中国农业科学 ›› 2007, Vol. 40 ›› Issue (9): 1907-1913 .

• 耕作栽培·生理生态 • 上一篇    下一篇

基于光谱指数的冬小麦变量施肥冠层光谱特征研究及产量分析

蒋阿宁,黄文江,赵春江,刘克礼,刘良云,王纪华   

  1. 国家农业信息化工程技术研究中心
  • 收稿日期:2006-09-06 修回日期:1900-01-01 出版日期:2007-09-10 发布日期:2007-09-10
  • 通讯作者: 赵春江

Study on characteristics of wheat canopy reflectance and wheat yield caused by variable nitrogen application based on Spectral index

  

  1. 国家农业信息化工程技术研究中心
  • Received:2006-09-06 Revised:1900-01-01 Online:2007-09-10 Published:2007-09-10

摘要: 【目的】由适时获得的高光谱数据代替传统繁琐的实验室土壤养分测定数据来进行变量施肥,实现冬小麦高产优质的目标。【方法】本研究利用冬小麦起身期和拔节期冠层光谱数据,选用反映冬小麦长势信息的优化土壤调节植被指数(OSAVI,optimization of soil-adjusted vegetation index)和变量施肥模型进行变量施肥管理(变量区),以相邻地块常规非变量(均一)施肥区(对照区)为对照,研究了不同氮肥处理冬小麦冠层光谱特征及其施肥效应。【结果】变量施肥之后两种氮肥处理在敏感波段670 nm和760~900 nm处反射率差异明显,而670nm和760~900nm是氮素和冠层的敏感波段,说明进行变量施肥时,利用基于这两个波段组合的光谱指数OSAVI优于其它波段组合的光谱指数;SAVI不同生育时期的变化情况,反映了变量施肥在调控作物长势及群体结构上的优势;与对照区相比变量区提高产量达378.72 kg•ha-1,并降低了各小区产量之间的变异,变量区土壤硝态氮浓度降低,氮肥利用率提高,生态效益较为明显。【结论】该技术通过改善冬小麦群体质量,延缓了植株衰老,促进干物质和氮积累,增加冬小麦产量和氮肥利用率。

关键词: 冬小麦, 冠层光谱, 变量施肥, 产量

Abstract: This study was to develop the time-specific and time-critical method to overcome the limitations of traditional field sampling methods for variable rate fertilization. Farmers, agricultural managers and grain processing enterprises are interested in measuring and assessing soil and crop status in order to apply adequate fertilizer quantities to crop growth. This paper focused on studying the relationship between vegetation index (OSAVI) and nitrogen content to determine the amount of nitrogen fertilizer recommended for variable rate management in precision agriculture. The uniform rate fertilizer management was chosen as the CK. Analyses revealed that the red edge of the wheat canopy reflectance spectrum had distinct “red shift” and increased red peak in variable-rate zones. The variable-rate nitrogen fertilization reduced the variability of wheat yield and OSAVI and increased wheat yield, compared to uniform rate fertilizer application. There was a big difference for canopy spectral reflectance between two nitrogen application types in wavebands of 670nm and 760-900nm at elongation stage.

Key words: Winter wheat, Spectral, Variable nitrogen application, Yield