利用光谱指数进行冬小麦变量施肥的可行性及其效益评价

The Feasibility and Benefit Evaluate of Variable Nitrogen FertilizationApplication on Winter Wheat Based on Canopies Spectroscopy Parameters

变量施肥技术作为精准农业一个新的发展方向,如果能以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指导变量施肥实践,那将对我国精准农业的发展具有重要的实践意义。研究根据冬小麦起身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)进行变量施肥,对光谱指数(OSAVI)指导变量施肥实践的可行性进行了探讨,结果表明起身拔节期的冠层光谱特征值与产量之间表现出很好的线性相关关系,可以根据起身期的冠层光谱特征值预测当季作物目标产量。对变量施肥效益也做了研究,结果显示通过变量施肥能够改善冬小麦的长势差异状况,显著提高了冬小麦籽粒产量,降低各处理产量之间的变异,但各处理籽粒品质之间的差异却略有增加。

：Among plant nutrients, nitrogen （N） is the most important and essential for growing crops and is also most concerning nutrient element for maintaining healthy environment. In 2001, N fertilizer prices nearly doubled as a result of increased natural gas prices. This was further troubling when considering that the world N use efficiency （NUE） in cereal grain production averages only 33%. Considering these poor use efficiencies and the associated costs of improper management, technological advances are needed to reduce excess nutrient applications. From the last few years, precision agriculture has been used widely as a management tool to maximize yield and to minimize cost. The GPS and GIS technology has been a basis for precision farming and site-specific application of agricultural chemicals and nutrients has been one of the major concerns in precision farming. By applying nitrogen only where it is needed, farmers could optimize yield while minimizing the cost. The ultimate goal of this research is to develop a real-time multispectral sensor that can detect nitrogen deficiency in winter wheat plant using spectral response from plant canopies. This research was conducted to explore the feasibility of using spectral reflectance to predict nitrogen content in winter wheat plant varieties with varying color. The paper presents a statistical analysis on the feasibility of directing variable rate technology with spectrum characteristic parameters （OSAVI） of winter wheat erecting and elongation. Through analysis of OSAVI and yield, the spectrum characteristic parameters was closely correlated to the grain yield, it can be used to determine the in-season predicted grain yield, the result of variable-rate technology revealed that variable-rate technology ameliorated the winter wheat growth condition, improved the total dry biomass and yield, decreased the variety of yield and increased the winter wheat yield significantly, but it increased the variety of grain quality among each treatments, the protein content and wet gluten were decreased slightly too.