【目的】利用实时冠层反射光谱监测夏玉米植株氮素营养状况并推荐氮肥追用量,以实现玉米的高产、高效生产。【方法】研究于2012-2013年分别在洛阳嵩县试验站和延津试验站采用大田试验方法,基于不同基施氮量处理,通过冠层光谱测定计算夏玉米拔节期的差值植被指数,建立植株氮积累量估测模型,进而根据构建的氮肥调控模型确定玉米调控施氮量,并研究氮肥调控处理的生理效应。【结果】不同基施氮量处理下的玉米植株在氮肥调控前(拔节期)随着施氮量的增加处理间的生理指标差异明显。乳熟期氮肥调控处理的LAI、叶片氮含量、干物质量和氮素积累量较常规施氮处理分别提高2.2%、4.3%、5.7%和 8.7%。与常规施氮处理相比,调控处理的籽粒产量提高10.03%,氮肥利用率提高11.37%；氮肥农学效率和氮肥偏生产力也有明显提高。根据追氮调控模型,不同调控处理的总施氮量均控制在240-280ka/hm2之间,不仅有效改善了由于氮肥不足及氮肥过量造成的作物减产和环境污染问题,而且使净收入增加1989元/hm2。【结论】与传统常规施肥相比,氮肥调控处理的氮肥利用率和玉米产量有明显增加。
英文摘要:
【Objective】 The objective of the study is to estimate nitrogen (N) status of maize plant and recommend top-dressing N amount based on canopy reflectance spectra, so as to achieve higher yield and higher economic efficiency.【Method】From 2012 to 2013year, several field experiments with different levels of N applicatio were performed to studied in experimental station of Luoyang province Song county and experimental station of Yanjing. Established estimation modes of plant nitrogen accumulation based on differential vegetation index (DVI), and to the amounts of nitrogen fertilizer recommended for top-dressing of different treatments with varied basal N rates were calculated. Then study on the physiological effects of nitrogen regulation treatment.【Result】 The results showed that plants traits of different treatments with varied basal N rates had obvious differences at the in joining stage. Compared with the conventional nitrogen treatment, LAI, leaf nitrogen content, dry matter quality and ______________
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