[Effects of sugarcane-soybean intercropping on cane yield, quality and economic benefit under low nitrogen condition]

To explore the effects of sugarcane-soybean intercropping on cane yield, quality and economic benefit, three sugarcane cultivars (B8, ROC22 and GT21) planted under sugarcane monoculture and sugarcane-soybean intercropping with low nitrogen fertilization (urea application of 150 kg · hm(-2)). The field design was a split-plot with the cropping pattern being the principal factor and the sugarcane cultivar being the secondary factor. The results showed that the millable stalks, stalk diameter, cane yield and sugar production were significantly affected by sugarcane-soybean intercropping while the cane quality wasn' t changed obviously. Compared with sugarcane monoculture, the stalk diameter, millable stalks, cane yield and sugar production in the intercropping system were increased by 5.1%-8.7%, 7.9%-31.0%, 9.0%-40.5% and 5.6%-39.5%, respectively. The total incomes of cane and soybean, and sugar and soybean were increased by 58900-79300 yuan · hm(-2) and 58300-77200 yuan · hm(-2), respectively. Among the three sugarcane cultivars in the sugarcane-soybean intercropping pattern, the economic benefit was the highest in ROC22, while the ratoon cane yields of GT21 and B8 were higher than that of ROC22. The results also indicated that sugarcane-soybean intercropping is an effective planting method to reduce nitrogen fertilizer application and increase economic income in sugarcane production.