Seek bigger margin with nitrogen cuts
Radical advice from The Arable Group this week, which for the first time is advising its members to cut back on nitrogen doses and not to join the race for all-out maximum yield.
TAG’s Richard Overthrow, speaking at a members-only spring strategy meeting in Cirencester, advised growers to pay attention to margin rather than yield, and seek maximum financial return.
"It’s no longer economically viable to grow crops for maximum yield," he said. "Instead nitrogen doses should be applied according to calculations of the known, or predicted, break even ratio based on £/t of nitrogen relative to £/t grain price."
Delegates were urged to focus on the many backward winter cereal crops first. "Rare thick forward crops of cereals should either not be treated, or receive just a minimal dose. Prompt nitrogen treatment should be targeted to crops most in need of early nitrogen.
"It’s not that you’re looking for nitrogen to stimulate growth or bring poor crops forward: it won’t. But you must ensure that important growth isn’t further checked by a lack of nutrients," he advised.
"Tricky calculations may be required where high fertiliser and low grain prices have prompted a cut in the total planned nitrogen dose," he pointed out. "You’ll need to hold back enough for a sufficiently large main dose – sufficient to feed the important stem extension and yield-building phases.
"So where total nitrogen dose is reduced, the first dose may need to be smaller than normal to make sure enough is applied later. Backward crops, in particular, are unlikely to respond to large first doses anyway," advised Mr Overthrow.
The exception will be with second wheats, which benefit from a large first dose as a take-all control measure. In this scenario, the large first dose needed may be more than the economic optimum.
Nitrogen timing in spring cereals will take a similar line, delegates heard. "If sown in good time, the nitrogen can be split with the first dose applied as soon as tramlines are visible, and the remainder at mid-tillering. However, in later sown crops, all the nitrogen should be applied in one dose, pre-emergence if possible."
