Growing Technologies in Soilless Media
General 1. The main concept of growing under climate and fertigation controlled conditions is to create optimal growing conditions Light
Temperature Humidity
CO2
Water & Nutrients
General 2. Optimal climate control could be achieved by modern greenhouse equipped with the required elements the control of: o o o o o
Temperature Humidity Light CO2 Water & Nutrients
should be done according to plant needs by well developed software
Concept of Growing in Soilless Media
Soiless
Cultures Definition:
Every medium that plants can
be grown which is not soil and is
completely detached from the soil.
DIFFERENT TYPES OF SOILESS CULTURES IN THE WORLD ORGANIC SUBSTRATE
MINERAL SUBSTRATE SYNTHETIC SUBSTRATE
COMBINATIONS
Organic Mediums As sc. this medium varies greatly from batch to batch since it is derived from organic compounds which due to their nature vary as a result of their origin. We can divide the organic cultures into two groups: 1. mined natural sources i.e. peat , humus etc. 2. process natural sources i.e. coconut choir , sewage sludge, pine barks etc.
PEAT The most common and prolific type of soiless culture in the world today is peat. There are 200-300 million hectares of peat in the world most of it originate in Russia, Canada, Finland and USA Is created from partially decomposed plants that are grown in a climate having very high humidity and low temperatures.
PEAT –CONT’ About 90% of the plant residues in peat are comprise from organic matter including: cellulose, hemycellulose, lignin, protein compounds, fat chains and other components of organic matter that are dissolved in water.
PEAT 1
PEAT 3
PEAT 4
coir Coir does provide a suitable substrate for horticultural use as a soilless potting media. The material's high lignin content is longer lasting, holds more water, and does not shrink off the sides of the pot when dry allowing for easier rewetting. This light media has advantages and disadvantages that can be corrected with the addition of the proper amendment such as coarse sand for weight in interior plants like Draceana. Nutritive amendments should also be considered. Calcium and magnesium will be lacking in coir potting mixes, so a naturally good source of these nutrients is dolomitic lime which contains both. The addition of beneficial microbes to the coir media have been successful in tropical green house conditions and interior spaces as well. However, it is important to note that the microbes will engage in growth and reproduction under moist atmospheres producing fruiting bodies
Residues of coconut bark wires industry
coconut
coconut Peat, Compost, Coco peat, others
compost
t
Mineral - Inert Substrates Perlite, Rockwool, Volcanic stone (“Tuff”), Vermiculite
• No chemical reaction
• No microbial response • Low buffer capacity
• Low c.e.c capacity
Tuff
TUFF0f 1merom golan) Tuff (from the Italian, heights is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is compacted into a solid rock in a process called consolidation.
TUFF 2
TUFF 3
TUFF 4
mango
Tuffsoilless2.ppt
perlite Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian.. Perlite softens when it reaches temperatures of 850–900 °C (1,560– 1,650 °F). ") perlite has a bulk density around 1100 kg/m3 (1.1 g/cm3), while typical expanded perlite has a bulk density of about 30–150 kg/m3 (0.03-0.150 g/cm3).
In horticulture, perlite can be used as a soil amendment or alone as a medium for hydroponics or for starting cuttings. When used as an amendment it has high permeability / low water retention and helps prevent soil compaction
Spice asphodel
Perlite Perlite arie 1 פרליט אריה.ppt
rockwool Specific mineral wool products are stone/rock wool and slag wool. Europe also includes glass wool which, together with ceramic fiber, are completely man-made fibers. Applications of mineral wool include thermal insulation (as both structural insulation and pipe insulation, though it is not as fire-resistant as high-temperature insulation wool), filtration, soundproofing, and hydroponic growth medium.
Mineral wool products can hold large quantities of water and air that aid root growth and nutrient uptake in hydroponics; their fibrous nature also provides a good mechanical structure to hold the plant stable. The naturally high pH of mineral wool makes them initially unsuitable to plant growth and requires "conditioning" to produce a wool with an appropriate, stable pH
ROCKWOOL
combinations (mixed cultures) They are composed from at least two different complementary substrate i.e. tuff + compost, perlite + peat etc.
What Is the Advantage of Growing in Soilless Media?
1. Optimal moisture in the substrate.
2. Optimal nutrient supply. 3. Significant advantage in disinfecting between growing periods. 4. Water recycling: o Reduce expenses o Environment solution
What are the Characteristics of optimal Soilless Media?
1. High content of water-air ratio 3.5 -1 •
(general porosity 80-90 % volumetric)
2. Good nutrient storage 3. Low Volumetric Weight 4. Can be Leached quickly (salinity problem) 5. Structure stability 6. Availability and price
MAIN DESIRED PROPERTIES IN SOILESS CULTURE
1. PHYSICAL PROPERTIES.
2. CHEMICAL
PROPERTIES.
3. OTHER GENERAL PROPERTIES.
PHYSICAL PROPERTIES OF SPHAGNUM MOSS PEAT BULK DENSITY (gr/l)
60-100
TOTAL POROSITY (volume -%)
> 96
ORGANIC MATTER (weight- %)
> 98
ASH (weight- %)
<2
TOTAL- N (weight- %)
0.5-2.5
CEC (meq/100 gr)
110-130
pH (in water)
3.5-4.0
PHYSICAL PROPERTIES 1. HIGH EASILY AVAILABLE WATER TO THE PLANT. 2. HIGH AIR CONTENT AT LOW WATER TENSION. 3. PARTICLE SIZE DISTRIBUTION WHICH ALLOWS PROPERTY 1+2 CORRESPONDINGLY. 4. LOW BULK DENSITY - LIGHT WEIGHT. 5. HIGH POROSITY. 6. HIGH HYDRAULIC CONDUCTIVITY
-
BETTER DRAINAGE. 7. ABILITY TO ANCHOR THE PLANT. 8. SUBSTRATE VOLUME IS NOT CHANGED WITH TIME OR PACKING INFLUENCE
Physical Characteristics of Soil-less Media Character
Tuf Cocopeat Rockwool Perlite Optimal 0.8 M (Verdonck)
Air content % (tension of 10 cm)
20-26
30-33
23
24
20-30
Calculated porosity %
55-65
85-93
80-85
85-90
~ 85
Available water % (10- 50 cm)
12-15
20-24
55
21
Reserved water % (50-100 cm)
2.53.5
2-2.5
0.2
5
20-30
Volumetric weight (kg/m3)
12001300
80-90
90-110
60-80
4-10
BULK AND PARTICLE DENSITY VALUES OF VARIOUS SUBSTRATES SUBSTRATE
PARTICLE
BULK
DENSITY
DENSITY
(gr/cm3)
(gr/cm3)
PEAT
1.55
0.05-0.02
PINE BARK
1.9
0.1-0.25
SAND
2.62
1.35-1.50
PERLITE
2.37
0.03-0.16
VERMICULITE
2.61
0.08-0.13
SOIL
2.54
1.1-1.7
TYPE
CHEMICAL PROPERTIES 1. HIGH CATION EXCHANGE CAPACITY. 2. REASONABLE NUTRIENT ELEMENT LEVEL WHICH CAN BE EASY SUPPLIED TO THE PLANT. 3. HIGH BUFFER CAPACITY - CONSTANT pH LEVEL. 4. LOW ELECTRICAL CONDUCTIVITY. 5. ORGANIC SUBSTRATE- LOW C/N RATIO, SUBSTRATE DOES NOT DECOMPOSE
RELATIVE CEC OF VARIOUS MEDIUMS SUBSTRATE
RELATIVE CEC (by weight)
PEAT
14
HUMUS
20
VERMICULITE
15
SAND
0
MONTMORILONIT
10
Chemical Characteristics pH pH
Substrate
4.5 - 3.0
Peat
6.8 - 6.0
Saw dust
7.2 - 6.5
Perlite
7.0
Rockwool
9.0 - 5.5
Vermiculite
pH • Optimal pH 5 - 6.5 • Direct negative pH < 4 or pH > 8
Salination • Easy salt accumulation mainly Na, Cl, SO4 • Easy leaching
C/N RATIO OF VARIOUS ORGANIC MEDIUMS SUBSTRATE
C/N RATIO
“GREEN” PINE BARK
75-110
COMPOSTED PINE BARK
30-40
SLUDGE
50-80
PEAT
~50
OTHER PROPERTIES 1. FREE OF WEEDS AND SOIL PESTS. 2. PLANT DISEASES RESISTANCE. 3. ABILITY TO MANUFACTURE THE SAME PRODUCT MANY YEARS. 4. LOW COST. 5. AVAILABLE. 6. EASY TO BE MIXED WITH OTHER SUBSTRATE. 7. HIGH RESISTANCE TO EXTREME CHANGES (ENVIRONMENTAL,CHEMICAL & PHYSICAL).
SOILESS CULTURE PROPERTIES VERSUS SOIL PROPERTY
SOIL
PEAT
MOBILITY
LOW
HIGH
POROSITY
LOW
HIGH
BULK DENSITY
1.2-1.5
0.1-0.3
WEEDS
YES
NO
DISEASES
YES
NO
pH & NUTRIENT
LOW
HIGH
HUMUS CONTENT
LOW
HIGH
RISK DURING
HIGH
LOW
ELEMENTS CONTROL
GROWTH
Different Types of Containers • • • • • •
Polypropylene Polystyrene Bags Gutter Beds Containers
Different Types of Containers Bags
Different Types of Containers Gutters
substrate ami 1.ppt
י
hydrophonic
Water Status
â&#x20AC;˘ Water/air relation will be determined mainly by size of particles.
â&#x20AC;˘ Two main parameters should be considered:
80 78 76 74
38 36 34 32 30 28
72 70 68 66 64 62 60 58 56
26 24 22 20 18 16 14 12 10 0.2 0.5 1.0 2.0 4.0 6.0 Particle size (mm)
10.0
Air (volume %)
Water (volume %)
o amount of available water (in a given tension) o water content 84 o air content 82
Water Content In Various Substrate 100 90 80 70 60 50 40 30 20 10 0
Peat Perlite Peat+Cocoanut Lava+organic mater
Water retention curve
Water retention curve of various substrates in comparison with the “IDEAL” substrate
Fertigation in Substrate • Low root volume • Low nutrient storage • Trace elements-important to control • Low buffering capacity • Fast changes in pH • Salinity -control
Root Volume Cultivation
Root vol. (l/m2)
Water content (%)
Available water (l/m2)
Soil
500
30
150
Peat
25
50
12
Rockwool
15
60
10
Nutrient Storage Cultivation
Available water (l/m2)
N gr / m2
Soil
150
52
Peat
12
3.4
Rockwool
10
2.1
Trace Elements • It is necessary to add trace elements • Fe, Mn ,Zn, Cu, Mo, B - are most important • Fe , Mn,- deficiency caused by high pH
Nutrition Principles in Soilless Media 1. Determine the required nutrients for plant growth according to plant development status. 2. Adjust the nutrition procedure according to the substrate characteristics. 3. Determine the correct ratio between the various
elements. 4. Adjust the pH level. 5. Avoid salinity problems
Salinity • Water source
• Nutrient solution and
composition
• Drainage (Irrigation) policy
Measurements On-line EC pH
automatically done by controller
NO3 Cl
manually - every week
N-NO3 N-NH4 K P Ca Mg
2-4 weeks
Microelements
2-4 weeks Drainage
Water Consumption Is Determined By: • Climate conditions • Water availability in the substrate Climate • Plant status
conditions
Plant status
Available water in the substrate
Plant Status • Root system activity • Fruits load • Health status
Plant Parameters • Crop type • Crop stage • Quantitative measurements of water flux (heat pulse) • Estimation of water stem flux (heat flux)
Water Status in the Substrate • Water content in the substrate • Size particles • Substrate volume • Containers configuration
Water control • Drainage volume • Radiation • E.C level • Water quality
Evaluation
Water Uptake Evaluation • Climate parameters • Plants parameters • Water substrate status
• Transpiration models
Temperature Light intensity Wind speed Wind direction Rain (yes / no)
Vent position
CO2
1 0
2 3
CO2 X 10 00p pm
Temperature Humidity
Screen position
Pipe temperature Slab Weight Water content
EC pH Amount of water
Drain
Irrigation Control Practice
end
Irrigation Control Practice • Irrigation according to time or amount of water • Irrigation according to radiation • Radiation sum and correction according to drainage or other means • Transpiration and correction according drainage or other means
Irrigation Timing By hours Liter
07:00
12:00
18:00
Hour
Radiation Sum Joules/cm² 1000 800
600 400
200 Hour 6:00
9:00
12:00
15:00
18:00
Irrigation Timing By Radiation Sum Liter
07:00
12:00
18:00
Irrigation Timing By Radiation Sum I
II
III
IV
Joules/cm²
Liter
07:00
08:00
12:00
15:00
Irrigation Timing By Temperature using Sprinkler System Liter
Temp
06:00
12:00
18:00
Irrigation Timing Water content in media
weight kg
10:00
LITER
EC
Irrigation Timing According to drainage
LITER
EC
Irrigation Practice for Soilless Media
Netafim Patented Toothed Turbulent Flow Turbulent flow Short flow - path
Large and deep flow path
Netafim Compensated Non Leakage Dripper C.N.L. Flow Rate
Low C.N.L. High C.N.L. 2 l/h 3 l/h 4 l/h 6 l/h 12 l/h 8 l/h
C.N.L.
Irrigation off
Irrigation on C.N.L. Dripper
C.N.L. Dripper Pressure Traditional Drippers
Traditional Drippers
Flow
Continuous Self Cleaning - Pressure Regulating Netafim PC dripper
Differential pressure system
Self cleaning system
Dripper Manifold & Arrow Dripper
Pressure Regulation Mechanism in Netafim PC Drippers
Dripper History Turbulent:
Laminar:
First Experiments:
Arrow Dripper
Fertigation Control Practice
Dissolving Tank:
Nutrition Control • Supply the desired EC and pH (on line) • Measurement of the nutrients in the irrigation solution • Measurement manually or automatically EC and pH in the drainage
• Make the necessary changes in the nutrient composition in the irrigation solution
Dissolving Tank:
â&#x20AC;˘
Pre-treatment
Injecting acid and degassing of the CO2 before the dosing system, maintaining a buffer of 0.5 mmol / l.
CO2 CO2
HNO3
CO2
CO2
Technology & Products
The Dosing Unit Important Features:
Quick Action Valves
• Fast Response • Repeatability • Longevity (12 millions actions) • Chemical Resistance • Motive/Suction Ratio
Injector
EC & pH Measurement EC/pH
EC/pH
Homogeneous Solution
Dual Measurement Error E < 0.2 Control
Yes
No
OK
EC/pH
Reference
Open Tank Mixer System Pump
Venturi Injectors Quick Action Vales
pH
pH
ECT ECT
Netaflex ISA
Substrate & Infrastructure
Containers Size & Configuration Effect of container depth on air content Air capacity (% volume)
12 10 8 6 4
2 0 0
5
10
15
Container depth (cm)
20
25
Physical Characteristics Water availability
Water Content In Various Substrate 100 90 80 70 60 50 40 30 20 10 0
Peat Perlite Peat+Cocoanut Lava+organic mater
Water Content in 2 Substrates 90 80 70
60 50 40 30
Perlite+cocanut
20 10 0
Lava+organic mater
Water Content in 2 mixed Substrates 90 80 70 60 50 40 30 20 10 0
Peat+ocoanut+Perlite Lava+Organic Mater
Water Content in 2 mixed Substrates 90 80 70 60 50 40 30 20
Peat+Cocoanut+Perlite
10
Lava+Organic Mater
0
Chemical Characteristics Substrate absorbs NH4+ Ca+2 Na+ Mg+2 Fe+3 K+ H+
pH - Important Points 1. pH < 4 2. pH < 5
AL +++ problems
3. pH < 5
P Absorption
4. pH > 6.5
Problem of Fe++ uptake (in EDTA form)
5. pH > 6.5
P uptake significantly lower
Damage to rockwool
Adjust pH according to Bicarbonate 7.5
pH
5.0
2.5 0
50
100
150
200
Bicarbonate The pH of a nutrient solution falls much more rapidly when the bicarbonate content approaches zero.
Acid • In principle, acid is used to correct the pH by titrating the bicarbonate (HCO3-). • Increase the ratio NH4 / NO3
• There are instances in which it is necessary to increase the pH, by using an alkali such as KOH. • Increase the ratio NO3 / NH4
ACID When the bicarbonate level is high, it is necessary to use acid to adjust the pH.
chemical reaction: CO2 (HCO3-)
(HNO3)
H2O NO3
If CO2 is not released, it delays the process and causes instability of the pH and the EC levels.
Mineral Mediums Among the mineral mediums some of them are mined as they are or we crush them to get the desired particle size i.e. tuff (volcanic scoria), dune sand, gravel . The other group of mineral mediums are created with certain degree of heating process i.e. rockwool, perlite, vermiculite and expanded clay.
Nutrition
Water Status
â&#x20AC;˘ Water/air relation will be determined mainly by size of particles.
â&#x20AC;˘ Two main parameters should be considered:
80 78 76 74
38 36 34 32 30 28
72 70 68 66 64 62 60 58 56
26 24 22 20 18 16 14 12 10 0.2 0.5 1.0 2.0 4.0 6.0 Particle size (mm)
10.0
Air (volume %)
Water (volume %)
o amount of available water (in a given tension) o water content 84 o air content 82
Water Content In Various Substrate 100 90 80 70 60 50 40 30 20 10 0
Peat Perlite Peat+Cocoanut Lava+organic mater
Water retention curve
Water retention curve of various substrates in comparison with the “IDEAL” substrate
PEAT BOTANICAL ORIGIN 1. PEAT - MOSS - SPHAGNUM
2. TRUE MOSS - BRYALES 3. SEDGES 4. WOODY PLANTS