The cation exchangecapacity of soil affects the fertilization and liming practices. Soils withhigh CEC retain more nutrients than low CEC while large quantities offertilizers applied in a single application to sandy soils. Soil pH also got affectsby decreasing due to crop production on low CEC soils (Leticia S. Sonon 2008). The SoilpH also can affect CEC by changing the surface charge of colloids (Scow, K.
M1994). A higher concentration of H+neutralizes the negative charge of colloids, results in decreasing the CEC(Kuoe J. and Jonczyk K, 2008). Earthworms were also reported of increasethe availability of phosphorus by facilitating changes in the biogeochemicalstatus in burrow linings. Studies also reported that earthworms feed on soil organicmatter with low C: N ratio leaves the organic matter with a higher ratio of C& N (Bohlen et al., 1997; Ketterings et al., 1997) while soil invertebratesyield about 15% of C and 30% of N in several ecosystems (Anderson, 1995). Thepresence of earthworms in soil irrespective of ecological category increasedthe quantity of inorganic N (Cortez et al.
2000). Earthworm casts directly enhance the aggregation of the structure of thesoil particles thereby increasing the water-holding capacity of soils significantly. The agriculturalpractices such as irrigation, tillage, lime application, drainage, use ofpesticide and crop rotation, can significantly influence the biomass andactivity of earthworm (Edwards et al., 1996). Use of solid materials andorganic fertilizers obtained from plants and animal origins were also reportedincrease in earthworm populations (Leroy et al.
, 2007; Leroy et al., 2008;Reinecke et al., 2008). Forestecosystem contributes a lot of organic matter to the soil in the form ofleaves, twigs, stems, flowers and fruits, which after decomposition result inthe increase of organic carbon as well as release of various nutrients.
The forestcover improves the water stable aggregates across the soil, particularly indegraded lands. The incorporation of vegetation such as green manure in forestimprovesthe physicochemical properties of soil (J.C. Sharma, 2004)