A 20-year experiment was conducted to study the effects of different tillage systems on accumulation and mineralization of organic carbon in purple paddy soil.The experiment included four tillage treatments: Conventional tillage with rotation of rice and winter fallow system,no-tillage and ridge culture with rotation of rice and winter fallow system,no-tillage and ridge culture with rotation of rice and rape system,and conventional tillage with rotation of rice and rape system.The results showed that the or...