Submitted to: European Conference on Precision Agriculture Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/16/2003
Publication Date: 10/2/2003
Citation: Beesley, B., Carbone, G., Sadler, E.J., Camp, C., Evans, D.E., Millen, J.A. 2003. Using high resolution satellite imagery to detect spatial variability in corn. European Conference on Precision Agriculture Proceedings. p. 359-360. (CD-ROM)
Technical Abstract: Improved knowledge about spatially-varying crop response to irrigation and fertilizer application could improve field management and productivity. This study evaluates the use of high-resolution satellite imagery to detect differences in corn response to varying irrigation and nitrogen application. It complements a series of multi-year experiments investigating how spatial differences in soil type, irrigation, and fertilizer application interact to affect corn yield in a U.S. Atlantic Coastal Plain field. In these experiments, four irrigation treatments and two nitrogen treatments were used on twelve soil mapping units. Vegetation indices were computed from 4-meter multispectral IKONOS satellite imagery collected on 3 July 2000. We examined these indices with respect to the eight possible irrigation/fertilizer treatment classes and twelve soil types. We found that a simple infra-red to red ratio showed significant higher greenness values for corn with a nitrogen application rate of 225 kg/ha N versus 134 kg/ha. Additionally, greenness was higher for corn irrigated at 50% and 100% of the rate necessary to keep soil water constant, compared with rain fed corn. However, we found no significant difference in greenness between sample plots with an irrigation application of 150% of the rate required to maintain constant soil water versus 100% of the rate required to keep soil water constant. The specific relationships between greenness and irrigation or nitrogen application varied as a function of soil type.