Submitted to: Soil and Water Conservation Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: January 20, 2005
Publication Date: July 22, 2005
Citation: Daughtry, C.S.T., Doraiswamy, P.C., Stern, A.J., McMurtrey, J.E., Hunt, E.R. 2005. Assessing crop residue cover and soil tillage intensity [abstract]. Soil and Water Conservation Society Proceedings, Soil Water Conservation Society. 2005 CDROM. Technical Abstract: Crop residue management plays an important role in controlling soil erosion and determining soil organic carbon. Current methods of quantifying crop residue cover are inadequate for characterizing the spatial variability of residue cover within fields and across large regions. Our objectives were to evaluate several spectral indices for measuring crop residue cover and to categorize soil tillage intensity in agricultural fields based on crop residue cover. Hyperspectral data over the 400-2500 nm wavelength region were acquired with ground-based, airborne (AVIRIS), and satellite (Hyperion) sensors. Broad absorption features near 2100 nm and 2300 nm in the reflectance spectra of crop residues were associated with cellulose and lignin. However, these features were absent in the spectra of green vegetation and soils. Crop residue cover was linearly related to the Cellulose Absorption Index (CAI), which was defined as the relative depth of the 2100 nm absorption feature. Other spectral indices for crop residue were also evaluated. The best spectral indices for assessing residue cover were based on relatively narrow (10-50 nm) bands in the 2000-2400 nm region. Regional surveys of management practices that affect soil conservation and soil carbon dynamics may be feasible using advanced imaging systems.