Rainfall variability adaptation strategies: An ex-ante assessment of supplemental irrigation from farm ponds in southern Burkina Faso

Abstract

This study assesses the economic value of supplemental irrigation as a rainfall variability adaptation strategy in a small catchment in south-western Burkina Faso. The bio-economic model built for the catchment maximises net cash income by optimally allocating land, labour, water and capital. Yields vary according to soil type, agricultural practice and the type of rainy season. We introduced farm ponds as an adaptation strategy – called supplemental irrigation – for grain crops during long dry spells in the rainy season. Simulation results show that supplemental irrigation can be cost effective and increase incomes, particularly during years with poor rainfall. However, in this catchment, gains from supplemental irrigation are limited because labour and capital are constraints on pond implementation. (Résumé d'auteur

Year-Round Irrigation Schedule for a Tomato–Maize Rotation System in Reservoir-Based Irrigation Schemes in Ghana

“…Insufficient water availability, owing to variability in rainfall patterns and frequent dry spells exacerbated by climate change [1,2], threatens food security and rural livelihoods in Sub-Saharan Africa (SSA) [3]. In SSA, more than 95% of arable land is under rainfed crop production, which contributes 81% to the regional food basket [4,5].…”

“…On a continental scale, annual NPK losses averaged 54 kg ha −1 (and ranged between 9 kg ha −1 in Egypt and 88 kg ha −1 in Somalia), resulting in land degradation in more than 40% of Africa's total farmland [12,13]. These risks have further reduced the already insufficient financial capacity of farmers to invest in sustainable land management (SLM) strategies [3,5]. However, such strategies are key for optimizing trade-offs between food production and other agro-ecosystem services [12].…”

“…The reservoir-based irrigation schemes in SSA, which store water (i.e., mostly surface runoff) in the rainy season, were originally designed to supply water for dry season crop irrigation, the livestock sector, fish farming, and domestic use, excluding supplemental irrigation in the rainy season. However, increasing climate variability calls for exploring the feasibility of supplemental irrigation for crop cultivation in the rainy season [3]. Supplemental irrigation has considerable potential to increase grain yield, particularly if provided during the critical stages of the crop growing cycle (i.e., booting and grain filling) [18].…”

“…Moreover, the limited number of studies on supplemental irrigation in SSA have not explored the feasibility of using dry season water savings in reservoir-based irrigation schemes. For example, Sanfo et al [3] investigated the economic value of supplemental irrigation of grain crops using farm ponds of 300 m 3 capacity in south-western Burkina Faso, and reported that in years of low rainfall, supplemental irrigation could be a cost-effective intervention to reduce risks of crop failure and increase farmers' incomes. Fox and Rockström [37] also assessed the effect of supplemental irrigation, based on 150 m 3 capacity farm ponds, on the grain yield of sorghum in northern Burkina Faso and found that supplemental irrigation alone resulted in an approximately 56% increase in grain yield, making it a useful technology to mitigate dry spells and shorten the yield gap.…”

Role of climate change awareness in sustainable soil nutrient management by smallholder farms in Burkina Faso

“…sorghum) will decrease by up to 25.5-27% under climate change during 21st century. Adapting to climate change through adoption of supplemental irrigation for instance (Sanfo et al, 2017) and building farm resilience is paramount to improving food security and livelihood of smallholder farms.…”