Modelling Dynamics of Soil Organic Carbon under Different Tillage Systems

Information on performance of Rothamsted organic carbon turnover model (RothC model) in predicting soil organic carbon (SOC) changes in short-term experiments is lacking. The study aimed to evaluate the suitability of RothC model to predict soil organic carbon stock under different tillage systems and organic input addition levels. Six treatments were implemented: T1, conventional tillage in maize-wheat (CT); T2, deep tillage in maize-wheat once in three years (DT); T3, conventional tillage in maize-wheat with integrated nutrient management (CT-INM); T4, conventional tillage with brown manuring in maize + cowpea (1:2) wheat + pea (4:1) cropping sequence (CT-BM); T5, conservation tillage in maize-wheat cropping sequence (CST); T6, conservation tillage in maize-wheat cropping sequence with brown manuring (CST-BM). The analysis of data showed that Root Mean Square Error (RMSE) values were between 0 center dot 47 to 6.50 in T2 and T6, respectively. The value of the relative error was negative for all treatments, except T2. In almost all treatments, SOC stock increased with time and the rate of increase in SOC was higher in the initial years. The model showed that treatment with conservation tillage integrated with brown manuring (T6) had the highest potential to increase soil carbon stock in the long run. The model was found to be suitable for the estimation of SOC stock changes under the given set of experimental conditions.