Irrigated Corn Production and Management in the Texas High Plains

Corn is the major irrigated crop in the Texas High Plains (THP) and uses 53% of the total agricultural regional water resource budget. Currently, the declining water level of the Ogallala Aquifer, coupled with irrigation pumping restrictions by regional groundwater conservation districts, is challenging sustainable, high level corn production. The objective of this article is to review production levels and evaluate corn management practices in the THP with reduced or limited levels of irrigation. Long‐term field studies demonstrate that yield and water use efficiency (WUE) have increased significantly over the last forty years while seasonal corn evapotranspiration (ET) under full irrigation conditions has not increased. Among management practices, irrigation remains the single‐most important factor in corn production. With recent advances in corn breeding and genetics, irrigation requirements can be reduced by up to 25% in some years and result in similar yields as compared to irrigation amounts at the 100% ET level. Also, WUE is generally maximized at irrigation levels meeting 75–80% ET demand. Newly developed drought tolerant corn hybrids have been shown to provide yield benefits of 10–15% under limited (reduced) irrigation water levels. At the higher irrigation levels (75–100% ET requirement), corn yield increased as seeding rate increased initially but did not increase further when the seeding rate exceeded 94,000 seeds ha −1 . Also, a multi‐year planting date study indicated that high corn yields can still be achieved with a long‐season hybrid when planted in the middle of May and early June. When the planting date is delayed to late June and early July, mid‐ and short‐ season hybrids showed a yield advantage over the long season hybrids.