Effects of N fertilisation, bean spatial arrangements and residue on maize performance in a semi'arid area of Kenya

Abstract

Abstract In Kenya, two sites Kimutwa and Masii with dystric Nitisol and acrisol, respectively, were used to study the influence of four N rates (0, 25, 50 and 100 kg N ha't), two spatial arrangements (same and alternate rows) of beans and bean residue on maize performance. BothsoiltypeshadlowlevelsofN,andappliedNsignificantly increased dry matter yields and seed yields in almost all seasons. The N rate of 25 kg N ha'r was not adequate for growth, development and seed yield while the eft'ects of N rates of -50 and 100 kg N ha'r on seed yields did not differsignificantly. YieldresponsetoNbyintercroppedmaizewaslessthanthatofsolemaiz,e. Higherrainfall resulted inmore growth responses to N. Bean spatial arrangemenls altered N requirementby maize formaximum seed yield while bean residue generally improved the effect of applied N onmaize performance. Intercropping significantly delayed maize development ancl reduced dry matter yields, growth and ear weight though not in all seasons. Seed yields were significantly reduced by intercropping in some seasons while in others, they were comparabletothatofsolecropping. Thus,insomeseasons,totalgrainyieldsandlandequivalentratiosforthe intercropping systems were higher than those of sole cropping. Maize did not perform or respond uniforrnly to bean spatial arangemcnts across the sites.