Let the crop tell you how much nitrogen it needs

Put too much nitrogen on and not only are you wasting your time and money but also increasing the risk of N leaching to nearby waterways. Not putting enough on and you’re losing money from the potential yield you could have got – remember that fertilizer gives the best return on investment of all the inputs.

Crops are rapidly going through growth stages with the mild weather we’ve had and luckily it’s been dry enough to travel (now we’re heading towards too dry!) so fertilizer applications have been going on all over the country. How you’re cereals came out of winter would have denoted how much you went on with your first application and generally the second application is mostly similar year to year so it is the final timing where you can really adjust your N rate accordingly.

Use the crop as the best indicator of N uptake

Average optimum rates for winter wheat have been similar over the past 10 years of trials at 230kgN/ha, however each site within those varies a lot season to season. The 230kgN/ha is a good starting point to base your N recommendation on but adjustments, either up or down, need to be well considered.

The influencing factors for your decision are mineralisation within the soil and efficiency of utilisation by the plants – both of which are hard to measure accurately. Using the crop itself as the indicator of nitrogen uptake is the most effective to measure this variable. This can be done via tissue testing or using
tools such as the Yara N-Tester. to identify the levels of nitrogen within the plant and adjust your N rate and timing accordingly.