Integration of Cover Crops and No-till Improved Maize Yield in Eastern Uganda

Aims: The study evaluated the contributions of cover crops and no-till to the expression of crop maize yield.

Study Design: To test this, experiments were conducted for two consecutive years in a randomised complete block design arranged in a split plot with four replications

Place and Duration of Study: Busiu in Mbale district, Uganda between September 2009 and April 2011.

Methodology: Each experiment consisted of two no-till practices; herbicide no-till and slash no-till, four cover crops; mucuna (Mucuna pruriens L. DC.), lablab (Lablab purpureus), crotalaria (Crotalaria paulina), canavalia (Canavalia ensiformis) and one weedy fallow (control). No-till practices were allotted to the main plots while cover crops and weedy fallow to split plots. Data on cover-crop biomass, nutrient content, maize gain, cob and stover yields were recorded and analyzed to test for significant differences.

Results: The results showed significant differences in biomass, N, P and K among no-till practices. Biomass, N, P and K recorded in herbicide no-till were high compared to slash no-till. Canavalia and crotalaria produced higher biomass compared with the weedy fallow, mucuna and lablab. Nitrogen levels in all cover crops evaluated were significantly higher than that from weedy fallow. In relation to maize yield, herbicide no-till increased maize grain yield by 2.6 Mgha-1 compared to slash no-till. All cover crops increased maize yield compared with the weedy fallow. The average increment in maize yield due to cover crops ranged from 1.1-1.5 Mgha-1. The most beneficial combination was between canavalia and crotalaria with herbicide no-till which gave higher maize yield when compared with a combination of the same two cover crops with slash no-till.

Conclusion: The increase in maize yield noted in our findings indicated the potential of canavalia, crotalaria and herbicide no-till to improve maize production in Eastern Uganda.