Biological Systems Engineering
Date of this Version
2002
Citation
APPLIED SPECTROSCOPY Volume 56, Number 11, 2002
Abstract
Near-infrared spectroscopy was evaluated as a means to quantify the nitrogen content- in fresh cotton leaves (Gossypium hirsutum L. var. Delta Pine 90) subjected to a factorial design experiment of varying nitrogen and water applications. Absorbance spectra were collected in the 10000-4000 cm-1 (1000-2500 nm) region from fresh cotton leaves over a two month portion of the growing season. Total nitrogen content was quantified by a wet chemistry Kjeldahl method for validation purposes. Partial least-squares regression analysis, using an automated grid search method, selected the spectral region 6041 to 5651 cm-1 (1650-1770 nm) for analysis based on having the lowest standard error of prediction of total nitrogen content. This region includes protein spectral features. Nitrogen predictions resulted in a correlation coefficient of 0.83, and a standard error of prediction of 0.29% for nitrogen levels ranging from 3.1 to 5.2% total nitrogen. This approach has promise for providing rapid plant chemical analyses for cotton crop fertilization management purposes.
Included in
Bioresource and Agricultural Engineering Commons, Civil and Environmental Engineering Commons
Comments
Copyright 2002 Society for Applied Spectroscopy