Irrigated area in the Mid-South USA continues to increase and now totals four million ha. Because of low available water holding capacities and shallow root-limiting layers in many soils, irrigation management is difficult. Water quality and water use efficiency impacts under irrigation are poorly understood, but comprehension is necessary if conversion from groundwater to surface water supplies is to be justified. As irrigation has increased, the number of university research and extension personnel as well as the number of US Department of Agriculture personnel in the Agricultural Research Service and Natural Resources Conservation Service has not kept pace with the increase and the resulting challenges. A combined state and federal response to these challenges is needed to provide appropriate and effective problem solutions that ensure efficient water use and high crop water productivity while protecting water supplies and the environment.
Keywords: irrigation, sub-humid region irrigation, surface water supply, sprinkler irrigation, surface irrigation, aquifer depletion, water quality, water quantity, watersheds, irrigation management, water, water use efficiency, groundwater supply, USA irrigation