장기 무경운 벼 생산체계에서 토양의 이화학성, 쌀 수량 및 도정형질의 변화

This experiment was conducted to evaluate the differences in physicochemical properties of soil, grain yield and milling recovery ratio and grain appeareance of rice grown in long-term no-till and ordinary till systems. The paddy in no-till rice system was unploughed but straw-mulched for 15years from 1988 to 2002 at the Experimental Paddy of Gyeongnam Agricultural Reserch and Extension Services, while the paddy in ordinary till system was ploughed and puddle every crop year. A 5cm organic layer was formed in 11-year no-till rice system, in which exchangeable cation and phosphate were accumulated. In no-till paddy organic matter, bulk density and solid phase of surface soil significantly increased, while pH, exchangeable cation, phosphatw, liquid and gaseous, phases deereased. Tillage made the very top soil soft, but made deep soil below 5cm significantly hard. In the 1st year of no-till, topsoil showed hard, but in the process of the time in no-till system, the top-and sub soil showed softer. Yield and yield components of rice showed no differences between till-and no-till rice systems. Milling recovery ratio and grain appearance were not significantly different between no-till and till-rice systems.