Texture Controls On The Loading And Migration Of Irrigation-Derived Salts In The Rio Grande Agricultural Soil Along The US-Mexico Border

Salt loading due to intense irrigation can have adverse effects on the normal functioning of agricultural soils in the semi-arid western Texas soils. It can change the soil texture, porosity and permeability as well as the behaviors of clays. The salts also play critical roles in the uptake of water and nutrients by crops. Therefore, salt loading causes hostile environments which could lead to changes in soil structural stability and overall crop yield. The goal of this study was to examine how salts were loaded and transported in a pecan field located in the northern Chihuahuan Desert, near El Paso, Texas. We used a soil auger to extract soil samples from a pecan farm (Pecan 1) at about every ten-centimeter interval in depth for a total of three meters. After collection, each soil sample was characterized using water soluble and exchangeable extraction methods and tested for cation exchange capacity (CEC), pH, soil adsorption ratio (SAR), and exchangeable as well as water soluble cation levels. Results indicate that both exchangeable and water soluble cation concentrations as well as total CEC, are highest in soils composed heavily of clay, and lowest in soils with a sandy texture. It is important to understand how salt loading can affect soil composition and subsequently plant growth especially in agricultural areas. Future work will be done to look at salt loading at different locations in the northern Chihuahuan Desert to obtain a more complete analysis of the region.