Nutrient Management Planning for Field Production Horticulture

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Nutrient Management Planning for Field
Production Horticulture
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Nutrient Management Planning

1. What is it?
2. Why is it important?
3. How is it done?

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A. What is Nutrient Management Planning?
Nutrients Nutrients
In
Out
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Nutrient Management Planning

• Getting the balance right!

Nutrients In
Nutrients Out
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Why manage nutrients?

• Potential to reduce fertiliser costs
• Protect the environment
• Meet Nitrates Directive requirements
• Efficiently meet crop nutrient requirements

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How do you find the balance?

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

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1. Potential to reduce fertiliser costs

• 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!

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2. Protect the environment

• 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

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3. Meet Nitrates Directive requirements

• 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

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See pages 68 69 of the NAP Booklet
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Crop requirement for phosphate
See page 72 Nitrates Guidance Booklet
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4. Effectively meet crop nutrient needs

• 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

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4. Effectively meet crop nutrient needs

• Law of limiting factors
• Liebigs Barrell
• Water represents crop
• If even one nutrient (major or minor) isbelow
  crop requirement,the crop will not performto
  full potential

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4. Effectively meet crop nutrient needs

• 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

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Soil Analysis

• What information is on soil analysis?
• What key nutrient is missing?

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Estimate Nitrogen Requirement

• 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

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Estimate Nitrogen Requirment

• 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.

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Estimate Nitrogen Requirement

• 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)

MostNISoils
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Estimate Nitrogen Requirment
Low and medium N vegetables are crops such as
carrots, onions, radish, swedes or turnips where
the amount of crop residue is relatively small.
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Step 4 - What does the Crop Need?

• Crop requirement depends on
• Crop type
• Whats already in the soil

The higher the soil nutrient reserves (Soil
Index), the lower the need for additional
nutrients
RB 209
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What does the crop need?

• Index for Phosphorus (2)
• Index for Potassium (1)

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What does the crop need?
SNS, P, K Index SNS, P, K Index SNS, P, K Index SNS, P, K Index SNS, P, K Index SNS, P, K Index SNS, P, K Index
0 1 2 3 4 5 6
Kg/ha Kg/ha Kg/ha Kg/ha Kg/ha Kg/ha Kg/ha
Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips
Nitrogen (N) all soil types 170 130 100 70 20 0 0
Phosphate (P5O2) 200 150 100 50 0 0 0
Potash (K2O) 300 250 200 (2-) 150 (2) 0 0 0 0
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
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What does the crop need?
SNS, P, K Index SNS, P, K Index SNS, P, K Index SNS, P, K Index SNS, P, K Index SNS, P, K Index SNS, P, K Index
0 1 2 3 4 5 6
Kg/ha Kg/ha Kg/ha Kg/ha Kg/ha Kg/ha Kg/ha
Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips Turnips, Parsnips
Nitrogen (N) all soil types 170 130 100 70 20 0 0
Phosphate (P5O2) 200 150 100 50 0 0 0
Potash (K2O) 300 250 200 (2-) 150 (2) 0 0 0 0
What is the requirement? N index 1 P index
2 K index 1
130 kg/ha 100 kg/ha 250 kg/ha
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Input options

• 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

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Nutrients supplied by organic material

• RB209 gives nutrient availability for a range of
  manures, slurries and organic matter

Organic Matter type Nutrient content (kg/t) Nutrient content (kg/t) Nutrient content (kg/t)
N P K
Farm Yard Manure 1.8 3.5 7.2
Green Waste lt0.2 3.0 5.5
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Nutrients supplied by organic material

• 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

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Nutrients supplied by organic material
Organic Matter type Nutrient content (kg/t) Nutrient content (kg/t) Nutrient content (kg/t)
N P K
Green Waste lt0.2 3.0 5.5

• 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

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Nutrients supplied by organic material
Organic Matter type Nutrient content (kg/t) Nutrient content (kg/t) Nutrient content (kg/t)
N P K
Green Waste lt0.2 3.0 5.5

• 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

2.471 kg/ha
37.065 kg/ha
67.95 kg/ha
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Chemical Fertiliser

• 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

N P K
130 100 250
2.5 37 68
127.5 63 182
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Nutrients needed by crops for growth

• N Nitrogen
• P Phosphorus
• K Potassium
• S Sulphur

NO3 Nitrate P2O5 Phosphate
K2O Potash S04 Sulphate
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Step 6
Chemical Fertiliser
20 12 25
1 50kg bag/acre 125kg/ha
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Nutrient supplied by chemical fertiliser

• 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.

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20-12-25

• 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 r
  ate
• A) 10 bags/ha x 50kg 500 kg/ha application
  rate

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20 (N)-12(P)-25(K)

• 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

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20-12-25

• 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
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What we know so far...
(1) N Kg/ha (2) P2O5 (1) K20
A Crop requirement (Based on crop type soil analysis) 130 100 250
B Available nutrients green waste compost (5 ton/acre) 2.5 37 68
C Available nutrients Chemical fertiliser 20-12-25 (10bags/ha) 100 60 125
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What is the balance?
(1) N Kg/ha (2) P2O5 (1) K20
A Crop requirement 130 100 250
B Available nutrients green waste compost 2.5 37 68
C Available nutrients Chemical fertiliser 100 60 125
D Total Inputs (BC) 102.5 97 193
Balance left (A D)(Nutrient still required)
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What is the balance?
(1) N Kg/ha (2) P2O5 (1) K20
A Crop requirement 130 100 250
B Available nutrients green waste compost 2.5 37 68
C Available nutrients Chemical fertiliser 100 60 125
D Total Inputs (BC) 102.5 97 193
Balance left (A D)(Nutrient still required) 27.5 3 57
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Result

• From the given inputs of
• Existing soil nutrients
• Added organic matter
• Chemical fertiliser
• Most of the nutritional needs are met

Remaining Balance N P K
Remaining Balance 27.5 3 57
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Result

• 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 N P K
Remaining Balance 27.5 3 57
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Result

• Must not exceed
• Nitrogen requirement
• Phosphorus requirement
• Can lead to pollution

Remaining Balance N P K
Remaining Balance 27.5 3 57
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Summary

• N, P, K In N, P, K Out
• Nutrient sources soil, manure/organic matter and
  fertiliser
• Make best use of nutrient sources
• Save money
• Protect the environment
• Meet Nitrates Directive Requirements
• 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
• Help
• Crop Nutrient Recommendation Calculator
• Nitrates Guidance
• RB209
• Codes of Good Agricultural Practice

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Class exercise

• Nutrient Calculation