Wey, Hannah; Hunkeler, Daniel; Bischoff, Wolf-Anno and Bünemann, Else K. (2022) Field‑scale monitoring of nitrate leaching in agriculture: assessment of three methods. Environmental Monitoring and Assessment, 194 (4), pp. 1-20.
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Document available online at: https://link.springer.com/article/10.1007/s10661-021-09605-x
Summary
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.
EPrint Type: | Journal paper |
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Keywords: | Nährstoffmanagement, Stickstoff, Feldversuche, NitroGäu, Abacus, FiBL10106 |
Agrovoc keywords: | Language Value URI English nitrates http://aims.fao.org/aos/agrovoc/c_5187 English field trials -> field experimentation http://aims.fao.org/aos/agrovoc/c_33990 English leaching http://aims.fao.org/aos/agrovoc/c_15591 |
Subjects: | Soil > Nutrient turnover Environmental aspects > Air and water emissions |
Research affiliation: | Switzerland > FiBL - Research Institute of Organic Agriculture Switzerland > Crops > Field trials Switzerland > FiBL - Research Institute of Organic Agriculture Switzerland > Crops > Composting and fertilizer application > Nitrogen Switzerland > FiBL - Research Institute of Organic Agriculture Switzerland > Soil > Nutrient management |
DOI: | 10.1007/s10661-021-09605-x |
Related Links: | https://www.fibl.org/en/themes/projectdatabase/projectitem/project/1288 |
Deposited By: | Forschungsinstitut für biologischen Landbau, FiBL |
ID Code: | 44625 |
Deposited On: | 17 Nov 2022 10:04 |
Last Modified: | 17 Nov 2022 10:04 |
Document Language: | English |
Status: | Published |
Refereed: | Peer-reviewed and accepted |
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