Articles
Observation systems for monitoring phosphorous flows in water courses in an agricultural environment
Published : 1 February 2022
Abstract
This article presents two strategies implemented in the framework of the AgrHyS (Agro-Hydro Systèmes) observatory to measure large and rapid variations of phosphorous concentrations in the water courses of a small agricultural watershed in Brittany (Kervidy-Naizin, 5 km²). The main aim of this monitoring is to perform the detailed characterization of the temporal dynamics of phosphorous exports.
The first strategy (2007-2021) consists in combining the sampling of the water course with laboratory analysis by colorimetry. The second strategy (2016-2021) measures phosphorous flows by monitoring in situ at high frequency, using an automatic analyzer.
The "laboratory" method provides higher precision analysis for low concentrations. However, it requires a short transfer time for the samples to ensure their conservation, and the monitoring of flood episodes is difficult to carry out whereas the high frequency and in situ method presents a large number of advantages in terms of frequency and constancy. It avoids variable sample storage times and permits monitoring all the floods. Its two main disadvantages are, however, its dependency on the manufacturer’s reagents and its data management system, which requires improvement.
Finally, the comparison of the two methods did not allow us to answer the issue of the accuracy of one method in comparison with the other, regarding the quality of the measure itself. It is therefore necessary to continue the work of comparing the data obtained.
The first strategy (2007-2021) consists in combining the sampling of the water course with laboratory analysis by colorimetry. The second strategy (2016-2021) measures phosphorous flows by monitoring in situ at high frequency, using an automatic analyzer.
The "laboratory" method provides higher precision analysis for low concentrations. However, it requires a short transfer time for the samples to ensure their conservation, and the monitoring of flood episodes is difficult to carry out whereas the high frequency and in situ method presents a large number of advantages in terms of frequency and constancy. It avoids variable sample storage times and permits monitoring all the floods. Its two main disadvantages are, however, its dependency on the manufacturer’s reagents and its data management system, which requires improvement.
Finally, the comparison of the two methods did not allow us to answer the issue of the accuracy of one method in comparison with the other, regarding the quality of the measure itself. It is therefore necessary to continue the work of comparing the data obtained.
References
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