Utilizing dissimilar feedstocks derived biochar amendments to alter soil biological indicators in acidic soil of Northeast India

Biochar application to soil has been projected as an approach to improve soil quality, which can also influence soil microbial activities. In this experiment, we have utilized four dissimilar feedstocks derived biochar amendments. The highest microbial biomass carbon was found in Lantana camara (LC) biochar followed by pine needle (PN), maize stalk (MS) and lowest in black gram (BG) biochar. The dehydrogenase activity in different biochar treatment increased significantly along with control with increase in incubation days except pine biochar where dehydrogenase decreased. Biochar application in soil increased acid phosphatase compared to control. The highest alkaline phosphatase was found in MS and it was 20.56, 31.27, 42.52, 57.62 and 69.56 at 1, 7, 30, 60 and 90 days of incubation, respectively. The highest urease was found in LC followed by BG, MS and lowest in PN among the biochar at both the biochar application rate. The biochar application augmented the protease enzyme activity in soil, which might be due to augmenting the accessibility of inorganic nitrogen. The highest fluorescein diacetate was found in LC and it was 10.12, 17.62, 24.62, 32.86 and 37.56 at 1, 7, 30, 60 and 90 days of incubation, respectively. The increased biological indicator was more at 2.5 t/ha biochar application rate than 5.0 t/ha i.e. lower concentration of biochar enhanced more than higher concentration. This laboratory study demonstrated that biochar application can profit incubated acid soils by improving microbial biomass carbon up-lift while increasing potential soil enzyme activity.