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中国农学通报 ›› 2014, Vol. 30 ›› Issue (18): 49-54.doi: 10.11924/j.issn.1000-6850.2013-2912

所属专题: 水稻

• 农学 农业基础科学 • 上一篇    下一篇

基于高光谱的水稻土有机质含量估算研究

卢 岩 孙成明   

  • 收稿日期:2013-11-07 修回日期:2013-12-20 出版日期:2014-06-25 发布日期:2014-06-25
  • 基金资助:
    扬州大学大学生实践创新训练计划“土壤有机质高光谱模型预测与检验”(B12118);江苏高校优势学科建设工程资助项目“南方草山草坡生态系统碳源汇形成机理及碳储量优化计算方法研究”(2011-05)。

Estimation of Organic Matter Content in Paddy Soil Based on Hyperspectrum

  • Received:2013-11-07 Revised:2013-12-20 Online:2014-06-25 Published:2014-06-25

摘要: 利用高光谱技术可实现土壤有机质含量的快速、精确反演。然而运用不同的光谱预处理算法及建模方法获取的模型预测精度及稳定性不同。为了选取最佳土壤有机质估算模型,本研究应用ASD波谱仪测定河南省潢川县水稻土的光谱数据,比较使用2种建模方法组合18种光谱预处理转换算法建立模型的反演效果。对于多元逐步回归模型和偏最小二乘模型,使用SGF3-2预处理算法均获得了最佳的预测效果,所建模型具有较小的误差和较高的精度。相比使用多元逐步回归法,使用偏最小二乘回归法可以获取更稳定的预测模型。运用偏最小二乘模型结合SGF3-2预处理算法得到了最佳的水稻土有机质含量估算模型,模型预测均方根误差RMSEv=0.036,决定系数Rv2=0.89。选择最佳的建模方法结合预处理算法,可以改进模型反演精度。本研究对比的不同方法也可以应用到类似的土壤模型选取中。

关键词: 谷子, 谷子, 萌芽期, 抗旱性鉴定, 萌发抗旱指数

Abstract: The content of soil organic matter (SOM) could be obtained rapidly and accurately by using hyperspectral technology. But the model accuracy and stability are different by using different pre-processing transformations and multivariate techniques. In order to identify the best model to predict SOM, in this experiment, the spectral data of paddy soil in Huangchuan County of Henan Province was measured using ASD FieldSpec 3 Hi- Res hyperspectral meter, two multivariate techniques (Multiple Stepwise linear Regression (MSLR), Partial Least Squares Regression (PLSR)) and eighteen pre-processing transformations of spectra data were compared with the aim of identifying the predictive effects of SOM. The results showed that the SavitzkyGolay first derivative using binomial polynomial and three smooth points (SGF3- 2) was the best preprocessing transformation method,either using the MSLR model or PLSR model the predictive model had both low errors and high accuracy. Compared to using MSLR method, the use of PLSR method can obtain more robust prediction model. The combination of PLSR multivariate technique and SGF3- 2 pre- processing transformation provided the best prediction model with the root mean square error for the validation set RMSEv=0.036 and coefficient determination for the validation set Rv2 =0.89. To choose the suit multivariate technique combined with pre-processing transformation can improve model accuracy. These different methods used in this study can also be applied to similar soil models for selection.