Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 15, 2002
Publication Date: June 1, 2003
Citation: Hunt, E.R., Daughtry, C.S., McMurtrey, J.E., Walthall, C.L., Baker, J.A., Schroeder, J.C., Liang, S. 2003. Comparison of remote sensing imagery for nitrogen management. In: P.C. Robert, editor. Proceedings of the Sixth International Conference on Precision Agriculture 2002. [CDROM].
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 maize with five levels of applied nitrogen. Color infrared photographs with a pixel size of 0.2 m, taken from a radio-controlled model aircraft in August, showed strong relationships between vegetation indices and plant density, but no relationships with applied nitrogen. AISA Airborne Imaging Spectrometer data with pixel sizes of 2.5 m showed relationships with both density and applied nitrogen in August, because of the additional bands on the AISA sensor. Because most vegetation indices are highly correlated, there needs to be more than 3 or 4 broad bands in a sensor to separate out nitrogen deficiency from differences in plant density.