Carbon mineralization patterns of cotton leaves and stems in vertisols and inceptisols

In India, cotton crop residues available after cotton picking are considered as waste materials and disposed off the field. For developing better residue management practices, knowledge of the decomposition kinetics is needed. Short-term laboratory incubations were conducted to determine the pattern of C mineralization from cotton leaves and stems stem pieces (ca. 2 cm) vs. ground stem (0.25 mm)] in the two major soil groups (vertisols and inceptisols) on which cotton is grown to a large extent. The amount of C mineralized was significantly greater from leaf- (18.3% of added C) and ground stem-C (19% of added C) when compared to stem pieces-C (13.2% of added C). Differences between the residues were not seen in the inceptisols. The cumulative amount of C mineralized ranged from 9.6-11.5% of the added C. Narrowing the C:N ratio of stem did not enhance C mineralization.