Although the tool gives farmers a rough guide to economic optimums, the NFU always advises speaking to your agronomist first about what might be best for your crop and to explore potential alternative products available.
NIAB has adapted the tool from the RB209 (2010) tool to indicate how economic optimum nitrogen rates change on feed winter wheat, depending on nitrogen and grain prices.
With nitrogen prices highly volatile at present nothing can be certain, but the NIAB table demonstrates changes to applications that could be made.
Nitrogen use is normally seen as relatively unresponsive to price changes in the market, but given the exponential price rises recently, economic optimums have been revisited. Where prices are in excess of £500/t for Ammonium Nitrate (AN 34.5%N/t), wheat could receive 30-50 kgN/ha less, depending on circumstances and wheat market prices.
*Standard rates mentioned in the table would normally be referred to around 220 kgN/ha, but this is highly variable depending on conditions/farm/field.