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【目的】膜下滴灌玉米种植模式在松嫩平原西部大面积推广,研究该模式下不同叶龄追施不同氮肥量对玉米的干物质积累、氮肥利用及产量形成的影响,可为建立该种植模式玉米施肥制度提供理论依据。【方法】在底施N60 kg/hm~2、P_2O_590 kg/hm~2和K_2O 120 kg/hm~2的条件下,设置4个追施尿素态氮肥水平处理:0(N0)、40(N40)、90(N90)和140(N140)kg/hm~2,于叶龄指数为30%、45%、60%和75%时,随滴灌进行追施,以不追肥为对照(CK)。测定了不同处理玉米叶片光合效率、干物质积累和运转以及产量,计算了氮肥的利用率。【结果】随着玉米生育进程,在一定施肥范围内(0 150 kg/hm~2),玉米产量、叶面积指数、叶绿素含量、干物质积累、植株氮素积累、氮肥利用率、氮肥农学效率及氮收获指数均随施氮量的增加而增加,当氮肥超过一定数量时(200 kg/hm~2),各指标增加不明显,甚至下降。在叶龄指数为45%时追施90 kg/hm~2氮肥处理,叶面积指数及叶绿素含量分别为6.92和2.69 mg/g,籽粒产量为11957.89 kg/hm~2,干物质积累量、花后同化物输入籽粒量及花后同化物对籽粒的贡献率分别为423.76 g/plant、14451.50 kg/hm~2和85.86%;氮肥利用率、氮肥农学利用率分别为69.10%和38.38kg/kg,显著高于其他处理(P<0.05)。【结论】在松嫩平原西部膜下滴灌种植模式下,在玉米叶龄指数为45%时追施90 kg/hm~2氮肥,可显著提高光合利用率,改善玉米生育后期的氮素吸收和干物质积累并增加产量,提高玉米对氮肥的吸收利用效率。
【Objective】 The objective of this experiment was to popularize corn under the drip irrigation in the western part of the Songnen Plain. The effects of topdressing different nitrogen rates on dry matter accumulation, nitrogen use efficiency and yield formation of maize under different leaf ages were studied. Model corn fertilization system to provide a theoretical basis. 【Method】 Four topdressing urea nitrogen treatments (0 (N0), 40 (N40) were set up under N 60 kg / hm 2, P 2 O 5 590 kg / hm 2 and K 2 O 120 kg / ), 90 (N90) and 140 (N140) kg / hm ~ 2, respectively. When leaf age index was 30%, 45%, 60% and 75%, topdressing with drip irrigation. The photosynthetic efficiency, dry matter accumulation and operation, and yield of different treatment maize leaves were measured, and the utilization rate of nitrogen fertilizer was calculated. 【Result】 With the growth of maize, the yield of maize, leaf area index, chlorophyll content, dry matter accumulation, nitrogen accumulation in plant, nitrogen use efficiency and agronomic efficiency of nitrogen fertilizer within a certain fertilization range (0 150 kg / hm ~ And nitrogen index increased with the increase of nitrogen application rate. When the nitrogen fertilizer exceeded a certain amount (200 kg / hm ~ 2), the indexes increased little or even decreased. When the leaf age index was 45%, topdressing 90 kg / hm ~ 2 nitrogen fertilizer, the leaf area index and chlorophyll content were 6.92 and 2.69 mg / g, respectively, and the grain yield was 11957.89 kg / hm ~ 2. The contents of post-assimilate input grain and post-anthesis assimilate contribution to grain were 423.76 g / plant, 14451.50 kg / hm ~ 2 and 85.86%, respectively. The nitrogen use efficiency and nitrogen agronomy utilization rate were 69.10% and 38.38 kg / kg , Significantly higher than other treatments (P <0.05). 【Conclusion】 Under the condition of drip irrigation under plastic film in the west of Songnen Plain, topdressing 90 kg / hm ~ 2 nitrogen fertilizer at 45% leaf age index could significantly increase photosynthetic efficiency and improve nitrogen absorption and Dry matter accumulation and increase yield, improve corn absorption and utilization of nitrogen efficiency.