Groundwater Recharge in Pecan Orchards Under Different Irrigation Systems to Reduce the Impacts of Climate Change in the Southwest USA

Abstract

Water balance is important to provide information and to conserve water. The flow of water in the system can be used to help and manage water supply, changes in management can increase water productivity in arid regions. For this study, soil water content was measured from one soil column within the orchards using time-domain reflectometry probes installed at different depths in the root zone of pecan fields. This data was analyzed to compare the irrigation systems. Water that passes the root zone was considered deep percolation. This research compared the amount of water stored on each field and water consumed by the trees for the last four irrigation seasons 2020 - 2023. Quantifying water from irrigation was essential to know how much water would recharge the Mesilla basin. Percolation was higher in the flood section, with 52 % of the total water applied, while in the drip, percolation was less than 5% of the total water applied moving down in the field for the 2021 growing season. In addition, there were differences in crop yield between the irrigation systems. This study estimated recharge and modeled water flow through the soil in drip and flood-irrigated pecan orchards to understand better surface water and groundwater interactions for improved river basin water management strategies and quantifies water stored in the ground lost through evapotranspiration. In addition, this project evaluates which irrigation scenario could best grow sustainable pecans in arid regions, reducing water use while maintaining crop production. It presents a balance of the two irrigation systems to understand the implications of climate change on the water cycle and achieve sustainability in the crops grown in the area.