Organic and Natural Farming Practices Effect on Microbial Population, Dehydrogenase Activity and Microbial Biomass Carbon in the Rhizosphere Soil of Cabbage

In order to maintain a healthy soil, organic farming (OF) and natural farming (NF) should be practiced in addition to conventional farming. In order to evaluate soil fertility and productivity, a field experiment was conducted to study the microbial populations, dehydrogenase activities and biomass carbon in rhizosphere soils of cabbage under different farming systems over two years. Generally, microbial populations are expressed as colony forming units (CFU). Significantly higher microbial populations such as bacteria (34.15 x 106 CFU g-1of soil), fungi (19.08 x 103 CFU g-1of soil), actinomycetes (20.18 x 104 CFU g-1of soil), phosphate solubilizing microorganisms (11.45 x 104 CFU g-1of soil) and nitrogen fixers (14.78 x 104 CFU g-1of soil) were observed in rhizosphere soils after harvest of cabbage in organic farming followed by natural farming treatment. Dehydrogenase activity and microbial biomass carbon were significantly higher under organic farming. Lower microbial populations, dehydrogenase activity and microbial biomass carbon were found in conventional farming practices. It is concluded that application of organic farming inputs farm yard manure (FYM) and natural farming inputs, i.e. liquid organic manure (jeevamrutha), solid organic manure (ghanajeevamrutha) enhanced the soil microflora, dehydrogenase activity and microbial biomass carbon activities when compared to the conventional farming system.