Crop-climate ensemble scenarios to improve risk assessment and resilience in the semi-arid regions of West Africa

Abstract

Estimation of the response of rainfed crops to heat stress and water stress must adequately account for the uncertainty in climatic and non-climatic factors that affect impact assessments. The objective of this research was to narrow the range of values characterizing the limits within which estimates are expected to fall in the diagnostics of agroclimatic risks. Assessments were made by analyzing historical observations and evaluating the influence of heat stress and rainfall variability on crop water demand, biomass and grain yields of short-cycle cultivars of pearl millet and maize. We used a wide range of consistent and practical sets of crop model ensemble analyses (based on crop management practices such as plant density, fertilization levels, early/late sowing dates and soil types) and climate model ensembles from 2 climate change hypothesis (A1b and RCP8.5) over the West African Sudan-Sahel. Recent rainfall developments show that hazardous intra-seasonal rainfall distribution affects crop productivity, with increased frequency and intensity of daily rainfall, false start and early cessation of the rainy season and decreasing diurnal temperature range. In 2011−2050 perspectives, relative to the 1981−2010 baseline, a slight increase in temperature (i.e. + 0.6 to + 0.8°C) combined with a stationary to moderate decrease in precipitation leads to a 10 to 15% (8 to 15%) decrease in aboveground biomass production (grain yield). When the warming is moderate (i.e. +1.4 to 1.8°C), the decline in grain yield worsens (10 to 20%), despite a slight increase in rainfall projections. At these rates of loss in crop production, resilience can be reinforced. However, it will require that climate-smart crop management practices be embedded in sub-seasonal and interannual monitoring and early warning systems.

Simulation of the impact of climate change on peanut yield in Senegal

“…The minimum daily weather data required to run the DSSAT model includes daily precipitation, daily maximum and minimum temperatures and daily solar radiation. The DSSAT model has been extensively used worldwide to simulate the impact of climate change on crops (Rezzoug and Gabrielle, 2015;Waha et al, 2015;Salack et al, 2015). In this study, the crop model is used to estimate the impact of climate change on the peanut variety Virginia 897 during the near and the far future.…”

“…Compared to near future, a gradual increase in temperature is noted. Changes in temperature and rainfall could affect crop production (Salack et al, 2015;Potop et al, 2014). In the last part of this results discussion, we investigate the possible climate change impact on peanut cultivation during the near and the far future.…”

“…Agriculture constitutes approximately 46% of the country's total land area and supports 70% of the rural population (Colen et al, 2013;FAO, 2014). However, certain human activities such as agriculture are expected to be vulnerable to climate change (Salack et al, 2015). Moreover, in the semi-arid regions of West Africa like the Sahel, the adaptation capacity is very low (Boko et al, 2007).…”

Multiscale Remote Sensing to Map the Spatial Distribution and Extent of Cropland in the Sudanian Savanna of West Africa

“…Average temperature in the zone ranges from 24 °C to 32 °C in the south and north, respectively [31]. The Sudanian Savanna zone is sometimes divided into a northern semi-arid region (Sahelo-Sudanian) with a mean annual rainfall range of 500 to 800 mm and a southern sub-humid region (SudanoGuinean) having 800 to 1100 mm mean annual rainfall [32,33] (Figure 1). These two sub-divisions represent a climate gradient, with the Sudano-Guinean region having favorable climate conditions and a higher vegetation/tree cover.…”

“…Typically, rainfall lasts from May to October during which major agricultural activities are undertaken [31]. Total annual rainfall ranges between 500 and 1100 mm, although this is highly variable in space and time (inter and intra-annual) [32]. Average temperature in the zone ranges from 24 °C to 32 °C in the south and north, respectively [31].…”