Agricultural Diffuse Pollution Research Articles

Spatially-Distributed Cost-Effectiveness Analysis Framework to Control Phosphorus from Agricultural Diffuse Pollution.

Best management practices (BMPs) for agricultural diffuse pollution control are implemented at the field or small-watershed scale. However, the benefits of BMP implementation on receiving water quality at multiple spatial is an ongoing challenge. In this paper, we introduce an integrated approach that combines risk assessment (i.e., Phosphorus (P) index), model simulation techniques (Hydrological Simulation Program–FORTRAN), and a BMP placement tool at various scales to identify the optimal location for implementing multiple BMPs and estimate BMP effectiveness after implementation. A statistically significant decrease in nutrient discharge from watersheds is proposed to evaluate the effectiveness of BMPs, strategically targeted within watersheds. Specifically, we estimate two types of cost-effectiveness curves (total pollution reduction and proportion of watersheds improved) for four allocation approaches. Selection of a ‘‘best approach” depends on the relative importance of the two types of effectiveness, which involves a value judgment based on the random/aggregated degree of BMP distribution among and within sub-watersheds. A statistical optimization framework is developed and evaluated in Chaohe River Watershed located in the northern mountain area of Beijing. Results show that BMP implementation significantly (p >0.001) decrease P loss from the watershed. Remedial strategies where BMPs were targeted to areas of high risk of P loss, deceased P loads compared with strategies where BMPs were randomly located across watersheds. Sensitivity analysis indicated that aggregated BMP placement in particular watershed is the most cost-effective scenario to decrease P loss. The optimization approach outlined in this paper is a spatially hierarchical method for targeting nonpoint source controls across a range of scales from field to farm, to watersheds, to regions. Further, model estimates showed targeting at multiple scales is necessary to optimize program efficiency. The integrated model approach described that selects and places BMPs at varying levels of implementation, provides a new theoretical basis and technical guidance for diffuse pollution management in agricultural watersheds.

Constructed and riverine wetlands design considerations for domestic and agricultural diffuse pollution treatment—a case study from Turkey

In this study, a riverine constructed wetland system (RCWS) was monitored with the aim to investigate its functionality and cost-effectiveness in treating domestic wastewater. Turkey’s second biggest freshwater lake, Eğirdir lake, is becoming polluted directly and indirectly with both domestic and diffuse pollution sources. In this paper we: (1) describe a water quality monitoring campaign on an existing long drainage channel where the majority of pollution originates from untreated urban sewage (2) discuss the design parameters and some considerations for a new RCWS to diminish and eliminate domestic and diffuse pollution loads originating from Gelendost and Yaka. In our design considerations, (1) we projected population increase over a 30-year period, which resulted in total 12,000 population equivalent, including the drainage network run-off originating from agriculture; (2) we aim to achieve 90% reduction in chemical oxygen demand, 70% of nitrogen (N) and 40% of total phosphorus. To achieve design objectives, we propose that the new RCWS consists of six horizontal flow CW and seven FWS systems, laid out within the drainage channel bed itself. This project would represent one of the few systems specifically designed to provide diffuse pollution treatment, and would be the first system of this kind in Turkey.

Integrated Watershed Management for Lake Mogan with the focus of Agricultural Diffuse Pollution

Integrated Watershed Management for Lake Mogan with the focus of Agricultural Diffuse Pollution

Development of organic farming for the protection of water quality: Local projects in France and their policy implications

French public action privileges organic farming in areas with water quality problems as a way to prevent diffuse agricultural pollution. This article compares four projects connecting organic farming incentives with water quality protection. It aims at elucidating how concerned actors compromise with and implement public policy in locally specific ways. Our results show that these projects may come from two logics of public action. The first, supported by water-related actors, aims to improve drinking water quality and is focused on water catchments. The second is backed primarily by actors in agriculture and focuses on re-enforcing actions for the development of organic agriculture, carried out on a larger territorial scale. Actor networks involved in the projects differ according to local contexts, project backers, and objectives. They become more complex over time, leading actors for water, organic agricultural development, and economic production chains to work together. Actors’ visions and referentials change, influencing the projects’ initial objectives. The conclusion discusses such projects’ relevance and limits.

Intensive management in grasslands causes diffuse water pollution at the farm scale.

Arable land use is generally assumed to be the largest contributor to agricultural diffuse pollution. This study adds to the growing evidence that conventional temperate intensively managed lowland grasslands contribute significantly to soil erosion and diffuse pollution rates. This is the first grassland study to monitor hydrological characteristics and multiple pollutant fluxes (suspended sediment [SS] and the macronutrients: total oxidized nitrogen-N [TON], total phosphorus [TP], and total carbon [TC]) at high temporal resolution (monitoring up to every 15 min) over 1 yr. Monitoring was conducted across three fields (6.5-7.5 ha) on the North Wyke Farm Platform, UK. The estimated annual erosion rates (up to 527.4 kg ha), TP losses (up to 0.9 kg ha), and TC losses (up to 179 kg ha) were similar to or exceeded the losses reported for other grassland, mixed land-use, and arable sites. Annual yields of TON (up to 3 kg ha) were less than arable land-use fluxes and earlier grassland N studies, an important result as the study site is situated within a Nitrate Vulnerable Zone. The high-resolution monitoring allowed detailed "system's functioning" understanding of hydrological processes, mobilization- transport pathways of individual pollutants, and the changes of the relative importance of diffuse pollutants through flow conditions and time. Suspended sediment and TP concentrations frequently exceeded water quality guidelines recommended by the European Freshwater Fisheries Directive (25 mg L) and the European Water Framework Directive (0.04 mg soluble reactive P L), suggesting that intensively managed grasslands pose a significant threat to receiving surface waters. Such sediment and nutrient losses from intensively managed grasslands should be acknowledged in land management guidelines and advice for future compliance with surface water quality standards.

Regional water quality patterns in an alluvial aquifer: Direct and indirect influences of rivers

The influence of rivers on the groundwater quality in alluvial aquifers can be twofold: direct and indirect. Rivers can have a direct influence via recharge and an indirect one by controlling the distribution of fine-grained, organic-carbon rich flood deposits that induce reducing conditions. These direct and indirect influences were quantified for a large alluvial aquifer on the Swiss Plateau (50km2) in interaction with an Alpine river using nitrate as an example. The hydrochemistry and stable isotope composition of water were characterized using a network of 115 piezometers and pumping stations covering the entire aquifer. Aquifer properties, land use and recharge zones were evaluated as well. This information provided detailed insight into the factors that control the spatial variability of groundwater quality. Three main factors were identified: (1) diffuse agricultural pollution sources; (2) dilution processes resulting from river water infiltrations, revealed by the δ18OH2O and δ2HH2O contents of groundwater; and (3) denitrification processes, controlled by the spatial variability of flood deposits governed by fluvial depositional processes. It was possible to quantify the dependence of the nitrate concentration on these three factors at any sampling point of the aquifer using an end-member mixing model, where the average nitrate concentration in recharge from the agricultural area was evaluated at 52mg/L, and the nitrate concentration of infiltrating river at approximately 6mg/L. The study shows the importance of considering the indirect and direct impacts of rivers on alluvial aquifers and provides a methodological framework to evaluate aquifer scale water quality patterns.

Vertical and horizontal distribution of soil parameters in intensive agricultural zone and effect on diffuse nitrogen pollution

Understanding the spatial relationships of diffuse agricultural pollution with soil properties at a sub-basin scale is an innovative way to characterize the pollution yield. The objectives of this study was to identify the interaction of soil parameters with diffuse nitrogen (N) loading at spatial-vertical directions, which provide an optional method to assess the diffuse N pollution. The diffuse N loading of a sub-basin was simulated with the Soil and Water Assessment Tool with the consideration of land use (upland and paddy rice). Soil properties were analyzed in terms of eight parameters by employing a 1.5km-grid soil sampling process at two depths across multiple sub-basins. The spatial soil properties were interpolated for each sub-basin. The spatial distributions of total nitrogen (TN), iron (Fe), manganese (Mn), and cadmium (Cd) exhibited the same pattern at two soil depths, but the vertical patterns of available nitrogen (AN), soil organic carbon (SOC), sulfur (S) and lead (Pb) varied. Overlaying the diffuse N loading and land use distribution, it was found that the sub-basins of upland and paddy rice were primary contributors. The diffuse N discharged from upland sub-basins was about 50% lower than that from paddy rice. The correlation analysis of soil variables with diffuse N indicated that the top layer had a stronger relationship with the diffuse N than the subsurface, which had more direct impact on the pollution. A partial least squares (PLS) regression analysis was employed to identify the key soil variables in surface layer. The analysis indicated that the metal parameters (Fe, Mn, Cd, and Pb) were the important factors for diffuse N loading. However, the TN in the paddy rice was the principal predictor. With the soil property information, the diffuse N yield from the two types of farmlands can be assessed in a simplified way. The developed method in this paper is flexible and efficient, which also is compatible with results of the SWAT model.

ANNUAL DRAINAGE VOLUMES AND NITRATE-NITROGEN LEACHING UNDER SILAGE MAIZE IN WET AND DRY YEAR

The quantity of nitrate in groundwater is affected by diffuse agricultural pollution and hence, it is strongly linked to the amount of applied nitrogen (in surplus) on agricultural land. In order to determine nitrate-nitrogen leaching in diverse precipitation conditions, lysimetric field experiment was set in 2011 in Varaždin County, Croatia. Leachate from three zero-tension pan lysimeters on agricultural plot (maize) was collected twice a month or after abundant rainfall. Research results show that 25% of total precipitation leached in 2012 and 13% in 2013. ANOVA results confirm there is a statistically significant difference in NO3-N concentrations between hydrological dry and wet years. In dry years NO3-N concentrations vary from 36 to 56 mg/l and in 2013 from 8 to 40 mg/l.

Seasonal changes in the performance of a catch crop for mitigating diffuse agricultural pollution

An in situ technology for mitigating diffuse agricultural pollution using catch crops was developed for simultaneously preventing nitrate groundwater pollution, reducing nitrous oxide (N2O) gas emissions, and removing salts from the topsoil. Seasonal changes in the performance of a catch crop were investigated using lysimeters in a full-scale greenhouse experiment with 50 d cultivation of dent corn. Catch crop cultivation significantly reduced the leached mineral nitrogen by 89-91% in summer, 87-89% in spring, and 61-82% in winter, and it also significantly reduced the N2O emission by 68-84% in summer. The amounts of nitrogen uptake by the catch crop were remarkably higher than those of leached nitrogen and N2O emission in each season. Catch crop cultivation is a promising technology for mitigating diffuse agricultural pollution.

A new approach for reducing diffuse agricultural pollution in water supply ponds

Preserving the quality of raw water for drinking likely to be affected by diffuse pollution in water supply ponds (WSPs) is a major public health issue. We must therefore implement efficient and sustainable technical measures that guarantee the long-term protection of this resource. Such measures can prove to be a considerable constraint for farm managers and farm owners. It is consequently absolutely necessary that the compensation provided for is in line with these constraints. High stakes and high constraints must result in high compensation. The catchment protection perimeter tool, reviewed and enlarged to encompass up to 100% of the WSP, renewed and in-depth dialogue based on solid technical and economic studies and a new compensation method established from the principle of discounted loss capitalisation over a duration equal to the lease, are all new and promising tools to solve this essential problem for sustainable development throughout the territory and to preserve the health of its population.

Is it worth protecting groundwater from diffuse pollution with agri-environmental schemes? A hydro-economic modeling approach

In Europe, 30% of groundwater bodies are considered to be at risk of not achieving the Water Framework Directive (WFD) ‘good status’ objective by 2015, and 45% are in doubt of doing so. Diffuse agricultural pollution is one of the main pressures affecting groundwater bodies. To tackle this problem, the WFD requires Member States to design and implement cost-effective programs of measures to achieve the ‘good status’ objective by 2027 at the latest. Hitherto, action plans have mainly consisted of promoting the adoption of Agri-Environmental Schemes (AES). This raises a number of questions concerning the effectiveness of such schemes for improving groundwater status, and the economic implications of their implementation. We propose a hydro-economic model that combines a hydrogeological model to simulate groundwater quality evolution with agronomic and economic components to assess the expected costs, effectiveness, and benefits of AES implementation. This hydro-economic model can be used to identify cost-effective AES combinations at groundwater-body scale and to show the benefits to be expected from the resulting improvement in groundwater quality. The model is applied here to a rural area encompassing the Hesbaye aquifer, a large chalk aquifer which supplies about 230,000 inhabitants in the city of Liege (Belgium) and is severely contaminated by agricultural nitrates. We show that the time frame within which improvements in the Hesbaye groundwater quality can be expected may be much longer than that required by the WFD. Current WFD programs based on AES may be inappropriate for achieving the ‘good status’ objective in the most productive agricultural areas, in particular because these schemes are insufficiently attractive. Achieving ‘good status’ by 2027 would demand a substantial change in the design of AES, involving costs that may not be offset by benefits in the case of chalk aquifers with long renewal times.

Assessing the Influence of Catchment Land-Use Patterns on the Nutrients and Major Ions Chemistry of Drainage Water

This work describes the influence of soil use on the evolution of nutrients [ammonium (NH4), nitrate (NO3), nitrite (NO2), phosphate (PO4) phosphorus (P)] and major ions [calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), silicon (Si), chloride (Cl), sulfate (SO4)] concentrations in drainage water of a catchment with two consecutive land uses: first agricultural and then forest. This is a small catchment with previous agricultural diffuse and accidental pollution mainly due to the spreading of slurry. Ion concentrations were monitored over a period of approximately 6 years at the catchment outlet. Agricultural land use was replaced by eucalyptus plantations from mid-July 1998. Great temporal variability was observed for each ion and also among ions. The mean concentrations of studied ions were greatest during the agricultural period. The most pronounced differences occurred for NH4, PO4-P, NO2, and K. All presented the greatest concentration peaks in the agricultural phase, with the exception of Ca. During this period the following concentrations (mg L−1) were reached: NO3110, NH4 31, NO2 3.76, PO4-P 35.96, Ca 30, Mg 12.42, K 97, Na 50, Si 13.9, Cl 96, and SO4 16.6. The slurries seem to have contributed notably toward the increase in the concentration of nutrients and major ions in the drainage water of the catchment, affecting water quality.

Concept of an innovative water management system with decentralized water reclamation and cascading material-cycle for agricultural areas

Unlike in urban areas where intensive water reclamation systems are available, development of decentralized technologies and systems is required for water use to be sustainable in agricultural areas. To overcome various water quality issues in those areas, a research project entitled 'Development of an innovative water management system with decentralized water reclamation and cascading material-cycle for agricultural areas under the consideration of climate change' was launched in 2009. This paper introduces the concept of this research and provides detailed information on each of its research areas: (1) development of a diffuse agricultural pollution control technology using catch crops; (2) development of a decentralized differentiable treatment system for livestock and human excreta; and (3) development of a cascading material-cycle system for water pollution control and value-added production. The author also emphasizes that the innovative water management system for agricultural areas should incorporate a strategy for the voluntary collection of bio-resources.

Application of the FARMSCOPER tool for assessing agricultural diffuse pollution mitigation methods across the Hampshire Avon Demonstration Test Catchment, UK

Abstract Agricultural diffuse pollution is a significant contributor to water and air quality in many catchments and the need to control harmful emissions remains paramount for government policy. In England, the Demonstration Test Catchments (DTCs) have been established to provide a basis for testing on-farm mitigation measures using collaborative multi-partner research and some of this work is targeting the Hampshire Avon (∼1700 km2) catchment. To help provide integrated farm advice across England and Wales, a new Excel-based tool, FARM Scale Optimisation of Pollutant Emission Reductions (FARMSCOPER), has recently been developed for characterising diffuse agricultural pollutant emissions from representative farm types and quantifying the expected impacts of control options on those losses to the environment. Against this background, this paper describes the application of FARMSCOPER in the Hampshire Avon DTC in order to assess its utility at catchment scale and the potential benefits of relevant and practical mitigation options. Spatial datasets and the Agricultural Census returns for 2009 specific to the River Avon catchment were integrated to produce a collection of representative farm types which capture the characteristics of the local physical environment, land use patterns and farm management practices. FARMSCOPER was used to estimate the annual emissions of nitrate, phosphorus, sediment, nitrous oxide, methane and ammonia for each representative farm type. The scenarios investigated comprised baseline losses with no mitigation measures implemented, current emissions using information on the present implementation of options under existing schemes and initiatives and, the maximum potential reduction possible on the basis of implementing all available and relevant options. Model outputs suggested that reductions in pollutant loads in response to the existing uptake of mitigation methods are small (e.g. 10% for phosphorus, 7% for sediment, 4% for nitrate and 5% for nitrous oxide). FARMSCOPER suggested that technically feasible pollutant reductions on the basis of the implementation of more mitigation options could be of the order of 47% for phosphorus, 66% for sediment, 22% for nitrate and 16% for nitrous oxide. This work represents the first catchment scale application of the FARMSCOPER tool.

Monitoring agricultural diffuse pollution through a dense monitoring network in the River Eden Demonstration Test Catchment, Cumbria, UK

The water quality of our rivers and lakes is a reflection of the landscape over and through which it travels. The UK government, along with all European Union member states, are obliged under the Water Framework Directive (WFD) to aim for good ecological status of fresh water bodies by 2015. In order to evaluate the effectiveness of potential mitigation measures in reducing diffuse water pollution from agriculture at the catchment scale, the Demonstration Test Catchment (DTC) project was developed. The project is jointly funded by Defra, the Environment Agency (EA) and the Welsh Assembly Government (WAG). There are three DTCs across the country: the Eden catchment, Cumbria; the Wensum catchment, Norfolk and the Hampshire Avon catchment. The Eden DTC has established three ∼10 km2 focus catchments, chosen to reflect different farming practices, geologies, elevations and hydrological characteristics. Within each focus catchment, two sub‐catchments have been selected, one control and one mitigated, in which numerous existing and novel mitigation measures will be tested. It is hoped that the mitigation features will be multi‐purpose, having positive effects on pollutant retention, flooding, carbon sequestration, habitat creation and biodiversity. The effectiveness of these measures is assessed through networks of hydro‐meteorological and water‐quality instrumentation, most of which will provide data in near real time, with sub‐hourly time steps.

WHY ARE THERE SO FEW COOPERATIVE AGREEMENTS BETWEEN FARMERS AND WATER SERVICES IN FRANCE? WATER POLICIES AND THE PROBLEM OF LAND USE RIGHTS

ABSTRACTOne of the recurrent shortcomings of water policy in France is the control of diffuse agricultural pollution. Numerous lacunae and incoherencies in the French Rural, Public Health, and Environmental Codes have hindered the effective implementation of efficient protection measures. In this paper, we underline the extent to which these incoherencies have hampered the emergence of cooperative agreements (CAs) between farmers and drinking water service providers. The theoretical framework of institutional resource regimes (IRRs) provides a key to understanding the failure of public policy to impose restrictions on agricultural land use rights and to encourage voluntary arrangements concerning agricultural practices. The IRR framework was applied before 2005 to 12 cases of public attempts to negotiate a reduction in polluting practices. Our study enabled us to characterise the lack of extent and coherence of the water sector's IRR in France. Since 2005, regulatory changes have extended the scope of this IRR with a view to making water, agriculture and health policies more coherent. We discuss the complexity of the new approach, and question its capacity to mobilise the actors concerned around the territorial reorganisation of agriculture aimed at reducing diffuse pollution. Copyright © 2012 John Wiley & Sons, Ltd.

Fratta-Gorzone Guide Lines: Rehabilitation and renaturalization of a river in the Veneto region

The Fratta-Gorzone River is classified in the recent PTA plan as one of the most polluted rivers in the Veneto region. Its Basin -about 1.500 sqKm- includes all the main landscape ambits catalogued by the PTRC plan (from the pre-Alpes in Vicenza Province to the dune landscape of the Venice Lagoon southern part). The Fratta waterway is 93 km long and is known as the Rio Acquetta-Togna-Fratta Gorzone/Agno-Guà-Frassine-Santa Caterina-Gorzone River System. This Waterway System from one part has great elements of strenght as the rich riverine historical and landscape heritage, and from the other part has serious weaknesses due to the tanning district pollution and to the diffuse agricultural, urban and industrial pollution. Fratta is a medium-high hydraulic risk zone. Until Know all the Planning Instruments and Practices deal with the northern part of Fratta. The more recent Plan too –the “Accordo di Programma Quadro 05/12/2005”- has as focal point the reduction of pollution (chrome and chloride mainly) and the use of traditional treatment systems (linked with some constructed wetland systems). Our Paper present the last 2009 Scenario-Plan, promoted by an anusual Group: Water Consorzio LEB with the Regione Veneto supervision, AATO del Chiampo, Sentinella dei Fiumi Association, Coldiretti, IUAV University and two Private Industries.

Fuzzy expert system for the detection of episodes of poor water quality through continuous measurement

In order to prevent and reduce water pollution, promote a sustainable use, protect the environment and enhance the status of aquatic ecosystems, this article deals with the application of advanced mathematical techniques designed to aid in the management of records of different water quality monitoring networks. These studies include the development of a software tool for decision support, based on the application of fuzzy logic techniques, which can indicate water quality episodes from the behavior of variables measured at continuous automatic water control networks. Using a few physical–chemical variables recorded continuously, the expert system is able to obtain water quality phenomena indicators, which can be associated, with a high probability of cause–effect relationship, with human pressure on the water environment, such as urban discharges or diffuse agricultural pollution. In this sense, at the proposed expert system, automatic water quality control networks complement manual sampling of official administrative networks and laboratory analysis, providing information related to specific events (discharges) or continuous processes (eutrophication, fish risk) which can hardly be detected by discrete sampling.

Modelling long-term diffuse nitrate pollution at the catchment-scale: Data, parameter and epistemic uncertainty

Summary A model of catchment-scale nitrate transport is presented for a small, rural headwater basin (Alton Pancras: 2 ) in Dorset, UK, for the period 1930–2007. Estimates of annual nitrogen (N) loading were based on parish land-use data, held in the UK’s National Archives, and previously reported figures of typical UK N loadings from livestock, fertiliser, ploughing of permanent pasture, atmospheric deposition, biological fixation and crop uptake. Loading calculations were performed within an uncertainty framework to allow for the reliance on literature data sources. Loading calculations show that all significant sources must be included not just fertiliser application which, at most, contributes 50% of N input in any given year. A simple algorithm was used to transform estimated catchment N loading (1930–2007) into a river nitrate response (observed data: 1980–2004). This assumed N-loads were delayed by some catchment mean travel time (MTT), t a , attenuated according to a Peclet number, P e , converted into solute concentrations by a factor, α , to increase some initial baseline river concentration, C b . Simple graphical translation of estimated catchment N loading to the river concentration data suggested a MTT of around 37 years. As P e → ∞ , the transport model simplified to a linear relationship between catchment N load and river nitrate concentration response lagged by the MTT. Hence, the model results suggest that, in this catchment, advection is the dominant mechanism for transport of diffuse pollution from land to river: there is little or no dispersion present. The MTT ( t a ) was then reconsidered using an estimated distribution of unsaturated zone depths in the Alton Pancras catchment. Conclusions suggest that, in modelling of long-term nutrient transport, a detailed source term is of much greater importance than a complex hydrogeological model. Implications of epistemic uncertainty, long-term prediction and management of diffuse agricultural pollution are discussed.

Responses of toad tadpoles to ammonium nitrate fertilizer and predatory stress: Differences between populations on a local scale

Agriculture-related pollution is among the major causes of global amphibian population declines. The multiple stressors to which amphibians are exposed in the field, such as predation pressure, can make agrochemicals far more deadly than when they act in isolation. Even within a small area, diffuse agricultural pollution does not affect all aquatic environments equally, which could account for local differences in amphibian sensitivity to agrochemicals. We examined the combined effects of ammonium nitrate fertilizer (0 to 45.2 mg N-NH 4(+)/L) and predator stress on larval Western spadefoot toad (Pelobates cultripes), using adult caged male marbled newts (Triturus marmoratus) as predators. We compared the interaction between both stressors in tadpoles from two ponds separated by 3 km. No significant mortality was observed (survival > 80% in all cases). Local differences were detected when analyzing larval growth, with a significant interaction between factors for one of the two populations tested (Fornillos de Fermoselle). Although tadpoles exposed to 45.2 mg N-NH 4(+)/L were 7% smaller than controls, the presence of predators from a foreign community resulted in animals 15% larger than those raised without predators after 15 d of experiment. Interestingly, predators from the same community as the tadpoles did not affect larval growth. The length of the tadpoles from a nearby location (Mámoles) was unaffected after exposure to ammonium nitrate and predatory stress.