Sorghum (Sorghum bicolor) yield and water use efficiency depending on planting techniques and soil mulching in drought-prone areas, Babile District, Ethiopia

Abstract

Soil moisture stress is a major problem affecting the growth and yield of sorghum (Sorghum bicolor) crops during the main season in arid and semi-arid areas of East Hararghe, Ethiopia. The implementation of planting techniques and the application of mulching are very important and can influence the production of sorghum, as well as the efficiency of water use in the culture of this species. The present study employed an experimental design comprising nine treatments involving various combinations of planting techniques (tied-ridge plus furrow planting, tied-ridge plus ridge planting, and flatbed plus row planting) and mulching methods (plastic, straw, and no mulch). Each treatment was replicated three times Early in the sorghum growth cycle, mulching treatments enhanced soil water retention in the 0-90 cm profile compared to the non-mulched flatbed row planting control (FBN). Analysis of pooled data indicated that both main effects significantly influenced (P ≤ 0.01) key plant characteristics, including height, panicle dimensions, and leaf area. The tied-ridge furrow planting method with black plastic mulch (TFP) proved most effective in water conservation, boosting rainwater capture while minimising soil moisture loss through evaporation. Experimental results showed TFP outperforming FBN across all metrics: grain yield (6211.6 kg ha-1), biomass production (16211.3 kg ha-1), water use efficiency (19.9 kg ha-1 mm-1), and precipitation use efficiency (21.4 kg ha-1 mm-1). These findings suggest that implementing TFP techniques could substantially improve rainwater management and sorghum productivity, potentially increasing grain output in the study region and similar agricultural environments.