Assessment of Conservation Agricultural Practices on Soil Nutrient’s Stratification Ratio, Carbon Sequestration Rate, Management Indices and Crop Productivity in Southern Telangana India

Abstract The impending crisis for food production is the biggest threat to sustenance of soil resources due to industrial farming practices adopted by multitudes of farmers on all parts of the world inclusive of the Southern Telangana Zone (STZ) in India. This can extensively degrade the soil if not substituted by soil resource-saving agricultural systems. This present experiment is implemented to assess the impact of contrasting tillage practices and weed control tactics on soil quality parameters (SQPs) and monitor the grain yield of maize after three-years in CA with a cotton-maize-Sesbania rostrata cropping system. Three tillage practices (main-plots); T1: CT(C)-CT(M)-fallow (NSr), T2: CT(C)-ZT(M)-ZT(Sr) and T3:ZT(C) + SrR-ZT(M) + CR-ZT(Sr) + MS and weed control tactics (sub-plots) involved; W1-chemical weed control, W2-Herbicide rotation, W3- Integrated weed management (IWM) and W4- single hand-weeded control in split-plot design. Sampling of the soil in the 0 − 15 and 15–30 cm, subsequent to harvesting of maize, was analyzed for pH, EC, soil macronutrient’s availability, soil organic carbon (SOC), and computed for stratification ratio (SR), C-sequestration rate (CSR), carbon management indices (CMI) and carbon retention efficiency (CRE) duly following the standard procedures. The salient findings indicated that 9.1%, 15.3% of SOC, 10.2%, 15.1% of available soil N, 12.2%, 19.6% of available soil P in the 0–15 cm and SR of 1.20 for SOC, 2.0–6.5% of active carbon (CACT) pool in the 0 − 30 cm was higher under T3 relative to T2, T1, respectively. Similarly, 36.0%, 58.1% of cumulative CSR, 29.4%, 58.8% of CRE in the 0 − 30 cm, and 17.0%, 30.3% of CMI in the 15–30 cm was higher T3 compared to T2, T1, respectively. The CPSV was the dominant contributor of SOC to total SOC over CACT in the 0–30 cm soil layer. The 49.0% and 52.0% of CACT pool were observed to be higher under T3 and single hand-weeded control, respectively. The T3 had higher Kernel yield (KY) of 8.4%, 11.6% in comparison with T2, T1, respectively. KY was also 23.4–43.1% greater under W1, W2, W3 over W4. The ZT with crop residue retention (T3), and IWM alternative to chemical weed control/ herbicide can be a viable solution to slow-down the soil degradation process and contribute towards enhanced crop productivity in cotton-maize-Sesbania rostrata cropping system in this zone.