Facing the challenges of global agriculture today: what can we do about drought
2013
Okono, A. | Monneveux, P. | Ribaut, J.M.
It is estimated that the planet's demand for food and feed crops will almost double by 2050 (Foley et al., 2011). Globally, rainfed agriculture is practised in 80% of the total agricultural area and generates 62% of the world's staple food (FAOSTAT, 2011). Taking into consideration global water scarcity and increases in demand for non-agricultural uses of water, expansion of the area under irrigation in developing countries does not appear to be a realistic scenario to address the challenge of food security. According to the latest climate change scenarios, 20-year extreme annual daily maximum temperature will likely increase by about 1–3°C by mid-21st century, and by about 2–5°C by the late 21st century, depending on the region and emissions scenario (IPCC, 2012). Based on historical data collected in Africa on more than 20,000 trials (1999–2007), each “degree day” spent above 30° reduced yield by 1% under optimal conditions, and that penalty rose up to 1.7% under water-limited conditions (Lobell et al., 2011). The impact of a changing climate is not only about temperature increase, but it is also affecting the magnitude of rainfall and its distribution, and therefore its availability at critical times of the crop cycle (Feng et al., 2013): in fact, while the total amount of rain increased in Africa over the last few years, the erratic and unpredictable nature of the drought and floods cycle also increased (Douglas et al., 2008). As such, improving the drought tolerance of crops, increasing the efficiency of water use and enhancing agricultural water productivity under rain-fed conditions is a number one priority today in a growing number of countries.
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