The agronomic properties of urea-containing compound fertilizers:I. High-nitrogen type

Abstract

SUMMARYThis paper reviews extensive work at Jealott's Hill and elsewhere in England and Wales on the agronomic effects of including various levels of urea in 2:1:1 NPK fertilizers combine-drilled with spring cereals.Little evidence of phytotoxicity was found with fertilizers containing up to 12% urea and providing about 0·6 cwt N/acre. The inclusion of 20% urea reduced braird more frequently on soils of high pH than did lower proportions although grain yields were seldom affected adversely. Such soils are not uncommon, especially in the barleygrowing areas of Southern and Eastern England, where perhaps a quarter of the cereal acreage may be located on soils of pH 7·7 and above.