**5. The remaining impact of legumes on agricultural systems**

Crop rotation can improve biomass production and can sequester carbon (C) and nitrogen (N) in the soil, mainly crop rotation with non-legumes, and C and N can be improved with effects consecutively, for example, the increase in maize yield in legume rotation is a 50% successful plantation when grown with sesame [22]. Intercropping with legumes may increase soil N, and this total N may not be available during the current growing season, improving soil fertility for successful cultivation [23]. Lopez and Mundt [24] observed that velvet bean (*Mucuna pruriens*), and sun-hemp (*Crotalaria juncea*) often resulted in maize yields of 4 to 7 mg/ ha even without applying additional nitrogen fertilizer in the next harvest. Yusuf et al. [25] reported that to maximize the contribution of legumes N to the next crop, it is essential to maximize the total amount of N in legumes, the amount of N mineralized legumes, and the effectiveness of legumes. The use of this mineral N and the amount of N derived from immobilization Nair et al. [26] observed that legumes, especially soybeans, cowpea, peas, and peanuts intercropping with maize have the remaining or residual effect on the yield of a subsequent wheat crop. Intercropping of sorghum with peanuts, cowpea, and green gram reduces the N demand of wheat fertilizer to 61, 83, and 38 kg/ha for a target yield of 4.0 tons/ ha. Grain legume crops have deep root systems in the soil so they can recycle crop nutrients that are deep in the soil profile and also have the ability to hold different nutrients in high amounts in their biological content (**Table 2**).
