2. A. What is it? B. Why is it important? C. How is it done?

3. InOut Nutrients

4. Getting the balance right! Nutrients In Nutrients Out

5. Why manage nutrients? 1. Potential to reduce fertiliser costs 2. Protect the environment 3. Meet Nitrates Directive requirements 4.Efficiently meet crop nutrient requirements

6.  Soil testing and analysis  Nutrient requirements for crop  Calculate what to put in / on the soil for crop

7.  Green waste or mushroom compost ◦ free or cost of delivery/spreading  Savings ◦ Slurry – saving up to £95/ha ◦ FYM – saving up to £309/ha ◦ Dependant on the nutrient requirement  Essentially, adding organic materials reduces the amount of chemical fertiliser required  Chemical fertiliser is expensive!

8.  Remember... ◦ nutrients in result in nutrients out  Excessive fertiliser, slurry, manure can result in: ◦ Leaching ◦ Soil particle loss ◦ Nutrient runoff causing enrichment or eutrophication  Biggest trheat to NI waterways ◦ Waste of money

9.  Nutrients N and P can become pollutants if over applied  Nitrated Directive sets out rules/regs for arable and grassland crops  Need to follow guidance on soil analysis

10. See pages 68 & 69 of the NAP Booklet

11. Crop requirement for phosphate See page 72 Nitrates Guidance Booklet

12.  Remember main crop nutrients:  N = Nitrogen  P = Phosphorus  K = Potassium  Also Sulphur, Magnesium and Calcium ◦ These do not appear directly on fertiliser but are often incorporated

13.  Law of limiting factors  Liebigs Barrell  Water represents crop  If even one nutrient (major or minor) is below crop requirement, the crop will not perform to full potential

14. Step 1 - Soil analysis Step 2 - What does the soil analysis mean? Step 3 - Estimate Nitrogen requirements Step 4 - What nutrients does the crop require? Step 5 - How many nutrients can be supplied by organic manures? Step 6 - Which chemical fertiliser can supply the remaining nutrients required

15.  What information is on soil analysis?  What key nutrient is missing?

16.  Nitrogen is not included in soil analysis  Estimated after considering ◦ rainfall ◦ soil type ◦ previous cropping  Soil Nitrogen Supply (SNS) Index – the higher the index, the lower the requirement  RB209

17.  Rainfall in Northern Ireland is classed as ◦ Moderate/Medium (600-700mm annual rainfall or 150-250mm excess winter rainfall) ◦ OR ◦ High (over 700mm annual rainfall or over 250mm excess winter rainfall)  Depending on moderate or high rainfall, SNS index will vary slightly.

18.  Soil type affects HOW nutrients are retained  Light and/or shallow soils have POOR retention (leaching)  Medium, deep clay or deep silt soils have MODERATE – GOOD retention  Soils with over 10% organic matter can retain TOO MUCH, meaning nutrients may not be available to the plant (lock-up) Most NI Soils

19. Low and medium N vegetables are crops such as carrots, onions, radish, swedes or turnips where the amount of crop residue is relatively small.

20. Crop requirement depends on: Crop type What’s already in the soil The higher the soil nutrient reserves (Soil Index), the lower the need for additional nutrients RB 209

21.  Index for Phosphorus(2)  Index for Potassium(1)

22. SNS, P, K Index 0123456 Kg/ha Turnips, Parsnips Nitrogen (N) –all soil types 170130100702000 Phosphate (P 5 O 2 )20015010050000 Potash (K 2 O)300250200 (2-) 150 (2+) 0000 We know from high rainfall that N needs index 1 We know from soil analysis that P needs index 2 and K needs index 1

23. SNS, P, K Index 0123456 Kg/ha Turnips, Parsnips Nitrogen (N) –all soil types 170130100702000 Phosphate (P 5 O 2 )20015010050000 Potash (K 2 O)300250200 (2-) 150 (2+) 0000 What is the requirement? N = index 1 = P = index 2 = K= index 1 = 130 kg/ha 100 kg/ha 250 kg/ha

24.  Soil ◦ Soil analysis - index shows the recommended amount of P and K to add to soil ◦ SNS index gives recommended amount of N to add  Manure / green waste / slurry ◦ Adds both nutrients and organic matter to help with soil structure  Chemical fertiliser ◦ Adds the remaining nutrients necessary to meet crop requirements

25.  RB209 gives nutrient availability for a range of manures, slurries and organic matter: Organic Matter type Nutrient content (kg/t) NPK Farm Yard Manure 1.83.57.2 Green Waste <0.23.05.5

26.  Assume you have 10 ton green waste compost to apply over 2 acres (i.e. 5 ton/acre)  To find the volume applied of a particular organic material:  Ton/acre applied x 2.471 = volume applied t/ha  5 ton/acre x 2.471 = 12.355 t/ha

27.  Volume applied =12.355 t/ha  To find the nutrient content of a particular organic material:  Kg/t Nutrient applied x volume applied t/ha = nutrient content  N = 0.2 x 12.355  P = 3.0 x 12.355  K = 5.5 x 12.355 Organic Matter type Nutrient content (kg/t) NPK Green Waste<0.23.05.5

28.  Volume applied =12.355 t/ha  To find the nutrient content of a particular organic material:  Kg/t Nutrient applied x volume applied t/ha = nutrient content  N = 0.2 x 12.355  P = 3.0 x 12.355  K = 5.5 x 12.355 Organic Matter type Nutrient content (kg/t) NPK Green Waste<0.23.05.5 =2.471 kg/ha =37.065 kg/ha =67.95 kg/ha

29.  You now know:  Nutrient requirement for crop from the soil analysis  Nutrient content of adding an organic matter (example)  Now you need to add chemical fertiliser to make up the balance NPK 130100250 2.53768 127.563182

30. N Nitrogen P Phosphorus K Potassium S Sulphur ………NO 3 Nitrate ………P 2 O 5 Phosphate ………K 2 O Potash ………S0 4 Sulphate Nutrients needed by crops for growth

31. Chemical Fertiliser 20 12 25 % Nitrogen (N) % Potash (K 2 0) % Phosphate (P 2 0 5 ) Step 6 1 50kg bag/acre = 125kg/ha

32.  We need ◦ 127.5kg/ha N, 63kg/ha P, 182 kg/ha K  1 50kg bag/acre = 125kg/ha  Need to find out what 20-12-25 fertiliser really offers in order to find out the balance.

33.  Calculate the amount of N, P & K supplied when applying 10 bags of 20-12-25 per hectare. ◦ One bag of fertiliser = 50kg  A) number of bags/ha x 50kg = application rate  A) 10 bags/ha x 50kg = 500 kg/ha application rate

34.  Remember application rate = 500kg/ha  B) % nutrient x application rate kg/ha = nutrient applied 100(kg/ha)  N = 20 x 500kg/ha = 100  P = 12 x 500kg/ha = 100  K = 25 x 500kg/ha = 100

35.  Remember application rate = 500kg/ha  B) % nutrient x application rate kg/ha = nutrient applied 100(kg/ha)  N = 20 x 500kg/ha = 100  P = 12 x 500kg/ha = 100  K = 25 x 500kg/ha = 100 100 kg/ha Nitrogen 60 kg/ha Phosphorus 125 kg/ha Potassium

36. (1) N Kg/ha (2) P 2 O 5 (1) K 2 0 A Crop requirement (Based on crop type & soil analysis) 130100250 B Available nutrients green waste compost (5 ton/acre) 2.53768 C Available nutrients Chemical fertiliser 20-12-25 (10bags/ha) 10060125 What we know so far...

37. (1) N Kg/ha (2) P 2 O 5 (1) K 2 0 ACrop requirement 130100250 BAvailable nutrients green waste compost 2.53768 CAvailable nutrients Chemical fertiliser 10060125 D Total Inputs (B+C) 102.597193 Balance left (A – D) (Nutrient still required) What is the balance?

38. (1) N Kg/ha (2) P 2 O 5 (1) K 2 0 ACrop requirement 130100250 BAvailable nutrients green waste compost 2.53768 CAvailable nutrients Chemical fertiliser 10060125 D Total Inputs (B+C) 102.597193 Balance left (A – D) (Nutrient still required) 27.5357 What is the balance?

39.  From the given inputs of ◦ Existing soil nutrients ◦ Added organic matter ◦ Chemical fertiliser  Most of the nutritional needs are met Remaining Balance NPK 27.5357

40.  What happens with the remaining balance?  Fertiliser application may be split over 2 or more treatments (in seed bed, over crop, etc), allowing opportunity to...  Use straight fertiliser (just N or K)  Could change an input (try calculation using FYM or slurry) Remaining Balance NPK 27.5357

41.  Must not exceed ◦ Nitrogen requirement ◦ Phosphorus requirement  Can lead to pollution Remaining Balance NPK 27.5357

42. 1. N, P, K In = N, P, K Out 2. Nutrient sources soil, manure/organic matter and fertiliser 3. Make best use of nutrient sources  Save money  Protect the environment  Meet Nitrates Directive Requirements 4. How?  Soil sampling and analysis is the starting point  Estimate crop needs  Use manure/organic matter effectively  Only use fertiliser to top-up any outstanding crop needs 5. Help  Crop Nutrient Recommendation Calculator  Nitrates Guidance  RB209  Codes of Good Agricultural Practice

43. Nutrient Calculation