Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 11/20/2005
Publication Date: 11/20/2005
Citation: Daughtry, C.S.T., Doraiswamy, P.C., Hunt, E.R., Prueger, J.H., Vyn, T.J., Bernacchi, C. 2005. Remote sensing crop residue cover and soil tillage intensity [abstract]. American Society of Agronomy, Agronomy Abstracts. 2005 CDROM.
Technical Abstract: Crop residues play important roles in 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 measure crop residue cover and to categorize soil tillage intensity using satellite remotely sensed data. Hyperion imaging spectrometer and Landsat TM data were acquired in May and June 2004 over a test site in central Iowa. In 2005, additional sites were added in Iowa, Illinois, and Indiana. Crop residue cover was measured in corn and soybean fields using line-point transects. Spectral residue indices using Landsat TM bands were weakly related to crop residue cover. With the Hyperion data, crop residue cover was linearly related to the Cellulose Absorption Index (CAI), which is the relative intensity of cellulose and lignin absorption features near 2100 nm. Coefficients of determination (r2) for crop residue cover as a function of CAI were 0.85 for the May and 0.77 for the June 2004 Hyperion data. Three tillage intensity classes, corresponding to intensive (<15% residue cover), reduced (15-30% cover), and conservation (>30% cover) tillage, were correctly identified in 66-68% of fields. Classification accuracy increased to 80-82% for two classes, i.e., conventional (intensive + reduced) and conservation tillage. By combining information on previous season's (2003) crop classification with crop residue cover after planting in 2004, an inventory of soil tillage intensity by previous crop type was generated for the whole Hyperion scene. Analyses of the 2005 data are underway and will be presented. Regional surveys of soil management practices that affect soil conservation and soil carbon dynamics are possible using advanced multispectral or hyperspectral imaging systems.