Influence of rainwater harvesting practices on the sorghum (Sorghum bicolor L.) grain yields in the sub-tropical deserts of Sudan ​

Abstract

Food security is climate dependent in the Darfur region, Sudan; ultimately, the extreme drought events have derailed the region into “the world’s first climate change conflict”. Most of the ongoing climate resilience efforts in the region depend on rainwater harvesting (RWH) practices. The objective of this study is to be better understanding of the variability in the performance of the adopted RWH practices in the Darfur region. Datasets of 148 farmers were collected during the year 2022 through a structured questionnaire in the South Darfur state and analyzed based on two different modeling frameworks in the R package: the deep machine learning (the Bagging algorithms) and the logit models. The dependent variable is the rainfed sorghum grain yield, and the independent variables were RWH practices, education level, family size, and distance to the farm. The standardized precipitation index (SPI) explained that every two years the region is experiencing a drought event (1980-2015), with an annual rainfall of 396 mm ± 100 mm. About 82% of farmers mainly adopted RWH for food security in face of the decreased rainfall. The adopted RWH practices (mainly terracing) have increased sorghum grain yields by 72% - 147%. The best grain yield is associated with spate irrigation, and the poorest with illiteracy. The large family size ( greater than 9 people) and good education level offset the negative impacts of both illiteracy and the longer distance to the farm. The terracing and terracing + mulching + deep tillage (as a single package) practices were the most laborious and unsustainable practices in the Darfur region, and are not recommended, especially when the farm distance is greater than 5 km