浙江农业学报 ›› 2019, Vol. 31 ›› Issue (9): 1523-1530.DOI: 10.3969/j.issn.1004-1524.2019.09.17

• 环境科学 • 上一篇    下一篇

基于可见-近红外光谱预处理建模的土壤速效氮含量预测

方向, 金秀, 朱娟娟, 李绍稳*   

  1. 安徽农业大学 信息与计算机学院,智慧农业技术与装备安徽省重点实验室,安徽 合肥 230036
  • 收稿日期:2019-04-28 出版日期:2019-09-25 发布日期:2019-10-11
  • 通讯作者: *李绍稳,E-mail: shwli@ahau.edu.cn
  • 作者简介:方向(1995—),男,安徽舒城人,硕士研究生,主要从事土壤速效养分高光谱检测研究。E-mail: 2928676905@qq.com
  • 基金资助:
    农业部948项目(2015-Z44,2016-X34)

Prediction of soil available nitrogen content based on visible and near infrared spectroscopy preprocess and modeling

FANG Xiang, JIN Xiu, ZHU Juanjuan, LI Shaowen*   

  1. Anhui Province Key Laboratory of Intelligent Agriculture Technology and Equipment, School of Information & Computer, Anhui Agricultural University, Hefei 230036, China
  • Received:2019-04-28 Online:2019-09-25 Published:2019-10-11

摘要: 以皖南地区采集的188份黄红壤样本为研究对象,利用地物非成像光谱仪获取原始光谱数据。首先,分析样本在350~1 657 nm波段经过预处理变换的平均光谱反射率曲线特征,再基于原始光谱,以及经29种预处理变换后的光谱,分别结合偏最小二乘回归(PLSR)和径向基核函数(RBF)-PLSR算法,建立60个针对土壤速效氮含量的预测模型,并进行模型优化;然后,以模型的决定系数(R2)和相对分析误差(RPD)来评价模型性能。结果显示,基于Savitaky-Golay卷积平滑和对数变换预处理的光谱,用PLSR建立的模型最适用于土壤速效氮含量的校正预测,其在建模集中R2=0.94、RPD=3.88,预测集中R2=0.91、RPD=3.38。该模型达到A类预测精度,可实现对土壤速效氮含量的定量估测。

关键词: 高光谱分析, 土壤速效氮, 预处理, 模型

Abstract: In the present study, 188 yellow-red loam soil samples were collected in Southern Anhui, and the original spectrum was obtained by non-imaging spectrometer. Firstly, the characteristics of the average spectral reflectance curve at 350-1 657 nm were analyzed after preprocessing. Based on the original spectrum and spectra after 29 preprocesses, a total of 60 models were constructed either by partial least squares regression (PLSR) or radial basis function (RBF)-PLSR, and the constructed models were optimized and evaluated by the models' decision coefficient (R2) and relative percent deviation (RPD). It was shown that the PLSR model constructed on spectra after Savitaky-Golay filtering and log transformation (SG+LG/PLSR model) was most suitable for the prediction of soil available nitrogen content. Its R2 and RPD were 0.94 and 3.88 in calibration set and were 0.91 and 3.38 in prediction set, which belonged to A level, and indicated that this model was feasible for soil available nitrogen content prediction.

Key words: hyperspectral analysis, soil available nitrogen, preprocessing, model

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