Soil Microbial Community Responses to Alternative Land-Use Practices Impacted Soil Inorganic and Organic Carbon Pools in Arid Saline-Soils

Increasing and conserving soil carbon stocks in arid-saline soils is critical for soil quality and productivity. However, salinity stress and diminishing availability of freshwater resources for irrigation continue to negatively impact soil productivity and carbon sequestration potential. Using treated wastewater and implementing climate-smart cropping systems are promising alternative practices for sustainable production in arid-lands. Soil microbial community responses and impacts on soil carbon pools, including inorganic carbon stocks, must be understood for continuous and sustainable implementation of alternative practices. This study was conducted to investigate soil microbial community shifts and carbon pools under a combination of agronomic treatments comparing two cropping systems (bioenergy sorghum (So) and switchgrass (Sg)), two irrigation water sources (wastewater (Ww) and freshwater (Fw)), and gypsum amendment (GA), and a native background control (BC), located on a saline-soil under arid climate. After three years of initiating the treatments, soil samples were collected during the active growing season and analyzed for total carbon (TC), total organic carbon (TOC), total inorganic carbon (TIC), microbial biomass-carbon (MBC) and microbial community structure using 16S and ITS amplicon sequences.