Abstract:
The study was carried out to investigate the soil microbial biomass C, N and P of major agroecosystems prevalent in East Siang district, Arunachal Pradesh viz., Soybean, Millet, Maize
and Vegetable agro-ecosystem. The study was conducted for a period of an annual cycle during
the year 2010-11. Microbial biomass C and N ranged between 199.61 and 238.35 µg g-1 and
15.46 and 26.55 μg g-1 respectively.It was found to be higher in the surface soil layer than the
subsurface layer in all the agro-ecosystems. Microbial biomass P significantly varied among
the seasons and sites (P<0.05). Microbial C/N ratio was found to be higher in subsurface soil
layer than the surface soil layer and the ratio varied between 8.83 and 13.94 in all the sites.
Microbial biomass C contribution to total soil organic carbon was 1.13%-3.37%. Microclimatic
variations and different agricultural practices were found to affect the changes in microbial
biomass.
