Essential nutrients’ availability in pecan orchards affected by salinity in southern New Mexico and western Texas

Abstract Pecans Carya illinoinensis (Wangenh.) K. Koch are widely cultivated in the semi‐arid and arid regions of New Mexico and Texas, where irrigation relies heavily on the Rio Grande River and brackish groundwater. This study evaluated the impact of these water sources on soil physicochemical properties, nutrient availability, and pecan tree performance across six orchards along the Rio Grande in southern New Mexico and western Texas over two growing seasons. Soil samples were analyzed for texture, ion concentrations, sodium adsorption ratio (SAR), electrical conductivity (EC), and pH. Pecan performance was assessed using stem water potential (SWP) and leaf and kernel nutrient concentrations. Soil texture significantly influenced magnesium (Mg), calcium (Ca), and sodium (Na). The highest SAR (11.75) and EC (6.21 dS/m) were observed in loamy soil at Fabens 2, with pH ranging from 7.3 to 7.5. SWP values ranged from −12 to −14 bar in clayey soils and −10 to −12.5 bar in sandy soils. Leaf and kernel nutrient concentrations varied by location, with the highest zinc (Zn) levels in Fabens 2 (leaf: 160 mg/kg) and Derry (kernel: 120 mg/kg), and peak phosphorus (P) in Derry (leaf: 1195 mg/kg) and Las Cruces (kernel: 2858 mg/kg). Loamy soils with higher EC supported elevated Zn, Na, and potassium (K) in leaves, while sandy loams promoted higher Mg and kernel nutrient accumulation. In leaf, Zn decreased with Mg and K, while Na was strongly antagonistic to Ca and Mg. In the kernel, P, Mg, Ca, and K increased together. Zn tended to decline as P and K were raised. Seasonal variations showed greater Mg, Ca, and Na in leaves in October, while P and Ca in kernels peaked in 2015. A massive increase in nutrients from soil to leaf, then a decrease in the kernel. These findings underscore the need for site‐specific nutrient management and regular soil and tissue testing to optimize fertilization and mitigate imbalances.