Efficient agricultural practices in Africa reduce crop water footprint despite climate change, but rely on blue water resources

Abstract

Alarming projections of climate change, decline in crop yields, and increased food demand constitute daunting threats to African food production and sustainable water management. Here, we map this complex water-food nexus by combining gridded climate data and process-based crop modelling to quantify scenarios of crop water footprint under Representative Concentration Pathway 2.6 and Representative Concentration Pathway 6.0 for time horizons 2040, 2070 and 2100. We show that high-input agricultural management coupled with the expansion of irrigation infrastructure could generate an average reduction of water use intensity up to 64% for staple crops, but only 5% for cash crops, by 2040. Notwithstanding the positive effect of intensification, between 82 Km3 (2040) and 102 Km3 (2100) of additional blue water will be required to sustain the increased yields. Our scenarios are suited for identifying locations where crops are subject to high climate impacts and where crop production shows trade-offs between high-input management and irrigation demand.

Agro-technology for climate-smart agriculture and resilience to climate extremes in sub-Saharan Africa

“…The high CSI values associated with HT futures are evident in the significant reduction in GHGI (supplementary material: figure SI.1) and an approximate tripling of WP (supplementary material: figure SI.2). Other model-generated evidence indicates that high-input agricultural management, combined with expanded irrigation infrastructure, could reduce water use intensity of staple crops such as maize by up to 64% (Giordano et al 2023).…”

A Framework for Assessing Food Baskets Based on Water and Carbon Footprints

“…Determining the blue water footprint can be considered an important indicator in agricultural water management [34]. This indicator has been used to better manage agricultural water resources in various studies in arid regions [35,36]. In this study, instead of using the evapotranspiration parameter that has been used to calculate the water footprint [37], the Gross Irrigation Water Requirement (GIWR) parameter was used.…”