Abstract:

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.