Abstract
The use of crop canopy reflectance sensors is being studied intensively in sugarcane crops; however, real-time measurements of plant height provide another possibility for estimating the spatial variability of biomass and nitrogen uptake by the crop during the in-season fertilization period. An ultrasonic proximity sensor system was deployed to measure crop canopy height. The data were combined with commercially available canopy optical reflectance measurements to characterize spatial variability of crop growth in two commercial areas (a sandy soil field and a clay soil field) during two different growing stages. After mapping, ten points in each field were defined to determine plant biomass and N-uptake through manual sampling and traditional measurements. Through the data analysis, a pixel by pixel comparison was performed to relate the interpolated maps obtained using different sensor systems. The ten points in each field were used to relate the actual biomass and N-uptake with the sensor data. It was shown that all correlations were significant and there was a slight indication that canopy reflectance sensing produced a better assessment of crop growth at the earlier growth stage whereas the ultrasonic sensor resulted in more accurate predictions at the later growing stage.
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References
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Aknowledgements
This work would not be possible without the collaboration of São Martinho’s Mill team, Máquinas Agrícolas Jacto and Yara Hanninghof. We also acknowledge the Research and Projects Financing (FINEP) from the Ministry of Science and Technology through the PROSENSAP project for financial support and the National Council for Scientific and Technological Development (CNPq) for providing the doctoral scholarship to the first author.
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Portz, G., Amaral, L.R., Molin, J.P., Adamchuk, V.I. (2013). Field comparison of ultrasonic and canopy reflectance sensors used to estimate biomass and N-uptake in sugarcane. In: Stafford, J.V. (eds) Precision agriculture ’13. Wageningen Academic Publishers, Wageningen. https://doi.org/10.3920/978-90-8686-778-3_12
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DOI: https://doi.org/10.3920/978-90-8686-778-3_12
Publisher Name: Wageningen Academic Publishers, Wageningen
Online ISBN: 978-90-8686-778-3
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