| Autor: |
Sumner, Zachary Thomas |
| Předmět: |
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| Zdroj: |
Theses and Dissertations. |
| Druh dokumentu: |
Text |
| Popis: |
Single-rate blanket application of fertilizer nitrogen (N) can result in an over or under application. Variable rate (VR) applications tailored to actual crop demands can improve N use efficiency in spatially variable soils. The objective of this study was to compare and improve relationships derived between corn canopy reflectance and corn N status acquired with two sensing platforms. Four fertilizer N rates were used, from deficient to excess, to create varying corn N status. Sensing and biophysical sampling was taken throughout the season for analysis and comparison to calculated vegetation indices (VIs). Results show strong relationships between VIs and corn N concentration and the strongest found using combined indices that incorporate the red-edge wavelength (720 nm). Relationships strengthened at latter growth stages. Results and models from this study demonstrate the utility of using remote sensing technologies to more accurately predict corn N status for eventual use in VR prescription development. |
| Databáze: |
Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
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