer dry conditions limit pasture production.

Increases grass palatability Grasses in the sward become more palatable through nitrogen ÿ xation by legumes.

Legumes ÿ x about 30 kg nitrogen (N) per tonne of DM grown. For example, four tonne DM of sub clover grown over a year would ÿ x at least 120 kg N/ha. This extra nitrogen is taken up by grasses. Grasses with more crude protein (about 4 per cent N) are much more attractive than N deÿ cient leaves (less than 2.5 per cent N).

The amount of nitrogen present in the leaf is used to estimate the amount of protein in the grass.

Survives on drier sites

On drier sites (sunny hill faces, stony soils) most perennial legumes (with the exception of lucerne) may not survive summer drought (such as white clover).

Annual clovers can survive from year to year as they set large amounts of seed in early summer before dying.

This provides a seedbank and rapid regeneration of seedlings in autumn.

Pasture & Fertiliser 2023 AUTUMN

Research shows plantain can reduce nitrogen leaching by 20-60 percent

Innovative new research has signalled feeding cows the leafy herb plantain can reduce nitrogen leaching from dairy farms by 20 to 60 percent.

The results, from the DairyNZled Plantain Potency and Practice (PPP) Programme, prove using Ecotain plantain in pasture can signiÿ cantly reduce nitrogen entering waterways.

Farm trials at Massey University and initial results from a trial at Lincoln University are showing similar trends.

Ecotain environmental plantain reduces nitrogen leaching by increasing cows’ urine volume, therefore diluting the nitrogen in urine and reducing the total amount of nitrogen excreted in urine. It also retains nitrogen in the soil, preventing it entering waterways.

Nitrate leaching occurs due to the high concentration of nitrogen in a urine patch.

Plants can only use part of the nitrogen in the small space of the urine patch, with the remaining nitrogen lost to ground water or nitrous oxide gas.

Ecotain plantain has two e° ects on urinary nitrogen, and both reduce nitrate leaching.

The ÿ rst e° ect is to dilute the urine by increasing urine volume. The higher volume means that the cow is urinating more frequently resulting in a higher number of urine patches across the paddock.

This means that each urine patch has a lower concentration of nitrogen, so the nitrogen is spread more evenly across the paddock.

The result is that plants are able to use a higher proportion of the nitrogen in each patch, and the amount of leaching reduces.

The second e° ect is to reduce the total amount of nitrogen excreted via urine. More nitrogen is excreted via faeces which has a much lower risk of leaching.

In addition to the e° ects on urinary nitrogen, Ecotain plantain has an ability to hold onto nitrogen in the soil for longer, further enabling the plants to use the nitrogen before it is lost.

The programme uses Ecotain environmental plantain from Agricom because it has proven e° ectiveness.

An evaluation system is available to assess the

environmental beneÿ ts of all plantain cultivars sold by a range of providers.

At the Massey University farm trial, scientists are measuring nitrogen leaching from paddocks grazed by 80 dairy cows.

After two years, the trial results have shown reduced nitrogen leaching by 20 to 60 percent in perennial ryegrass and clover pastures containing 30 to 50 percent Ecotain plantain.

The results are compared to traditional perennial ryegrass and clover paddocks (the most common pasture types in New Zealand).

There was no di° erence in milk production between the plantain and control pastures in the trial.

The amount of reduced nitrogen leaching depends on the quantity of plantain in the pasture, the soil type, climate and farm system. The Massey University trial will continue for a further two years.

Initial results from the programme’s Lincoln University study in Canterbury, on lighter soils under irrigation, show similar trends to the Massey University trial, with

a 38-50 percent reduction in nitrogen leaching from pasture containing 24 percent Ecotain plantain. More data are being collected to conÿ rm these results.

The trials are part of the nationwide PPP research and development programme that partners with dairy farmers, industry and government.

“These are exciting results –we now have robust scientiÿ c evidence that Ecotain plantain is an e° ective solution to help dairy farmers further reduce farm footprint and continue playing their part in improving water quality,” says DairyNZ chief executive Dr Tim Mackle. “Plantain can bring signiÿ cant beneÿ ts to local waterways and communities – we all want healthy freshwater to swim and play in, and dairy farmers can conÿ dently use Ecotain plantain on-farm to support that.”

For more information on the programme, visit dairynz.co.nz/ plantain-programme

For more information on how plantain works, visit: dairynz. co.nz/plantain-beneÿ ts