Optimal Irrigation Water Allocation for Enhanced Productivity of Pepper (Capsicum annuum L.) and Economic Gain: Evidence From the Semi-Arid Region of Ethiopia

Abstract

This study was conducted to assess the effects of different irrigation levels on pepper yield and related attributes. The experiment included five irrigation levels: 60%, 80%, 100%, 120% and 140% management-allowed depletion (MAD). The highest pepper yield was observed under the 120% MAD, with yields of 2.09 and 2.10 t/ha during the 2017 and 2019 experimental years, respectively. Conversely, the lowest pepper yield was recorded under the 60% MAD, with yields of 1.66 and 1.71 t/ha during the 2017 and 2019 experimental seasons, respectively. In terms of water productivity, the lowest values of 0.3 (2017) and 0.33 kg/m3 (2019) were obtained under 60% MAD, whereas the highest values of 0.39 (2017) and 0.42 kg/m3 (2019) were recorded under the 120% MAD. The 120% MAD yielded the highest economic gain of $12,127. On the basis of these findings, applying 120% MAD is more favourable for pepper production in semi-arid areas of Ethiopia and similar environments. This approach balances water availability and plant needs by allowing slightly greater soil moisture depletion, enhancing its ability to withstand water stress and reducing the frequency and volume of irrigation. This lowers labour and water costs, contributing to greater economic efficiency.