Abstract: With typical rice cultivars as materials,the growth and development characteristics and nutrient uptake in rice under site-specific nitrogen management(SSNM)were studied.SSNM could decrease N rate to a greater extent without any sacrifice in grain yield,when compared with farmers’ fertilizer practice(FFP).Number of productive panicles under SSNM was a little lower than that under FFP,but productive tiller rate was much higher under SSNM.Leaf area index(LAI)and root weight were lower under SSNM than those under FFP before panicle initiation,but the results were reversed after heading stage.SSNM increased efficient and high efficient LAI rates at the heading stage,dry matter accumulation from heading to maturity stage,ratio of root to shoot,photosynthetic rate in flag leaves after heading stage and light transmission rate in rice population at the full heading stage.The uptake peaks of N,P,K under SSNM were all from panicle initiation to heading.During this period,the uptakes of N,P,K were about 45.6%-46.2%,39.6%-43.6%,and 44.2%-45.2% of total at maturity,which were all much higher than those under FFP.Reasons for yield increase and nutrient uptake laws in rice under SSNM were discussed.

Key words: rice, site-specific nitrogen management, yield, growth and development, nutrient uptake

摘要： 以代表性水稻品种为材料，研究了实地氮肥管理模式下水稻的生长发育和养分吸收规律。与农民习惯施肥方法相比，实地氮肥管理在产量不降低甚至有所提高的前提下可以较大幅度地降低施氮量。实地氮肥管理水稻有效穗数有所下降，但其分蘖成穗率明显提高。穗分化前实地氮肥管理水稻叶面积指数和根质量低于农民习惯施肥法，抽穗后结果则相反。实地氮肥管理提高了抽穗期水稻的有效叶面积和高效叶面积的比率、抽穗至成熟的干物质积累、抽穗后根冠比和剑叶的光合速率以及齐穗期群体透光率。实地氮肥管理水稻对氮、磷、钾的吸收高峰均出现在穗分化至抽穗期，此阶段氮、磷、钾的吸收量约占最终总吸收量的45.6%~46.2%、39.6%~43.6％和44.2%～45.2％，均明显高于农民习惯施肥方法。对实地氮肥管理产量提高原因及养分吸收规律进行了讨论。

关键词: 水稻, 实地氮肥管理, 产量, 生长发育, 养分吸收