Evapotranspiration and Crop Coefficient for Pecan Treesin El Paso, Texas

摘要

In this study three-year daily actual pecan evapotranspiration (ET) was measured using an Open Path Eddy Covariance (OPEC) system for improved pecan irrigation scheduling in the west Texas. To monitor the amount and timing of water consumption ofpecantrees, a monitoring network for measuring evapotranspiration with ET tower with an OPEC system, soil moisture and groundwater levels was installed at a Pecan Orchard in Tornillo, El Paso County, Texas. Three-year data (2012-2014) were analyzed and summarized in order to quantify the pecan ET at site. The results showed that the actual pecan ETs range from 1054mm to 1167 mm for the growing season of March-October as compared to reference ET ranging from 1528 mm to 1635mm calculated by using ASCE standardized method. Maximum daily evapotranspiration range from 8.7mm to 9.4mm and all the maximum values occurred at the end of June and the beginning of July. The daily and monthly pecan tree crop coefficients were determined. The results from this study provide guidelines for precision irrigation for achieving better water conservation and improved production ofpecans in the region.