Impacts of conventional, sustainable and organic farming system on soil microbial population and soil biochemical properties, Puducherry, India

This research under field experimental conditions in agro ecosystem investigated the effects of different farm management practices (Conventional, Sustainable and Organic) on soil biochemical and microbial populations including soil physical, chemical and biological factors. Three composite soil samples were collected from each of the 10 farms from the fall of January 2012 to May 2012. Composite samples were done by sampling approximately 15kg of soil from each of the three farming systems (Conventional, Sustainable and Organic) using augur at 0-15cm cm depth. Soils from organic farms had improved soil chemical parameters (total elements and plant available nutrients) and higher level of total N, total P, total K, total Ca, total Mg, total Fe, total Cu, organic C, NH₄-N, NO₃-N, extractable P, SO₄-S and soluble Na. In addition, β- glucosidase activities, soil respiration and microbial population (bacteria, fungi, actinimycetes, beijerinckia, azotobacter, rhizobium, bacillus and phosphobacteria) were higher in soils from organic farming than sustainable and conventional farms. This study shows organic farming was improving the soil health and plant available nutrients without any inorganic external inputs.