Diversity of Soil Microbes under Different Ecosystem Landuse Patterns

Abstract

The impact of aboveground vegetation and soil characteristics on belowground microbial population was tested by analyzing the soil under three different landuse patterns viz., rice field, coconut plantation and Ipomea sp. dominated site at Madurai, Tamilnadu, South India. In the present study there are about 22 different species of bacteria and 41 fungal strains were isolated from all the three land use patterns. Among the 22 different species of bacteria, 9 were unidentified and the remaining 13 species were represented from 9 genera, 5 families, 4 orders, 2 class and 2 phyla. In the case of fungi, 33 strains belonging to 2 phyla, 5 subphyla, 7 classes, 8 orders, 8 families and 16 genera were isolated and identified and the remaining 8 strains were unidentified. The diversity analysis of bacterial population revealed high Shannon and Simpson Index values in coconut plantation and rice field respectively for bacteria. Whereas, the Shannon value was high for fungi in rice field and high Simpson value was recorded in coconut plantation. The relationship between soil moisture, pH and organic matter content indicated the existence of a positive correlation between moisture and organic matter content against Colony Forming Unit (CFUs) and a trend of negative correlation between pH and CFUs. The data obtained for CFUs of bacteria and fungi in three different land use patterns were subjected to ANOVA (one-way) and resulted in non significance at 5% level for bacteria and < 0.05 significance for fungi. A maximum number of CFUs of bacteria, fungi and plant biomass were found in rice field. Among the three different landuse patterns, the rice field harbours rich bacterial and fungal populations due to the availability of optimum pH, high moisture, organic content and aboveground biomass with moderate aboveground plant diversity.