Effect of Interplanting with Zero Tillage and Straw Manure on Rice Growth and Rice Quality

The interplanting with zero-tillage of rice, i.e. direct sowing rice 10-20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technology in wheat-rice rotation system. To study the effects of interplanting with zero tillage and straw manure on rice growth and quality, an experiment was conducted in a wheat-rotation rotation system. Four treatments, i.e. ZIS （Zero-tillage, straw manure and rice interplanting）, Zt （Zero-tillage, no straw manure and rice interplanting）, PTS （Plowing tillage, straw manure and rice transplanting）, and PT （Plowing tillage, no straw manure and rice transplanting）, were used. ZtS reduced plant height, leaf area per plant and the biomass of rice plants, but the biomass accumulation of rice at the late stage was quicker than that under conventional transplanting cultivation. In the first year （2002）, there was no significant difference in rice yield among the four treatments. However, rice yield decreased in interplanting with zero-tillage in the second year （2003）. Compared with the transplanting treatments, the number of filled grains per panicle decreased but l000-grain weight increased in interplanting with zero-tillage, which were the main factors resulting in higher yield, tnterplanting with zero-tillage improved the milling and appearance qualities of rice. The rates of milled and head rice increased while chalky rice rate and chalkiness decreased in interplanting with zero-tillage. Zero-tillage and interplanting also affected rice nutritional and cooking qualities. In 2002, ZIS showed raised protein content, decreased amylose content, softer gel consistency, resulting in improved rice quality. In 2003, zero-tillage and interplanting decreased protein content and showed similar amylose content as compared with transplanting treatments. Moreover, protein content in PTS was obviously increased in comparison with the other three treatments. The rice in interplanting with zero-tillage treatments had higher peak viscosity and breakdown, lower setback, showing better rice taste quality. The straw manure had no significant effect on rice viscosity under interplanting with zero-tillage, but had the negative influence on the rice taste quality under transplanting with plowing tillage.