Kinetics of carbon mineralization in soil amended with leaf litter residues under laboratory conditions
摘要
Carbon mineralization of the leaf litter residues is a crucial process in soil that aids in forecasting CO2 emissions to the atmosphere. A short-term laboratory study was conducted using soil with selected leaf litter residues (Shorea robusta, Tectona grandis, Schleichera oleosa, and Albizia lebbeck), and monitored CO2 emissions for carbon mineralization over a period of 56 days. Chemical parameters of litter and soil were determined by the standard method. Carbon mineralization was calculated by an exponential model (C = C0 (1 − e−kt). The experimental results revealed that the emission status of CO2 declined until fourteen days. Afterwards, declining trend was slow down until forty-two days, and finally stabilized within 56 days. The rate of carbon degradation of different tree species demonstrated that T. grandis litter amended soil has higher decay rate (0.025 d−1) in comparison to S. robusta litter amended soil (0.009 d−1). On the other hand, highest CO2 emissions was recorded for S. oleosa (0.338 mg C g−1 soil) and the lowest for S. robusta (0.264 mg C g−1 soil) litter amended soil. Again, potential mineralizable (C0k) rate of S. oleosa and T. grandis residues containing soil was higher. The chemical constituents of different litter were also suggested that the litter having high nitrogen and low C/N ratio of T. grandis and S. oleosa, have faster carbon mineralization. Therefore, from the present study, it can be concluded that T. grandis and S. oleosa litter useful improvement of soil quality.