| A laboratory incubation experiment was carried out to study the effects of different application rates of Orychophragmus violaceus on soil fertility. The results showed that the soil pH was reduced by application Orychophragmus violaceus. Compared to control soil, at the end
of the incubation the soil pH of 45 000 kg·hm-2（TⅠ）and 90 000 kg·hm-2 （TⅡ）application amounts was reduced by 0.24 and 0.41, respectively. The contents of soil total N, available P and available K increased 0.06 g·kg-1, 2.00 mg·kg-1, 26.28 mg·kg-1 for TⅠ, and 0.09 g·kg-1, 3.32 mg·kg-1, 63.00 mg·kg-1 for TⅡ. At 15 d after incubation, the soil available N contents of TⅠ and TⅡ reached the maximum, being 51.45 mg·kg-1 and 60.20 mg·kg-1 respectively. However, no significant effect was detected among the treatments after 60 d. Soil organic carbon content increased in the first 22 d, and after that no significant differences existed among treatments. Compared to the control soil, at the end of the incubation, soil organic carbon contents of TⅠa
nd TⅡ increased by -0.06 g·kg-1 and 0.33 g·kg-1, while the soil C/N ratio decreased by 2.02 and 1.51 respectively. |