Potential Soil Carbon Mineralization and Mineralization Kinetics Under Diverse Cover Crop Residues.

Global warming and environmental degradation associated with agriculture raise concern on how alternative agricultural practices can improve in soil organic matter cycling and agroecosystem resilience. This study aims to estimate soil organic carbon (SOC) mineralization and their kinetics under different residue management. A laboratory incubation study was conducted on soil samples manipulated with three rates (0, 5 and 10 Mg ha^-1) of pea (P), oat (O), and canola (CN) residues. Two kinetic models were fitted to observe SOC mineralization data for estimating labile organic carbon (C₀), and decomposition rate constants (k) for CC residues amended soils. The best model was selected based on AICC, RMSE, NRMSE, and r-value. The CC residues stimulated cumulative SOC mineralization (C_min) irrespective of CC type and rate of residue addition. Doubling the rate of CC residue addition increased C_min by 74%, 93% and 73%% for CN, P and O, respectively. The C₀ varied with the residue amount while k varied with CC type. The C₀ was 297% to 858% greater with 10 Mg ha^-1 and 297% to 456% greater with 5 Mg ha^-1 residue addition while k was 122% to 297% greater with 10 Mg ha^-1 and 94% to 240% greater with 5 Mg ha^-1 residue addition compared to the treatment with no residue addition. The CC residues can increase SOC cycling in agroecosystems.