Effect of Arbuscular Mycorrhizal Fungi Symbiosis with Haloxylon ammodendron and Atriplex canescens on Soil Available Water and Glomalin Concentration under Drought and Salinity Stresses

This research was performed to determine the effect of inoculation of two species of arbuscular mycorrhizal fungi (AMF) on soil available water (SAW) and glomalin concentration under drought and salinity stresses according to a factorial based on completely randomized design with three replications. Treatments included two plant species Atriplex canescens and Haloxylon ammodendron with inoculation of two fungal species Glomus geosporum and Glomus mosseae plus two levels of salinity stress at 7 and 14 dS m-1, and two levels of drought stress including maximum allowable depletion (MAD) of 50 and 80%. After one year of treatments, plant available water (PAW), least limiting water range (LLWR), integral water capacity (IWC), total and easily extractable glomalin concentration and soil organic carbon (SOC) content were measured. Results indicated a significant increase in SOC, glomalin concentration, PAW, LLWR, and IWC by increasing the salinity level in treatments inoculated with G. mosseae and G. geosporum. The highest percentages of increase in PAW (147%), LLWR (140%) and IWC (85%) as compared with control were observed under combined salinity and low drought treatment (14 dS cm-1 + MAD of 50%) in A. canescens inoculated by G. geosporum. The highest concentrations of total glomalin and easily extractable glomalin were observed in both plant species under salinity of 14 dS m-1 and severe drought treatment (MAD of 80%) with the inoculation by G. geosporum and G. mosseae. Overall the results of this research indicated a reduction in negative consequences of drought and salinity stresses in the soil under cultivation of A. canescens and H. ammodendron, with application of mycorrhizal fungi.