Managing Drylands for Sustainable Agriculture

Major constraints to rainfed production systems in the world’s drylands include low and highly variable rainfall, nutrient deficiencies and land degradation by wind and water erosion. Although the same principles to cope with these limitations could be in theory applied to all dryland situations, there is no a universal recipe for sustainable dryland agriculture. In this chapter, the authors recall some of the challenges that have been identified for semiarid rainfed farming systems, namely soil conservation, water use efficiency, nutrient use efficiency and climate change mitigation, as well as some sustainable cropping and management strategies that have been formulated and recommended to address them appropriately. To this end, the authors provide examples supporting those practices mainly from semiarid Mediterranean agroecosystems. Among all the strategies discussed in this Chapter, and despite their limitations, the maintenance of a protective crop residue cover and the reduction of tillage operations appear to be the simplest technological options not only to control soil erosion but also to improve water and nutrient use efficiency and mitigate greenhouse gas emissions. The authors conclude that sustainable agricultural management in drylands should be primarily based on conservation agriculture practices and associated local-based crop residue management systems.