一种林地土壤氮磷钾含量快速测定的新方法

为实现林地土壤肥力的快速监测，笔者提出一种基于可见/近红外光谱技术，同时进行杉木林土壤全氮、全磷与全钾测定的新方法。以FieldSpec?3地物光谱仪采集杉木林土壤48份，随机分成校正集（32份）和检验集（16份）。光谱采用S.Golay实现平滑去噪与标准归一化进行背景去除后，选取350~2350 nm的反射光谱，以偏最小二乘算法（PLS）建立回归模型。结果表明，3种肥力指标测定模型均具有较高的精度，其校正集R2与预测模型R2分别在0.892与0.884以上。说明以可见/近红外光谱实现土壤中全氮、全磷与全钾的同时测定可行，从而为林地土壤肥力的快速监测提供了一种新方法。

A New Method for Rapid Measurement of N, P, K Contents of Forest Soil

To achieve the rapid monitoring of forest soil fertility, a new method was put forward to measure the total N, total P and total K concurrently by visible/near infrared reflectance spectra. 48 fir soil samples were collected using a FieldSpec?3 visible/near infrared spectrometer. All samples were divided randomly into 2 groups, one group with 32 samples used as calibrated set, and another with 16 samples used as validated set. The original spectra were pretreated by the methods of S.Golay smoothing and standard normal variate, and then the PLS model was established with the spectra in the range of 350~2350 nm. The result showed that the accuracy of the model was high, and the calibration R2 and validation R2 of the total N, P and K models were above 0.892 and 0.884 respectively. The results indicated that it was feasible to measure the total N, P and K contents in fir soil concurrently by visible/near reflectance spectra, and a new method was put forward to monitor the forest soil fertility rapidly.