The USDA Agricultural Research Station-Hydrology and Remote Sensing Laboratory (ARS-HRSL) had developed a remote sensing method capable of measuring crop residue cover. This method utilized the cellulose absorption index (CAI) at the short wave infrared region of the spectrum to differentiate soil from plant residues. The method worked well in humid areas in Iowa, where it was calibrated and tested, but it had not been tested in the ecologically fragile, semi-arid conditions of the Northern Great Plains (NGP) region. The effectiveness of CAI in differentiating crop residue from soil was affected by different soil and residue moisture levels and soil spectral properties, and needed to be evaluated in the NGP agricultural setting. This [...]