Wheat

Nutrition check list

Good crop nutrition will help to achieve maximum crop productivity for maximum profits with minimal impact on the environment while adhering to all legislation. Some basics principles should be followed to achieve these goals:

  1. Identify the soil type in order to understand nutrient requirements.

  2. Analyse soil for nutrient content every 3-5 years and adapt nutrient inputs to maintain values of:

     
    pH 6.5 (5.8 peat soils)
    P Index 2
    K Index 2-
    Mg Index 2
  3. Determine the Soil Nitrogen Supply (SNS) either by field assessment method or by sampling and analysis for soil mineral nitrogen.

  4. Determine nutrient supply from organic sources and deduct available nutrient sources from total crop requirement.

  5. Apply Phosphorus and Potassium to maintain nutrients from crop removal and apply additional quantities if soil indices are low.

  6. Apply nutrients at the correct timing to match plant demand.

  7. Check that the fertiliser spreader or sprayer is calibrated to deliver nutrient accurately.

  8. Record all fertilisers and organic materials used.

Nitrogen

N max limit

For crops grown in Nitrate Vulnerable Zones (NVZs) there are rules limiting the amount of nitrogen that can be applied. These limits are not necessarily the optimum for agronomic performance but are the maximum allowable in these areas.
 
In NVZ zones, the average nitrogen application rate (from manufactured fertiliser and crop-available nitrogen from any organic manure) must not exceed the N Max limit. It is also good practice to follow these guidelines for land outside of NVZ zones. The N Max limit applies to the average across the farm.

For full details of N Max limits please refer to the DEFRA document; Guidance on complying with the rules for Nitrate Vulnerable Zones in England for 2013 to 2016.

The table below highlights different N Max limits depending on expected crop yield and soil type.

    N Max limits*
Crop Expected yield Non-shallow soils Shallow soil type (not over sandstone)
Winter Wheat 8 220 240
9 240 260
10 260 280
11 280 300
12 300 320
13 320 340
14 340 360
Spring Wheat 7 180 n/a
8 200 n/a
9 220 n/a
10 240 n/a
11 260 n/a
12 280 n/a

1* An additional 40kg N/ha is allowed for milling wheat varieties.

2* An additional 80kg N/Ha is permitted to all crops grown in fields where the previous or current crop received an application of straw for mulching or paper sludge.

Nitrogen Input

The tables below highlight the nitrogen inputs required based on SNS and soil type.
 

Wheat, autumn and early winter sown - Nitrogen

SNS Index
  0 1 2 3 4 5 6
kg N/ha
Light sand soils 160 130 100 70 40 0-40 0-40
Shallow soils 280 240 210 180 140 80 0-40
Medium soils 250 220 190 160 120 60 0-40
Deep clay soils 250 220 190 160 120 60 0-40
Deep silty soils 220 190 160 130 100 40 0-40
Organic soils       120 80 40-80 0-40

Wheat, spring sown - Nitrogen

SNS Index
  0 1 2 3 4 5 6
kg N/ha
Light sand soils 160 130 11 70 40 0-40 0
All other mineral soils 210 180 150 120 70 40 0-40
Organic soils       120 70 40 0-40
Peaty soils             0-40

Crop nutrient removal

Significant nutrients are removed from the field during crop removal. The levels of these nutrients that are removed from the system will vary significantly depending on yield and  whether the straw is removed or incorporated back into the field. In order to maintain soil nutrient levels the nutrients that are removed with the crop need to be replaced by either fertiliser applications and/or organic  additions.

The table below indicates the level of nutrients required to maintain soil indices at target Index 2 across a range of yield levels:

      Nutrient requirements (kg/ha)
Crop Straw management Yield (t/ha) P2O5 K2O MgO
Winter Wheat Straw ploughed-in/incorporated 8 60 45 16
10 75.6 56.2 20
12 91.2 67.4 24
14 106.8 78.6 28
Straw removed 8 65 85 20.8
10 81.8 105.8 26
12 98.6 126.6 31.2
14 115.4 147.4 36.4
Spring Wheat Straw ploughed-in/incorporated 6 45 35 16.2
8 62.2 58.6 21.6
10 79.4 82.2 27
Straw removed 6 50 70 16.2
8 67.2 93.6 21.6
10 84.4 117.2 27

Sulphur: RB209 - Where sulphur is deficient then 25-40kg SO3 should be applied early spring before stem extension.

Magnesium: RB209 - At Mg Index 0, magnesium should be applied every 3-4 years at 50-100kg MgO/Ha