Impact of Soil and Water Conservation Structures on Microbial Population in Different Depths of Soil

Abstract

A study was conducted to assess the enumeration of microbial population in different soil and water conservation structures in a watershed area of Mysore district during the year 2012. Contour bund recorded highest Azotobacter population in 0-15 cm, 15-30 cm and 30-45 cm depths (40.66, 38.89 and 23.81 x10⁵ CFU g^-1, respectively). Highest PSP population was recorded at the depth of 0-15 cm in Boulder bund(31.52x10⁵ CFU g^-1 soil) structure followed by Contour bund (30.89x10⁵ CFU g^-1 soil). AM fungi population was highest in Boulder bund with 70.69 spore count 50 g^-1 soil followed by Contour bund (65.43 spore count 50 g^-1 soil). Highest mean population of Azospirillum was recorded in Boulder bund with 24.68 x10⁵CFU g^-1. Bacterial population was highest in Contour bund (32.56 x10⁵ CFU g^-1). Actinomycetes population was highest in Boulder bund (9.67 x10³ CFU g^-1 of soil) which was followed by Contour bund with 8.88 x10³CFU g^-1. In the present study, surface/shallow depths of soil recorded higher microbial population as compared to deeper depths of the soil irrespective of soil and water conservation structures associated with organic matter. It is revealed that, Contour bund, Boulder bund, Rock fill dam can accumulate higher organic matter and resulted in higher, population of microflora.