Irrigation optimization enhances water management and tree performance in commercial citrus groves on sandy soil.

Abstract

Citrus production in Florida accounts for nearly 50% of national production in the United States. The goal of this study was to determine the impact of varying irrigation levels on tree growth, leaf nutrient concentrations, and water relations at selected citrus tree densities. During most of the year, significant water distribution and movement were detected across soil horizons as a function of irrigation applied and capillary water rising from the water table. As a result, significant fibrous root length densities (FRLD), median root lifespan, and leaf nutrient concentration were observed in the three-row and two-row experiments with deficit (50%-crop evapotranspiration, ETc) and moderate (78%-ETc) irrigation regimes, respectively. Stomata conductance and stem water potential (y) portray less water stress of the trees when they received moderate irrigation in the low and moderate tree densities than the highest tree density. Moderate irrigation triggered FRLD and improved root survival probability and root lifespan. As a result, irrigation management improved water availability, plant nutrition, and tree growth while efficiently utilizing resources.