Aufsatz
Precision mapping
(Design and testing of a Global Positioning System-based radiometer for precision mapping of pearl millet total dry matter in the Sahel)
Abstract
The nondestructive determination of plant total dry matter (TDM) in the field is greatly preferable to the harvest of entire plots in areas such as the Sahel where small differences in soil properties may cause large differences in crop growth within short distances. Existing equipment to nondestructively determine TDM is either expensive or unreliable. Therefore, two radiometers for measuring reflected red and near-infrared light were designed, mounted on a single wheeled hand cart and attached to a differential Global Positioning System (GPS) to measure georeferenced variations in normalized difference vegetation index (NDVI) in pearl millet fields [Pennisetum glaucum (L.) R. Br.]. The NDVI measurements were then used to determine the distribution of crop TDM. The two versions of the radiometer could (i) send single NDVI measurements to the GPS data logger at distance intervals of 0.03 to 8.53 m set by the user, and (ii) collect NDVI values averaged across 0.5, 1, or 2 m. The average correlation between TDM of pearl millet plants in planting hills and their NDVI values was high (r^2 = 0.850) but varied slightly depending on solar irradiance when the instrument was calibrated. There also was a good correlation between NDVI, fractional vegetation cover derived from aerial photographs and millet TDM at harvest. Both versions of the rugged instrument appear to provide a rapid and reliable way of mapping plant growth at the field scale with a high spatial resolution and should therefore be widely tested with different crops and soil types.
Citation
In: Agronomy journal. Madison, Wis. : American Society of Agronomy. 92.2000, S. 1086-1095Collections
Publikationen (Fachgebiet Ökologischer Pflanzenbau und Agrarökosystemforschung in den Tropen und Subtropen)Citation
@article{urn:nbn:de:hebis:34-2007020917138,
author={Lawrence, Peter R. and Gérard, Bruno and Moreau, Caroline and Lhériteau, Fabrice and Bürkert, Andreas},
title={Precision mapping},
year={2000}
}
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2007-02-09T10:39:09Z 2007-02-09T10:39:09Z 2000 1435-0645 0002-1962 urn:nbn:de:hebis:34-2007020917138 http://hdl.handle.net/123456789/2007020917138 233764 bytes application/pdf eng Urheberrechtlich geschützt https://rightsstatements.org/page/InC/1.0/ 630 Precision mapping Aufsatz The nondestructive determination of plant total dry matter (TDM) in the field is greatly preferable to the harvest of entire plots in areas such as the Sahel where small differences in soil properties may cause large differences in crop growth within short distances. Existing equipment to nondestructively determine TDM is either expensive or unreliable. Therefore, two radiometers for measuring reflected red and near-infrared light were designed, mounted on a single wheeled hand cart and attached to a differential Global Positioning System (GPS) to measure georeferenced variations in normalized difference vegetation index (NDVI) in pearl millet fields [Pennisetum glaucum (L.) R. Br.]. The NDVI measurements were then used to determine the distribution of crop TDM. The two versions of the radiometer could (i) send single NDVI measurements to the GPS data logger at distance intervals of 0.03 to 8.53 m set by the user, and (ii) collect NDVI values averaged across 0.5, 1, or 2 m. The average correlation between TDM of pearl millet plants in planting hills and their NDVI values was high (r^2 = 0.850) but varied slightly depending on solar irradiance when the instrument was calibrated. There also was a good correlation between NDVI, fractional vegetation cover derived from aerial photographs and millet TDM at harvest. Both versions of the rugged instrument appear to provide a rapid and reliable way of mapping plant growth at the field scale with a high spatial resolution and should therefore be widely tested with different crops and soil types. open access Design and testing of a Global Positioning System-based radiometer for precision mapping of pearl millet total dry matter in the Sahel In: Agronomy journal. Madison, Wis. : American Society of Agronomy. 92.2000, S. 1086-1095 Lawrence, Peter R. Gérard, Bruno Moreau, Caroline Lhériteau, Fabrice Bürkert, Andreas Sahel Perlhirse Trockenmasse GPS <Satellitengeodäsie> Kartierung
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