**4.5 Role of legume crops on improving soil chemical properties**

Soil chemical properties for sustainability are connected with the capability to provide vitamins for crop and retaining/denaturing hazardous chemical compounds or factors to the agroecosystem. Soil cation alternate capability (CEC), pH, nutrient levels, and soil organic carbon concentration are the primary chemical elements used toward the evaluation of soil fertility. Soil chemical properties have been associated with leguminous crops, and thus, the particulars of a soil property are easily interpreted and permit a rapid enhancement of the soil chemical properties through N-fixation and root biomass. Legume-based rotation induces modifications in the pH of the rhizosphere sector of soil. Root exudation of legumes and change or release of organic acids on the epidermal cell of root surfaces can also enhance P availability [27]. In addition, changes in pH are broadly recognized to affect the increase and undertaking of microorganisms [28], which are additionally necessary aspects in nutrient cycling processes. Leguminous green manure is a well-known generator of soil natural matter. Green manure, apart from increasing soil N, releases P, continues and renews the soil natural carbon, and improves soil chemical characteristics. Incorporation of legume residues is really useful to the soil for growing soil natural carbon awareness which is not only vital to agricultural productiveness however also to sequestration of C from atmospheric CO2 [29]. Observed that when leguminous cover plants are used as green manure and incorporated into the soil, their residues make bigger availability of N, P, K, and trace elements to the succeeding plants due to the lowering of the soil pH brought about by the CO2 produced in the process of decomposition [30].
