Soil Carbon and Nitrogen dynamics of Rice-Wheat Agro-ecosystems under Conservation and Conventional Practices

Abstract:

Agriculture play a strategic role in the socio-economic development of a country by ensuring food demand and supply for its population .Therefore globally maintaining the agro-ecosystems sustainability is utmost priority. Even sustainable agriculture is the fundamental agenda (2.4.1) of UN SDGs (2030).To attain agro-ecosystems sustainability, prerequisite is maintaining the individual farm-level sustainability, which requires farmer’s contribution to use suitable management practices. Agro-ecosystems sustainability and productivity is majorly dependent on its soil quality and health. Soil is the reservoir of important nutrients needed for crops growth, shortage or dis-balance of any of the nutrient affect the crop growth and yield. To maintain soil quality and ensure food and nutritional security, farm management practices should be sustainable and resilient. With this background, the present study conducted to assess Soil Carbon and N dynamics under Conventional (multiple tillage with complete burning of crop residues) and Conservation agriculture (CA) practices (zero tillage with retention of crop residues) practices at two soil- depths (0-5) and (5-15)cm. In (0-5)cm depth soil samples SOC, SOM, MBC, Total N, Available N and Nitrate-N were 17.7%, 16.7%, 6.9%, 9.1%, 26.3% and 10.2% more under CA practice as compared to Conventional practice, respectively. In (5-15) cm depth, soil samples’ MBC, Available N and Nitrate N were 71.6 %, 17.5%, 10.5% higher under CA as compare to Conventional practice, respectively. Whereas, SOC and TN were 5.6% and 20% less respectively. Results of the study indicate that CA practice enhance soil C and N content at (0-5)cm layer. However CA practice impact on soil C and N content was not persistent at (5-15) cm. depth. The study shows that CA practice impact on soil C and N content at different depth is governed by multiple factors. These factors and their role need to be quantified to strengthen the CA practice.

Keywords: Agro-ecosystems, Sustainability, Soil Carbon, Soil Nitrogen, Conservation Agriculture, Soil Quality