Impact of Irrigation Water Salinity and Plant Growth Promoting Rhizobacteria on Some Soil Properties in Pot Experiment

Increasing use of saline water resources for irrigation of agricultural lands, especially in arid and semi-arid areas, in addition to the accumulation of salts in the soil, has caused the loss of various properties of the soil and reduced the yield of agricultural products. Plant growth promoting rhizobacteria (PGPR) by producing different compounds can improve soil properties and reduce the negative effects of salinity stress on soil and plants function. In this study, the effect of PGPR [Control (PGPR0), Pseudomonas sp. 1 (PGPR1) and Pseudomonas sp. 2 (PGPR2)] and different levels of irrigation water salinity (0, 5 and 10 dS.m-1) on some soil properties in the rhizosphere of pistachio seedlings was investigated. The results showed that with the increase in irrigation water salinity, the amount of electrical conductivity (EC), soluble forms of sodium (Nas) and magnesium (Mgs), sodium absorption ratio (SAR), HCO3 and soil moisture content (Өm) increased by 3.8 times, 5.2 times, 2.5 times, 2.3 times, 23% and 59%, respectively, but the amount of pH, available phosphorus (AP) and organic matter (OM) decreased by 2%, 25% and 20%, respectively. However, treatment with PGPRs increased the content of AP (35-78%), available potassium (10-18%), OM (18-29%) and Өm (48%) and decreased the content of Nas (12-14%), ECe (10-12%), pH (3%) and SAR (14%) in different irrigation water salinity levels. Regarding to the presented result, using salt-tolerant bacteria in agricultural lands with saline water and soil can mitigate the negative effects of salinity stress on soil properties.