Soil biological properties and carbon dynamics subsequent to organic amendments addition in sodic black soils

The field experiments on calcareous sodic Vertisols were conducted on farmer’s fields in Purna valley of Vidarbha region of Maharashtra. The treatments comprised of different green manures (GMs); crop residues (CRs); gypsum. The chemical and biological properties after 2 years experiment showed that the application of gypsum recorded significant drop in pH and exchangeable sodium percentage (ESP) as compared to organic amendments. But later has outperformed with respect to biological activities viz., dehydrogenase activity (DHA) and microbial respiration and carbon sequestration by enhancing soil organic carbon (SOC), soil organic carbon (SOC) stock, soil microbial biomass carbon (SMBC) and labile carbon pool (POXC). Among the different organic amendments the application of dhaincha improved SMBC by 90%, microbial respiration by 104%, POXC by 59% and DHA by 265% as compare to control. High ESP of these soils showed negative relationship with microbial respiration and POXC (r = 0.48 and r = 0.43, p = < 0.05). While addition of biomass showed positive relationship with SMBC, microbial respiration, POXC and DHA (r = 0.93, r = 0.81, r = 0.83 and r = 0.91 p = < 0.01). The results of study showed green manuring in sodic black soil found to be alternative choice to gypsum, which besides gradual reclamation also enhance biological properties and carbon sequestration.