Coupling of surface water and groundwater nitrate-N dynamics in two permeable agricultural catchments
Article
Article Title | Coupling of surface water and groundwater nitrate-N dynamics in two permeable agricultural catchments |
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ERA Journal ID | 5187 |
Article Category | Article |
Authors | Mellander, P. - E. (Author), Melland, A. R. (Author), Murphy, P. N. C. (Author), Wall, D. P. (Author), Shortle, G. (Author) and Jordan, P. (Author) |
Journal Title | The Journal of Agricultural Science |
Journal Citation | 152, pp. S107-S124 |
Number of Pages | 18 |
Year | 2014 |
Publisher | Cambridge University Press |
ISSN | 0021-8596 |
1469-5146 | |
Digital Object Identifier (DOI) | https://doi.org/10.1017/S0021859614000021 |
Abstract | The current study investigated the coupling of groundwater and surface water nitrogen (N) dynamics over 3 years, and considered intensive agricultural land-management influences over this period where the risk of N loss to water was considered high. Groundwater N (as nitrate) was monitored monthly in different strata and zones in four hillslopes, two in each of two agricultural catchments of c. 10 km2, and stream water N flux was monitored sub-hourly in the catchment outlets. Field nutrient sources were connected to surface water via groundwater; the groundwater along hillslopes was seen to be influenced spatially and temporally by management, geology and weather as observed in the concentration variability of nitrate in groundwater. Based on spatio-temporal averages of nitrate-N concentration, groundwater status was considered good (at least below a maximum acceptable concentration (MAC) of 11·3 mg/l). However, zones coincident with land-use change (ploughing and reseeding, typical of a management event in intensive landscapes), showed high spatio-temporal variability in nitrate-N concentration, exceeding the MAC temporarily, before recovering. This spatio-temporal variability highlighted the need for insight into these differences when interpreting groundwater quality data from a limited number of basin-scale sampling points and occasions. In both catchments the 3-year mean nitrate-N concentration in stream water was similar to the spatio-temporal mean concentration in groundwater. The magnitude and variability of loads, however, were more related to changes in annual runoff rather than changes in annual groundwater nitrate-N status. In one wet year, nitrate-N loads exceeded 48 kg/ha from an Arable catchment and 45 kg/ha from a grassland catchment (close to double the loss in a dry year). |
Keywords | groundwater; water composition; water quality; agricultural catchment; concentration (composition); intensive agriculture; land use change; nitrogen cycle; permeability; spatiotemporal analysis; water chemistry |
ANZSRC Field of Research 2020 | 300202. Agricultural land management |
410404. Environmental management | |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Byline Affiliations | Teagasc Agriculture and Food Development Authority, Ireland |
National Centre for Engineering in Agriculture | |
University College Dublin, Ireland | |
University of Ulster, United Kingdom | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q2wxy/coupling-of-surface-water-and-groundwater-nitrate-n-dynamics-in-two-permeable-agricultural-catchments
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