Studies on Soil Physico-chemical Properties in Rice Based Cropping Systems of Long Term Fertilizer Experiments

Soil samples collected from All India Coordinated Rice Improvement Programme from three different locations initiated in 1989-90 viz. Maruter(Andhra Pradesh-Rice Rice cropping system), Titabar (Assam-Rice Rice cropping system) and Mandya-(Karnataka- Rice Cowpea cropping system); with 8 treatments involving combinations of organic and inorganic sources of nutrients and three replications laid under Randomized Block Design, were collected, processed and analyzed for different soil physicochemical properties viz. pH, EC, OC and CEC properties to study the effect of varied fertilization practices in the long run which help in assessing the soil health status. Results showed that over 30 years of continuous experimentation the soils physico-chemical properties did not vary significantly among different treatments except organic carbon content. It ranged from 0.52-0.63%, 0.22-0.31% and 0.26-0.40% in Maruteru, Titabar and Mandya respectively. The results clearly brought out that monocropping over 30 years without any manures and fertilizers completely resulted in the depletion of nutrients. Inclusion of the pulse crop (cowpea) improved the soil fertility status especially in organic carbon