The effect of variations in maize stover placement on maize growth and nitrogen uptake in continuous maize cropping systems in two regions of Kenya.

Abstract

Stover placement (surface mulch, incorporated or a mixture of mulch and incorporation) was compared with stover removal in the presence and absence of 50kg N fertilizer/ha in trials over two successive seasons in continuous maize cropping systems in two regions in Kenya. Stover applied at 4 tonnes DM/ha was found to have highly variable effects on maize growth and yield according to site., method of stover placement, N application and season. Relative to controls without stover, stover incorporation reduced yield by 39% in the first season, followed by yield increases of 15% in the second season. In the first season there was little or no response to N in the presence of stover. Low N uptake and N use efficiency suggested N immobilization in the incorporation treatment. Yield responses and large N uptake in the following season suggested mineralization of N immobilized in the previous season. Surface mulching at the Kabete site increased grain yields in the first season by 39% and 6% compared to stover removal without and with fertilizer, resp. In the second season, surface mulching markedly reduced yields possibly due to a combination of reduced phytotoxicity and N immobilization. At the Katumani site, stover amendments increased yields compared to removal in both seasons with incorporation results being superior to surface mulch. At this site, in both seasons, application of N reduced the effect of stover mulching and incorporation. You must log in to CAB Direct in order to view search results. If you have forgotten your log