Controlled Release Fertiliser in Horticulture AusVeg May 2013 Andrew Olley National Agronomy Services Manager
Nutrient delivery via fertilisers into Horticultural crops is often poorly converted through to crop yield and quality A number of factors have influence over nutrient efficiency such as -Loss Mechanisms after application -Timing applications -Labour and capital constraints for delivery -Weather events -Antagonism between competing nutrients -Choice of nutrient form
Science and field experience of growers / advisors have developed fertiliser strategies to supply crops with their nutrient needs with improved efficiencies. Such practices include: -Spilt applications of granular products -Nutrient delivered through irrigation “Fertigation” -Foliar and liquid soil applications -Nutrient formulation changes -Monitoring nutrient status SAP, Leaf, Solute testing
These advances have greatly improved the supply of nutrient to crops. However this is most often achieved by excess nutrient supply to try ensure the crop is not yield limited by nutrient. In many instances 100 % or greater of key nutrients over the actual crop requirements are applied with the following effects -Increased spend on fertiliser -Capital intensive delivery systems -Labour intensive management systems -High cost nutrient formulations
Field crop production operation at tighter margins and high risk has not allowed the uptake of technologies in nutrient delivery used in higher value plant production systems. Amenity Horticulture “Nursery & Turf Industries” with higher margins have been able to develop sophisticated nutrient products -Slow Release chemistry Protected Cropping industry reliance on high density production which comes at a higher capital costs developed exact nutrient delivery systems - Hydroponic nutrient formulation
Slow Release fertiliser products offer the potential to field producers however limitations to commercial adoption have been: -High manufacturing cost per kg nutrient supplied -Freight costs to import from overseas -Fixed N:P:K analysis not suited to local conditions -Nutrient release rate dominated by soil temperature hence complex process to select right product and release rate through the year -Low availability in the market from supply companies
Impact fertilisers were contacted by Everris BV in early 2012 to distribute a commercially available nutrient delivery technology that has been extensively used commercial agriculture. Investigation of the technology on offer and its use in overseas fertiliser markets revealed a solution to increase fertiliser use efficiency for crop production in Australia was available.
Controlled Release Granule Technology Elemental sulphur coating Polymer coating Urea, MOP, SOP core
N 39 Urea K 43 MOP Immersed in water for 10 weeks
“Slow Release Coatings” Laboratory Data, Everris BV. Netherlands
Controlled Release Technology 100 38:0:0:13 Agrocote N 38 90 80 70 N release (%) 60 50 15°C 40 30 25°C 20 35°C 10 0 0 20 40 60 80 Time (days) Laboratory Data, Everris BV. Netherlands
Technology Urea, MOP, SOP core Elemental sulphur coating Polymer coating •Crystalline 8 member ring •Brittle at room temperature •Forms cracks permeable to moisture •Release less temperature sensitive
Agrocote N39 Release Curve Agrocote N39 Release Curve Return Home . . Total N release kgs N release kgs per day 200 kgs - 78 kgs N 80 3.0 90 % 70 2.5 80 % 60 T o ta l N i tr o g e n r e l e a s e (k g s ) D a i l y N i tr o g e n r e l e a s e (k g s ) 2.0 50 40 1.5 30 1.0 20 0.5 10 0 0.0 0 10 20 30 40 50 60 70 80 90 100 110 120 Time (days)
Agrocote N38 Release Curve Agrocote N38 Release Curve Return Home . . Total N Release kgs kgs N per day 200 kgs - 76 kgs N 70 1.8 80 % 1.6 60 65 % 1.4 50 T o ta l N i tr o g e n r e l e a s e (k g s ) D a i l y N i tr o g e n r e l e a s e (k g s ) 1.2 50 % 40 1.0 0.8 30 0.6 20 0.4 10 0.2 0 0.0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Time (days)
Agrocote Blend Release Curves Nitrogen 100 kgs / ha - Custom Nitrogen release curves can be created with blends 30 % Agrocote N 50 % Agrocote N 70 % Agrocote N 70 % Urea N 50 % Urea N 30 % Urea N
Compatibilities Highly compatible with existing fertiliser components MAP DAP ZincStar MES10 Urea SOA Compounds MOP SOP HiMag (MgS04) MgO TSP SSP Zinc Copper Boron
Conventional Potato Fertiliser Program Crop Daily N Nitrogen Applications Nitrogen Root zone N Applied
Controlled Release Potato Fertiliser Program Crop Daily N Nitrogen Applications Nitrogen Root zone Conv N Applied
Nitrogen Losses in Crops • Volatilization Urea ammonia gas losses from surface application • Denitrification Nitrogen losses in water-logged soils • Leaching Nutrient movement of Nitrate below the crop root zone
The three main losses of applied N & K to the crop are greatly reduced De Nitrification Volatilization Leaching Agrocote only losses N & K while conditions favoring loss occur. The proportion of Total N & K loss is small. Hence the efficiency of nutrient uptake by the crop is greatly improved. Polymer and Sulphur coating control N release rate
Potassium Products MOP and SOP available Controlled release greatly decreases the Salt Index of MOP and hence can be used on higher EC soils and Irrigation water. High seed safety due to coating on MOP Potassium releases over a 4 month period
Conductivity of MOP versus Agrocote MOP
Agrocote in Potatoes Conventional Fertiliser Program: Planting Blend: 10:6:12:15 at 1000 kg/ha Side-dress 1: 23:0:20: 10 at 150 kg/ha Side-dress 2: 23: 0:20:10 at 150 kg/ha Side-dress 3: 18:0:25:12 at 150 kg/ha Side-dress 4: 12:0:30:15 at 150 kg/ha Total Nutrient Applied kgs/ha N 210 P 60 K 266
Agrocote in Potatoes Agrocote Fertiliser Program: Agrocote Planting Blend: 14: 6:19:9 at 950 kgs / ha 36 % total N as CR Nitrogen 50 % total K as CR Potassium Total Nutrient Applied kgs/ha N 153 P 60 K 178 Equivalent Nutrient Program (based on Agrocote efficiency 0.5) N 209 P 60 K 267
Overseas Experience Bananas Central America • Conventional: 400 kg N, 50 kg P, 546 kg K /ha/yr Agromaster: 200 kg N, 27 kg P, 243 kg K • Reduced N and K rates to 50% and 44%, respectively • Reduced from 12 to 3 applications per year
Overseas Experience Pineapple Central America •Conventional : –Monthly N&K side dressed for 3 months –Foliar NPK for 8 months –Total rate 780 kg N, 27 kg P, 530 kg K/ha •Agromaster: –Single Agromaster 2wks after planting (100% coated N&K) –Replaces 3 side-dressings and 1 foliar application –Rate reduction: •55% of first 4 applications •85% of N and K overall
Summary Key Advantages to growers & industry -Improved nutrient use efficiency -Less freight, handling and application costs -Reduces potential nutrient gaps in crop growth -Increased quality through consistent crop nutrition -Greatly reduced nutrient losses on and off farm -Addition to all common fertiliser blends as a component -Nitrogen and Potassium Controlled Release -Negates the need for high capital delivery systems -Commercially available, trained resellers
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