【摘要】 以大豆品种东农52为试材,采用裂区设计,设置3个密度和3种施氮方式,研究了启动氮加追氮对不同密度大豆氮素吸收的影响。结果表明:相同密度下,启动氮加追氮处理与氮作基肥一次施用相比,R5期后氮积累量和氮同化贡献率显著增加,其中25万株.hm-2密度下启动氮加R4追氮处理的氮积累量增加109.5%(P<0.01)。相同施肥条件下,R5期前氮积累量随密度增加而增加,而R5期后启动氮加R4追氮处理25万株.hm-2密度下的氮素积累量较20和30万株.hm-2分别增加27.4%和16.0%(P<0.05)。R5期后氮积累量和氮同化贡献率与产量呈极显著正相关。25万株.hm-2密度下启动氮加R4追氮处理获得了最高产量,与其它各处理相比提高了9.1%～25.6%(P<0.05)。更多还原

【Abstract】 A split-plots designed field experiment with three densities and three N treatments using soybean cv.Dongnong 52 was conducted to study the effects of starter-N plus top-dressing N on N absorption of soybean under different densities.Results showed that N accumulation and contribution rate of N assimilation after R5 of starter-N plus top-dressing N treatment increased significantly compared to those of using N only as basal fertilizer under same density.N accumulation after R5 of starter-N plus top-dressing N at R4 was 109.5% higher than using N only as basal fertilizer(P < 0.01) under the density of 250 000 plants.ha-1.When N was equally applied among treatments,N accumulation before R5 increased with higher density,but N accumulation after R5 of starter-N plus top-dressing N at R4 under the density of 250 000 plants.ha-1 was 27.4% and 16.0% higher(P < 0.05) than 200 000 and 300 000 plants.ha-1,respectively.The highest yield was achieved by starter-N plus top-dressing N at R4,yield of which was 9.1%-25.6% higher than other treatments(P < 0.05).更多还原