Irrigation technology and water conservation: A review of the theory and evidence

Climate change, population growth, and economic development increase competition for water and exacerbate water scarcity- and drought-related losses (IPCC 2014), resulting in the identification of water crises as the greatest global societal threat (WEF 2019). Farming currently accounts for roughly 70 percent of freshwater withdrawals worldwide (FAO 2019) and often constitutes the least productive (i.e., lowest value) use of freshwater resources (Damania et al. 2017). In this context, providing safe, stable, and profitable food production while making incremental water available to alternative uses, including the environment, requires efficiency improvements in agricultural water management (UN 2015).