Farmers in Yorkshire have taken part in an informal competition to improve the efficiency of spring nitrogen use by better matching applications to crop requirements.

The inaugural Sustainable Landscapes “Nitrogen Super League” was held last season, as part of ongoing work by the Sustainable Futures programme, in collaboration with Yara.

Eight teams of three farmers were each provided with their own N-Tester device to help determine crop requirements ahead of key fertiliser timings.

See also: The farm project tackling flood risk and improving water quality

“The aim is to encourage farmers to move away from taking a standard approach to applying fertiliser and tailor inputs more to what the plant needs,” says project co-ordinator Steve Cann.

“This will improve nitrogen use efficiency, which has financial and environmental benefits.

“We work with farmers and several large brands to improve the resilience of supply chains.

“To do this, we have to ensure every link is profitable, and for arable farmers one big area is nitrogen. It has always been high on the agenda, but particularly so given the increase in fertiliser prices.”

Sustainable Futures also works with Yorkshire Water to find practical ways of reducing the risk of nitrates entering watercourses, and he believes improving nitrogen use efficiency could be a key part of this.

Winning approach

Last year’s competition was won by a team that included Thirsk farmer Tony Bell and two other local farmers, Mike Collinson and Joss Spilman.

The team’s trial was hosted on Mr Bell’s 265ha farm, which grows wheat, oilseed rape, potatoes and maize on predominantly light land. His wheat area is split between September-sown Dawsum and Gleam, and October-drilled Skyscraper.

The trial area was within a 15ha field of 28 September-sown feed wheat Gleam, after oilseed rape, split into two 4ha plots (the remaining area consisted of headlands).

One plot followed the standard farm strategy, while applications in the other area were adjusted according to regular N-Tester readings.

The device measures nitrogen in crop leaves, based on chlorophyll content.

Yield and nitrogen use were compared across the two plots.

Tony Bell © Paiul Spackman

“Although the N-Tester recommended an additional application in April on that area, total nitrogen use was 7kg N/ha lower than the farm standard of 228kg N/ha,” says Mr Bell (see table and graph).

“The first application was an ammonium sulphate/potash blend, applied at the end of February. Nitram was then applied during March, April and May.”

Mr Bell notes the final application was later than normal last year due to cool, dry conditions during April. This also prompted him not to apply fertiliser to the farm standard plot in early/mid-April, when the extra application was recommended on the N-Tester area.

Despite receiving slightly less nitrogen overall, the N-Tester area yielded 0.3t/ha more, at 11.56t/ha, and nitrogen use efficiency was higher at 77%.

“It was the best yield seen on the farm, but helped by the consistent rain during May and June,” says Mr Bell. “This suited the farm, which is predominately light sandy soils that aren’t traditional wheat-growing land, and have historically yielded nearer 9t/ha.”

Mr Bell was very pleased with the result, despite only a relatively small difference in nitrogen use, which at last year’s lower fertiliser prices, averaging £250/t, gave a modest saving.

But, with wheat prices at more than £200/t, there was an improved margin on the crop due to the increased yield, he notes.

Grain protein

“Protein content of the wheat from the N-Tester area was also higher, although this did not translate into more value, as the wheat was sold for feed.”

This season, Mr Bell has used the N-Tester across the whole farm, and hopes it will again improve nitrogen use efficiency over and above traditionally applied fertiliser.

“I welcome the opportunity to put more science into fertiliser applications, by responding to crop needs, rather than applying based on the calendar as in previous years,” he says.

Although last year’s Nitrogen Super League was a test event that has not been run as a competition this year, Mr Cann says N-Testers have been rolled out to more farmer members this year and he hopes to launch a larger competition across the farmer groups next season.