Nitrogen studies in a coffee soil III. The comparative efficiency of ammonium sulphate and urea fertilizers in the presence and absence of an organic mulch measured in terms of crop yield

Abstract

The work reported in two previous papers, Robinson (1960a, b) led to certain conclusions which required evaluation in terms of coffee yields (Coffee arabica Linn). The work describes changes in nitrate and ammonia-N in the Kikuyu red loam coffee topsoil, both natural and fertilizer derived, in the presence and absence of mulches.This paper presents early coffee yield results which have been obtained from field trials laid down on the Coffee Research Station, Ruiru, Kenya, to measure the effect of treatments based on the conclusions drawn from the soil studies.