Some effects of type and rate of application of N fertilizer, and stage of growth at which it was applied, to winter wheat on a Gault Clay soil

Abstract

Soils derived from Gault Clay in the eastern region of England are notorious for giving very variable yields of wheat. Whereas in recent years yields on other soil types have increased remarkably, largely owing to the use of high-yielding varieties and increased use of nitrogen (e.g. Holbrook, Osborne & Ridgman, 1982), yields from Gault Clay soils have remained at much the same level as the best crops of 30 years ago.