Assessment and simulation of crop water productivity under different soil moisture conditions in irrigated fields

Aim of the study: To assess and simulate crop water productivity (CWP) under different soil moisture conditions in irrigated fields. Area of the study: The study was undertaken in Bontanga irrigation scheme in the Northern Region of Ghana. Materials and methods: The experiment was laid out in a randomized complete block design. Three irrigation blocks were selected. Each block had two plots of chilli pepper and two plots of okra such that each crop was subjected to water stress and non-water stress conditions under furrow irrigation. At the end of the growing season, the collected data on crop yield and the amount of water applied were used to estimate CWP. The AquaCrop model was applied to simulate CWP under non-water-stress and water-stress conditions. Main results: Results revealed that, by maintaining an ideal volumetric moisture content of 15.4–22 % in sandy loam soils, CWP values of 2.08 and 1.40 kg m-3 can be attained for okra and chilli pepper, respectively. However, under water stress conditions with a volumetric moisture content in the range 12–15.4 %, simulated results showed that CWP could drop to 1.82 and 1.34 kg m-3 for okra and chilli pepper, respectively. Research highlights: The study underscores the importance of soil moisture management in agricultural fields in order to improve CWP. These efforts will help in implementing sustainable water management strategies aimed at maximizing crop yield per water drop under changing climatic conditions, thereby supporting Sustainable Development Goals (SDGs) 2, 6, and 13.