Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2003
Publication Date: November 3, 2003
Citation: Daughtry, C.S., Hunt, E.R., Doraiswamy, P.C., McMurtrey, J.E. 2003. Remote sensing crop residue cover and tillage intensity [CD-ROM]. Agronomy Abstracts. Madison, WI: American Society of Agronomy. Technical Abstract: Conservation tillage practices leave most crop residue on the soil surface and can increase soil organic carbon, improve soil structure, and decrease soil erosion. Inventories of crop residue cover and soil tillage intensity are important inputs for assessing the spatial variability of soil carbon dynamics. Our objectives were to determine the spectral reflectance of mixtures of crop residues and soils and to classify soil tillage intensity using remotely sensed data. Reflectance spectra of green vegetation, crop residue, and soils were measured over the 400-2500 nm wavelength region. The spectra of dry crop residues displayed a broad absorption feature near 2100 nm, associated with cellulose-lignin, that was absent in spectra of soils. Crop residue cover was linearly related to the Cellulose Absorption Index (CAI), which was defined as the relative depth of this absorption feature. Green vegetation cover in the scene attenuated CAI, but was linearly related to the Normalized Difference Vegetation Index (NDVI). A novel method was proposed to assess soil tillage intensity classes using CAI and NDVI and tested using imaging spectrometer data. Remotely sensed classes agreed well with ground observations. Regional surveys of soil conservation practices that affect soil carbon dynamics appear feasible using advanced hyperspectral imaging systems.