Effects of deficit irrigation strategies on soil salinization and sodification in a semiarid drip-irrigated peach orchard

•40% and 9% water savings under sustained and regulated deficit irrigation, respectively.•Higher ECe, Cle and SARe increases in sustained deficit irrigation.•ECe, Cle and SARe correlated with field-wide leaching fraction and water deficit.•Peach trees unaffected by irrigation treatments, but yield declined with ECe.•No salinity and sodicity increases along the five years analyzed. Deficit irrigation strategies save water, but may enhance soil salinization and sodification when irrigated with low-quality waters. The objectives of this five-year study performed in the middle Ebro Basin (Spain) were to quantify these processes and assess their potential deleterious impact on the response of peach trees subjected to full irrigation (FULL), sustained deficit irrigation (SDI, irrigated at 62.5% of FULL) and regulated deficit irrigation (RDI, irrigated at 50% of FULL in Stage II of fruit development). In relation to FULL, water savings were 40% in SDI and 9% in RDI. Soil salinity (ECe), chloride concentration (Cle) and sodicity (SARe) measured in the saturation extract of 480 soil samples generally increased in the irrigation seasons, particularly in the more severe deficit irrigation strategy (SDI). These increases were counteracted by the leaching of salts induced by high leaching fractions (LF) and low water deficits (WD) attained during the non irrigation seasons. The changes in ECe, Cle and SARe measured between sampling dates were significantly correlated (p