FERTILIZER USE SURVEY by B. Coulter, W. Murphy, N. Culleton, G. Quinlan and L.Connolly

The Data Source – Teagasc National Farm Survey Data for More than 1200 farms surveyed each year Survey farms were randomly selected to represent the major farm systems and sizes using information from the CSO Census of Agriculture Detailed information about fertilizer usage for each crop on the farm

Crop Included Grassland Crops: Grazing, Silage Hay Tillage Crops: Winter and spring wheat Winter, spring and malting barley Winter and spring oats Potatoes Sugar beet and fodder beet Other crops e.g. maize, turnips, kale etc.

Fertilizer Information For Each Crop: Area of the crop Number of 50 kg bags used in each application Type of fertilizer used (91 different compounds) Up to 11 applications for grass; up to 6 applications for tillage crops

Main Farm Variables 1. Farm enterprise 2. Farm size 3. Stocking rate 4. Soil suitability class 5. Geographic region

Farm Enterprise Dairying Drystock farming Sheep farming Tillage

Soil Use Class Farms classified according to their location on General Soil Map (Gardiner and Radford, 1982) Four groups depending on the range of soil use capability  Soil use class 1 can grow the widest range of crops without limitation  Soil use class 4 contains farms with limited to extremely limited use range.

Representation Number of Irish farms represented by one survey farm* System Farm Size (ha) 2 – > 50 Dairy Cattle Sheep Tillage * 1210 farms in the survey represent 114,000 Irish farms

Validation Comparison: National annual sales (tonnes/yr) of N, P and K with calculated usage based on the survey NPK National Sales (tonnes/yr) 388,10043,800111,100 Calculated usage (tonnes/yr) 383,00044,700111,300

Regional N, P and K application rates for grazing (kg/ha) REGIONNPKAreaFarms South-East120* Dublin66† Mid-East Midlands Border South-West South West Overall * S.E. 5.8 † S.E. 26.1

N and P application rates for grazing (kg/ha)

Duration of Grazing Season

Effect of soil use class on N, P, K for grazing ClassSOIL UseNPK 1Wide Moderately Wide Somewhat Limited Limited85818

Dairy fertilizer application for grazing at different stocking rates (kg/ha) STOCKING RATENPKFarms < >

Surveyed N usage and Teagasc N advice for grazed grassland (kg/ha) STOCKING RATE Surveyed N Usage Teagasc N Advice <

P and K usage and Teagasc P & K advice for grazing on dairy farms STOCKING RATE (LU/ha) P Usage (kg/ha) P Advice (kg/ha) K Usage (kg/ha) K Advice (kg/ha) <

Silage Nutrient usage of N, P and K was 120, 13 and 41 kg/ha respectively. N use was 13% below Teagasc advice for crops with full use of slurry P and K use were between advised rates for silage using (a) no-slurry and (b) slurry Usage declined by 11, 15 and 20% from usage in 2000.

N and K application rates for silage (kg/ha)

Fertilizer Compounds for Grazing COMPOUND NPK No of Times Used Percentage of Each Element CAN UREA :7: :10: :06: High N Compounds* * Typical composition 23:2.5:5

Fertilizer Compounds for Silage COMPOUND NPK No of Times Used Percentage of Each Element CAN UREA :7: :06: High N Compounds* * Typical composition 23:2.5:5

High N Compounds: Comparison with 2000 For grazing, use of high N compounds for N, P and K increased by 12-14% since 2000 For silage, the increase was 16-18%. A similar trend was found between 1995 and This “little and often” approach is environmentally friendly for P

Grassland N Usage Since 1995

Grassland P & K Usage Since 1995

Winter Barley Grown only in SE, ME and border regions (32 farms) Mean N usage was 167 kg/ha Calculated Teagasc advice is ~ 156 kg/ha Mean P and K usage were 30 and 71 kg/ha P & K match Teagasc advice N usage for increased by 8% since 2000 compared to a 5% drop in national N sales

Spring Barley Grown in all regions (184 farms) Mean N usage was 123 kg/ha Calculated Teagasc advice is ~ 118 kg/ha Mean P and K usage were 26 and 55 kg/ha P & K match Teagasc advice N & K usage increased by 7-8% since 2000 compared to a 5-9% drop in national N sales

Winter Wheat Grown only in 4 regions (48 farms) Mean N usage was 203 kg/ha Calculated Teagasc advice is ~ 172 kg/ha Mean P and K usage were 23 and 55 kg/ha P matches Teagasc advice but K is lower N, P & K usage decreased by 2%, 17% and 31% since 2000

Spring Wheat Grown only in 6 regions (52 farms) Mean N usage was 152 kg/ha Calculated Teagasc advice is kg/ha depending on expected yield Mean P and K usage were 24 and 53 kg/ha P & K use consistent with Teagasc advice N usage decreased by 5% since 2000 but P and K increased by 33 and 26%

Compounds for Cereals N mainly supplied by CAN (some 10:10:20) P & K mainly supplied by 18:6:12 and 10:10:20 for winter and spring barley, winter and spring wheat

Sugar Beet Grown only in 4 regions (67 farms) Mean N usage was 159 kg/ha Teagasc advice is kg/ha depending on summer rainfall and years in ley prior to tillage Mean P and K usage were 24 and 157 kg/ha Teagasc P & K advice is 39 and 170 kg/ha N, P and K usage decreased by 1%, 14% and 5% since 2000

Mean Fertilizer Nutrient Use for Cereal Crops from CEREALS NPK Mean Farm Area (ha) No of Farms (kg/ha)

Mean Fertilizer Nutrient Use for Root Crops from ROOT CROPS NPK Mean Farm Area (ha) No of Farms (kg/ha)

Compounds for Roots Compound used depending on crop S/A used only on potatoes No straight P or K used Very wide variety of compounds used