Effects of intercropping row spaces between cassava and soybean on crop yields and economic profit

【Objective】 The present study analyzed the effects of different row spaces on agronomic traits,yields and crop population economic profit of cassava intercropped with soybean,thus providing theoretical basis for properly allocating row space between cassava and soybean and improving the economic profit of cassava planting.【Method】 Cassava cultivar Huanan 205 and soybean cultivar Guichun 15 were utilized and applied in the following seven intercropping treatments:cassava only(CC),soybean only(SS),cassava intercropped with soybean under row spaces of 30 cm(AB₃₀), 35 cm(AB₃₅),40 cm(AB₄₀),45 cm(AB₄₅) and 50 cm(AB₅₀),respectively. Plant height and stem diameter of cassava were measured in every month after intercropping treatment. Agronomic traits and yields of cassava and soybean were measured at harvest. Crop population economic profit and land equivalent ratio were calculated. The effects of intercropping row space on agronomic traits,yields and crop population economic profit of cassava and soybean were analyzed. 【Result】 The plant height and stem diameter of cassava under different intercropping row space treatments were lower than those of cassava only(CC). Intercropping row spaces were extremely significantly positively correlated with plant height,stem diameter and yield per unit area(P<0.01,the same below). The yield of soybean under different intercropping row space treatments was significantly lower than that of soybean only(SS) (P<0.05, the same below). Intercropping row spaces were significantly correlated with plant height,and extremely significantly positively correlated with branch number,pod number per plant,seed weight per plant,100-seed weight and yield per unit area of soybean. The yields of intercropping cassava and intercropping soybean under different intercropping row space treatments were significantly lower than those of cassava only and soybean only,with decreases of 14.47%-27.29% and 15.31%-33.93%,respectively. The total yield of AB₄₅(33540.10 kg/ha) was the highest one,and was significantly higher than other intercropping treatments. Total yield from the highest to the lowest was as follows:CC>AB₄₅>AB₅₀>AB₄₀>AB₃₅>AB₃₀>SS. The total economic profit of cassava and soybean intercropping combinations were significantly higher than that of cassava monoculture and soybean monoculture. The best income was under the AB₄₅ treatment(33585.86 yuan/ha),increased by 5.03%-148.57%,which was significantly higher than the rest of other treatments. The total economic profit of unit area from the highest to the lowest was as follows:AB₄₅>AB₅₀>AB₄₀>AB₃₅>AB₃₀>CC>SS. The total land equivalent ratio(LER) of the intercropping population was higher than 1.00(1.39-1.71),among which the highest was AB₄₅(1.71).【Conclusion】 The fixed width of cassava planting is 120 cm,and two rows of soybean are intercropped between cassava rows. When cassava intercrops with soybean under row spaces of 45 cm,the economic benefit of crop population is the best. This planting model can be popularized and applied in cassava plan-ting areas in Guangxi.