Impact of Soil Biological Parameters on Soil Health in the Intensively Cultivated Deltaic Inceptisol of Thanjavur, Tamil Nadu

An experiment was conducted during 2021-22 at Agricultural Research Station, Kattuthottam, Thanjavur, Tamil Nadu to identify the impact of biological parameters on different cropping sequences. Three soil samples were randomly taken from each replication of every treatment making a total of 90 samples in each season from different cropping sequences during active vegetative stage. The size of each plot is 40m2. Samples were analysed for soil biological parameters viz., Urease, Acid phosphatase, Dehydrogenase, Soil microbial count (Bacteria, fungi and actinomycetes) and Microbial Biomass Carbon. Different cropping sequences showed their effect as variations in soil biological properties. The cropping sequence T4, sunhemp-rice+dhaincha (10:1)-green gram showed more biological activity with urease activity of 40.6 NH4+ µg/g/h, acid phosphatase activity of 43.1 P-NP µg/g/h, dehydrogenase activity (137.9 TPF µg/g/day), microbial biomass carbon value (307 mg kg-1), bacterial count (55.6 cfu g-1 soil), fungal count (23.5 cfu g-1 soil) and actinomycetes count (41.2 cfu g-1 soil). Rice-rice-sesame sequence was observed to have less biological activity than other cropping sequences.