Water-nitrogen Management under Supplementary Irrigation through Rainwater Harvesting Technique for Improving Soil Fertility, Tomato Yield and Water Productivity in the West African Sahel
Year: 2026
Type: article
Abstract: Supplementary irrigation using harvested water is widely promoted in Burkina Faso and is increasingly adopted nationally as a suitable practice for sustaining and/or improving rain-fed production. However, under current land degradation conditions, this approach should be sustainable, with optimal water amounts matched to N fertiliser to optimise productivity while improving soil fertility. A two-year (2023 and 2024) split-plot field experiment was conducted at Gomtoaga village (12.24° N and 1.24° W), Koubri District, Burkina Faso, to identify an optimal water-nitrogen combination for improving soil fertility, yield, and water-use efficiency. Two forms of urea, pearled urea (PU) and deep placement of super granule urea (DPU), were combined with three water amounts (D100, D75, and D50), representing 100%, 75%, and 50% of tomato net irrigation, respectively. The results indicated that the PU + D75 combination increased soil microbial CO2 release (152%), microbial biomass (145%), OM (210%), C (215%), N (44%), and yield (34%), whereas DPU + D75 increased soil P (121%) and K (324%). The highest water productivity (43.34 kg/m3) and the lowest water cost (55.52 F CFA) for producing 1 kg of tomato were obtained under DPU + D50. Therefore, DPU + D50 and PU + D75 may be considered adapted practices for coping with water scarcity and improving land productivity, respectively. A cost-benefit analysis is required to identify the most beneficial combination by balancing farm returns and sustainable production.
Language: English
Subfield: Soil Science
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W7170047212