1
|
Liu Z, Du Y, Deng Y, Huang Y, Zhao X, Li Q. Enrichment of geogenic phosphorus in a coastal groundwater system: New insights from dissolved organic matter characterization. CHEMOSPHERE 2023; 322:138214. [PMID: 36841455 DOI: 10.1016/j.chemosphere.2023.138214] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 02/13/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
High concentrations of geogenic phosphorus (P) in coastal aquifer systems pose a serious and continuous threat to the health of marine ecosystems. A major source for geogenic P enrichment in aquifer systems is the mineralization of P-containing organic matter. However, the mechanisms that drive the enrichment remain unclear. Therefore, our study sought to characterize the occurrence, sources, and enrichment mechanisms of geogenic P in a coastal confined aquifer system of the Pearl River Delta, southern China. To achieve this, we conducted Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and fluorescence excitation-emission-matrix spectra (EEMs) as well as hydrochemistry and stable carbon isotope analyses. Our findings indicated that intense degradation of P-containing organic matter produced up to 8.07 mg/L of geogenic P in a reducing environment with abundant organic matter. The dissolved organic matter (DOM) of high-P groundwater (P > 1 mg/L) contained more humic-like fluorophores and exhibited higher humification. Groundwater with high P concentrations contained more aliphatic compounds and highly unsaturated-low O compounds, and the enrichment of P was mostly associated with CHOP compounds in the region of aliphatic compounds and CHON2P compounds in the region of highly unsaturated-low O compounds. Different types of dissolved organic phosphorus (DOP) can be mineralized into P, and even the mineralization of phosphonates takes precedence over the more unstable phosphate esters. P produced by the metabolism of different types of DOP was assimilated by marine microorganisms (e.g., heterotrophic bacteria and archaea), and the newly synthesized organic P compounds by chemosynthesis were subsequently released into the groundwater. Over time, P continues to be enriched in the aquifer system. This study provides new insights into subsurface P cycling in coastal aquatic systems.
Collapse
Affiliation(s)
- Zhaohui Liu
- State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430078, China; Geological Survey Institute, China University of Geosciences, Wuhan, 430074, China
| | - Yao Du
- State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430078, China.
| | - Yamin Deng
- State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430078, China
| | - Yanwen Huang
- State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, School of Environmental Studies & State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430078, China
| | - Xinwen Zhao
- Wuhan Center of China Geological Survey, Wuhan, 430205, China
| | - Qinghua Li
- Wuhan Center of China Geological Survey, Wuhan, 430205, China
| |
Collapse
|
2
|
Pan Z, Hu M, Shen H, Wu H, Zhou J, Wu K, Chen D. Quantifying groundwater phosphorus flux to rivers in a typical agricultural watershed in eastern China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:19873-19889. [PMID: 36242662 DOI: 10.1007/s11356-022-23574-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Increasing evidence indicates that groundwater can contain high dissolved phosphorus (P) concentrations, thereby contributing as a potential pollution source for surface waters. However, limited quantitative knowledge is available concerning groundwater P fluxes to rivers. Based on monthly hydrochemical monitoring data for rivers and groundwater in 2017-2020, this study combined baseflow separation methods and a load apportionment model (LAM) to quantify contributions from point sources, surface runoff, and groundwater/subsurface runoff to riverine P pollution in a typical agricultural watershed of eastern China. In the studied Shuanggang River, most total P (TP) and dissolved P (DP) concentrations exceeded targeted water quality standards (i.e., TP ≤ 0.2 mg P L-1, DP ≤ 0.05 mg P L-1), with DP (76 ± 20%) being the major riverine P form. Observed DP concentrations in groundwater were generally higher than those of river waters. There was a strong correlation between river and groundwater P concentrations, implying that groundwater might be a considerable P pollution source to rivers. The nonlinear reservoir algorithm estimated that baseflow/groundwater contributed 66-68% of monthly riverine water discharge on average, which was consistent with results estimated by an isotope-based sine-wave fitting method. The LAM incorporating point sources, surface runoff, and groundwater effectively predicted daily riverine TP [calibration: coefficient of determination (R2) = 0.76-0.82, Nash-Sutcliffe Efficiency (NSE) = 0.61-0.77; validation: R2 = 0.88-0.98, NSE = 0.54-0.64] and DP loads (calibration: R2 = 0.73-0.84, NSE = 0.67-0.72; validation: R2 = 0.88-0.97, NSE = 0.56-0.83). The LAM estimated point source, surface runoff, and groundwater contributions to riverine loads were 15-18%, 14-35%, and 46-70% for TP loads and 7-9%, 10-32%, and 59-82% for DP loads, respectively. Groundwater was the dominant riverine P source due to long-term accumulation of P from excess fertilizer and farmyard manure applications. The developed methodology provides an alternative method for quantifying P pollution loads from point sources, surface runoff, and groundwater to rivers. This study highlights the importance of controlling groundwater P pollution from agricultural lands to address riverine water quality objectives and further implies that decreasing fertilizer P application rates and utilizing legacy soil P for crop uptake are required to reduce groundwater P loads to rivers.
Collapse
Affiliation(s)
- Zheqi Pan
- College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
| | - Minpeng Hu
- College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
- Department of Natural Resources and Environmental Sciences, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Hong Shen
- College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
- Ministry of Education Key Laboratory of Environment Remediation and Ecological Health, Zhejiang University, Hangzhou, 310058, China
| | - Hao Wu
- College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
- Ministry of Education Key Laboratory of Environment Remediation and Ecological Health, Zhejiang University, Hangzhou, 310058, China
| | - Jia Zhou
- College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, 310058, China
| | - Kaibin Wu
- College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, 310058, China
| | - Dingjiang Chen
- College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang Province, China.
- Zhejiang Ecological Civilization Academy, Anji, 313399, China.
- Academy of Ecological Civilization, Zhejiang University, Hangzhou, 310058, China.
| |
Collapse
|
3
|
Barcala V, Jansen S, Gerritse J, Mangold S, Voegelin A, Behrends T. Phosphorus adsorption on iron-coated sand under reducing conditions. JOURNAL OF ENVIRONMENTAL QUALITY 2023; 52:74-87. [PMID: 36368314 DOI: 10.1002/jeq2.20432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
Mitigation measures are needed to prevent large loads of phosphate originating in agriculture from reaching surface waters. Iron-coated sand (ICS) is a residual product from drinking water production. It has a high phosphate adsorption capacity and can be placed around tile drains, taking no extra space, which increases the farmers' acceptance. The main concern regarding the use of ICS filters below groundwater level is that limited oxygen supply and high organic matter concentrations may lead to the reduction and dissolution of iron (hydr)oxides present and the release of previously adsorbed phosphate. This study aimed to investigate phosphate adsorption on ICS at the onset of iron reduction. First, we investigated whether simultaneous metal reduction and phosphate adsorption were relevant at two field sites in the Netherlands that use ICS filters around tile drains. Second, the onset of microbially mediated reduction of ICS in drainage water was mimicked in complementary laboratory microcosm experiments by varying the intensity of reduction through controlling the oxygen availability and the concentration of degradable organic matter. After 3 yr, ICS filters in the field removed phosphorus under low redox conditions. Over 45 d, the microbial reduction of manganese and iron oxides did not lead to phosphate release, confirming field observations. Electron microscopy and X-ray absorption spectroscopy did not evince systematic structural or compositional changes; only under strongly reducing conditions did iron sulfides form in small percentages in the outer layer of the iron coating. Our results suggest that detrimental effects only become relevant after long periods of operation.
Collapse
Affiliation(s)
- Victoria Barcala
- Inland Water Systems, Deltares, Daltonlaan 600, Utrecht, The Netherlands
- Dep. of Earth Sciences, Faculty of Geosciences, Utrecht Univ., 8 Princetonlaan, Utrecht, The Netherlands
| | - Stefan Jansen
- Deltares, Unit Subsurface and Groundwater Systems, Daltonlaan 600, Utrecht, The Netherlands
| | - Jan Gerritse
- Deltares, Unit Subsurface and Groundwater Systems, Daltonlaan 600, Utrecht, The Netherlands
| | - Stefan Mangold
- Karlsruhe Institute of Technology, Institute for Photon Science and Synchrotron Radiation, Eggenstein-Leopoldshafen, Germany
| | - Andreas Voegelin
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, Duebendorf, Switzerland
| | - Thilo Behrends
- Dep. of Earth Sciences, Faculty of Geosciences, Utrecht Univ., 8 Princetonlaan, Utrecht, The Netherlands
| |
Collapse
|
4
|
Atcheson K, Mellander PE, Cassidy R, Cook S, Floyd S, McRoberts C, Morton PA, Jordan P. Quantifying MCPA load pathways at catchment scale using high temporal resolution data. WATER RESEARCH 2022; 220:118654. [PMID: 35635916 DOI: 10.1016/j.watres.2022.118654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/18/2022] [Accepted: 05/21/2022] [Indexed: 06/15/2023]
Abstract
Detection of the agricultural acid herbicide MCPA (2-methyl-4-chlorophenoxyacetic acid) in drinking water source catchments is of growing concern, with economic and environmental implications for water utilities and wider ecosystem services. MCPA is poorly adsorbed to soil and highly mobile in water, but hydrological pathway processes are relatively unknown at the catchment scale and limited by coarse resolution data. This understanding is required to target mitigation measures and to provide a framework to monitor their effectiveness. To address this knowledge gap, this study reports findings from river discharge and synchronous MCPA concentration datasets (continuous 7 hour and with additional hourly sampling during storm events) collected over a 7 month herbicide spraying season. The study was undertaken in a surface (source) water catchment (384 km2-of which 154 km2 is agricultural land use) in the cross-border area of Ireland. Combined into loads, and using two pathway separation techniques, the MCPA data were apportioned into event and baseload components and the former was further separated to quantify a quickflow (QF) and other event pathways. Based on the 7 hourly dataset, 85.2 kg (0.22 kg km-2 by catchment area, or 0.55 kg km-2 by agricultural area) of MCPA was exported from the catchment in 7 months. Of this load, 87.7 % was transported via event flow pathways with 72.0 % transported via surface dominated (QF) pathways. Approximately 12 % of the MCPA load was transported via deep baseflows, indicating a persistence in this delayed pathway, and this was the primary pathway condition monitored in a weekly regulatory sampling programme. However, overall, the data indicated a dominant acute, storm dependent process of incidental MCPA loss during the spraying season. Reducing use and/or implementing extensive surface pathway disconnection measures are the mitigation options with greatest potential, the success of which can only be assessed using high temporal resolution monitoring techniques.
Collapse
Affiliation(s)
- Kevin Atcheson
- School of Geography and Environmental Sciences, Ulster University, Coleraine, UK.
| | - Per-Erik Mellander
- Agricultural Catchments Programme, Teagasc, Johnstown Castle, Wexford, Ireland
| | - Rachel Cassidy
- Agri-Environment Branch, Agri-Food and Biosciences Institute, Belfast, UK
| | - Sally Cook
- School of Geography and Environmental Sciences, Ulster University, Coleraine, UK
| | - Stewart Floyd
- Agri-Environment Branch, Agri-Food and Biosciences Institute, Belfast, UK
| | - Colin McRoberts
- Agri-Environment Branch, Agri-Food and Biosciences Institute, Belfast, UK
| | - Phoebe A Morton
- Agri-Environment Branch, Agri-Food and Biosciences Institute, Belfast, UK
| | - Phil Jordan
- School of Geography and Environmental Sciences, Ulster University, Coleraine, UK
| |
Collapse
|
5
|
Patterns and Drivers of Groundwater and Stream Nitrate Concentrations in Intensively Managed Agricultural Catchments. WATER 2022. [DOI: 10.3390/w14091388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The environmental loss of nitrogen in agricultural landscapes has pervasive consequences, including human health implications, eutrophication, loss of habitat biodiversity and greenhouse gas emissions. The efficacy of mitigation strategies designed to control or prevent nitrate contamination of waterbodies requires an understanding of catchment scale pressures and processes. Groundwater and stream nitrate concentrations fluctuate over temporal scales ranging from the daily to the decadal. Identifying spatiotemporal trends and dominant drivers of nitrate in water is challenging as the drivers are intertwined. The effects of agronomic, meteorological and hydrogeological drivers on groundwater and stream nitrate were investigated over seven years in two well-drained agricultural catchments, dominated by tillage and grassland farming, respectively. A significant positive temporal trend in nitrate concentration was observed in the tillage catchment, whereas no long-term trend was observed in the grassland catchment. Agronomic, meteorological and hydrogeological factors were significantly related to temporal nitrate changes across both catchments. Clearly identifying the drivers influencing temporal changes in nitrate concentrations is critical to improving water quality. The study highlighted that to reduce groundwater nitrate levels in areas of high risk (thin soils, low clay content and shallow groundwater), nitrogen applications need to be reduced and/or tailored, particularly at times of restricted crop growth.
Collapse
|
6
|
Mellander PE, Jordan P. Charting a perfect storm of water quality pressures. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 787:147576. [PMID: 34000530 DOI: 10.1016/j.scitotenv.2021.147576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/15/2021] [Accepted: 05/02/2021] [Indexed: 06/12/2023]
Abstract
The agri-food economy can be a significant driver of water quality pressures but the role of hydro-meteorological patterns in a changing climate also requires consideration. For this purpose, an assessment was made of a ten-year synchronous high temporal resolution water quality and hydro-meteorological dataset in Irish agricultural catchments. Changes occurring to rainfall intensity and soil temperature patterns were found to be important drivers of nutrient mobility in soils. There were links between the intensity of the North Atlantic Oscillation over the decade and large shifts in baseline nutrient concentrations in catchments. The data also revealed extreme weather impacts to pollution patterns including short periods of rain induced nutrient flux, that exceeded average annual mass loads in these catchments, and drought influences on point source pollution. These influences need consideration, and may require different mitigation strategies, as links between water quality land use pressure and water quality state in regulatory reviews. In a decade of both increased land use source and hydro-meteorological transport pressures, water quality natural capital in Ireland has faced a perfect storm. Such conditions are difficult to model and only revealed in high temporal resolution datasets.
Collapse
Affiliation(s)
- Per-Erik Mellander
- Agricultural Catchments Programme, Department of Environment, Soils and Landuse, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Co. Wexford, Ireland.
| | - Phil Jordan
- School of Geography and Environmental Sciences, Ulster University, Coleraine, Northern Ireland, UK
| |
Collapse
|
7
|
He S, Lu J. Dissolved phosphorus export through baseflow in an intensively cultivated agricultural watershed of eastern China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:10.1007/s11356-021-12802-3. [PMID: 33634396 DOI: 10.1007/s11356-021-12802-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Inputs of phosphorus (P) during baseflow period usually come from groundwater, bed sediments, and some other sources. Baseflow P can have critical effects on nutrient enrichment of surface waters in some intensively cultivated agricultural watersheds. This study was conducted to estimate the baseflow dissolved phosphorus (DP) export in a typical rainy agricultural watershed of eastern China using a recursive tracing source algorithm (RTSA) and reveal the rules and trends of baseflow DP loads and concentrations. Results indicated that RTSA provided a satisfactory prediction for baseflow DP load (Nash-Sutcliffe efficiency (NSE) = 0.72, R2 = 0.74). From 2003 to 2012, the annual baseflow DP loads ranged from 0.159 (2004) to 0.771 (2012) kg/ha which contributed about 64.3% of the mean total annual DP export in stream (0.597 kg/ha). The annual flow-weighted DP concentrations in streamflow (0.076-0.125 mg/L) and baseflow (0.076-0.137 mg/L) far exceeded the eutrophication threshold of DP (0.01 mg/L). Significantly increasing trends were obtained in the streamflow and baseflow DP loads and the flow-weighted concentrations (Mann-Kendall test, Zs > 2.56, p < 0.01) because of the changes of hydro-meteorological conditions. This indicates that, in the context of global climate change, baseflow DP export would be one of key issues for nonpoint source pollution control in the intensive agricultural watershed.
Collapse
Affiliation(s)
- Shengjia He
- School of Environmental and Resource Sciences, Zhejiang A & F University, Lin'an, Hangzhou, 311300, China.
| | - Jun Lu
- China Ministry of Education Key Laboratory of Environment Remediation and Ecological Health, Zhejiang University, Hangzhou, 310058, China
| |
Collapse
|
8
|
Fresne M, Jordan P, Fenton O, Mellander PE, Daly K. Soil chemical and fertilizer influences on soluble and medium-sized colloidal phosphorus in agricultural soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:142112. [PMID: 33254851 DOI: 10.1016/j.scitotenv.2020.142112] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 08/24/2020] [Accepted: 08/29/2020] [Indexed: 06/12/2023]
Abstract
Colloid-facilitated transport can be important for preferential transfer of phosphorus (P) through the soil profile to groundwater and may in part explain elevated P concentrations in surface water during baseflow and particularly high flow conditions. To investigate the potential for colloidal P (Pcoll) mobilisation in soils, this study assessed the role of soil chemical properties and P fertilizer type on medium-sized soil Pcoll (200-450 nm) and its association with soil solution soluble bioavailable P (<450 nm). Hillslope soils from three agricultural catchments were sampled and untreated and treated (cattle slurry and synthetic fertilizer) subsamples were incubated. Soil supernatants were analysed for P and soil Water Dispersible Colloids (WDC) were extracted for analysis of P and P-binding materials. Soils physicochemical properties including degree of P saturation (DPS) and P sorption properties were determined. Results indicated that medium-sized Pcoll was mostly unreactive P associated to some extent to amorphous forms of Fe. Medium-sized Pcoll concentrations correlated negatively with soil maximum P sorption capacity and soluble P concentrations increased with increasing DPS. In soil with low sorption properties, cattle slurry increased soluble P concentrations by 0.008-0.013 mg l-1 and DPS but did not influence medium-sized Pcoll. Synthetic fertilizer increased medium-sized reactive Pcoll by 0.011 mg l-1 (0.088 mg kg-1 soil) and DPS in a soil with lower DPS whereas it decreased it by 0.005 mg l-1 (0.040 mg kg-1 soil) in a soil with higher DPS. Additional soil parameters (M3-Fe, M3-Al, M3-P, and DPS) should be included in soil testing, especially in Cambisol/Podzol soils, to identify critical areas where risks of Pcoll mobilisation are important. Further research should include the roles of finer colloidal and nanoparticulate (<200 nm) soil P fractions and soluble P to inform understanding of plant uptake and assess environmental risk.
Collapse
Affiliation(s)
- Maëlle Fresne
- Agricultural Catchments Programme, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Ireland; Crops, Environment and Land Use Programme, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Ireland; School of Geography and Environmental Sciences, Ulster University, Coleraine, UK.
| | - Phil Jordan
- School of Geography and Environmental Sciences, Ulster University, Coleraine, UK
| | - Owen Fenton
- Crops, Environment and Land Use Programme, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Ireland
| | - Per-Erik Mellander
- Agricultural Catchments Programme, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Ireland; Crops, Environment and Land Use Programme, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Ireland
| | - Karen Daly
- Crops, Environment and Land Use Programme, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Ireland
| |
Collapse
|
9
|
Thomas IA, Buckley C, Kelly E, Dillon E, Lynch J, Moran B, Hennessy T, Murphy PNC. Establishing nationally representative benchmarks of farm-gate nitrogen and phosphorus balances and use efficiencies on Irish farms to encourage improvements. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137245. [PMID: 32325548 DOI: 10.1016/j.scitotenv.2020.137245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 01/07/2020] [Accepted: 02/09/2020] [Indexed: 06/11/2023]
Abstract
Agriculture faces considerable challenges of achieving more sustainable production that minimises nitrogen (N) and phosphorus (P) losses and meets international obligations for water quality and greenhouse gas emissions. This must involve reducing nutrient balance (NB) surpluses and increasing nutrient use efficiencies (NUEs), which could also improve farm profitability (a win-win). To set targets and motivate improvements in Ireland, nationally representative benchmarks were established for different farm categories (sector, soil group and production intensity). Annual farm-gate NBs (kg ha-1) and NUEs (%) for N and P were calculated for 1446 nationally representative farms from 2008 to 2015 using import and export data collected by the Teagasc National Farm Survey (part of the EU Farm Accountancy Data Network). Benchmarks for each category were established using quantile regression analysis and percentile rankings to identify farms with the lowest NB surplus per production intensity and highest gross margins (€ ha-1). Within all categories, large ranges in NBs and NUEs between benchmark farms and poorer performers show considerable room for nutrient management improvements. Results show that as agriculture intensifies, nutrient surpluses, use efficiencies and gross margins increase, but benchmark farms minimise surpluses to relatively low levels (i.e. are more sustainable). This is due to, per ha, lower fertiliser and feed imports, greater exports of agricultural products, and for dairy, sheep and suckler cattle, relatively high stocking rates. For the ambitious scenario of all non-benchmark farms reaching the optimal benchmark zone, moderate reductions in farm nutrient surpluses were found with great improvements in profitability, leading to a 31% and 9% decrease in N and P surplus nationally, predominantly from dairy and non-suckler cattle. The study also identifies excessive surpluses for each level of production intensity, which could be used by policy in setting upper limits to improve sustainability.
Collapse
Affiliation(s)
- I A Thomas
- Environment and Sustainable Resource Management Section, School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland.
| | - C Buckley
- Agricultural Economics and Farm Surveys Department, Rural Economy & Development Centre, Teagasc, Mellows Campus, Athenry, Ireland.
| | - E Kelly
- Agricultural and Food Economics, School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland.
| | - E Dillon
- Agricultural Economics and Farm Surveys Department, Rural Economy & Development Centre, Teagasc, Mellows Campus, Athenry, Ireland.
| | - J Lynch
- Department of Physics, University of Oxford, Oxford, UK.
| | - B Moran
- Agricultural Economics and Farm Surveys Department, Rural Economy & Development Centre, Teagasc, Mellows Campus, Athenry, Ireland.
| | - T Hennessy
- Food Business and Development, Business School, University College Cork, College Road, Cork, Ireland.
| | - P N C Murphy
- Environment and Sustainable Resource Management Section, School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland; UCD Earth Institute, University College Dublin, Belfield, Dublin, Ireland.
| |
Collapse
|
10
|
Sources and Mechanisms of Low-Flow River Phosphorus Elevations: A Repeated Synoptic Survey Approach. WATER 2019. [DOI: 10.3390/w11071497] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High-resolution water quality monitoring indicates recurring elevation of stream phosphorus concentrations during low-flow periods. These increased concentrations may exceed Water Framework Directive (WFD) environmental quality standards during ecologically sensitive periods. The objective of this research was to identify source, mobilization, and pathway factors controlling in-stream total reactive phosphorus (TRP) concentrations during low-flow periods. Synoptic surveys were conducted in three agricultural catchments during spring, summer, and autumn. Up to 50 water samples were obtained across each watercourse per sampling round. Samples were analysed for TRP and total phosphorus (TP), along with supplementary parameters (temperature, conductivity, dissolved oxygen, and oxidation reduction potential). Bed sediment was analysed at a subset of locations for Mehlich P, Al, Ca, and Fe. The greatest percentages of water sampling points exceeding WFD threshold of 0.035 mg L−1 TRP occurred during summer (57%, 11%, and 71% for well-drained, well-drained arable, and poorly drained grassland catchments, respectively). These percentages declined during autumn but did not return to spring concentrations, as winter flushing had not yet occurred. Different controls were elucidated for each catchment: diffuse transport through groundwater and lack of dilution in the well-drained grassland, in-stream mobilization in the well-drained arable, and a combination of point sources and cumulative loading in the poorly drained grassland. Diversity in controlling factors necessitates investigative protocols beyond low-spatial and temporal resolution water sampling and must incorporate both repeated survey and complementary understanding of sediment chemistry and anthropogenic phosphorus sources. Despite similarities in elevation of P at low-flow, catchments will require custom solutions depending on their typology, and both legislative deadlines and target baselines standards must acknowledge these inherent differences.
Collapse
|
11
|
Lynch J, Donnellan T, Finn JA, Dillon E, Ryan M. Potential development of Irish agricultural sustainability indicators for current and future policy evaluation needs. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 230:434-445. [PMID: 30300858 DOI: 10.1016/j.jenvman.2018.09.070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 09/16/2018] [Accepted: 09/21/2018] [Indexed: 06/08/2023]
Abstract
There is a significant and detailed range of sustainability indicators for Irish agri-food production, but there remain areas where further indicator development or new indicators could prove valuable. This review provides an outline of potential developments in Irish assessment of agricultural sustainability following the latest research and in order to meet policy demands. Recent research findings have suggested means of improved quantitative modelling of greenhouse gas emissions, but additional dietary and soil data may be important for this, especially for the potential inclusion of any soil sequestration. This information could also benefit more detailed modelling of nutrient losses to water. Specific concerns over pesticide and antibiotic use may require additional survey work on the particular locations or types of farms of interest. Biodiversity monitoring could be improved by expanding the range of results-oriented agri-environment schemes or employing remote-sensing habitat monitoring, likely supplemented with targeted field surveys for specific objectives. Farm-level economic sustainability is largely well-covered, but additional data collection may be of benefit to address specific issues such as labour costs. Recent additional surveys on farm-level social sustainability have addressed important social indicators of isolation and access to local services, and could be rolled out on a larger number of farms in the future. Wider societal concerns such as animal welfare, genetically modified materials in foodstuffs and antibiotic resistance have limited indicators currently available, and could also benefit from additional surveys. The breadth and detail required in agri-food sustainability indicators present a significant challenge to survey design and implementation, but many developments can be achieved without additional surveys through the use of remote sensing and geospatial technologies and integration of existing datasets. Despite the important benefits of further developments in Irish sustainability indicators, consideration must also be given to farmer confidentiality and survey fatigue.
Collapse
Affiliation(s)
- John Lynch
- Rural Economy and Development Programme, Teagasc, Mellows Campus, Athenry, Co. Galway, Ireland.
| | - Trevor Donnellan
- Rural Economy and Development Programme, Teagasc, Mellows Campus, Athenry, Co. Galway, Ireland
| | - John A Finn
- Environment Research Centre, Teagasc, Johnstown Castle, Co. Wexford, Ireland
| | - Emma Dillon
- Rural Economy and Development Programme, Teagasc, Mellows Campus, Athenry, Co. Galway, Ireland
| | - Mary Ryan
- Rural Economy and Development Programme, Teagasc, Mellows Campus, Athenry, Co. Galway, Ireland
| |
Collapse
|
12
|
Neidhardt H, Schoeckle D, Schleinitz A, Eiche E, Berner Z, Tram PTK, Lan VM, Viet PH, Biswas A, Majumder S, Chatterjee D, Oelmann Y, Berg M. Biogeochemical phosphorus cycling in groundwater ecosystems - Insights from South and Southeast Asian floodplain and delta aquifers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 644:1357-1370. [PMID: 30743848 DOI: 10.1016/j.scitotenv.2018.07.056] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/04/2018] [Accepted: 07/04/2018] [Indexed: 06/09/2023]
Abstract
The biogeochemical cycling of phosphorus (P) in South and Southeast Asian floodplain and delta aquifers has received insufficient attention in research studies, even though dissolved orthophosphate (PO43-) in this region is closely linked with the widespread contamination of groundwater with toxic arsenic (As). The overarching aim of this study was to characterize the enrichment of P in anoxic groundwater and to provide insight into the biogeochemical mechanisms underlying its mobilization, subsurface transport, and microbial cycling. Detailed groundwater analyses and in situ experiments were conducted that focused on three representative field sites located in the Red River Delta (RRD) of Vietnam and the Bengal Delta Plain (BDP) in West Bengal, India. The results showed that the total concentrations of dissolved P (TDP) ranged from 0.03 to 1.50 mg L-1 in groundwater, with PO43- being the dominant P species. The highest concentrations occurred in anoxic sandy Holocene aquifers where PO43- was released into groundwater through the microbial degradation of organic carbon and the concomitant reductive dissolution of Fe(III)-(hydr)oxides. The mobilization of PO43- may still constitute an active process within shallow Holocene sediments. Furthermore, a sudden supply of organic carbon may rapidly decrease the redox potential, which causes an increase in TDP concentrations in groundwater, as demonstrated by a field experiment. Considering the subsurface transport of PO43-, Pleistocene aquifer sediments represented effective sinks; however, the enduring contact between oxic Pleistocene sediments and anoxic groundwater also changed the sediments PO43--sorption capacity over time. A stable isotope analysis of PO43--bound oxygen indicated the influences of intracellular microbial cycling as well as a specific PO43- source with a distinct isotopically heavy signal. Consequently, porous aquifers in Asian floodplain and delta regions proved to be ideal natural laboratories to study the biogeochemical cycling of P and its behavior in groundwater environments.
Collapse
Affiliation(s)
- Harald Neidhardt
- Geoecology, Eberhard Karls University Tübingen, 72070 Tübingen, Germany.
| | - Daniel Schoeckle
- Isotope Geochemistry, Eberhard Karls University Tübingen, 72074 Tübingen, Germany
| | - Anna Schleinitz
- Geoecology, Eberhard Karls University Tübingen, 72070 Tübingen, Germany
| | - Elisabeth Eiche
- Institute of Applied Geosciences, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Zsolt Berner
- Institute of Applied Geosciences, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Pham T K Tram
- Research Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Vietnam National University, Hanoi, Viet Nam
| | - Vi M Lan
- Research Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Vietnam National University, Hanoi, Viet Nam
| | - Pham H Viet
- Research Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Vietnam National University, Hanoi, Viet Nam
| | - Ashis Biswas
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal 462066, India
| | - Santanu Majumder
- Groundwater Research Group, Texas A&M University, 3115 TAMU, College Station, TX, United States
| | - Debashis Chatterjee
- Department of Chemistry, University of Kalyani, Kalyani, 741235 Nadia, West Bengal, India
| | - Yvonne Oelmann
- Geoecology, Eberhard Karls University Tübingen, 72070 Tübingen, Germany
| | - Michael Berg
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| |
Collapse
|
13
|
McDowell RW, Schallenberg M, Larned S. A strategy for optimizing catchment management actions to stressor-response relationships in freshwaters. Ecosphere 2018. [DOI: 10.1002/ecs2.2482] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- R. W. McDowell
- AgResearch, Lincoln Science Centre; Private Bag 4749 Christchurch 8140 New Zealand
- Soil and Physical Sciences; Faculty of Agriculture and Life Sciences; Lincoln University; P.O. Box 84 Lincoln 7647 Christchurch New Zealand
| | - M. Schallenberg
- Department of Zoology; University of Otago; P.O. Box 56 Dunedin 9054 New Zealand
| | - S. Larned
- National Institute of Water and Atmospheric Research; P.O. Box 8602, 10 Kyle Street Riccarton Christchurch 8011 New Zealand
| |
Collapse
|
14
|
Schilling KE, Streeter MT, Isenhart TM, Beck WJ, Tomer MD, Cole KJ, Kovar JL. Distribution and mass of groundwater orthophosphorus in an agricultural watershed. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 625:1330-1340. [PMID: 29996430 DOI: 10.1016/j.scitotenv.2018.01.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/04/2018] [Accepted: 01/04/2018] [Indexed: 06/08/2023]
Abstract
Orthophosphorus (OP) is the form of dissolved inorganic P that is commonly measured in groundwater studies, but the spatial distribution of groundwater OP across a watershed has rarely been assessed. In this study, we characterized spatial patterns of groundwater OP concentrations and loading rates within the 5218ha Walnut Creek watershed (Iowa) over a two-year period. Using a network of 24 shallow (<6m) monitoring wells established across watershed, OP concentrations ranged from <0.01 to 0.58mg/l in all samples (n=147) and averaged 0.084±0.107mg/l. Groundwater OP concentrations were higher in floodplains and OP mass loading rates were approximately three times higher than in uplands. We estimated that approximately 1231kg of OP is present in floodplain groundwater and 2869kg is present in upland groundwater within the shallow groundwater zone (0-5m depth). Assuming no new inputs of OP to shallow groundwater, we estimated it would take approximately eight years to flush out existing OP mass present in the system. Results suggest that conservation practices focused on reducing OP loading rates in floodplain areas may have a disproportionately large water quality benefit compared to upland areas.
Collapse
Affiliation(s)
- Keith E Schilling
- Iowa Geological Survey, University of Iowa, Iowa City, IA, United States.
| | - Matthew T Streeter
- Iowa Geological Survey, University of Iowa, Iowa City, IA, United States
| | - Thomas M Isenhart
- Department of Natural Resources Ecology and Management, Iowa State University, Ames, IA, United States
| | - William J Beck
- Department of Natural Resources Ecology and Management, Iowa State University, Ames, IA, United States
| | - Mark D Tomer
- USDA Agricultural Research Service, National Laboratory for Agriculture and Environment, Ames, IA, United States
| | - Kevin J Cole
- USDA Agricultural Research Service, National Laboratory for Agriculture and Environment, Ames, IA, United States
| | - John L Kovar
- USDA Agricultural Research Service, National Laboratory for Agriculture and Environment, Ames, IA, United States
| |
Collapse
|
15
|
Integrated climate-chemical indicators of diffuse pollution from land to water. Sci Rep 2018; 8:944. [PMID: 29343796 PMCID: PMC5772433 DOI: 10.1038/s41598-018-19143-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 12/22/2017] [Indexed: 11/17/2022] Open
Abstract
Management of agricultural diffuse pollution to water remains a challenge and is influenced by the complex interactions of rainfall-runoff pathways, soil and nutrient management, agricultural landscape heterogeneity and biogeochemical cycling in receiving water bodies. Amplified cycles of weather can also influence nutrient loss to water although they are less considered in policy reviews. Here, we present the development of climate-chemical indicators of diffuse pollution in highly monitored catchments in Western Europe. Specifically, we investigated the influences and relationships between weather processes amplified by the North Atlantic Oscillation during a sharp upward trend (2010–2016) and the patterns of diffuse nitrate and phosphorus pollution in rivers. On an annual scale, we found correlations between local catchment-scale nutrient concentrations in rivers and the influence of larger, oceanic-scale climate patterns defined by the intensity of the North Atlantic Oscillation. These influences were catchment-specific showing positive, negative or no correlation according to a typology. Upward trends in these decadal oscillations may override positive benefits of local management in some years or indicate greater benefits in other years. Developing integrated climate-chemical indicators into catchment monitoring indicators will provide a new and important contribution to water quality management objectives.
Collapse
|
16
|
Leinweber P, Bathmann U, Buczko U, Douhaire C, Eichler-Löbermann B, Frossard E, Ekardt F, Jarvie H, Krämer I, Kabbe C, Lennartz B, Mellander PE, Nausch G, Ohtake H, Tränckner J. Handling the phosphorus paradox in agriculture and natural ecosystems: Scarcity, necessity, and burden of P. AMBIO 2018; 47:3-19. [PMID: 29159449 PMCID: PMC5722737 DOI: 10.1007/s13280-017-0968-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
This special issue of Ambio compiles a series of contributions made at the 8th International Phosphorus Workshop (IPW8), held in September 2016 in Rostock, Germany. The introducing overview article summarizes major published scientific findings in the time period from IPW7 (2015) until recently, including presentations from IPW8. The P issue was subdivided into four themes along the logical sequence of P utilization in production, environmental, and societal systems: (1) Sufficiency and efficiency of P utilization, especially in animal husbandry and crop production; (2) P recycling: technologies and product applications; (3) P fluxes and cycling in the environment; and (4) P governance. The latter two themes had separate sessions for the first time in the International Phosphorus Workshops series; thus, this overview presents a scene-setting rather than an overview of the latest research for these themes. In summary, this paper details new findings in agricultural and environmental P research, which indicate reduced P inputs, improved management options, and provide translations into governance options for a more sustainable P use.
Collapse
Affiliation(s)
- Peter Leinweber
- Department of Soil Science, Faculty for Agricultural and Environmental Sciences, University of Rostock, Justus-von-Liebig Weg 6, 18059 Rostock, Germany
| | - Ulrich Bathmann
- Leibniz-Institut für Ostseeforschung Warnemünde, Seestraße 15, 18119 Rostock, Germany
| | - Uwe Buczko
- Landscape Ecology and Site Evaluation, University of Rostock, 18059 Rostock, Germany
| | - Caroline Douhaire
- Forschungsstelle Nachhaltigkeit und Klimapolitik, Könneritzstraße 41, 04229 Leipzig, Germany
| | - Bettina Eichler-Löbermann
- Department of Crop Production, Faculty of Agricultural and Environmental Sciences, Justus-von-Liebig Weg 6, 18059 Rostock, Germany
| | - Emmanuel Frossard
- ETH Zurich, Research Station in Plant Sciences, Eschikon, 8315 Lindau, Switzerland
| | - Felix Ekardt
- Forschungsstelle Nachhaltigkeit und Klimapolitik, Könneritzstraße 41, 04229 Leipzig, Germany
| | - Helen Jarvie
- Centre for Ecology & Hydrology, Wallingford, Oxfordshire OX10 8BB UK
| | - Inga Krämer
- Leibniz Science Campus Phosphorus Research Rostock c/o, Leibniz Institute for Baltic Sea Research Warnemünde, Seestr. 15, 18119 Rostock, Germany
| | - Christian Kabbe
- P-REX Environment, Am Goldmannpark 43, 12587 Berlin, Germany
| | - Bernd Lennartz
- Department of Soil Physics, Faculty of Agricultural and Environmental Sciences, University of Rostock, Justusvon-Liebig Weg 6, 18059 Rostock, Germany
| | - Per-Erik Mellander
- Department of Environment, Soils and Landuse, Teagasc, Johnstown Castle Environmental Research Centre, Johnstown Castle, Co. Wexford Ireland
| | - Günther Nausch
- Baltic Sea Institute for Baltic Sea Research Warnemünde (IOW), Seestrasse 15, 18109 Rostock, Germany
| | - Hisao Ohtake
- Phosphorus Atlas Research Institute, Waseda University, Wakamatsu-cho 2-2, Shinjuku-ku, Tokyo, 162-0056 Japan
| | - Jens Tränckner
- Water Management, Faculty of Agricultural and Environmental Sciences, Satower Strasse 48, 18059 Rostock, Germany
| |
Collapse
|
17
|
Dupas R, Mellander PE, Gascuel-Odoux C, Fovet O, McAleer EB, McDonald NT, Shore M, Jordan P. The role of mobilisation and delivery processes on contrasting dissolved nitrogen and phosphorus exports in groundwater fed catchments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:1275-1287. [PMID: 28531946 DOI: 10.1016/j.scitotenv.2017.05.091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 06/07/2023]
Abstract
Diffuse transfer of nitrogen (N) and phosphorus (P) in agricultural catchments is controlled by the mobilisation of sources and their delivery to receiving waters. While plot scale experiments have focused on mobilisation processes, many catchment scale studies have hitherto concentrated on the controls of dominant flow pathways on nutrient delivery. To place mobilisation and delivery at a catchment scale, this study investigated their relative influence on contrasting nitrate-N and soluble P concentrations and N:P ratios in two shallow groundwater fed catchments with different land use (grassland and arable) on the Atlantic seaboard of Europe. Detailed datasets of N and P inputs, concentrations in shallow groundwater and concentrations in receiving streams were analysed over a five year period (October 2010-September 2015). Results showed that nitrate-N and soluble P concentrations in shallow groundwater give a good indication of stream concentrations, which suggests a dominant control of mobilisation processes on stream exports. Near-stream attenuation of nitrate-N (-30%), likely through denitrification and dilution, and enrichment in soluble P (+100%), through soil-groundwater interactions, were similar in both catchments. The soil, climate and land use controls on mobilisation were also investigated. Results showed that grassland tended to limit nitrate-N leaching as compared to arable land, but grassland could also contribute to increased P solubilisation. In the context of land use change in these groundwater fed systems, the risk of pollution swapping between N and P must be carefully considered, particularly for interactions of land use with soil chemistry and climate.
Collapse
Affiliation(s)
- Rémi Dupas
- INRA, Agrocampus Ouest, UMR1069 SAS, F-35000 Rennes, France.
| | - Per-Erik Mellander
- Teagasc Agricultural Catchments Programme, Johnstown Castle, Wexford, Co Wexford, Ireland
| | | | - Ophélie Fovet
- INRA, Agrocampus Ouest, UMR1069 SAS, F-35000 Rennes, France
| | - Eoin B McAleer
- Teagasc Agricultural Catchments Programme, Johnstown Castle, Wexford, Co Wexford, Ireland; Geology Department, School of Natural Sciences, Trinity College, Dublin 2, Ireland
| | - Noeleen T McDonald
- Teagasc Agricultural Catchments Programme, Johnstown Castle, Wexford, Co Wexford, Ireland
| | - Mairead Shore
- Teagasc Agricultural Catchments Programme, Johnstown Castle, Wexford, Co Wexford, Ireland
| | - Phil Jordan
- School of Geography and Environmental Sciences, Ulster University, Coleraine, N. Ireland, UK
| |
Collapse
|
18
|
Mockler EM, Deakin J, Archbold M, Gill L, Daly D, Bruen M. Sources of nitrogen and phosphorus emissions to Irish rivers and coastal waters: Estimates from a nutrient load apportionment framework. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 601-602:326-339. [PMID: 28570968 DOI: 10.1016/j.scitotenv.2017.05.186] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/19/2017] [Accepted: 05/20/2017] [Indexed: 05/09/2023]
Abstract
More than half of surface water bodies in Europe are at less than good ecological status according to Water Framework Directive assessments, and diffuse pollution from agriculture remains a major, but not the only, cause of this poor performance. Agri-environmental policy and land management practices have, in many areas, reduced nutrient emissions to water. However, additional measures may be required in Ireland to further decouple the relationship between agricultural productivity and emissions to water, which is of vital importance given on-going agricultural intensification. The Source Load Apportionment Model (SLAM) framework characterises sources of phosphorus (P) and nitrogen (N) emissions to water at a range of scales from sub-catchment to national. The SLAM synthesises land use and physical characteristics to predict emissions from point (wastewater, industry discharges and septic tank systems) and diffuse sources (agriculture, forestry, etc.). The predicted annual nutrient emissions were assessed against monitoring data for 16 major river catchments covering 50% of the area of Ireland. At national scale, results indicate that total average annual emissions to surface water in Ireland are over 2700tyr-1 of P and 82,000tyr-1 of N. The proportional contributions from individual sources show that the main sources of P are from municipal wastewater treatment plants and agriculture, with wide variations across the country related to local anthropogenic pressures and the hydrogeological setting. Agriculture is the main source of N emissions to water across all regions of Ireland. These policy-relevant results synthesised large amounts of information in order to identify the dominant sources of nutrients at regional and local scales, contributing to the national nutrient risk assessment of Irish water bodies.
Collapse
Affiliation(s)
- Eva M Mockler
- UCD Dooge Centre for Water Resources Research and UCD Earth Institute, University College Dublin, Dublin 4, Ireland.
| | - Jenny Deakin
- Environmental Protection Agency, Clonskeagh, Ireland
| | | | - Laurence Gill
- Department of Civil, Structural and Environmental Engineering, Trinity College, Dublin, Ireland
| | - Donal Daly
- Environmental Protection Agency, Clonskeagh, Ireland
| | - Michael Bruen
- UCD Dooge Centre for Water Resources Research and UCD Earth Institute, University College Dublin, Dublin 4, Ireland
| |
Collapse
|
19
|
Gu S, Gruau G, Dupas R, Rumpel C, Crème A, Fovet O, Gascuel-Odoux C, Jeanneau L, Humbert G, Petitjean P. Release of dissolved phosphorus from riparian wetlands: Evidence for complex interactions among hydroclimate variability, topography and soil properties. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 598:421-431. [PMID: 28448934 DOI: 10.1016/j.scitotenv.2017.04.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/31/2017] [Accepted: 04/03/2017] [Indexed: 06/07/2023]
Abstract
In agricultural landscapes, establishment of vegetated buffer zones in riparian wetlands (RWs) is promoted to decrease phosphorus (P) emissions because RWs can trap particulate P from upslope fields. However, long-term accumulation of P risks the release of dissolved P, since the unstable hydrological conditions in these zones may mobilize accumulated particulate P by transforming it into a mobile dissolved P species. This study evaluates how hydroclimate variability, topography and soil properties interact and influence this mobilization, using a three-year dataset of molybdate-reactive dissolved P (MRDP) and total dissolved P (TDP) concentrations in soil water from two RWs located in an agricultural catchment in western France (Kervidy-Naizin), along with stream P concentrations. Two main drivers of seasonal dissolved P release were identified: i) soil rewetting during water-table rise after dry periods and ii) reductive dissolution of soil Fe (hydr)oxides during prolonged water saturation periods. These mechanisms were shown to vary greatly in space (according to topography) and time (according to intra- and interannual hydroclimate variability). The concentration and speciation of the released dissolved P also varied spatially depending on soil chemistry and local topography. Comparison of sites revealed a similar correlation between soil P speciation (percentage of organic P ranging from 35-70%) and the concentration and speciation of the released P (MRDP from <0.10 to 0.40mgl-1; percentage of MRDP in TDP from 25-70%). These differences propagated to stream water, suggesting that the two RWs investigated were the main sources of dissolved P to streams. RWs can be critical areas due to their ability to biogeochemically transform the accumulated P in these zones into highly mobile and highly bioavailable dissolved P forms. Hydroclimate variability, local topography and soil chemistry must be considered to decrease the risk of remobilizing legacy soil P when establishing riparian buffer zones in agricultural landscapes.
Collapse
Affiliation(s)
- Sen Gu
- Observatoire des Sciences de l'Univers de Rennes, CNRS, UMR 6118 Géosciences Rennes, Campus de Beaulieu, 35042 Rennes, France.
| | - Gérard Gruau
- Observatoire des Sciences de l'Univers de Rennes, CNRS, UMR 6118 Géosciences Rennes, Campus de Beaulieu, 35042 Rennes, France
| | - Rémi Dupas
- INRA, UMR 1069 Sol Agro et hydrosystème Spatialisation, 35042 Rennes, France; Department Aquatic Ecosystem Analysis, UFZ - Helmholtz-Centre for Environmental Research, Brueckstr. 3a, 39114 Magdeburg, Germany
| | - Cornélia Rumpel
- CNRS, Institut d'Ecologie et des Sciences de l'Environnement de Paris, Campus AgroParisTech, 78850 Thiverval-Grignon, France
| | - Alexandra Crème
- CNRS, Institut d'Ecologie et des Sciences de l'Environnement de Paris, Campus AgroParisTech, 78850 Thiverval-Grignon, France
| | - Ophélie Fovet
- INRA, UMR 1069 Sol Agro et hydrosystème Spatialisation, 35042 Rennes, France
| | | | - Laurent Jeanneau
- Observatoire des Sciences de l'Univers de Rennes, CNRS, UMR 6118 Géosciences Rennes, Campus de Beaulieu, 35042 Rennes, France
| | - Guillaume Humbert
- INRA, UMR 1069 Sol Agro et hydrosystème Spatialisation, 35042 Rennes, France
| | - Patrice Petitjean
- Observatoire des Sciences de l'Univers de Rennes, CNRS, UMR 6118 Géosciences Rennes, Campus de Beaulieu, 35042 Rennes, France
| |
Collapse
|
20
|
Shore M, Murphy S, Mellander PE, Shortle G, Melland AR, Crockford L, O'Flaherty V, Williams L, Morgan G, Jordan P. Influence of stormflow and baseflow phosphorus pressures on stream ecology in agricultural catchments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 590-591:469-483. [PMID: 28284645 DOI: 10.1016/j.scitotenv.2017.02.100] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/10/2017] [Accepted: 02/11/2017] [Indexed: 05/07/2023]
Abstract
Stormflow and baseflow phosphorus (P) concentrations and loads in rivers may exert different ecological pressures during different seasons. These pressures and subsequent impacts are important to disentangle in order to target and monitor the effectiveness of mitigation measures. This study investigated the influence of stormflow and baseflow P pressures on stream ecology in six contrasting agricultural catchments. A five-year high resolution dataset was used consisting of stream discharge, P chemistry, macroinvertebrate and diatom ecology, supported with microbial source tracking and turbidity data. Total reactive P (TRP) loads delivered during baseflows were low (1-7% of annual loads), but TRP concentrations frequently exceeded the environmental quality standard (EQS) of 0.035mgL-1 during these flows (32-100% of the time in five catchments). A pilot microbial source tracking exercise in one catchment indicated that both human and ruminant faecal effluents were contributing to these baseflow P pressures but were diluted at higher flows. Seasonally, TRP concentrations tended to be highest during summer due to these baseflow P pressures and corresponded well with declines in diatom quality during this time (R2=0.79). Diatoms tended to recover by late spring when storm P pressures were most prevalent and there was a poor relationship between antecedent TRP concentrations and diatom quality in spring (R2=0.23). Seasonal variations were less apparent in the macroinvertebrate indices; however, there was a good relationship between antecedent TRP concentrations and macroinvertebrate quality during spring (R2=0.51) and summer (R2=0.52). Reducing summer point source discharges may be the quickest way to improve ecological river quality, particularly diatom quality in these and similar catchments. Aligning estimates of P sources with ecological impacts and identifying ecological signals which can be attributed to storm P pressures are important next steps for successful management of agricultural catchments at these scales.
Collapse
Affiliation(s)
- Mairead Shore
- Agricultural Catchments Programme, Teagasc, Johnstown Castle, Wexford, Ireland; Environment Section, Wexford County Council, Carricklawn, Wexford, Ireland.
| | - Sinead Murphy
- Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland, Galway, Ireland
| | - Per-Erik Mellander
- Agricultural Catchments Programme, Teagasc, Johnstown Castle, Wexford, Ireland; Teagasc, Johnstown Castle Environment Research Centre, Wexford, Co. Wexford, Ireland
| | - Ger Shortle
- Agricultural Catchments Programme, Teagasc, Johnstown Castle, Wexford, Ireland
| | - Alice R Melland
- National Centre for Engineering in Agriculture, University of Southern Queensland, Toowoomba 4350, Queensland, Australia
| | - Lucy Crockford
- Crops and Environment Section, Harper Adams University, Newport TF10 8NB, United Kingdom
| | - Vincent O'Flaherty
- Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland, Galway, Ireland
| | - Lauren Williams
- Aquatic Services Unit, Environmental Research Institute, University College Cork, Ireland
| | - Ger Morgan
- Aquatic Services Unit, Environmental Research Institute, University College Cork, Ireland
| | - Phil Jordan
- Agricultural Catchments Programme, Teagasc, Johnstown Castle, Wexford, Ireland; School of Geography and Environmental Sciences, Ulster University, Coleraine, Ireland
| |
Collapse
|
21
|
Cassidy R, Doody DG, Watson CJ. Impact of legacy soil phosphorus on losses in drainage and overland flow from grazed grassland soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 575:474-484. [PMID: 28029454 DOI: 10.1016/j.scitotenv.2016.07.063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/07/2016] [Accepted: 07/09/2016] [Indexed: 05/26/2023]
Abstract
Rates and quantities of legacy soil phosphorus (P) lost from agricultural soils, and the timescales for positive change to water quality, remain unclear. From 2000 to 2004 five 0.2ha grazed grassland plots located on a drumlin hillslope in Northern Ireland, received chemical fertiliser applications of 0, 10, 20, 40, 80kgPha-1yr-1 resulting in soil Olsen P concentrations of 19, 24, 28, 38 and 67mgPL-1, respectively, after which applications ceased. Soil Olsen P and losses to overland flow and drainage were monitored from 2005 to 2011 on an event and weekly flow proportional basis, respectively. Soluble reactive P and total P time series were synchronised with daily rainfall and modelled soil moisture deficits. From 2005 to 2011 soil Olsen P decline was proportional to soil P status with a 43% reduction in the plot at 67mgPL-1 in 2004 and a corresponding 12% reduction in the plot with lowest soil P. However, there was no significant difference in the flow-weighted mean concentration for overland flow among plots, all of which exceeded 0.035mgL-1 in >98% of events. Strong interannual and event variations in losses were observed with up to 65% of P being lost during a single rainfall event. P concentrations in drainage flow were independent of Olsen P and drain efficiency was potentially the primary control on concentrations, with the highest concentrations recorded in the plot at 38mgL-1 Olsen P in 2004 (up to 2.72mgL-1). Hydrological drivers, particularly antecedent soil moisture, had a strong influence on P loss in both overland and drainage flow, with higher concentrations recorded above a soil moisture deficit threshold of 7mm. This study demonstrates that on some soil types, legacy P poses a significant long term threat to water quality, even at agronomically optimum soil P levels.
Collapse
Affiliation(s)
- Rachel Cassidy
- Agri-Environment Branch, Agri-Food and Biosciences Institute (AFBI), Newforge Lane, Belfast, BT9 5PX, Northern Ireland.
| | - Donnacha G Doody
- Agri-Environment Branch, Agri-Food and Biosciences Institute (AFBI), Newforge Lane, Belfast, BT9 5PX, Northern Ireland
| | - Catherine J Watson
- Agri-Environment Branch, Agri-Food and Biosciences Institute (AFBI), Newforge Lane, Belfast, BT9 5PX, Northern Ireland
| |
Collapse
|
22
|
Rode M, Wade AJ, Cohen MJ, Hensley RT, Bowes MJ, Kirchner JW, Arhonditsis GB, Jordan P, Kronvang B, Halliday SJ, Skeffington RA, Rozemeijer JC, Aubert AH, Rinke K, Jomaa S. Sensors in the Stream: The High-Frequency Wave of the Present. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:10297-10307. [PMID: 27570873 DOI: 10.1021/acs.est.6b02155] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
New scientific understanding is catalyzed by novel technologies that enhance measurement precision, resolution or type, and that provide new tools to test and develop theory. Over the last 50 years, technology has transformed the hydrologic sciences by enabling direct measurements of watershed fluxes (evapotranspiration, streamflow) at time scales and spatial extents aligned with variation in physical drivers. High frequency water quality measurements, increasingly obtained by in situ water quality sensors, are extending that transformation. Widely available sensors for some physical (temperature) and chemical (conductivity, dissolved oxygen) attributes have become integral to aquatic science, and emerging sensors for nutrients, dissolved CO2, turbidity, algal pigments, and dissolved organic matter are now enabling observations of watersheds and streams at time scales commensurate with their fundamental hydrological, energetic, elemental, and biological drivers. Here we synthesize insights from emerging technologies across a suite of applications, and envision future advances, enabled by sensors, in our ability to understand, predict, and restore watershed and stream systems.
Collapse
Affiliation(s)
- Michael Rode
- Department of Aquatic Ecosystem Analysis and Management, Helmholtz Centre for Environmental Research-UFZ , Brueckstrasse 3a, D-39114 Magdeburg, Germany
| | - Andrew J Wade
- Department of Geography and Environmental Science, University of Reading , Whiteknights, Reading, United Kingdom
| | - Matthew J Cohen
- School of Natural Resources and Environment, University of Florida , Gainesville, Florida 32611, United States
| | - Robert T Hensley
- School of Forest Resources and Conservation, University of Florida , Gainesville, Florida 32611, United States
| | - Michael J Bowes
- Centre for Ecology and Hydrology, Wallingford, Oxon. OX10 8BB, United Kingdom
| | - James W Kirchner
- Department of Environmental Sciences, Swiss Federal Institute of Technology-ETH , Zürich, Switzerland
- Swiss Federal Research Institute, WSL , Birmensdorf, Switzerland
| | - George B Arhonditsis
- Ecological Modelling Laboratory, Department of Physical and Environmental Sciences, University of Toronto , Toronto, Ontario Canada
| | - Phil Jordan
- School of Environmental Sciences, Ulster University , Coleraine, Northern Ireland, United Kingdom
| | - Brian Kronvang
- Department of Bioscience and DCE-National Centre of Environment and Energy, Aarhus University , Vejlsøvej 25, DK-8600 Silkeborg, Denmark
| | - Sarah J Halliday
- Department of Geography and Environmental Science, University of Reading , Whiteknights, Reading, United Kingdom
| | - Richard A Skeffington
- Department of Geography and Environmental Science, University of Reading , Whiteknights, Reading, United Kingdom
| | | | - Alice H Aubert
- Department of Environmental Social Sciences, Eawag, Überlandstrasse 133, 8600 Dübendorf, Switzerland
| | - Karsten Rinke
- Department of Lake Research, Helmholtz Centre for Environmental Research-UFZ , Brueckstrasse 3a, D-39114 Magdeburg, Germany
| | - Seifeddine Jomaa
- Department of Aquatic Ecosystem Analysis and Management, Helmholtz Centre for Environmental Research-UFZ , Brueckstrasse 3a, D-39114 Magdeburg, Germany
| |
Collapse
|
23
|
Valera CA, Valle Junior RF, Varandas SGP, Sanches Fernandes LF, Pacheco FAL. The role of environmental land use conflicts in soil fertility: A study on the Uberaba River basin, Brazil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 562:463-473. [PMID: 27107645 DOI: 10.1016/j.scitotenv.2016.04.046] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/07/2016] [Accepted: 04/07/2016] [Indexed: 06/05/2023]
Abstract
In the Uberaba River basin (state of Minas Gerais, Brazil), pastures for livestock production have invaded areas of native vegetation (Cerrado biome), while already existing pastures were invaded by crop agriculture, with an expansion of sugar cane plantations in the most recent years. In some areas of the basin, these land use changes were classified as environmental land use conflicts because the new uses were not conforming to land capability, i.e. the soil's natural use. Where the areas in conflict became dense, some soil properties have changed significantly, namely the organic matter content and the exchangeable potassium concentration, which have decreased drastically (5kg/m(3) per 10% increase in the conflict area) threatening the fertility of soil. Besides, these changes may have triggered a cascade of other environmental damages, specifically the increase of soil erosion and the degradation of water quality with negative impacts on aquatic biodiversity, related to a disruption of soil organic matter structural functions. Because half the Uberaba catchment has been considered is a state of accentuated environmental degradation, not only caused by environmental land use conflicts, conservation measures have been proposed and requested for immediate implementation across the watershed.
Collapse
Affiliation(s)
- C A Valera
- Promotoria de Justiça do Ministério Público do Estado de Minas Gerais, Brazil
| | - R F Valle Junior
- Instituto Federal do Triângulo Mineiro, Campus de Uberaba, Estado de Minas Gerais, Brazil
| | - S G P Varandas
- Centro de Investigação e Tecnologias Agroambientais e Biológicas, Universidade de Trás-os-Montes e Alto Douro, Ap 1013, 5001-801 Vila Real, Portugal
| | - L F Sanches Fernandes
- Centro de Investigação e Tecnologias Agroambientais e Biológicas, Universidade de Trás-os-Montes e Alto Douro, Ap 1013, 5001-801 Vila Real, Portugal
| | - F A L Pacheco
- Centro de Química de Vila Real, University of Trás-os-Montes and Alto Douro, Ap 1013, 5001-801 Vila Real, Portugal.
| |
Collapse
|
24
|
Shore M, Jordan P, Melland AR, Mellander PE, McDonald N, Shortle G. Incidental nutrient transfers: Assessing critical times in agricultural catchments using high-resolution data. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 553:404-415. [PMID: 26933967 DOI: 10.1016/j.scitotenv.2016.02.085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/12/2016] [Accepted: 02/12/2016] [Indexed: 06/05/2023]
Abstract
Managing incidental losses associated with liquid slurry applications during closed periods has significant cost and policy implications and the environmental data required to review such a measure are difficult to capture due to storm dependencies. Over four years (2010-2014) in five intensive agricultural catchments, this study used high-resolution total and total reactive phosphorus (TP and TRP), total oxidised nitrogen (TON) and suspended sediment (SS) concentrations with river discharge data to investigate the magnitude and timing of nutrient losses. A large dataset of storm events (defined as 90th percentile discharges), and associated flow-weighted mean (FWM) nutrient concentrations and TP/SS ratios, was used to indicate when losses were indicative of residual or incidental nutrient transfers. The beginning of the slurry closed period was reflective of incidental and residual transfers with high storm FWM P (TP and TRP) concentrations, with some catchments also showing elevated storm TP:SS ratios. This pattern diminished at the end of the closed period in all catchments. Total oxidised N behaved similarly to P during storms in the poorly drained catchments and revealed a long lag time in other catchments. Low storm FWM P concentrations and TP:SS ratios during the weeks following the closed period suggests that nutrients either weren't applied during this time (best times chosen) or that they were applied to less risky areas (best places chosen). For other periods such as late autumn and during wet summers, where storm FWM P concentrations and TP:SS ratios were high, it is recommended that an augmentation of farmer knowledge of soil drainage characteristics with local and detailed current and forecast soil moisture conditions will help to strengthen existing regulatory frameworks to avoid storm driven incidental nutrient transfers.
Collapse
Affiliation(s)
- Mairead Shore
- Agricultural Catchments Programme, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Co. Wexford, Ireland
| | - Phil Jordan
- School of Geography and Environmental Sciences, Ulster University, Coleraine, N. Ireland, United Kingdom
| | - Alice R Melland
- National Centre for Engineering in Agriculture, University of Southern Queensland, Toowoomba, Australia
| | - Per-Erik Mellander
- Agricultural Catchments Programme, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Co. Wexford, Ireland
| | - Noeleen McDonald
- Agricultural Catchments Programme, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Co. Wexford, Ireland
| | - Ger Shortle
- Agricultural Catchments Programme, Teagasc, Johnstown Castle Environment Research Centre, Wexford, Co. Wexford, Ireland
| |
Collapse
|