【摘要】 【目的】以寒地5个粳稻品种为试验材料,研究实地氮肥管理的增产机理。【方法】2004和2005年,通过农民习惯施肥和实地氮肥管理的大田对比试验和不同SPAD阈值的小区试验,探讨实地氮肥管理对水稻群体质量、干物质积累规律和氮积累的影响。【结果】与农民习惯施肥相比,实地氮肥管理使氮肥总量平均减少了33.8%,水稻成穗率平均提高了12.3%(P<0.05),灌浆期水稻叶面积指数提高了14.1%～27.6%(P<0.05),抽穗期以后水稻干物质增加了4.3%～29.1%,抽穗后干物重与产量呈极显著正相关关系(P<0.01),产量平均增加了9.8%;抽穗后氮积累量增加了11.8%～55.1%(P<0.05),氮肥吸收利用率和农学利用率分别提高了38.5%～133.4%(P<0.05)和39.78%～194.26%(P<0.05)。【结论】该技术通过改善水稻群体质量,增加抽穗后LAI,促进干物质和氮积累,增加水稻产量和氮肥利用率。更多还原

【Abstract】 【Objective】Using 5 rice varieties in cold areas,the effects of increasing yield and mechanism of site-specific nitrogen management(SSNM) were studied;【Method】Scientists conducted research on critical SPAD value and experiments of two fertilization methods,SSNM and farmer’s fertilization practice(FFP).These were done to study the effects on rice population quality and dry matter accumulation of rice,as well as N uptake;【Result】compared with FFP,SSNM significantly decreased the average N rate by 33.8%,significantly increased average earbearing tiller rate and LAI after grain filling stages by 12.3% and 14.1%-27.6%.It also improved dry matter weight and N uptake after heading period by 0.4%-29.1% and 11.8-55.1%(P<0.05),and heightened recovery efficiency and agronomic efficiency by 38.5%~133.4%(P<0.05) and 39.78%-194.26%(P<0.05),respectively.It increased the average yield by 1.1%-33.3% in 2004 and 2005.【Conclusion】The results suggested that accumulation rate of dry matter and N makes rice yield and N use efficiency increase because of improving rice population and increasing LAI after heading period.更多还原