ARCHIVE: Fertiliser Manual (RB209)

Wheat, spring sown – Nitrogen


  SNS Index
  0 1 2 3 4 5 6
  kg N/ha
Light sand soils 160 13 100 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

Nitrogen

For crops drilled before March, apply nitrogen at early stem extension but not before early April or after early May. For amounts greater than 70 kg N/ha, apply 40 kg N/ha of the total in the seedbed except on light sand soils. On these soils apply 40 kg N/ha at the 3 leaf stage but not before March.

For late-drilled crops, all the nitrogen can be applied in the seedbed except on light sand soils where amounts greater than 70 kg N/ha should be split with 40 kg N/ha in the seedbed and the remainder by the 3 leaf stage.

Bread making varieties

In some circumstances, an application of nitrogen in addition to that given in the table may be economically worthwhile to boost the grain protein concentration. Typically an application of an extra 40 kg N/ha will increase grain protein by 1.1%. Application of this additional nitrogen during stem extension may give a small yield increase as well as an increase in grain protein. Application as a foliar urea spray during, but not later than, milky ripe stage will result in a larger increase in grain protein content but cannot be expected to increase yield.

The effect of economic changes on nitrogen rates

The recommendations in the table are based on a breakeven ratio of 5.0 (see page 32). If the price of nitrogen or the price of grain changes, use the winter sown wheat table above to decide on an amount to add to or subtract from the nitrogen application.

Don’t forget to deduct nutrients applied as organic manures (see Section 2)

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