Restoration of Degraded Soil in the Nanmangalam Reserve Forest with Native Tree Species: Effect of Indigenous Plant Growth-Promoting Bacteria

Table 1

Methods for soil characteristics.

Estimation	Method
Soil properties
Bulk density (BD)	Core method [22]
Soil pH	Potentiometry 1 : 25 (soil-water) [22]
Electrical conductivity (EC)	Conductometry (1 : 2 soil-water suspension) [22]
Biological properties
Soil organic carbon (SOC)	CHSN/O Elemental Analyzer [23]
Microbial biomass carbon (MBC)	Fumigation extraction method [24]
Microbial biomass nitrogen (MBN)	Fumigation extraction method [24]
Soil basal respiration	Estimation of CO2 evolved during the incubation of soil in a closed system [25]
Urease activity	Determination of ammonia released after the incubation of soil samples with urea solution for 2 hr at 37°C [26]
Phosphatase activity	Determination of p-nitrophenol released after the incubation of soil with p-nitrophenyl phosphate for 1 hr at 37°C [26]
β-glucosidase activity	The determination of the released p-nitrophenol after the incubation of soil with p-nitrophenyl glucosidase solution for 1 hr at 37°C [27]
Phenol oxidase	To measure phenol oxidase enzyme activity, 3,4-dihydroxy-L-phenylalanine (DOPA) was used as a substrate. The mixture was incubated at 20°C for 1 h. After that, it was centrifuged, and absorbance of the supernatant was measured at 460 nm using a UV spectrophotometer [18]
Dehydrogenase	Estimation of TTC reduction of soils [28]
Catalase	Determination of H2O2 consumed by the soil [29]