光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
Spectroscopy and Spectral Analysis
2015年
9期
2516-2520
,共5页
贾生尧%杨祥龙%李光%张建明
賈生堯%楊祥龍%李光%張建明
가생요%양상룡%리광%장건명
近红外光谱%土壤速效磷%速效钾%递归偏最小二乘
近紅外光譜%土壤速效燐%速效鉀%遞歸偏最小二乘
근홍외광보%토양속효린%속효갑%체귀편최소이승
Near infrared spectroscopy%Soil available phosphorus%Available potassium%Recursive partial least squares
土壤速效磷与速效钾在近红外区没有直接与它们相关的吸收峰,只能借助与其他拥有直接吸收峰物质(有机质,碳酸盐,粘土矿物,水分等)之间的相关关系而被近红外光谱技术所预测。这种相关关系会随着土壤样品构成的不同而不断变化,因此采用固定结构的近红外光谱模型很难对速效磷与速效钾取得较好的预测效果。提出采用递归偏最小二乘法(RPLS)在预测过程中递归更新土壤速效磷与速效钾的回归系数,以提高模型的预测能力;比较了偏最小二乘法(PLS),局部加权 PLS(LW-PLS),滑动窗口 LW-PLS(LW-PLS2)和 RPLS 对于土壤速效磷与速效钾含量的预测结果。194份土壤样品根据土壤类型分为建模集与预测集:建模集包含120份人为土样品;预测集则包含29份铁铝土样品,23份人为土样品和22份初育土样品。结果表明:RPLS 模型取得了最优的预测结果,获得的决定系数(R 2)分别为0.61与0.76,预测相对分析误差(RPD)分别为1.60与2.05。说明 RPLS 通过不断更新模型的回归系数,能够适应新加入建模集样品的信息。相比于其他方法,预测精度更高,适用范围更广。
土壤速效燐與速效鉀在近紅外區沒有直接與它們相關的吸收峰,隻能藉助與其他擁有直接吸收峰物質(有機質,碳痠鹽,粘土礦物,水分等)之間的相關關繫而被近紅外光譜技術所預測。這種相關關繫會隨著土壤樣品構成的不同而不斷變化,因此採用固定結構的近紅外光譜模型很難對速效燐與速效鉀取得較好的預測效果。提齣採用遞歸偏最小二乘法(RPLS)在預測過程中遞歸更新土壤速效燐與速效鉀的迴歸繫數,以提高模型的預測能力;比較瞭偏最小二乘法(PLS),跼部加權 PLS(LW-PLS),滑動窗口 LW-PLS(LW-PLS2)和 RPLS 對于土壤速效燐與速效鉀含量的預測結果。194份土壤樣品根據土壤類型分為建模集與預測集:建模集包含120份人為土樣品;預測集則包含29份鐵鋁土樣品,23份人為土樣品和22份初育土樣品。結果錶明:RPLS 模型取得瞭最優的預測結果,穫得的決定繫數(R 2)分彆為0.61與0.76,預測相對分析誤差(RPD)分彆為1.60與2.05。說明 RPLS 通過不斷更新模型的迴歸繫數,能夠適應新加入建模集樣品的信息。相比于其他方法,預測精度更高,適用範圍更廣。
토양속효린여속효갑재근홍외구몰유직접여타문상관적흡수봉,지능차조여기타옹유직접흡수봉물질(유궤질,탄산염,점토광물,수분등)지간적상관관계이피근홍외광보기술소예측。저충상관관계회수착토양양품구성적불동이불단변화,인차채용고정결구적근홍외광보모형흔난대속효린여속효갑취득교호적예측효과。제출채용체귀편최소이승법(RPLS)재예측과정중체귀경신토양속효린여속효갑적회귀계수,이제고모형적예측능력;비교료편최소이승법(PLS),국부가권 PLS(LW-PLS),활동창구 LW-PLS(LW-PLS2)화 RPLS 대우토양속효린여속효갑함량적예측결과。194빈토양양품근거토양류형분위건모집여예측집:건모집포함120빈인위토양품;예측집칙포함29빈철려토양품,23빈인위토양품화22빈초육토양품。결과표명:RPLS 모형취득료최우적예측결과,획득적결정계수(R 2)분별위0.61여0.76,예측상대분석오차(RPD)분별위1.60여2.05。설명 RPLS 통과불단경신모형적회귀계수,능구괄응신가입건모집양품적신식。상비우기타방법,예측정도경고,괄용범위경엄。
Soil available phosphorus (P)and available potassium (K)don’t possess direct spectral response in the near infrared (NIR)region.They are predictable because of their correlation with spectrally active constituents (organic matter,carbonates, clays,water,etc.).Such correlation may of course differ between the soil sample sets.Therefore,the NIR calibration models with fixed structure are difficult to achieve good prediction performances for soil P and K.In this work,the method of recursive partial least squares (RPLS),which is able to update the model coefficients recursively during the prediction process,has been applied to improve the predictive abilities of calibration models.This work compared the performance of partial least squares re-gression (PLS),locally weighted PLS (LW-PLS),moving window LW-PLS (LW-PLS2)and RPLS for the measurement of soil P and K.The entire data set of 194 soil samples was split into calibration set and prediction set based on soil types.The calibra-tion set was composed of 120 Anthrosols samples,while the prediction set included 29 Ferralsols samples,23 Anthrosols sam-ples and 22 Primarosols samples.The best prediction results were obtained by the RPLS model.The coefficient of determination (R 2 )and residual prediction deviation (RPD)were respectively 0.61,0.76 and 1.60,2.05 for soil P and K.The results indicate that RPLS is able to learn the information from the latest modeling sample by recursively updating the model coefficients.The proposed method RPLS has the advantages of wider applicability and better performance for NIR prediction of soil P and K com-pared with other methods in this work.