Reviewing our options: Managing water-limited soils for conservation and restoration

The Food and Agriculture Organization considers around a quarter of global land to be degraded. Of particular concern are threats to soils in water-limited regions, which are critical to food and economic security in countries across the globe but are under increasing pressure due to human use and climatic forcing. These soils have been used to feed and provide resources and services to human societies for millennia, with earliest land-uses dating back to prehistoric times. With the adoption of modern, frequently unsuitable agricultural practices combined with the population pressures and shifting consumption patterns, soils in water-limited regions have come under threat, resulting in degradation and in worst-case scenarios, desertification. Here, we review the current state of soils in water-limited environments and provide a guide to management for conservation and restoration of these fragile soils. Options to manage specific threats to soil functionality, namely, erosion, soil salinity, loss of functionality due to landscape homogenization, degradation of soil organic matter, and climate vulnerability are presented for specific land-uses using a whole-system approach management framework.