Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: September 9, 2004
Publication Date: November 9, 2004
Citation: Daughtry, C.S.T., Doraiswamy, P.C., Stern, A.J., Hunt, E.R. 2004. Assessing soil tillage intensity [abstract]. American Society of Agronomy Meetings. 2004 CDROM. Technical Abstract: Management of plant litter or crop residues in agricultural fields is an important consideration for reducing soil erosion and increasing soil organic carbon. Current methods of quantifying crop residue cover are inadequate for characterizing the spatial variability of residue cover within fields or across large regions. Our objectives were to evaluate several spectral indices for measuring crop residue cover using ground-based, aircraft, and satellite hyperspectral data and to categorize soil tillage intensity in agricultural fields based on crop residue cover. Reflectance spectra of mixtures of crop residues, green vegetation, and soil were acquired over the 400-2500 nm wavelength region. Broad absorption features near 2100 nm and 2300 nm in the reflectance spectra of crop residues were associated with cellulose and lignin. These features were not evident in the spectra of green vegetation and soils. Crop residue cover was linearly related to the relative depth of the 2100 nm absorption feature. Spectral indices using relatively narrow (10-50 nm) bands correctly identified tillage intensity classes in >90% of the fields at sites in Maryland and Iowa. Regional surveys of soil management practices that affect soil conservation and soil carbon dynamics are possible using advanced imaging systems.