Improved Irrigation Methods for Conserving Freshwater in the Irrigated Pecans of the Desert Southwest U.S.

Rio Grande Project area, covering far west Texas and southern New Mexico, is experiencing record water shortages due to prolonged drought conditions. Pecan (Carya illinoinensis) is a major crop grown the region. It is a water intensive and salt sensitive crop, which requires about 5 feet of irrigation per year. Border irrigation, a type of flood irrigation wherein water is applied from a field irrigation ditch at its upper end to leveled plots divided by earthen ridges, is the oldest and most common irrigation method used in the region. This method of irrigation can lead to over irrigation and wastage of precious freshwater. Pecan growers are generally reluctant to adopt alternative methods of irrigation because of the fear of salt accumulation in the root zone. This study evaluated drip and surface flooding irrigartion methods effects on water use, in-shell nut yield and soil salinity.