杂交中稻、再生稻两季增产的施肥技术研究

为提高杂交中稻、再生稻两季单产，多次试验其施肥技术，结果表明，中稻适当减少基、蘖肥用作穗（粒）肥，使其前期促蘖壮蘖，中期稳长，群体适中，后期个体健壮，抗逆力增强，光合效率和N肥利用率均提高，因此头、二季均较“重底早追施肥法”显著增产，尤其与穗型较小的品种、中苗移栽、穴植双株、适当密植和增施N肥、中期增施K肥等措施并用时效果更佳。N素基、蘖、穗肥比例为5：2：3的两季增产率均高于其他参试8种单项增产措施，起关键作用的是穗（粒）肥，随施N总量增加而提高其所占比例，对两季总产的配合效应愈好。穗（粒）肥施期则根据中期长势长相而定，一般宜在孕穗期或齐穗期施用。

XStudy on the fertilizing technology of increasing grain yield of hybrid mid dle-season rice and ratooning rice

Fertilizing trials were conducted to research the yi eld increaseeffects of hybrid middle-season rice and ratooning rice.Results in dicated that using the decreased fertilizer in establishing and tillering t o booting stages can promote tillering quickly, grow steadiy in middle stage, in c rease resistance to stress and form proper tiller population and healthy plants in late stage. This fertilizing method can also advance photosynthetic rate and nitrogen utilization ratio, increase 1000-grain weight of main rice and rat o oning bud survival rate, promote ratooning bud growth, increase ratooning plants population and spikes, advance main and ratooning rice grain yield. This method s especially suited to the hybrid rice combinations charactered by small spike; While for the treatment transplanted with double seedling per hill, properly in creasing plant density and nitrogen utilization, applying potassium after mi ddle sta ge,the effect was more notable. When nitrogen was applied before transplanting( 50%), tillering （20％） and booting （30％）, the grain yield of main and r atooning rice was higher than those of other eight individual ratooning cultivat ing measures. Appling booting （or grain） fertilizer was the key factor in this fertilizing method, suitable fertilizing time was usually in booting or heading stage according to the growing conditions in middle stage.