Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: April 4, 2002
Publication Date: July 15, 2002
Citation: Hunt,E.R., Daughtry, C., McMurtrey, J., Walthall, C., Liang, S., 2002. Comparison of remote sensing imagery for nitrogen management. In: Proceedings of 6th International Conference on Precision Agriculture, July 14-17, 2002, Minneapolis, Minnesota.
Different types of remotely sensed imagery are available and many claims have been made about the usefulness of these data for nutrient management. We set up an experiment at the Beltsville Agricultural Research Center, with three planting dates of corn with 5 levels of applied nitrogen. Color infrared photographs with a pixel size of 0.5 m, taken from radio- controlled model aircraft, showed strong relationships between vegetation indices and density, but no relationships with applied nitrogen. AISA Airborne Imaging Spectrometer data with pixel sizes of 4 m showed relationships with both density and applied nitrogen, because of the additional bands on the AISA sensor. These findings were replicated with low-altitude Airborne Visible Infrared Imaging Spectrometer (AVIRIS) data (4 m pixels), but not with high altitude AVIRIS data (20 m pixels), but this was in part explained by earlier date of acquisition. Because most vegetation indices are highly correlated, there needs to be more than 3 or 4 bands in a sensor to separate out nitrogen deficiency from differences in plant density.