Physiological and agronomic approaches for improving water-use efficiency in crop plants

Water is the lifeline for crop production worldwide. However, the changing climate is causing erratic rains and frequent episodes of drought, and a continuous decline in freshwater resources. This situation requires strategies for water-efficient crop production. Wise use of water in crop production and improved crop water-use efficiency may help to produce ‘more crop per drop’. This review discusses physiological and agronomic considerations for improving water-use efficiency in crop plants, which primarily depend on canopy size, leaf morphology, leaf and shoot anatomy, root architecture, water uptake capacity, and maintenance of tissue water status. Developing genotypes with improved water productivity and modified planting times, seeding rates and planting geometries will improve water-use efficiency in crop plants. Improved irrigation scheduling, use of high-efficiency irrigation systems, better soil fertility management, and mulching to reduce soil evaporation and manage weeds should further improve crop water-use efficiency in the field. Research and development gaps for increasing our understanding of the physiological responses of plants to water supply using novel approaches linked to environmental physiology are also explored.