Abstract: Field experiment was carried out to study the effects of the optimal fertilization practice（OPT） on the growth, yield formation and nitrogen utilization. The results showed as follows: compared with farmer's fertilization practice（FFP）, OPT had more effective panicles, more glume flowers per panicle, higher seed setting rate, and therefore increased the grain yield. OPT reduced ineffective tillers, increased the tiller-earing rate and finally improved the effective panicles. OPT also increased the LAI, the SPAD of the flag leaf, the photosynthetic potentials and the accumulation of photosynthesizes materials. Simultaneously OPT could increase the nitrogen utilization, reduce the soil N dependent rate. In this experiment, OPT still obtained the high and stable yield by use of 80% nitrogen and phosphorus compared to FFP, and realized the fertilizer and pollution decreasement. OPT is an ideal fertilization practice of double-cropping rice.

Key words: double-cropping rice, optimal fertilization practice, growth, yield formation, nitrogen utilization

摘要： 利用田间小区试验，以不施肥和农民习惯施肥模式为对照，研究节肥控污施肥模式对双季稻生长发育、产量形成及氮肥吸收利用等的影响。试验结果表明，节肥控污施肥模式的双季稻的有效穗数、每穗颖花数、结实率均比农民习惯施肥模式有所增加而增产。与农民习惯施肥模式相比，节肥控污施肥模式能减少无效分蘖，提高分蘖成穗率，最终提高成穗数；能提高双季稻中后期的LAI和剑叶SPAD值及光合势，增加光合物质积累量；同时也能提高氮肥利用率，减少稻株对土壤氮素的依赖。本试验中，节肥控污施肥模式可实现在农民习惯施肥模式节氮磷20%的基础上，取得双季稻的高产稳产，实现节肥控污，是双季稻区较为理想的施肥模式。

关键词: 双季稻, 节肥控污施肥模式, 生长发育, 产量形成, 氮素利用