ESTABLISHMENT OF LOW COST NO-TILLAGE CULTIVATIONS AND INVENTION OF NEW CONTROLLED AVAILABILITY FERTILIZERS FOR THEM WITH SPECIAL REFERENCE TO ENVIRONMENTAL PROBLEMS

在水稻和玉米免耕（NT）栽培中，采用控制效价肥料（CAF），在保持高产的同时降低劳动力成本和环境退化。采用s型CAF （POCUs-100； 100天释放期-聚烯烃包膜尿素）作为NT移栽系统苗箱单次基施全氮，开发了创新的水稻栽培方法。在苗箱中施用POCUs-100的NT系统的糙米产量与施用速效肥的常规耕作（CT）系统相同或更高。水稻植株基底pocus1 -100- n的回收率（73 ~ 83%）远高于RAF(20 ~ 39%)，从而大大减少了肥料造成的环境退化。在此基础上，针对日本东北部水田土壤排水量较差的特点，采用y形沟和CAF技术，开发了无覆盖水稻免耕直播技术。y型垄沟和CAF与含硝、氨的POCUs-100和Long 40配用可促进水稻成苗。在玉米凹痕栽培中，研究了免耕条件下CAF （POCU-30+POCU-70）与玉米种子的共施效果，并与RAF与玉米种子的共施效果进行了比较。CAF小区玉米出苗率达90%以上，而RAF小区由于燃烧问题，出苗率不足40%。在玉米干物质产量方面，施磷肥的玉米与施磷肥和施磷肥的玉米相同或更高。因此,它被认为NT CAF在水稻和玉米种植是创新可行的方法来减少劳动力和环境退化,同时保持高收益。

No-tillage (NT) cultivation of both rice and corn were conducted using controlled availability fertilizer (CAF) to reduce both labor costs and environmental degradation while maintaining high yields.Innovative rice cultivation methods was developed by using sigmoid type of CAF (POCUs-100 ; 100-days release duration-polyolefin coated urea) as a single basal application of total nitrogen in nursery box for the NT transplanting system. Brown rice yields of NT system with POCUs-100 in nursery box were statistically the same or grater than those of conventional tillage (CT) system with readily available fertilizer (RAF). Recoveries of basal POCUs-100-N of rice plants (73-83%) were much higher than those of RAF (20-39%) and thus reduced greatly environmental degradation caused from fertilizer. Further more, no-tilled direct seeding of rice without soil cover were developed using Y-shape furrow and CAF considering the dominant presence of poor drained paddy soils in north eastern Japan. Seedling establishment of rice was improved by using both Y-shape furrow and CAF in combination with POCUs-100 and Long 40 containing nitrate and ammonia.In dent corn cultivation, Co-situs application of CAF (POCU-30+POCU-70) and corn seeds in no-tillage system was studied in comparison with that of RAF and corn seeds. Emergence rate of corn seedling was more than 90% in CAF plot while that in RAF plot was less than 40% because of burning problem. The dry matter production of corn in NT with CAF was the same or greater than that in CT system applied both basal and top-dressed RAF.Therefore, it was concluded that NT with CAF in both rice and corn cultivation is innovative feasible method to reduce both labor and environmental degradation while maintaining high yield.