Amid some confusion, Defra launched its long-awaited Fertiliser Manual online on the second day of Cereals, although information on any changes it contained was hard to come by at the event. Three years after the revision process got under way, the replacement for RB209 was published on the Defra website on 10 June, allowing growers and advisers to download it free of charge.
Those who prefer a printed version will be able to order a copy from www.tso.co.uk, providing they pay £24.99 to cover production costs. This format will be available from 30 June.
Containing the latest recommendations for the application of lime and major nutrients to most crops, the 10-section Fertiliser Manual also provides guidance on the supply of nutrients from organic manures and has extensive coverage of environmental considerations.
The grassland section had the most amendments and now follows a farm systems-based approach, said Prof Keith Goulding of Rothamsted Research, who led the revision. “The nitrogen recommendations for grassland are based on new analysis of existing nitrogen response data,” he said.
This means that calculations are now done according to the need to supply sufficient home-grown forage for particular animal production systems, at varying levels of production intensity.
“It will allow farmers using different stocking rates and feeding different levels of concentrates to get relevant recommendations for the whole-season total nitrogen requirement.”
Other differences include a revised SNS index system, together with higher nitrogen recommendations for wheat, reflecting the higher yield potential of newer varieties. Nitrogen recommendations for potatoes have decreased slightly, while those for sugar beet have gone up.
A further change was to oilseed rape magnesium applications, said Mr Goulding. “It’s now recommended to apply 50-100kg/ha of MgO every three to four years at soil index 0 and 1,” he added. “Previously that was only the case where sugar beet and potatoes weren’t in the rotation.”