7 September 2001

ICMINACTION: 11

Fertiliser management

With such a wide choice of fertilisers on the market, growers need to be aware that the quality of the product determines how well it spreads, advises independent fertiliser and application specialist John Crow.

"Two different calibration procedures should be done on any fertiliser spreader," he says. "One is for application rate, which should be carried out according to the instruction booklet, and the other is for spread pattern."

The two are related and both must be done to ensure the right amount of fertiliser is applied to the right place. "A 20% variation either way and there will be visible signs in the crop. And of course applying too much has implications for leaching, as well as financial losses."

With more fertiliser blends being used on farm, he urges growers to ensure they have been size matched. "Blends have two potential problems – they are prone to segregation and they wear the machines spreading mechanism quickly.

"As blends tend to be spread in the autumn, growers often forget to check for damage grooves before they apply spring nitrogen. If grooves are present or the blades are damaged, the nitrogen gets shattered as it is being applied."

tray tested with every fertiliser product used on an

annual basis. "Nitrogen

fertilisers have an SP rating on the bag – this is an indication of their consistency. Look for products with a 5 rating."

Extra care is needed when making applications to headlands.