Quantitative Determination of Hydrolytic Nitrogen Content in Soil by Near Infrared Spectroscopy Combined with Competitive Adaptive Reweighted Sampling Variable Selection Algorithm
为了能够快速准确地掌握整个昆明地区土壤水解性氮含量的情况,收集963个不同类型的土壤样品,采用竞争自适应重加权采样(Competitive adaptive reweighted sampling,CARS)变量选择方法筛选波长变量,并建立水解性氮的偏最小二乘法(Partial least squares,PLS)分析模型。结果表明,采用CARS方法优选波长变量后,模型参数有所改善,交互验证标准偏差(Root mean square error of cross validation,RMSECV)由31.63降至25.55,交互验证相关系数(Correlation coefficientof cross validation
In order to quickly and accurately grasp the hydrolytic nitrogen content of soil in the whole Kunming area
963 soil samples of different types were collected.Partial least squares(PLS) combined with competitive adaptive reweighted sampling(CARS) method used to screen the spectral wavelength variables was adopted to establish an analysis model for hydrolytic nitrogen.Results showed that the parameters for the model were improved after the optimization of wavelength variables by CARS
and the root mean square error of cross validation(RMSECV) was reduced from 31.63 to 25.55
the correlation coefficient of cross validation(Rcv) was increased from 0.78 to 0.84
and the external verification results of the model were basically consistent with the internal cross verification results.Meanwhile
near infrared spectroscopy combined with CARS method could be used to effectively establish a near infrared(NIR) mathematical model for hydrolytic nitrogen content in different soil types in Kunming area under the modeling of a large number of representative samples
which is suitable for the NIR detection of other components in soil and has an important guiding significance.