Investigation on the physico-chemical properties of soil and mineralization of three selected tropical tree leaf...

Plant leaf litter has a major role in the structure and function of soil ecosystems as it is associated with nutrient release and cycling. The present study is aimed to understand how well the decomposing leaf litter kept soil organic carbon and nitrogen levels stable during an incubation experiment that was carried out in a lab setting under controlled conditions and the results were compared to those from a natural plantation. In natural site soil samples, Anacardium. occidentale showed a higher value of organic carbon at surface (1.14%) and subsurface (0.93%) and Azadirachta. indica exhibited a higher value of total nitrogen at surface (0.28%) and subsurface sample (0.14%). In the incubation experiment, Acacia auriculiformis had the highest organic carbon content initially (5.26%), whereas A. occidentale had the highest nitrogen level on 30th day (0.67%). The overall carbon-nitrogen ratio showed a varied tendency, which may be due to dynamic changes in the complex decomposition cycle. The higher rate of mass loss and decay was observed in A. indica leaf litter, the range of the decay constant is 1.26-2.22. The morphological and chemical changes of soil sample and the vermicast were substantained using scanning electron microscopy (SEM) and Fourier transmission infrared spectroscopy (FT-IR).