A four-year( 2010-2013) field experiment was carried out to explore the effects of three planting patterns( sugarcane,soybean monoculture and sugarcane-soybean 1: 2 intercropping) with two nitrogen input levels( 300 and 525 kg · hm-2) on soybean nitrogen fixation,sugarcane and soybean nitrogen accumulation,and ammonia volatilization and nitrogen leaching in sugarcane field.The results showed that the soybean nitrogen fixation efficiency( NFE) of sugarcane-soybean intercropping was lower than that of soybean...