Waveband selection for determination of nitrate in soil using mid-infrared attenuated total reflectance spectroscopy.
This paper investigates the possibility of determining nitrate concentration in soil pastes using spectral absorbance at several fixed wavebands. A three-step procedure for determining the most appropriate wavebands, as well as their width, is described. This procedure is applied to a dataset that includes eleven soils with various nitrate concentrations ranging from 0 to approximately 150 mg [N]/kg [dry soil]. The results show that nitrate concentration can be determined quite acceptably using only four 12 cm(-1) wide wavebands, centered at 1280, 1330, 1379, and 1430 cm(-1). The prediction errors range from approximately 1.5 to 14.0 mg [N]/kg [dry soil], depending on soil composition and moisture content, with the lighter and more vulnerable (pollution-wise) soils having errors inferior to 10 mg [N]/kg [dry soil]. These results are similar to results obtained by applying partial least square to the 'continuous' spectrum, and indicate that the development of a soil nitrate attenuated total reflectance (ATR) sensor based on a few fixed mid-infrared (MIR) wavebands could be considered.
Linker
Raphael
R
Faculty of Civil and Environmental Engineering, Lowdermilk Division of Agricultural Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
D000383:Agriculture / Q000379:methods*; D005308:Fertilizers; D008962:Models, Theoretical; D009566:Nitrates / Q000032:analysis*; D012044:Regression Analysis; D012987:Soil / Q000032:analysis*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
D005308:Fertilizers; D009566:Nitrates; D012987:Soil