Impact of pH, EC, OC and TN on Microbial Population Across Different Soil Depth of Balangir, Odisha

Abstract

The present study shows the variation of  soil microbial population across different depth in agricultural soil (AS), Pesticide treated soil (PTS) and forest soil (FS) of Patanagarh, Balangir district, Odisha. Soil samples were collected from four depth intervals (0, 15, 30 and 60 cm) to analyse the vertical changes in soil characteristics and fertility status. Microorganisms play a vital role in improving growth and performance of different crops. Microbial population was estimated from different soil types and presented in CFU/g of soil. Total bacterial population was increased with increased rate from top layer to 30cm depth which was decreasing with increasing depth due to alteration in physicochemical properties. The reduction in microbial population in PTS relative to AS may be attributed to the adsorption of microorganisms onto agrochemicals, which failed to safeguard themselves from pesticides.  In forest soil, bacterial population was higher as compare to other because of high organic matter (r= 0.785) and available nutrients (r= 0.838; p<0.01) in soil with favourable PH (r= 0.865). Fungal population also followed same pattern as bacteria and relative proportion of fungi increases from top layer to 15cm and found to be highest in 30cm depth soil because of increase nutrients concentration (OC; r=0.696;TN; r=0.729;P<0.01) ,PH(r= 0.771) and  EC(r= 0.729; p<0.01). Fungi are predominantly located in topsoil (up to 10 cm in depth) and are infrequently encountered at 60 cm depth. Additionally, the lowest ACM count in 60cm and highest count was found in 30cm depth, can be explained by the fact that actinomycetes are relatively regulated by physicochemical attributes and available nutrients.