ORGANIC VS. CONVENTIONAL: EFFECTS ON PHYSICO-CHEMICAL AND BIOCHEMICAL INDICES OF SOILS

The present study was carried out to evaluate the different soil indices in respect of physico-chemical and biochemical properties as affected by two different farming systems viz. conventional and organic. To do this, soil samples were collected from different crop fields practiced under conventional and organic systems. All the soil samples were analysed following standards procedures. The results showed significantly (p<0.05) lower pH and higher electrical conductivity (EC) of soils in most of the crop fields under organic farming system compared to their corresponding conventional fields. Though organic carbon (OC) was non-significantly (p>0.05) higher in soils of organic crop fields, total nitrogen (TN) was significantly (p<0.05) higher in organic crop fields than the conventional one. The activities of urease, phosphatase and aylsulfatase among different crop fields significantly differed (p<0.05) under both organic and conventional farming systems. With the exception of brinjal field, the urease enzyme activity was found higher in all the crop fields under organic farming practices compared to their corresponding crop fields of conventional system. On the other hand, the aylsulfatase activity was found higher in soils of all the crop fields except for tomato under conventional farming system relative to their respective organic crop fields. A negative significant (p<0.05) correlation between OC and pH while a positive significant (p<0.05) correlation between OC and TN was observed in organic farming system. The hierarchical clustering dendrogram based on soil enzyme activities and physico-chemical properties showed clear separation between organically and conventionally managed soils. The present study concludes that management practices significantly shape soil biochemical properties.