2.2 Soil analysis
Samples were chosen randomly and analyzed in the laboratory after
passing through a 2-mm sieve and air dried. For measuring microbial
characteristics and soil enzyme activity, samples were incubated at 25
ÂșC and 60% water holding capacity (WHC). Soil variables were measured
using standard methods, bulk density (BD), water stable aggregate
content (WSA), soil organic matter (SOM), available nitrogen (AN),
available phosphorus (AP), available potassium (AK), and cation exchange
capacity (CEC) (Bao, 2000). To determine the clay content, we used a
Microtrac S3500 laser particle size analyzer (Microtrac Inc., USA) to
obtain the volume ratio, which was converted to mass ratio using an
empirical equation (Li et al., 2015). Soil pH was measured in MIlli-Q
water (soil: solution ratio = 1: 2.5(w: v)). TOC/TN analyzer (Shimaduz
Corp, Kyoto, Japan) used to measure soil dissolved organic carbon (DOC),
and total dissolved nitrogen (TDN) (extracts 1M KCL (1:10 (w: v) for 60
min)) (Jones et al., 2005). Chloroform fumigation-extraction method
(48h) determined Soil microbial biomass carbon (MBC) and microbial
biomass nitrogen (MBN) (Vance et al., 1987). MBC and MBN amounts were
calculated by subtraction concentration of the fumigated sample from the
non-fumigated sample, and the result was multiplied by a conversion
factor of 2.22 and 1.85, respectively (Brookes et al., 1985). Invertase
(INV), Catalases (CAT), Phosphates (ACP), and Urease (U.R. were measured
by colorimetric enzyme assay in soil suspensions (Sinsabaugha, et al,
2000; Hou Q, et al, 2020).