Evaluating crop management options for sorghum, pearl millet and peanut to minimize risk under the projected midcentury climate scenario for different locations in Senegal

Abstract

With the growth of population, climate change is a threat to global food security. Understanding and identifying appropriate options of cropping systems and management practices at spatial (locations) and temporal (climate change) scale is important and required. A simulation study was carried out on 13 different locations of Senegal with the objectives of (i) assessing impacts of midcentury climate change scenario across different spatial scales and (ii) evaluating effects of crop management strategies (date of planting, planting density, nitrogen fertilizer management, irrigation, and crop rotations) to reduce risk under current and midcentury climates. Simulation results showed that N fertilization, planting date, and irrigation greatly affected sorghum and millet yield, which can be considered as suitable crop management options to reduce risks under the projected midcentury climate in Senegal although the impact varied by location. The response to N was highly related to water availability or rainfall. In contrast, peanut yield was not sensitive to N application. Early planting (01 to 10-June) improved yield for all three crops across 9 of the locations whereas yield of the three crops in the northern Senegal (Podor, Dagan, Louga and Kanel) remains low and thus was not improved by change in planting date. The length of growing season during the midcentury period decreased at least by up to three weeks due to late onset of rain for some locations, implying that shorter and high-yielding cultivar will be more suitable under future climate. Climate change slightly decreased sorghum yield during the midcentury (likely due to increased temperature and decreased rainfall) although response varied by location while millet yield was either improved or unchanged for most locations. Peanut yields decreased on average by 16 to 20% during the midcentury period regardless of all factors tested. Yield decreases for peanut might be due to increased duration of elevated temperatures and late initiation and shorter duration of rainy season, which implied breeding for heat and drought tolerance, and shorter season varieties might be beneficial. Of all crops evaluated, millet performed well under future climate compared to sorghum or peanut in Senegal although this may be affected by varietals factors. Changes in production systems, particularly focusing on tolerant crops as millet and sorghum will be critical.