实时氮肥调控对夏玉米产量和氮素利用效率的影响

2012~2013年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。结果表明,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,调控处理的玉米子粒产量提高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240~280 kg/hm2,可改善氮肥不足及氮肥过量造成的作物减产和环境污染问题。

Effects of Real-time Nitrogen Regulation for Yield and Utilization of Summer Maize

From 2012 to 2013, several field experiments with different levels of N application were performed in experimental station of Song county and Yanjing experimental station of Luoyang province. Established estima- tion modes of plant nitrogen accumulation based on differential vegetation index(DVI), to the amounts of nitrogen fer- tilizer recommended for top-dressing of different treatments with varied basal N rates were calculated, and study the physiological effects of nitrogen regulation treatment. 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 nitrogen accumulation amount with the regulation treat- ments were increased by 2.2%, 4.3%, 5.7% and 8.7%, respectively at milk maturity stage. The grain output of the regulation treatments increased by 10.03%, the utilization of nitrogen fertilizer increased by 11.37%, and AE and PEP increased obviously. According to the regulation model of nitrogen fertilizer, the total nitrogen application amount of different regulation treatments was controlled between 240-280 ka/ha. The problem of crop yield reduc- tion and environmental pollution caused by the shortage of nitrogen fertilizer and excessive nitrogen fertilizer was solved.