Wednesday, November 4, 2009: 11:30 AM
Convention Center, Room 408-409, Fourth Floor
Cereal based cropping systems in South Asia are faced, today, with stagnation in crop productivity and slow down in agricultural growth. The cropping systems differ in the a) history of cropping, b) crop rotation, c) type and magnitude of tillage, d) inherent soil C and nutrient status, and e) resource use pattern. Declining soil health is considered as one of the key factors of degrading system productivity and resource base. The basic assessment of soil health is necessary to evaluate the degradation status and changing trends following different land use and management interventions. Soil health is a complex term and cannot be measured directly, but soil properties that are sensitive to changes in management can be used as indicators. Our objective was to determine the effect of different cereal based cropping systems on soil health indicators. Four different cropping systems viz. Rice-Rice, Rice-Wheat, Maize- Wheat and Rice-Maize with cropping history of more than 5 years were selected for the purpose. For each set of soil sample collected from cropping system, a corresponding soil sample was collected from an uncultivated area. The uncultivated area taken from an adjacent site where disturbance from agricultural activity was minimal was considered a natural control. Compared with corresponding uncultivated area, cultivation resulted in decrease in most of the soil health indicators viz. Total C, Total N, Av K, Organic C, MnOxC, HWEC and PMN. Highest decrease in Total C and Organic C was observed in Rice-wheat cropping system. Reduction in microbial count (flooded incubations) was observed in 70, 50, 80 and 40 percent of studied soils in rice-wheat, rice-rice, maize-wheat and rice-maize cropping system, respectively. Similarly, 40, 83, 100 and 60 percent of studied soils showed a decrease in mean weight diameter under respective four cropping systems.