机构地区:[1]中国农业大学农学与生物技术学院 [2]青岛市农业技术推广站,青岛266071
出 处:《生态学报》2006年第7期2275-2280,共6页Acta Ecologica Sinica
基 金:国家"863"资助项目(2002AA6Z3201);国家自然科学基金资助项目(30471015)~~
摘 要:在冬小麦-夏玉米一年两熟模式下,玉米品种“郑单958”(植株密度9株/m^2)和小麦品种“93-9”(基本苗704株/m^2),冬小麦基施144kg N/hm^2,研究了玉米5个施N量(0、90、180、270和360kg/hm^2)对后茬小麦期间土壤剖面硝态氮含量、无机氮总量,以及小麦氮素吸收利用和产量的影响.结果表明:(1)与不施氮相比,玉米施氮显著增加小麦季0~200cm土壤硝态氮含量;自拔节起,0~40cm、0~130cm和0~200cm硝态氮含量均随施氮量增加而递增,在硝态氮含量较高的小区增幅也大.(2)轮作一周期后,不施氮和施氮360kg/hm^2显著影响0~130cm和0~200cm无机氮总量,但在90~270 kg/hm^2之间,施氮量的影响不明显.(3)施氮小于180kg/hm^2时,成熟期小麦植株氮素和籽粒氮素积累量、氮肥利用率均随施氮量增加而递增,但不明显.(4)与不施氮相比,施氮90kg/hm^2的小麦产量和麦玉轮作总产均增加但不明显,施氮180 kg/hm^2均显著增加,施氮270kg/hm^2与180kg/hm^2无明显差异.本试验条件下,夏玉米施氮90~180 kg/hm^2是适宜的.Continuous applying N at high rate in crop production in China resulted in increasing basal soil N content and decreasing N fertilizer use efficiency. Moreover, it caused severe underground water pollution in many areas. Therefore, how to optimal use N fertilizer was facing scientists. There were lots of researches on the nitrate dynamics with N fertilizer treatments during winter wheat-summer maize rotation system, especially during summer-maize season. Due to high variation of rainfall and temperature during maize growth season in China, it was difficult to determine the optimal N fertilizer rate applied to maize only by studies on relationship of maize N requirements and soil nitrate dynamics. The objective of this study was to understand the effect of N rates applied to maize on soil nitrate content and crop yield during winter wheat growth season. A field trial with the summer maize-winter wheat rotation was carried out in Huang-Huai-Hai Plain, North China, in 2002 - 2003. Five rates of nitrogen fertilizer (i .e. 0, 90, 180, 270 and 360 kg N hm^-2) were applied to maize with high-yield hybrid "Zhengdan 958" and the population of 9 plants m^-2. 2/3 of the total N fertilizer was applied at sowing stage and 2/3 of that at 10-unfolded leaf stage. Mter maize harvest, wheat as the following crop was planted in former crop plots with cuhivar “97-3” and seed rate of 704 grain m^-2. N rate of 144 kg hm^-2 was applied at wheat sowing. Except for precipitation of 112.1 mm during wheat season,two times of irrigation with 75 mm at each time were done on April 13, and May 9, 2003, respectively. The trial was completely randomized design with three replicates. Plot size was 6 m by 6 m. The vocation between maize harvest and wheat sowing was 15 days. The soil in the trial field was light salted loam in 0 - 130 cm soil layers and loam in 130 - 200 cm soil layers. There was just ploughed during the vocation of the cropping system. In addition to N fertilizer, P2O5 and K2O were dressed on the day of maize sow
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