Effect of organic amendments and microbial application on sodic soil properties and growth of an aromatic crop

•Land degradation through soil sodication is of concern.•We used sludge, vermicompost and salt tolerant microbes for its reclamation.•Treatments have higher effects on EC, P, NO3-N and microbial activities.•Microbial use showed significant effect on microbial activities.•Effect of organic amendments was more significant than microbial application.

In this experiment, we studied the effects of microbial inoculation, vermicompost and sludge application on physical, chemical and microbial properties of sodic soil and growth of Ocimum basilicum (holy basil). Sodic soil collected from natural field was amended with two bacterial strains A and C (isolated from the same soil), vermicompost and tannery sludge @ 5 t ha−1 upto 0-15 cm soil depth of field buried cement barrels (125 cm height, 49.5 cm diameter) in such a way that nine treatments (control sodic soil (T0), vermicompost or VC (T1), VC + strain A (T2), VC + strain C (T3), VC + strain A and C (T4), tannery sludge or TS (T5), TS + strain A (T6), TS + strain C (T7), and TS + strain A and C (T8) were formed. After application of these treatments, soil was incubated for one month at constant moisture. After one month of incubation period, 35 days old seedlings of O. basilicum were planted in barrels. Significant changes in soil properties (physico-chemical, microbial and enzyme activities), due to application of microbes and organic amendments, were observed after one month of incubation (AIS) and at crop harvest (ACH). On an average soil pH, electrical conductivity (EC), exchangeable sodium (Na), soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), soil respiration (SR), microbial quotient (Cmic:Corg), and metabolic quotient (qCO2) were significantly higher in incubated soils than crop harvested soils. Study concludes that use of vermicompost, sludge and microbial inoculants increase soil fertility and enhance yield and oil quality of Ocimum basilicum. Furthermore, incubation for one month before crop plantation was sufficient time for amendments to facilitate changes in sodic soil properties.