The research on 20 crops of rice in successive 10 years proved that every crop ofrice cultivated with the reduced-tillage broadcast sowing technique with no ploughing butjust harrowing enjoyed a 4.2%~15.4%higher yield as compared with that cultivated withthe fulltillage broadcast sowing technique.The yield increase was due to better panicle andgrain traits ,which were associated with the improvement of the nutrient and physical char-acters of the soil in the tillage layer and the consequent promotion of the...