Estimation of enzymatic, microbial, and chemical properties in Brown soil by microcalorimetry

The study was conducted with the objective to assess soil enzymatic, microbial, and chemical properties by customary methods and results obtained by conventional methods, corroborated with microcalorimetry. The experiment was laid out in a randomized complete block design with ten treatments in triplicates. The RS and GM were used at three rates (0, 5, and 25 mg g(-1) soil, respectively). The soils were maintained at two water levels 25 % (W1) and 200 % (W2) of soil water-holding capacity. All soil enzymatic, microbial, and chemical properties were measured by standard methods. The incorporation of GM and RS, especially at high rates and water levels, 25 % (W1) and 200 % (W2) significantly (p < 0.05) affected the soil enzymatic, microbial, and chemical properties compared to controls. The microcalorimetric parameters P (max) and k were positively correlated, whereas t (max) negatively linked with the results of enzymatic, microbial, and chemical properties at p < 0.01. Conversely, Q elucidated non-significant correlation (p < 0.05) to urease (0.248), neutral phosphatase (0.281), dehydrogenase (0.291), MBC (0.283), MBP (0.277), DOC (0.269), DON (0.190), SOM (0.284), and pH (0.047). Our results suggested that calorimetric parameters P (max), t (max), and k are highly sensitive and could be used as indices of soil enzymatic, microbial, and chemical properties, while Q is an indigent indicator.