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An assessment was conducted on the performance of Rothamsted Carbon Model (RothC) model’s in simulating Soil Organic Carbon (SOC) dynamics over a 112-year period involving organic and mineral fertilization practices in a sandy-loam Alfisol. The crop rotation of the experiment included maize and sunflower. The model performance was evaluated by Coefficients of Root Mean Square Error (RMSE) and Efficiency factor (EF). Subsequently, model was utilized to forecast SOC dynamics over a 25-year period under similar pedoclimatic conditions. The results of the RothC simulations demonstrated Nitrogen, Phosphorus and Pottassium (NPK) + Farm Yard Manure (FYM) increased SOC stocks at the 0–15 cm soil depth (RMSE = 1.36, EF = 0.66). The SOC stocks reached steady state for the treatments FYM (every year) (RMSE = 0.99; EF = 0.49). RothC clearly simulated SOC reductions in control plot (RMSE = 12.37; EF = 0.58) and inorganic fertilizers applied plot (RMSE = 1.17; EF = 0.64). The carbon sequestration potential of the treatment which received NPK+ FYM is 147 kg ha−1 yr−1 during 2032 and it showed an improvement over the future years. Similarly, FYM treatment plot showed a sequestration potential of 96 kg ha−1 yr−1 and it showed a static rate in the future trend. However, 100% NPK plot shows declining trend which was 59 kg ha−1 yr−1. In conclusion, our findings indicate that the RothC model effectively predicts C dynamics in the Permanent Manurial Experiment plot, provided accurate initialization and appropriate parameterization of the model are ensured. [ABSTRACT FROM AUTHOR]

Global climate change has increased the events and intensity of extreme events. Tamil Nadu is located in the southern peninsula region of India, which has benefitted both from the south-west monsoon (SWM) and the north-east monsoon (NEM). Although variations in the monsoon pattern increased events of drought. The IMD gridded (1991–2020) and projected global climate model data (EC_Earth3_Veg_LR) were used to anticipate the drought-risk-prone zones over Tamil Nadu by using the standardized precipitation index. During both the SSP245 and SSP585 scenarios of the near (2021–2050) and mid (2051–2080) century periods, an increase in rainfall amount was expected with a high coefficient of variation (CV) across the region. The CVs of the future SWM and NEM seasons were expected to range from 20% to 60% and 25% to 50% respectively. Increased variability often leads to an increase in number of drought events. Regardless of scenarios, the southern zone was expected to experience more drought events, followed by the northwestern zone during SWM. Drought events during the NEM were expected to increase in northeastern zone districts. Changes in cropping patterns and policymaking for future risk-prone areas were undertaken as a proactive response to mitigate potential agricultural challenges. [ABSTRACT FROM AUTHOR]