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土壤速效磷含量近紅外光譜田間快速測(cè)定方法
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“十二五”國(guó)家科技支撐計(jì)劃資助項(xiàng)目(2012BAH29B00)


Detection of Soil Available P Content Based on Near Infrared Spectra
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    摘要:

    為實(shí)現(xiàn)對(duì)土壤速效磷含量的快速測(cè)定,,以關(guān)中塿土為材料,,研究基于光譜分析的土壤速效磷含量測(cè)定方法,。首先用便攜式近紅外頻譜儀在不同采樣高度下,采集土壤樣本900~1700nm波長(zhǎng)范圍的漫反射光譜,,采用3倍標(biāo)準(zhǔn)差準(zhǔn)則和主成分分析得分圖對(duì)異常樣本進(jìn)行判別和剔除,,然后對(duì)比分析4種波長(zhǎng)選擇方法對(duì)建模效果的影響,發(fā)現(xiàn)基于穩(wěn)定的競(jìng)爭(zhēng)性自適應(yīng)加權(quán)抽樣法的結(jié)果最佳,,最后通過(guò)分析不同非線性建模方法對(duì)預(yù)測(cè)結(jié)果影響實(shí)驗(yàn),,探明最小二乘支持向量機(jī)方法的預(yù)測(cè)結(jié)果最好。實(shí)驗(yàn)結(jié)果表明,,采樣高度為10cm時(shí)本文建立模型的土壤速效磷含量預(yù)測(cè)決定系數(shù)為0.8581,,均方根誤差為10.8801,具有較高的精度,,可對(duì)土壤速效磷含量進(jìn)行快速預(yù)測(cè),。

    Abstract:

    The aim of this research is to realize the rapid measurement of soil available P content. The suitable proportion of available P could promote the crops grow. Taking ‘Lou’ soil as sample, the soil diffusion reflectance spectrum in 900~1700nm under different observation heights were collected by using the portable spectrographs. Firstly, five observation heights (5, 7, 10, 12, 15cm) were compared, and 10cm was considered to be the best. The abnormal samples were identified and eliminated by using 3 times standard deviation and principal component analysis method. That effectively improved the model precision. Then, the effect of four different wavelengths selecting methods (SPA, CARS, sCARS, RF) on modeling was analyzed. The result showed that sCARS was the best. Finally,the different nonlinear modeling methods (RBF neural network, WNN, LSSVM) were experimented. The results proved that LSSVM had the best result. When the observation height was 10cm, the modeling prediction correlation coefficient was 0.8581, and the prediction root mean square error was 10.8801. The results showed a high accuracy and feasibility of soil available P content prediction.

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何東健,陳 煦,任嘉琛,王梅嘉.土壤速效磷含量近紅外光譜田間快速測(cè)定方法[J].農(nóng)業(yè)機(jī)械學(xué)報(bào),2015,46(3):152-157. He Dongjian, Chen Xu, Ren Jiachen, Wang Meijia. Detection of Soil Available P Content Based on Near Infrared Spectra[J]. Transactions of the Chinese Society for Agricultural Machinery,2015,46(3):152-157.

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  • 收稿日期:2014-07-22
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  • 在線發(fā)布日期: 2015-03-10
  • 出版日期: 2015-03-10
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