Assessing Soil Bund and Haricot Bean-Maize Intercropping Effects on Productivity of Maize at Arjo, Eastern Wollege Zone, Oromia, Ethiopia

Abstract

Soil fertility depletion is a major challenge to agricultural productivity and natural resources integrity in the highlands of Ethiopia. Improving crop management practices are believed to mitigate the effect and increase crop productivity. An on-farm study was conducted during the cropping season of 2017 in Arjo District, Eastern Wollega of Oromia Regional State with the objective of evaluating soil bund and maize (Zea Mays L.)-Haricot bean (Phaseolus Vulgaris) intercropping effects on maize productivity and soil moisture availability. The study involved a split plot design where soil bund (with and without) and intercropping (sole-maize and maize- haricot bean intercropping) were the main and sub plot factors, respectively replicated on 15 farmers’ fields. Soil moisture content during the growing season and agronomic parameters (Days to maturity, hundred seeds weight, biomass, and grain yield of maize) were determined. Analysis of Variance (ANOVA) was carried out to test the main and interaction effect of the treatments. Results showed that soil bund increased soil moisture availability during the entire growing period, which may be related to the likely reduction in surface runoff and increase infiltration. Consequently, the maize yield and most of the yield components were significantly increased due to soil bund. On average, soil bund increased maize grain yield from 5998 kgha^-1 to 6668 kgha^-1with a corresponding increase in biomass from 13973 kgha^-1 to18056 kgha^-1. Also, significantly higher maize grain (6783 kgha^-1) and biomass (18256 kgha^-1) yield were obtained due to intercropping of maize  with haricot bean than sole maize, which resulted in 14831 kgha^-1 biomass and 5882 kgha^-1 grain  yield. Because of the higher soil moisture during the grain filling period with soil bund, which extended days to maturity has led to the increased hundred seeds weight, biomass, and grain yield. Therefore, the use of soil bund and intercropping of maize with haricot bean have a potential for increasing crop productivity. However, as this is based on a single year data, further investigation is needed to establish undisputed evidence base to recommend the practices as a strategy to reverse land degradation, increase productivity and build resilience and increase adaptation to shocks such as climate change.

Keywords: Haricot-Bean, Intercropping, Maize, Maize Productivity, soil moisture content