Optimizing Spatial Arrangement and Variety Selection for Sustainable Maize–Common Bean Intercropping in Eastern Ethiopia

Abstract

Addressing food security in land-constrained regions requires sustainable intensification practices. This study evaluated the effects of spatial arrangement and bean variety selection on productivity and economic returns of maize–common bean intercropping in East Hararghe, Ethiopia. A two-year field experiment was conducted across two locations using a randomized complete block design with three replications. Treatments included five intercropping arrangements (1: 1 and 1: 2 maize: bean rows) with two bean varieties (Awash 2 and KATB1), alongside sole cropping controls. Sole maize produced the highest grain yield (7579.9 kg ha -1 ), but intercropping with Awash 2 in a 1: 1 arrangement achieved statistically similar maize yield (7208.9 kg ha -1 ) while significantly enhancing system profitability. All intercropping systems demonstrated land use efficiency, with Land Equivalent Ratio (LER) values exceeding 1 (1.194–1.283). Awash 2 outperformed KATB1 in intercropped bean yield, pods per plant, and seeds per pod. The 1: 2 arrangement favored bean yield (599.3 kg ha -1 for Awash 2), whereas the 1: 1 arrangement optimized combined economic yield (7844.2 kg ha -1 ) and Monetary Advantage Index (MAI = 80,939 ETB ha -1 ). Maize intercropped with Awash 2 in a 1: 1 row arrangement offers the best compromise between maintaining maize yield and maximizing overall system productivity and profitability.