8 June 2001

F&M curbs variable fertiliser technique

By Wendy Owen

MANY patchy crops in the Vale of York, ideally suited to variable-rate fertiliser treatment, have missed out on the technique this season because of foot-and-mouth.

York-based contractor Clive Blacker had high hopes of using his hired tractor-mounted nitrogen sensor widely for work on crops affected by earlier flooding in the area. But F&M restrictions cut his opportunities by 75%.

"This is the third season I have used the Hydro N sensor and it would have really come into its own this year," says Mr Blacker, who has used the machine on all his 283ha (700-acre) arable farm at Shipton-by-Beningborough.

"It is not just about saving money on fertiliser, it is about getting better crop returns. In many cases, I use no more fertiliser than I would normally apply. It is a Robin Hood theory, saving nitrogen in areas where it is not needed and giving it to patches of poorer growth to get a more even and better quality crop."

Now Mr Blacker plans to use the crop maps to adjust seed rate, fungicide and growth regulator applications.

Last year he hosted a 17ha (42-acre) trial by the machines makers, Hydro-Agri, examining yield improvements and returns in winter wheat. The field was split into three. His standard 180kg/ha N application gave 9.56t/ha.

A variable-rate N treatment based on the sensor and using 115kg/ha gave 9.91t/ha and boosted the return by £41.10/ha.

The other treatment also applied 115kg/ha, but uniformly across the plot. Yield dropped to 9.01t/ha, with returns ending £22.70/ha below his standard practice. &#42

VARIABLE N FERTILISER

&#8226 Flooded crops ideal test.

&#8226 Scope limited by F&M.

&#8226 >£41/ha extra in 2000 wheat.

&#8226 Potential in other crops.

Wide potential for range of crops

The N sensor has wide potential, says Hydro-Agri plant nutritionist Miles Harriman.

"It has been used on cereals for three years but it is now being tested on potatoes, sugar beet and oilseed rape. It might also be used commercially in future to apply variable-rate growth regulators and fungicides. It works by measuring crop density and the amount of chorophyll in the plant, adjusting N rates according to plant needs. It can assess any crop, but the system needs software to translate that into an application rate."