Seasonal and Depth-wise variation in Microfungal Population Numbers in Nameri forest soil, Assam, Northeast India

Soil microflora was isolated by serial dilution plate method using different culture media. The
highest fungal population was recorded in spring at the topsoil (1–9 cm), and decreased in other
seasons with increasing depths. Twenty-one fungal species belonging to 14 genera were recovered
from all depths throughout the seasons with the highest population and relative abundance of
Aspergillus flavus (8.4%), followed by Penicillium chrysogenum (8.0%) and lowest by Rhizopus
oryzae, R. nodosus and Trichophyton sp. (2.8% each). Phycomycetes (80.1%) were dominant in the
study site followed by Zygomycetes (14.1%), Ascomycetes (3.7%) and sterile mycelia (2.1%). Soil
pH, moisture content, organic C (Corg), total N concentration (Ntot) and available K had positive
correlations (p<0.05 and <0.01) with the fungal colony forming unit. Difference in soil depth and
seasonal variation have an influence on the microfungal population numbers as well as their species
composition in Nameri forest soil.