Soil Moisture Status in an Irrigated Pecan Field

Abstract

In this paper, the authors have modified a traditional transpiration formula using a soil-gas stress response function of the soil water content to appropriately depict the leaf water head. This allowed identification of the soil waterlogging (gas deficit) stress status. The authors then analyzed the status of soil moisture in an irrigated pecan field in El Paso, Texas, using a drainage equation and a modified transpiration formula. In the formula, four soil moisture statuses were identified: waterlogging stress (gas deficit), favorable water uptake, tolerable moisture deficit, and intolerable moisture deficit. Among these, the water uptake favorable and tolerable moisture deficit statuses are the two favorable for healthy pecan growth and good production. Waterlogging (gas deficit) and intolerable moisture deficit statuses are detrimental for pecan growth. The results also showed that soil moisture status is significantly different during the four growing stages of irrigated pecans: budbreak, early shooting-leafing, primary shooting-leafing-blooming, and fruiting. The results provide guidelines for precision irrigation for achieving water conservation and improved production of pecans and other similar crops.