Biomass Accumulation and Weed Suppression by Winter Cereal Cover Crops in Maize-based Cropping Systems in the Eastern Cape, South Africa

Abstract

White oats (Avena sativa variety Sederberg), triticale (Triticale secale variety Korog), italian rye grass (Lolium multiflorum variety Energa) and barley (Hordeum vulgare variety SVG 13) were evaluated for biomass yield and weed suppression. A follow up maize trial was conducted to test the residual effect of cover crops. Triticale achieved the highest biomass yield of 13910 kg ha -1 and Italian ryegrass the lowest of 6452 kg ha -1 . Cover crop treatments consistently had lower weed dry weight (p<0.01) during cover crop phase and in subsequent maize compared to the weedy fallow. Italian ryegrass had the lowest weed dry weight but was similar to white oat and triticale in control of weeds. There were no significant differences in total soil nitrogen and phosphorus amongst the cover crop treatments and with the weedy fallow but significant difference (p<0.05) in maize yield was observed between the cover crop treatments and the weedy fallow. White oats produced the highest maize grain yield (6369 kg ha -1 ), which was 33% more than the weedy fallow plot having the least maize grain yield of 4784 kg ha -1 . It was concluded that it may be feasible to increase cover crop biomass yield in conservation agriculture systems in the Eastern Cape through the selection of white oat and triticale as cover crops. © 2015 Friends Science Publishers