This technical document contains clear and practical guidelines on how to implement ‘real’ water savings in agriculture through interventions for enhancing crop water productivity. A distinction is made between real water savings and ‘apparent’ water savings. Apparent water savings record reductions in water withdrawals but do not account for changes in water consumption. Real water savings record reductions in water consumption and non-recoverable return flows (runoff or percolation). This guidance document emphasizes the paradox of water savings at field and basin scales, which usually do not translate into increased water availability for other users as is commonly believed. An intervention framework groups water savings interventions into three categories: water management; soil and land management; and agronomy.
An inventory of publications lists information on each intervention in terms of changes of the application of irrigation water, water consumption (i.e. evapotranspiration), crop yield, and water productivity. The best interventions for achieving higher water productivity mostly relate to agronomic practices. Reductions in water consumption (evapotranspiration) are achieved through selected agronomic and water management practices.
Realizing real water savings is context-specific. This guidance document provides information on the expected changes at field scale resulting from various interventions. The impact in a larger context requires analysis at district level or basin scale. The ‘follow the water’ concept introduces water accounting terms to communicate the categories of water flows in a system. ‘Water saved,’ for example, is the amount of water resulting from reducing consumption and/or the non-recoverable fraction of the return flows that can be made available for alternative uses. Following the concepts and guidelines in this document, decision-makers can improve the management of their water systems by introducing sustainable interventions to achieve real water savings.
Food and Agriculture Organization of the United Nations and FutureWater
Van Opstal, J., Droogers, P., Kaune, A., Steduto, P. and Perry, C. . 2021. Guidance on realizing real water savings with crop water productivity interventions. Wageningen, FAO and FutureWater. https://doi.org/10.4060/cb3844e