Studies On The Influence Of Intercropping Sugarcane With Soybean On Soil Fertility Status And Growth Of Sugarcane

The intercropping experiments were conducted using sugarcane(Saccharum Hybrid Complex) variety ROC 22 with the best local soybean varieties of Guangxi, viz., willow bean 3, GuiChun 2 (mid-maturing) and GuiChun No.8. The changes in soil nutrient status, morphological characteristics and juice quality of sugarcane were investigated during the early flowering and pod bearing stage of soybeans intercropped with sugarcane at different sowing time. After harvesting, the yields of sugarcane and soybean in different intercropping density treatments were recorded. The results of the present study will provide a useful information on potential use of land resources for sustaining the productivity and earning higher economic benefits. The summary of the results is as follows:(1) Sugarcane intercropping with mid-maturing soybean variety GuiChun 2 significantly increased the soil fertility level, as revealed by a significant increase in total nitrogen, alkali-hydrolyzable nitrogen (38.16mg/kg), total phosphorus, rapidly-available phosphorus (9.14 mg/kg) and organic matter content, compared to control.The soil nutrient content improved most significantly in treatments with sowing on February 17th amongst all treatments, where the total N, alkali-hydrolyzable N and rapidly-available P contents enhanced by 0.31g/kg,56.56 mg/kg and 23.93 mg/kg, respectively, compared to control. Intercropping a row of soybean alternate to the row of sugarcane enhances the soil fertility level significantly in terms of improving total N, rapidly-available P, rapidly-available K and organic material content. It was concluded that intercropping sugarcane with alternate rows of mid maturing soybean varieties did not affected the growth of sugarcane, and helped in conserving the soil nutrients and improving soil fertility status. (2) After harvest, the height of sugarcane plants and field brix, etc., did not showed any significant differences with control (only sugarcane). The quality indices of sugarcane intercropped with soybean, viz., sucrose content, apparent purity and gravity purity, etc., surpassed to the sugarcane plants cultured alone. These results revealed that sugarcane intercropped with soybean does not affect the normal growth and juice quality of sugarcane. Compared to the sugarcane cultivation as solo crop, its intercropping with soybean gave higher total economic returns.(3) In the sugarcane intercropping with soybean, amongst different sowing dates of soybean, the first one with the late-ripening soybean variety showed highest yield, when planted in single row alternatively with each row of sugarcane compared to intercropping two rows of early-maturing soybean. The second and third sowing dates with the one row of early-maturing soybean variety recorded the second highest compared to intercropping two rows of soybean. On the basis of effects of intercropping on improving the soil fertility status, mid-maturing soybean variety was found suitable for intercropping with the sugarcane. However, with regard to yield and quality of sugarcane and the economic benefits, the late ripening soybean varieties proved better. Considering all the factors together, the best effects were observed when sugarcane was intercropped with two rows of mid-maturing soybean variety at the second sowing date.