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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Soil, Water & Air Resources Research » Research » Publications at this Location » Publication #358608
Title: Water-use efficiency: Advances and challenges in a changing climate

Author
item Hatfield, Jerry
item DOLD, CHRISTIAN - Orise Fellow

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2018
Publication Date: 2/19/2019
Citation: Hatfield, J.L., Dold, C. 2019. Water-use efficiency: Advances and challenges in a changing climate. Book Chapter. 10:1-14. https://doi.org/10.3389/fpls.2019.00103.
DOI: https://doi.org/10.3389/fpls.2019.00103

Interpretive Summary:

Technical Abstract: Water use efficiency (WUE) is defined as the amount of carbon assimilated as biomass or grain produced per unit of water used by the crop. One of the primary questions being asked is how WUE will respond to a changing climate with changes in temperature, precipitation, and carbon dioxide (CO2). At the leaf level, increasing CO2 increases WUE until the leaf is exposed to temperatures exceeded the optimum for growth (i.e., heat stress) and then WUE begins to decline. Leaves subjected to water deficits (i.e., drought stress) also show a decline in WUE. The positive response of leaf level WUE to CO2 is directly related to the processes controlling the exchange of CO2 and H2O between the leaf and the air surrounding the leaf. There are a variety of methods available to screen genetic material for enhanced WUE under scenarios of climate change. When we extend from the leaf to the canopy, the dynamics of crop water use and biomass accumulation has to consider the soil water evaporation rate, transpiration from the leaves, and the growth pattern of the crop. Enhancing WUE at the canopy level can be achieved by adopting practices that reduce the soil water evaporation component and divert more water into transpiration through crop residue management, mulching, row spacing, and irrigation. Climate change will affect plant growth, but we have opportunities to enhance WUE through crop selection and cultural practices to offset the impact of a changing climate.