Effect of Straw Management, Tillage and Cropping Sequence on Weed Population Dynamics in South-Eastern Highlands of Ethiopia

Abstract

Four multi-factor crop management trials were initiated in 1992 in the southeastern highlands of Ethiopia. Two of the trials were based on mechanised tillage, while two trials were based on the traditional ox-plow of Ethiopia. The trials examined the effects of alternative practices of crop residue management, tillage and cropping sequence on weed population dynamics. Partial removal or
retention of stubble was followed by increase in the population density of some broadleaf weed species, while burning had the opposite effect. Burning of crop stubble also markedly reduced the total grass weed population as compared to the other straw management treatments. Broadleaf weed population were not affected by tillage practices in either the ox-plow or mechanised trials. Grass weeds, however, increased significantly in density under minimum or zero tillage. Amount of Broadleaf weeds did not vary markedly in response to cropping sequence, but most of the grass weed population decreased in the faba bean rotation.