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Field-scale monitoring of nitrate leaching in agriculture: assessment of three methods
Deterioration of groundwater quality due to nitrate loss from intensive agricultural systems can only be mitigated if methods for in-situ monitoring of nitrate leaching under active farmers’ fields are available. In this study, three methods were used in parallel to evaluate their spatial and tempor...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer International Publishing
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8648662/ https://www.ncbi.nlm.nih.gov/pubmed/34870763 http://dx.doi.org/10.1007/s10661-021-09605-x |
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author | Wey, Hannah Hunkeler, Daniel Bischoff, Wolf-Anno Bünemann, Else K. |
author_facet | Wey, Hannah Hunkeler, Daniel Bischoff, Wolf-Anno Bünemann, Else K. |
author_sort | Wey, Hannah |
collection | PubMed |
description | Deterioration of groundwater quality due to nitrate loss from intensive agricultural systems can only be mitigated if methods for in-situ monitoring of nitrate leaching under active farmers’ fields are available. In this study, three methods were used in parallel to evaluate their spatial and temporal differences, namely ion-exchange resin-based Self-Integrating Accumulators (SIA), soil coring for extraction of mineral N (Nmin) from 0 to 90 cm in Mid-October (pre-winter) and Mid-February (post-winter), and Suction Cups (SCs) complemented by a HYDRUS 1D model. The monitoring, conducted from 2017 to 2020 in the Gäu Valley in the Swiss Central Plateau, covered four agricultural fields. The crop rotations included grass-clover leys, canola, silage maize and winter cereals. The monthly resolution of SC samples allowed identifying a seasonal pattern, with a nitrate concentration build-up during autumn and peaks in winter, caused by elevated water percolation to deeper soil layers in this period. Using simulated water percolation values, SC concentrations were converted into fluxes. SCs sampled 30% less N-losses on average compared to SIA, which collect also the wide macropore and preferential flows. The difference between Nmin content in autumn and spring was greater than nitrate leaching measured with either SIA or SCs. This observation indicates that autumn Nmin was depleted not only by leaching but also by plant and microbial N uptake and gaseous losses. The positive correlation between autumn Nmin content and leaching fluxes determined by either SCs or SIA suggests autumn Nmin as a useful relative but not absolute indicator for nitrate leaching. In conclusion, all three monitoring techniques are suited to indicate N leaching but represent different transport and cycling processes and vary in spatio-temporal resolution. The choice of monitoring method mainly depends (1) on the project’s goals and financial budget and (2) on the soil conditions. Long-term data, and especially the combination of methods, increase process understanding and generate knowledge beyond a pure methodological comparison. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10661-021-09605-x. |
format | Online Article Text |
id | pubmed-8648662 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Springer International Publishing |
record_format | MEDLINE/PubMed |
spelling | pubmed-86486622021-12-08 Field-scale monitoring of nitrate leaching in agriculture: assessment of three methods Wey, Hannah Hunkeler, Daniel Bischoff, Wolf-Anno Bünemann, Else K. Environ Monit Assess Article Deterioration of groundwater quality due to nitrate loss from intensive agricultural systems can only be mitigated if methods for in-situ monitoring of nitrate leaching under active farmers’ fields are available. In this study, three methods were used in parallel to evaluate their spatial and temporal differences, namely ion-exchange resin-based Self-Integrating Accumulators (SIA), soil coring for extraction of mineral N (Nmin) from 0 to 90 cm in Mid-October (pre-winter) and Mid-February (post-winter), and Suction Cups (SCs) complemented by a HYDRUS 1D model. The monitoring, conducted from 2017 to 2020 in the Gäu Valley in the Swiss Central Plateau, covered four agricultural fields. The crop rotations included grass-clover leys, canola, silage maize and winter cereals. The monthly resolution of SC samples allowed identifying a seasonal pattern, with a nitrate concentration build-up during autumn and peaks in winter, caused by elevated water percolation to deeper soil layers in this period. Using simulated water percolation values, SC concentrations were converted into fluxes. SCs sampled 30% less N-losses on average compared to SIA, which collect also the wide macropore and preferential flows. The difference between Nmin content in autumn and spring was greater than nitrate leaching measured with either SIA or SCs. This observation indicates that autumn Nmin was depleted not only by leaching but also by plant and microbial N uptake and gaseous losses. The positive correlation between autumn Nmin content and leaching fluxes determined by either SCs or SIA suggests autumn Nmin as a useful relative but not absolute indicator for nitrate leaching. In conclusion, all three monitoring techniques are suited to indicate N leaching but represent different transport and cycling processes and vary in spatio-temporal resolution. The choice of monitoring method mainly depends (1) on the project’s goals and financial budget and (2) on the soil conditions. Long-term data, and especially the combination of methods, increase process understanding and generate knowledge beyond a pure methodological comparison. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10661-021-09605-x. Springer International Publishing 2021-12-06 2022 /pmc/articles/PMC8648662/ /pubmed/34870763 http://dx.doi.org/10.1007/s10661-021-09605-x Text en © The Author(s) 2021 https://creativecommons.org/licenses/by/4.0/Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Article Wey, Hannah Hunkeler, Daniel Bischoff, Wolf-Anno Bünemann, Else K. Field-scale monitoring of nitrate leaching in agriculture: assessment of three methods |
title | Field-scale monitoring of nitrate leaching in agriculture: assessment of three methods |
title_full | Field-scale monitoring of nitrate leaching in agriculture: assessment of three methods |
title_fullStr | Field-scale monitoring of nitrate leaching in agriculture: assessment of three methods |
title_full_unstemmed | Field-scale monitoring of nitrate leaching in agriculture: assessment of three methods |
title_short | Field-scale monitoring of nitrate leaching in agriculture: assessment of three methods |
title_sort | field-scale monitoring of nitrate leaching in agriculture: assessment of three methods |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8648662/ https://www.ncbi.nlm.nih.gov/pubmed/34870763 http://dx.doi.org/10.1007/s10661-021-09605-x |
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