#$%^&*AU2020100016A420200213.pdf#####ABSTRACT The present invention takes annual cultivation of triple-cropping crops as a cycle, including annual rotational tillage with rotary tillage for early rice and no-tillage for late rice and winter crops, and annual rice field-upland field rotation combining dry cultivation of winter crops and water cultivation of early rice and late rice, as well as a method of annular straw rotational return cultivation with winter crop straw and early rice straw returning to the field and late rice straw not returning to the field. The practical problems of long-term single soil cultivation, continuous cropping in the winter fallow period, straw burning, heavy metal pollution, and the like in the existing double cropping rice field are solved. The content of organic matter in soil is increased, the soil nutrient sustaining capability is enhanced, heavy metal Cd pollution to the soil is alleviated, the farmland ecological environment is protected, and sustainable, balanced and safe production of rice is achieved.1/3 Cd 0.5 -b 0.45 - bB b ~0.4 -cc .0-35 S0.3 *025 0.2 0. 15 0. 1 0.05 .CK TI T2 T3 FIG.1I
