BALANCE AND ADJUSTMENT OF ZINC IN PADDY FIELD ECOSYSTEM
稻田生态系统中锌的平衡与调节

The experiments were conducted to study zinc adsorption and desorption equilibrium, zinc diffusion, move and enrichment in soil, and zinc uptake , accumulation and consumption of plant in paddy and paddy soil system.It was investigated that input and output of zinc in paddy soil for illustrating the cycle of zinc in paddy field ecosystem. Input way and input amount of zinc in proper order were fertilization (organic and chemical fertilizers) > rainfall >irrigation >seedling transplantation; Output way of zinc was mainly crop harvest,while field drainage and soil body leaching of zinc were very little. Zinc income and expenses balance in paddy field was a little deficit in nutrient pool of soil root horizon, which didn't decrease zinc content of soil plough horizon. However, zinc fertilization was still needed to replenish zinc for crop growing normally on the zinc deficient soil . In this paper, it were put forward the adjusting principles and technical measures for maitaining suitable zinc-supplying to crop and fine zinc-cycling in paddy field ecosystem.