Impact of Long-Term Manuring and Fertilization on Silt and Clay Protected Carbon in two Alfisols with Varying Texture

摘要

Fine textured soil have greater potential for physical protection of soil organic matter (SOM) as compared to coarse fraction. One of the principal factor responsible for the association of C with silt and clay fraction is soil texture and clay minerology. Our hypothesis was to study how soils with dissimilar climate texture and duration of manuring and fertilization influence C retention in two Alfisols with similar clay mineralogy (kaolinite dominant). The C carrying capacity of silt+clay fraction was estimated by a mathematical model developed by Hassink (1997). The study revealed that texture plays a significant role in determining C carrying capacity of silt and clay fraction of Alfisols of Bhubaneswar, Odisha and Pattambi, Kerala. The sandy clay loam soils of Pattambi stabilized more silt+clay protected C than sandy loam soil of Bhubaneswar. The application of 100%NPK, 150% NPKand 100% NPK+ FYMpromoted stabilization ofC in silt and clay fraction compared to 50% NPKand unfertilized control treatment. In general, the C retention potential of subsoil was higher than the surface-soil at both the sites indicating greater C sequestration potential.