Mitigation effect of dry spells in Sahelian rainfed agriculture: Case study of supplemental irrigation in Burkina Faso

Abstract

This study aims to isolate the supplemental irrigation (SI) scenario from permeable rainwater harvesting basins (RWHBs) best suitable to mitigate the long dry spells (DSs) in Burkinabe Sahel (BS). The water flow in the soil was studied on corn crop during 2013 and 2014 depending on the available water in the monitored RWHB. The experimental design was a block Fisher with four treatments (one under rainfed regime and three under supplemental irrigation). Measurements of the soil water content revealed periods of corn water sufficiency in plots under SI. Average corn yields were respectively 4500 and 4600 kg ha-1 for 2013 and 2014 on plots under SI against 3700 and 3800 kg ha-1 for those in rainfed regime. The average contribution of the SI in increasing corn yield was respectively 24 and 26% in 2013 and 2014 for three supplemental irrigations (SIs), against 19 and 17% for two SIs. With these SIs, the water balance in the RWHB gave respectively at the end of 2013 and 2014, an available water of 60 and 81 mm. The suitable strategy of the SI to mitigate DSs effect in BS was applying two SIs with a dose at least 40 mm around the mid-season. (Résumé d'auteur

Potassium Silicate, Against Water Stress, in Sweet Corn Plant Growth Traits

“…The need to maintain plant quality in water scarcity condition, a common situation in the Brazilian Cerrado Savanna (Heinemann et al, 2009), is one of the main agricultural challenges in Brazil. The climatic events, such as El Niño (Li et al, 2011), reduce precipitation, even during the rainy season, leading to plant water stress (Doto et al, 2015).…”

An Alternative Strategy for Mitigating the Effect of Rainfall Variability in Burkinabe Sahel

“…Thus, thanks to RWHB, the Sahelian farmers can produce corn; a crop neglected in favor of sorghum and millet because of its high sensitivity to water stress but valorizes better water than these cereals. This can diversify their cereal ration as showed [11]. In addition, the scenario of two SI can better allow farmers to practice market gardening at the end of the mid-season with the available water depth in the RWHB when corn is sowed in the third 10-day period in June.…”

“…The RWHB selected in the present study was the one studied by [11] in truncated pyramid shape. Its characteristics are summarized in Table 1.…”

“…The tillable soil was sandy loam with 0.9% of organic matter and 1.6 g•cm −3 for the bulk density. Optimal agronomic practices recommended by the Institute of Environment and Agricultural Research in Burkina Faso were conducted during the experiment [11].…”

“…Thus, to exploit this potential, the Ministry of Agriculture, Hydraulic and Fisheries Resources and the International Institute for Water and Environmental Engineering (2iE) developed a SI project for sustainable agricultural production. To achieve this goal, excavated rainwater harvesting basins (RWHB) were built in the Sahelian zone for the practice of SI on-farm during dry spells [11]. The technique involves collecting runoff in basins to irrigate rainfed crops.…”