Use of radial basis function networks and near-infrared spectroscopy for the determination of total nitrogen content in soils from Sao Paulo State.
Total nitrogen has been determined by using a model developed between the conventional chemical measurements and diffuse reflectance spectra in the near-infrared region. Samples (244) from different types of soils with total nitrogen contents ranging from 0.20 to 13.60% (m/m) were modeled by partial least-squares regression (PLS), multi-layer perceptron feed-forward networks (MLP) and radial basis function networks (RBFN). The RBFN model produced a better square error of prediction (SEP) of 0.048 and R(2) = 0.93 in a procedure that is simpler, faster and less dependent on the initial conditions.
Fidêncio
Paulo H
PH
Universidade Federal do Tocantins, Gurupi, TO, Brazil. fidencio@ufv.br
Poppi
Ronei J
RJ
de Andrade
João C
JC
de  Abreu
Mônica F
MF