Water for Food, Fuel, Fiber and Feed in the Great Plains: Will Technological Improvements Be Enough for the Future?.

Declining ground water levels, water compacts and agreements plus moratoriums on both surface and ground water development in parts of the High Plains Aquifer have been complicated by drought recently. Past demands for water included food, fiber and feed, but with an emerging bioenergy emphasis, we must look at water supplies to see how they will be shared between competing uses, including a growing urban population. On a world scale, adequate water for food security is more critical than in North America. From 1950 to 2000, irrigated area in the world more than doubled. Sprinkler irrigation increased significantly and water applied per unit area decreased. Irrigated acres in the US increased from 2002 to 2007 with significant increases in NE, AK, LA, and GA and with major declines in CA, TX, CO, WA and FL. In an increasingly water-short world, the interacting effects of water, plant species and variety, and soil fertility must be considered. Producing more food or the same amount with less water will require improved efficiency as well as different crops and cropping systems. Much of the current interest in potential improvements in water use efficiency that may be made with plant breeding seem optimistic. Past data and current trends would suggest that agronomic management will contribute equally to efficiency enhancements. Water quantities currently available, changes in recent irrigation, crops and cropping systems, water timing, plant water use efficiencies or water productivity and research from deficit irrigation experiments will be reviewed for different crops.