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Sample records for agricultural non-point sources

  1. [Spatial distribution and pollution source identification of agricultural non-point source pollution in Fujiang watershed].

    PubMed

    Ding, Xiao-Wen; Shen, Zhen-Yao

    2012-11-01

    In order to provide regulatory support for management and control of non-point source (NPS) pollution in Fujiang watershed, agricultural NPS pollution is simulated, spatial distribution characteristics of NPS pollution are analyzed, and the primary pollution sources are also identified, by export coefficient model (ECM) and geographic information system (GIS). Agricultural NPS total nitrogen (TN) loading was of research area was 9.11 x 10(4) t in 2010, and the average loading was intensity was 3.10 t x km(-2). Agricultural NPS TN loading mainly distributed over dry lands, Mianyang city and gentle slope areas; high loading intensity areas were dry lands, Deyang city and gentle slope areas. Agricultural land use, of which contribution rate was 62. 12%, was the most important pollution source; fertilizer loss in dry lands, of which contribution rate was 50.49%, was the prominent. Improving methods of agricultural cultivation, implementing "farm land returning to woodland" policy, and enhancing treatment efficiency of domestic sewage and livestock waster wate are effective measures.

  2. [Spatial heterogeneity and classified control of agricultural non-point source pollution in Huaihe River Basin].

    PubMed

    Zhou, Liang; Xu, Jian-Gang; Sun, Dong-Qi; Ni, Tian-Hua

    2013-02-01

    Agricultural non-point source pollution is of importance in river deterioration. Thus identifying and concentrated controlling the key source-areas are the most effective approaches for non-point source pollution control. This study adopts inventory method to analysis four kinds of pollution sources and their emissions intensity of the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in 173 counties (cities, districts) in Huaihe River Basin. The four pollution sources include livestock breeding, rural life, farmland cultivation, aquacultures. The paper mainly addresses identification of non-point polluted sensitivity areas, key pollution sources and its spatial distribution characteristics through cluster, sensitivity evaluation and spatial analysis. A geographic information system (GIS) and SPSS were used to carry out this study. The results show that: the COD, TN and TP emissions of agricultural non-point sources were 206.74 x 10(4) t, 66.49 x 10(4) t, 8.74 x 10(4) t separately in Huaihe River Basin in 2009; the emission intensity were 7.69, 2.47, 0.32 t.hm-2; the proportions of COD, TN, TP emissions were 73%, 24%, 3%. The paper achieves that: the major pollution source of COD, TN and TP was livestock breeding and rural life; the sensitivity areas and priority pollution control areas among the river basin of non-point source pollution are some sub-basins of the upper branches in Huaihe River, such as Shahe River, Yinghe River, Beiru River, Jialu River and Qingyi River; livestock breeding is the key pollution source in the priority pollution control areas. Finally, the paper concludes that pollution type of rural life has the highest pollution contribution rate, while comprehensive pollution is one type which is hard to control.

  3. Agricultural non-point source pollution in China: causes and mitigation measures.

    PubMed

    Sun, Bo; Zhang, Linxiu; Yang, Linzhang; Zhang, Fusuo; Norse, David; Zhu, Zhaoliang

    2012-06-01

    Non-point source (NPS) pollution has been increasingly serious in China since the 1990s. The increases of agricultural NPS pollution in China is evaluated for the period 2000-2008 by surveying the literature on water and soil pollution from fertilizers and pesticides, and assessing the surplus nitrogen balance within provinces. The main causes for NPS pollution were excessive inputs of nitrogen fertilizer and pesticides, which were partly the result of the inadequate agricultural extension services and the rapid expansion of intensive livestock production with little of waste management. The annual application of synthetic nitrogen fertilizers and pesticides in China increased by 50.7 and 119.7%, respectively, during 1991-2008. The mitigation measures to reduce NPS pollution include: correct distortion in fertilizer prices; improve incentives for the recycling of organic manure; provide farmers with better information on the sound use of agro-chemicals; and tighten the regulations and national standards on organic waste disposal and pesticides use.

  4. Agricultural non-point source pollution in the Western Coal Field region of Kentucky

    SciTech Connect

    Snell, J.D.; Sendlein, L.V.A. . Dept. of Geological Sciences)

    1993-03-01

    As part of a general plan to characterize the extent of agricultural non-point source pollution in the different physiographic regions of Kentucky, two sites located in the Western Coal Field Physiographic provinces representing farmland drained by field tiles were chosen for ground water monitoring. These two sites are similar geologically, but the levels of Nitrate-N have proven to be drastically different between the two areas. A total of 24 wells and 3 lysimeters were installed at the two sites in three nested areas. Although both study sites are located in lowland valleys in fine grained lacustrine deposits, the materials at the Hopkins County site are slightly coarser grained. The wells in Hopkins County, with the exception of the two in the riparian zone, yield water consistently and substantially higher in Nitrate-N than wells in Daviess County. The Nitrate-N levels regularly hover near or exceed the EPA limit in Hopkins County, whereas the levels in Daviess County are near and in most cases far below the 0.53 ppm background level for the region. Pesticide concentrations are minor in both areas with small spikes of contamination noted in shallow wells shortly after application. The concentration of both the pesticides and the Nitrate-N drops off quickly with depth in both counties yielding relatively clean water below the lacustrine deposits.

  5. Optimization strategy integrity for watershed agricultural non-point source pollution control based on Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Gong, Y.; Yu, Y. J.; Zhang, W. Y.

    2016-08-01

    This study has established a set of methodological systems by simulating loads and analyzing optimization strategy integrity for the optimization of watershed non-point source pollution control. First, the source of watershed agricultural non-point source pollution is divided into four aspects, including agricultural land, natural land, livestock breeding, and rural residential land. Secondly, different pollution control measures at the source, midway and ending stages are chosen. Thirdly, the optimization effect of pollution load control in three stages are simulated, based on the Monte Carlo simulation. The method described above is applied to the Ashi River watershed in Heilongjiang Province of China. Case study results indicate that the combined three types of control measures can be implemented only if the government promotes the optimized plan and gradually improves implementation efficiency. This method for the optimization strategy integrity for watershed non-point source pollution control has significant reference value.

  6. NON-POINT SOURCE POLLUTION

    EPA Science Inventory

    Non-point source pollution is a diffuse source that is difficult to measure and is highly variable due to different rain patterns and other climatic conditions. In many areas, however, non-point source pollution is the greatest source of water quality degradation. Presently, stat...

  7. Reducing future non-point source sediment and phosphorus loading under intensifying agricultural production in the Ethiopian highlands

    NASA Astrophysics Data System (ADS)

    Mogus, Mamaru; Schmitter, Petra; Tilahun, Seifu; Steenhuise, Tammo

    2016-04-01

    Intensification of agriculture will bring along non-point source pollution in the Ethiopian highlands resulting in eutrophication of lakes. The first signs of eutrophication have been observed already in Lake Tana. The lake it supports the lives of millions in the surrounding through fishing, tourism, transportation and hydropower.Presently, information on non-point source pollution is lacking in the Ethiopian highlands. There are few studies carried out in the highlands on the extent and the source areas of pollution, and models are not available for predicting sediment and phosphorus loading other than those developed for temperate climates. The objective of this chapter is to review existing non-point source studies, report on our findings of sediment and phosphorus sources that are related the non-point source pollution of Lake Tana and to present a non-point source model for the Ethiopian highland based on the Parameter Efficient Semi-distributed Watershed Hydrology Model (PED-WHM).In our research we have found that the saturation excess runoff from valley bottoms and from degraded lands are prevalent in the Ethiopia highlands. The periodically runoff source areas are also the sources for the non-point source pollution and by concentrating best management practices in these source areas we expect that we can reduce pollution without affecting the profitability of the existing farms. The water balance component of the non-point source model has been performing well in predicting both the discharge and the location of the runoff source areas. Sediment and phosphorus prediction models have been developed and are currently being tested for the 7km2Awramba watershed and the 1350 km2Gumara basin. Initial results indicate that 11.2 ton/ha/year sediment load and an accumulation rate of 17.3 mg/kg/year of dissolved phosphorus from Gumara watershed joining the lake. By developing best management practices at this time before non-point source pollution is rampant and

  8. [Three patterns of interaction between soil and non-point source P-pollutants in agricultural watershed].

    PubMed

    Wang, Xia-hui; Yin, Cheng-qing; Yan, Xiao; Shan, Bao-qing; Wang, Wei-dong

    2004-07-01

    Typical agricultural watershed was selected to study the interactions between soil matrix and non-point source P-pollutants in surface runoff under simulative conditions. The soil samples were taken in different spatial locations in this watershed and were under different degree of human disturbance. The results showed that the interactions between different soil matrix and phosphorus could be divided into three patterns:retention, release and combination of retention and release. Soil of retention pattern has strong adsorption capacity of phosphate and will retain phosphorus from polluted runoff. Soil of release pattern has significant desorption capacity of phosphate and will release phosphorus to the runoff. Soil of retention and release combination pattern will retain or release phosphorus according to the phosphate concentration in the polluted runoff. These results showed that soil matrix in different spatial locations in the agricultural watershed have different ecological functions and environmental values under the processing of natural conditions and human disturbance. From the view of occurrence of non-point source pollution, these soils could become the sink of pollutants as well as the source of pollutants. Under some conditions, there has a conversion between sink and source of them. These results are valuable for control of non-point source pollution on watershed level, identification of key source area of pollutants and improvement of efficiency of control measures.

  9. User's Guide for the Agricultural Non-Point Source (AGNPS) Pollution Model Data Generator

    USGS Publications Warehouse

    Finn, Michael P.; Scheidt, Douglas J.; Jaromack, Gregory M.

    2003-01-01

    BACKGROUND Throughout this user guide, we refer to datasets that we used in conjunction with developing of this software for supporting cartographic research and producing the datasets to conduct research. However, this software can be used with these datasets or with more 'generic' versions of data of the appropriate type. For example, throughout the guide, we refer to national land cover data (NLCD) and digital elevation model (DEM) data from the U.S. Geological Survey (USGS) at a 30-m resolution, but any digital terrain model or land cover data at any appropriate resolution will produce results. Another key point to keep in mind is to use a consistent data resolution for all the datasets per model run. The U.S. Department of Agriculture (USDA) developed the Agricultural Nonpoint Source (AGNPS) pollution model of watershed hydrology in response to the complex problem of managing nonpoint sources of pollution. AGNPS simulates the behavior of runoff, sediment, and nutrient transport from watersheds that have agriculture as their prime use. The model operates on a cell basis and is a distributed parameter, event-based model. The model requires 22 input parameters. Output parameters are grouped primarily by hydrology, sediment, and chemical output (Young and others, 1995.) Elevation, land cover, and soil are the base data from which to extract the 22 input parameters required by the AGNPS. For automatic parameter extraction, follow the general process described in this guide of extraction from the geospatial data through the AGNPS Data Generator to generate input parameters required by the pollution model (Finn and others, 2002.)

  10. LANDSCAPE INFLUENCES ON NON-POINT SOURCED NUTRIENTS FOR AGRICULTURAL WATERSHEDS IN OHIO

    EPA Science Inventory

    In stream nutrient concentrations for a set of 35 small agricultural subwatersheds in southwestern Ohio have been monitored with respect to both water quality and biological integrity measures over a five year period. The dominant land cover in all of these subwatersheds is row ...

  11. Long-term agricultural non-point source pollution loading dynamics and correlation with outlet sediment geochemistry

    NASA Astrophysics Data System (ADS)

    Ouyang, Wei; Jiao, Wei; Li, Xiaoming; Giubilato, Elisa; Critto, Andrea

    2016-09-01

    Some agricultural non-point source (NPS) pollutants accumulate in sediments in the outlet sections of watersheds. It is crucial to evaluate the historical interactions between sediment properties and watershed NPS loading. Therefore, a sediment core from the outlet of an agricultural watershed was collected. The core age was dated using the 210Pb method, and sedimentation rates were determined using the constant rate of supply (CRS) model. The total nitrogen (TN), total phosphorus (TP), Cd, Pb, Cu, Ni and Cr accumulations in the sediment generally showed fluctuating increases, with the highest sedimentation fluxes all occurring in approximately 1998. The measurement of specific mass sedimentation rates reflected a record of watershed soil erosion dynamics. Using SWAT (Soil and Water Assessment Tool) to simulate long-term watershed agricultural NPS pollution loadings, the historical interactions between sediment properties and NPS loadings were further evaluated. The N leaching process weakened these interactions, but the historical accumulations of TP and heavy metals in sediments generally correlated well with watershed NPS TP loading. The regression analysis suggested that Pb and Cr were the most suitable indexes for assessing long-term NPS TN and TP pollution, respectively. Assessing the NPS loading dynamics using the vertical characteristics of sediment geochemistry is a new method.

  12. A simulation-based interval two-stage stochastic model for agricultural non-point source pollution control through land retirement.

    PubMed

    Luo, B; Li, J B; Huang, G H; Li, H L

    2006-05-15

    This study presents a simulation-based interval two-stage stochastic programming (SITSP) model for agricultural non-point source (NPS) pollution control through land retirement under uncertain conditions. The modeling framework was established by the development of an interval two-stage stochastic program, with its random parameters being provided by the statistical analysis of the simulation outcomes of a distributed water quality approach. The developed model can deal with the tradeoff between agricultural revenue and "off-site" water quality concern under random effluent discharge for a land retirement scheme through minimizing the expected value of long-term total economic and environmental cost. In addition, the uncertainties presented as interval numbers in the agriculture-water system can be effectively quantified with the interval programming. By subdividing the whole agricultural watershed into different zones, the most pollution-related sensitive cropland can be identified and an optimal land retirement scheme can be obtained through the modeling approach. The developed method was applied to the Swift Current Creek watershed in Canada for soil erosion control through land retirement. The Hydrological Simulation Program-FORTRAN (HSPF) was used to simulate the sediment information for this case study. Obtained results indicate that the total economic and environmental cost of the entire agriculture-water system can be limited within an interval value for the optimal land retirement schemes. Meanwhile, a best and worst land retirement scheme was obtained for the study watershed under various uncertainties.

  13. Spatial and temporal variations in non-point source losses of nitrogen and phosphorus in a small agricultural catchment in the Three Gorges Region.

    PubMed

    Chen, Chenglong; Gao, Ming; Xie, Deti; Ni, Jiupai

    2016-04-01

    Losses of agricultural pollutants from small catchments are a major issue for water quality in the Three Gorges Region. Solutions are urgently needed. However, before pollutant losses can be controlled, information about spatial and temporal variations in pollutant losses is needed. The study was carried out in the Wangjiagou catchment, a small agricultural catchment in Fuling District, Chongqing, and the data about non-point source losses of nitrogen and phosphorus was collected here. Water samples were collected daily by an automatic water sampler at the outlets of two subcatchments from 2012 to 2014. Also, samples of surface runoff from 28 sampling sites distributed through the subcatchments were collected during 12 rainfall events in 2014. A range of water quality variables were analyzed for all samples and were used to demonstrate the variation in non-point losses of nitrogen and phosphorus over a range of temporal and spatial scales and in different types of rainfall in the catchment. Results showed that there was a significant linear correlation between the mass concentrations of total nitrogen (TN) and nitrate (NO3-N) in surface runoff and that the relationship was maintained with changes in time. Concentrations of TN and NO3-N peaked after fertilizer was applied to crops in spring and autumn; concentrations decreased rapidly after the peak values in spring but declined slowly in autumn. N and P concentrations fluctuated more and showed a greater degree of dispersion during the spring crop cultivation period than those in autumn. Concentrations of TN and NO3-N in surface runoff were significantly and positively correlated with the proportion of the area that was planted with corn and mustard tubers, but were negatively correlated with the proportion of the area taken up with rice and mulberry plantations. The average concentrations of TN and NO3-N in surface runoff reached the highest level from the sampling points at the bottom of the land used for corn

  14. Spatial and temporal variations in non-point source losses of nitrogen and phosphorus in a small agricultural catchment in the Three Gorges Region.

    PubMed

    Chen, Chenglong; Gao, Ming; Xie, Deti; Ni, Jiupai

    2016-04-01

    Losses of agricultural pollutants from small catchments are a major issue for water quality in the Three Gorges Region. Solutions are urgently needed. However, before pollutant losses can be controlled, information about spatial and temporal variations in pollutant losses is needed. The study was carried out in the Wangjiagou catchment, a small agricultural catchment in Fuling District, Chongqing, and the data about non-point source losses of nitrogen and phosphorus was collected here. Water samples were collected daily by an automatic water sampler at the outlets of two subcatchments from 2012 to 2014. Also, samples of surface runoff from 28 sampling sites distributed through the subcatchments were collected during 12 rainfall events in 2014. A range of water quality variables were analyzed for all samples and were used to demonstrate the variation in non-point losses of nitrogen and phosphorus over a range of temporal and spatial scales and in different types of rainfall in the catchment. Results showed that there was a significant linear correlation between the mass concentrations of total nitrogen (TN) and nitrate (NO3-N) in surface runoff and that the relationship was maintained with changes in time. Concentrations of TN and NO3-N peaked after fertilizer was applied to crops in spring and autumn; concentrations decreased rapidly after the peak values in spring but declined slowly in autumn. N and P concentrations fluctuated more and showed a greater degree of dispersion during the spring crop cultivation period than those in autumn. Concentrations of TN and NO3-N in surface runoff were significantly and positively correlated with the proportion of the area that was planted with corn and mustard tubers, but were negatively correlated with the proportion of the area taken up with rice and mulberry plantations. The average concentrations of TN and NO3-N in surface runoff reached the highest level from the sampling points at the bottom of the land used for corn

  15. Comparative study on nutrient removal of agricultural non-point source pollution for three filter media filling schemes in eco-soil reactors.

    PubMed

    Du, Fuyi; Xie, Qingjie; Fang, Longxiang; Su, Hang

    2016-08-01

    Nutrients (nitrogen and phosphorus) from agricultural non-point source (NPS) pollution have been increasingly recognized as a major contributor to the deterioration of water quality in recent years. The purpose of this article is to investigate the discrepancies in interception of nutrients in agricultural NPS pollution for eco-soil reactors using different filling schemes. Parallel eco-soil reactors of laboratory scale were created and filled with filter media, such as grit, zeolite, limestone, and gravel. Three filling schemes were adopted: increasing-sized filling (I-filling), decreasing-sized filling (D-filling), and blend-sized filling (B-filling). The systems were intermittent operations via simulated rainstorm runoff. The nutrient removal efficiency, biomass accumulation and vertical dissolved oxygen (DO) distribution were defined to assess the performance of eco-soil. The results showed that B-filling reactor presented an ideal DO for partial nitrification-denitrification across the eco-soil, and B-filling was the most stable in the change of bio-film accumulation trends with depth in the three fillings. Simultaneous and highest removals of NH4(+)-N (57.74-70.52%), total nitrogen (43.69-54.50%), and total phosphorus (42.50-55.00%) were obtained in the B-filling, demonstrating the efficiency of the blend filling schemes of eco-soil for oxygen transfer and biomass accumulation to cope with agricultural NPS pollution. PMID:27441855

  16. Characterizing Non-Point Source Pollution From Agricultural Landscape Using Remote Sensing And Gis - A Case Study From Sugarcreek Headwaters, Ohio, USA

    NASA Astrophysics Data System (ADS)

    Prasad, V. K.; Stinner, B.; McCartney, D.

    Ohio is typical among many mid west and eastern states in US that are experiencing elevated inputs of anthropogenic pollutants, especially from agricultural sources. In this study, we designed an integrated Remote sensing and GIS based approach to investigate and understand the role of landscape complexity affecting the spatial and temporal variation in pollutant loads in one of the most impaired headwater streams in Ohio. LANDSAT ETM+ data in conjunction with digital elevation model were used to compute the hydrological and watershed parameters, viz., wetness index, topographic index, soil loss, flow direction, flow accumulation, stream networks, stream orders, etc. These parameters were used in Geographic Information Systems framework along with step wise multiple linear regression to understand the spatial and temporal variation in pollutant loads. Among the different parameters, results suggested elevation range and upstream flow length as best predictors for nitrate, flow direction and upstream flow length for ammonia and slope and elevation range for phosphate loads. Methodology followed in the study and the results obtained suggest potential use of Remote sensing and GIS for characterizing non-point source pollution.

  17. Geospatial data resampling and resolution effects on watershed modeling: A case study using the agricultural non-point source pollution model

    USGS Publications Warehouse

    Usery, E.L.; Finn, M.P.; Scheidt, D.J.; Ruhl, S.; Beard, T.; Bearden, M.

    2004-01-01

    Researchers have been coupling geographic information systems (GIS) data handling and processing capability to watershed and waterquality models for many years. This capability is suited for the development of databases appropriate for water modeling. However, it is rare for GIS to provide direct inputs to the models. To demonstrate the logical procedure of coupling GIS for model parameter extraction, we selected the Agricultural Non-Point Source (AGNPS) pollution model. Investigators can generate data layers at various resolutions and resample to pixel sizes to support models at particular scales. We developed databases of elevation, land cover, and soils at various resolutions in four watersheds. The ability to use multiresolution databases for the generation of model parameters is problematic for grid-based models. We used database development procedures and observed the effects of resolution and resampling on GIS input datasets and parameters generated from those inputs for AGNPS. Results indicate that elevation values at specific points compare favorably between 3- and 30-m raster datasets. Categorical data analysis indicates that land cover classes vary significantly. Derived parameters parallel the results of the base GIS datasets. Analysis of data resampled from 30-m to 60-, 120-, 210-, 240-, 480-, 960-, and 1920-m pixels indicates a general degradation of both elevation and land cover correlations as resolution decreases. Initial evaluation of model output values for soluble nitrogen and phosphorous indicates similar degradation with resolution. ?? Springer-Verlag 2004.

  18. Tackling non-point source water pollution in British Columbia: An action plan

    SciTech Connect

    1998-12-31

    Efforts to protect British Columbia water quality by regulating point discharges from municipal and industrial sources have generally been successful, and it is recognized that the major remaining cause of water pollution in the province is from non-point sources. These sources are largely unregulated and associated with urbanization, agriculture, and other forms of land development. The first part of this report reviews the provincial commitment to clean water, the effects of non-point-source (NPS) pollution, and the management of NPS in the province. Part 2 describes the main causes of NPS in British Columbia: Land development, agriculture, stormwater runoff, on-site sewage systems, forestry and range activities, atmospheric deposition, and boating/marine activities. Finally, it presents key components of the province`s NPS action plan: Education and training, prevention at site, land use planning and co-ordination, assessment and reporting, economic incentives, legislation and regulation, and implementation.

  19. Tackling non-point source water pollution in British Columbia: An action plan

    SciTech Connect

    Not Available

    1998-01-01

    Efforts to protect British Columbia water quality by regulating point discharges from municipal and industrial sources have generally been successful, and it is recognized that the major remaining cause of water pollution in the province is from non-point sources. These sources are largely unregulated and associated with urbanization, agriculture, and other forms of land development. The first part of this report reviews the provincial commitment to clean water, the effects of non-point-source (NPS) pollution, and the management of NPS in the province. Part 2 describes the main causes of NPS in British Columbia: Land development, agriculture, stormwater runoff, on-site sewage systems, forestry and range activities, atmospheric deposition, and boating/marine activities. Finally, it presents key components of the province's NPS action plan: Education and training, prevention at site, land use planning and co-ordination, assessment and reporting, economic incentives, legislation and regulation, and implementation.

  20. [Purification capacity of ditch wetland to agricultural non-point pollutants].

    PubMed

    Jiang, Cui-ling; Cui, Guang-bo; Fan, Xiao-qiu; Zhang, Yi-bing

    2004-03-01

    Ditch wetlands have the capacity to remove and purify non-point pollutants from agricultural drainage by sediment retention, plant absorption and microorganism decomposition. Phragmites communis and Zizania latifolia are two main kinds of plants growing naturally in ditch wetlands in the lower reaches of the Yangtze River. They can absorb N and P efficiently, which is the main mechanism of non-point source pollutants purification by wetlands. The harvest of Phragmites communis and Zizania latifolia will take away 463-515 kg/hm2 of N and 127-149 kg/hm2 of P each year, it equal to N and P discharged from 2.3-3.2 hm2 and 1.3-3.0 hm2 of fields respectively in this area. The absorption and decomposition capacity of Zizania latifolia wetland is higher than Phragmites communis wetland. After harvest of plants, wetlands are uncovered to sunlight and oxygen that speeds the transportation and decomposition of nutrients. The amount of organic matters, TN and TP are higher in sediment of harvested area than in that of control. Therefore, seasonal harvest of plants is an efficient measure for wetlands to purify nutrients and alleviate eutrophication of lakes. PMID:15202249

  1. [Transformation of Non-point Source Soluble Nitrogen in Simulated Drainage Ditch].

    PubMed

    Li, Qiang-kun; Song, Chang-ji; Hu, Ya-wei; Peng, Cong; Ma, Qiang; Jiang, Zheng-xi; Ju, Yi-rheng

    2016-02-15

    The drainage ditch has a compound ecosystem structure consisting of water, sediment and plants. Migration and transformation of the non-point source solute is important to study interception, control and management of agricultural non-point source pollution in the drainage ditch. Based on the experiment on static simulation of drainage ditches, the article used typical non-point source soluble nitrogen as an example to analyze the changing process of nitrogen content in water, sediment and reeds, and to study the effects of the sediment adsorption and desorption, reeds growth and death in different periods on nitrogen concentration in water. The article discussed nitrogen migration in water-sediment-reeds compound ecosystem and its influence on nitrogen concentration in water. The results showed that both adsorption and desorption in sediment and absorption and assimilation of reeds growth had effect on nitrogen concentration in water. The effect before October was reducing the nitrogen concentration in water, which was the process of nitrogen purification in water. After October, the nitrogen concentration in water increased and made it easy to form secondary nitrogen pollution. Meanwhile, the migration in the water-sediment-seeds ecosystem in simulated drainage ditch had close ties, any migration and transformation of nitrogen in a single medium or between different mediums would cause adjustment of nitrogen concentration in water.

  2. [Transformation of Non-point Source Soluble Nitrogen in Simulated Drainage Ditch].

    PubMed

    Li, Qiang-kun; Song, Chang-ji; Hu, Ya-wei; Peng, Cong; Ma, Qiang; Jiang, Zheng-xi; Ju, Yi-rheng

    2016-02-15

    The drainage ditch has a compound ecosystem structure consisting of water, sediment and plants. Migration and transformation of the non-point source solute is important to study interception, control and management of agricultural non-point source pollution in the drainage ditch. Based on the experiment on static simulation of drainage ditches, the article used typical non-point source soluble nitrogen as an example to analyze the changing process of nitrogen content in water, sediment and reeds, and to study the effects of the sediment adsorption and desorption, reeds growth and death in different periods on nitrogen concentration in water. The article discussed nitrogen migration in water-sediment-reeds compound ecosystem and its influence on nitrogen concentration in water. The results showed that both adsorption and desorption in sediment and absorption and assimilation of reeds growth had effect on nitrogen concentration in water. The effect before October was reducing the nitrogen concentration in water, which was the process of nitrogen purification in water. After October, the nitrogen concentration in water increased and made it easy to form secondary nitrogen pollution. Meanwhile, the migration in the water-sediment-seeds ecosystem in simulated drainage ditch had close ties, any migration and transformation of nitrogen in a single medium or between different mediums would cause adjustment of nitrogen concentration in water. PMID:27363139

  3. Quantification and index of non-point source pollution in Taihu Lake region with GIS.

    PubMed

    Guo, H Y; Wang, X R; Zhu, J G

    2004-01-01

    The contribution of phosphorus and nitrogen from non-point source pollution (NPS) in the Taihu Lake region was investigated through case study and surveying in the town of Xueyan, From experimental results coupled with survey and statistics in the studied area, the distribution of nitrogen and phosphorus input to the water body is achieved from four main sources: agricultural land, village, the town center and the poultry factory. The results showed that about 38% of total phosphorus (TP) and 48% of total nitrogen (TN) discharged is from agricultural land, 33% of TP and 40% TN from village residents, 25% of TP and 10% of TN from the town center and 4% of TP and 2% of TN from the poultry factory. The Agricultural Non-point Pollution Potential Index (APPI) system for identifying and ranking critical areas of NPS was established with a Geographic Information Systems (GIS)-based technology. Quantification of the key factors in non-point sources pollution was carried out utilizing the following: Sediment Production Index (SPI), Runoff Index (RI), People and Animal Loading Index (PALI) and Chemical Use Index (CUI). These are the core parts of the model, and the weighting factor of each index was evaluated according the results of quantification. The model was successfully applied for evaluating APPI in Xueyan. Results from the model showed that the critical area identified for NPS control in Xueyan. The model has several advantages including: requiring fewer parameters, easy acquirement of these parameters, friendly interface, and convenience of operation. In addition it is especially useful for identifying critical areas of NPS when the basic data are not fully accessible, which is the present situation in China. PMID:15499770

  4. [Identifying critical source areas for non-point phosphorus loss in Chaohu watershed].

    PubMed

    Zhou, Hui-Ping; Gao, Chao

    2008-10-01

    Agricultural non-point phosphorus (P) pollution is an important cause of eutrophication in many freshwater systems. Identifying areas that at high risk for P loss to surface water in watershed and concentrating management efforts on these minimal portions of lands are better measures than implementing general strategies over a broad area. A modified version of P index was used to assess P loss risk and identify critical source areas in Chaohu watershed at a regional scale. Soil P sorption index and degree of P sorption saturation were introduced as source factors to show the inherent ability of P transport in soil-water interface. Distance from sources to Chaohu Lake was also considered as a new transport factor to show the influence from sources to final receiving water. The ranking schemes were modified according to available data and scale of study area. The soil P sorption indexes show mild spatial variations in watershed. However, the values are relative low which implies higher loss risk. Distinct spatial variations are found in the degree of soil P sorption saturation. More than 40% of the watershed is saturated over 25% by P. The results show prominent spatial variations of non-point P pollution risk index in Chaohu watershed. Highest risk areas, take up about 5% of the watershed, spread near the downstream parts of main rivers to Chaohu Lake. These should be regarded as critical source areas to be treated in priority. It indicates that P index is a rapid and simple tool to identify critical source areas of non-point P pollution at the regional scale and it enables managers to implement best management practice (BMPs) in a high priority to minimize P loss to sensitive watercourses.

  5. Controlled-release fertilizer (CRF): a green fertilizer for controlling non-point contamination in agriculture.

    PubMed

    Mao, Xiao-yun; Sun, Ke-jun; Wang, De-han; Liao, Zong-wen

    2005-01-01

    Fertilizers contribute greatly to high yields but also result in environmental non-point contamination, including the emission of greenhouse gas (N2O) and eutrophication of water bodies. How to solve this problem has become a serious challenge, especially for China as its high ecological pressure. Controlled-release fertilizer(CRF) has been developed to minimize the contamination while keeping high yield and has become a green fertilizer for agriculture. Several CRFs made with special coating technology were used for testing the fertilizer effects in yield and environment through pot experiment and field trial. The result indicated that the CRFs had higher N use efficiency, thus reducing N loss through leaching and volatilization while keeping higher yields. Comparing with imported standard CRFs, the test on CRFs showed similar fertilizer effect but with much lower cost. CRFs application is becoming a new approach for minimizing non-point contamination in agriculture. PMID:16295884

  6. Controlled-release fertilizer (CRF): a green fertilizer for controlling non-point contamination in agriculture.

    PubMed

    Mao, Xiao-yun; Sun, Ke-jun; Wang, De-han; Liao, Zong-wen

    2005-01-01

    Fertilizers contribute greatly to high yields but also result in environmental non-point contamination, including the emission of greenhouse gas (N2O) and eutrophication of water bodies. How to solve this problem has become a serious challenge, especially for China as its high ecological pressure. Controlled-release fertilizer(CRF) has been developed to minimize the contamination while keeping high yield and has become a green fertilizer for agriculture. Several CRFs made with special coating technology were used for testing the fertilizer effects in yield and environment through pot experiment and field trial. The result indicated that the CRFs had higher N use efficiency, thus reducing N loss through leaching and volatilization while keeping higher yields. Comparing with imported standard CRFs, the test on CRFs showed similar fertilizer effect but with much lower cost. CRFs application is becoming a new approach for minimizing non-point contamination in agriculture.

  7. Natural Wetlands Mediate Non-point Source Water Pollution From Irrigated Pastures

    NASA Astrophysics Data System (ADS)

    Knox, K.; Dahlgren, R. A.; Tate, K. W.

    2005-12-01

    Non-point source discharge from grazed pastures may be high in nutrients, sediment, and pathogens, three major contributors to water quality impairment in California. Intercepting pollution at its source and managing water quality within the landscape are essential to maintaining healthy downstream waters. We investigated the efficacy of flow-through wetlands interspersed throughout the agricultural landscape to reduce non-point source pollution of tailwater from cattle-grazed, irrigated pastures in the Sierra Nevada Foothills of California. Wetlands are known to positively impact water quality through ecological processes such as filtration, sedimentation, microbial transformations and plant uptake of nutrients. Influent and effluent water of small (0.25 ha), natural wetlands located downstream from flood irrigated pastures was analyzed for Escherichia coli, NO3-N, total N, total suspended solids (TSS), total P, and dissolved organic carbon (DOC) throughout two summer irrigation seasons (June to October). We compared reductions of sediment, nutrients and E. coli provided by a healthy, non-degraded wetland with reductions from flow through a channelized, degraded wetland. Large reductions in E. coli (>75%) and TSS (>50%) were observed in water exiting the healthy wetland while nutrient and DOC (~ 20%) concentrations were less affected by flow through the wetland. The channelized wetland provided smaller reductions in all constituents than did the non-degraded wetland. Results from this study demonstrate that small flow-through wetlands can improve water quality through the attenuation of E. coli and suspended sediments, and to a lesser degree DOC and nutrients.

  8. Simulation of Non-point Source Pollution in the Songhua River Basin Using GBNP Model

    NASA Astrophysics Data System (ADS)

    Pan, J.; Tang, L.; Chen, Y. D.

    2015-12-01

    China is facing increasingly severe water pollution issue with rapid socio-economic development. Non-point source pollution, which is rarely monitored, has become the main forms of water pollution in China. In this study, the Geomorphology-Based Non-point source Pollution (GBNP) model was used to simulate the processes of rain-runoff, soil erosion, sediment routing and pollutant transport in the Songhua River basin from 2001 to 2010. The spatio-temporal variation of non-point source pollution and river water quality were analyzed based on the simulation outputs. In the entire basin, the annual mean loading of TN, TP and soil erosion are 270,000 ton/a, 42,200 ton/a and 55,900,000 ton/a, respectively. The point and non-point source pollution respectively account for 44.9% and 55.1% in TN loading. For TP loading, the proportions of point and non-point source pollution are 14.4% and 85.6%, respectively. It suggests that the non-point source pollution control and treatments should be paid more attention in the Songhua River basin. The inter-annual and intra-annual variations of non-point source pollution components and potential driving mechanisms are further examined. The annual loading of soil erosion, TN and TP are highly correlated with annual runoff, with the correlation coefficients of 0.75, 0.91 and 0.92, respectively, which implies that rain-runoff could be the main driving force of non-point pollution. The monthly sediment concentration in the watercourse is high in flood season and low in non-flood season, which agrees well with the seasonality of monthly runoff. By contrast, the concentrations of TN and TP in watercourse show the opposite features.

  9. [Spatial discharge characteristics and total load control of non-point source pollutants based on the catchment scale].

    PubMed

    Wang, Xia-Hui; Lu, Jun; Zhang, Qing-Zhong; Wang, Bo; Yao, Rui-Hua; Zhang, Hui-Yuan; Huang, Feng

    2011-09-01

    Agricultural non-point source pollution is one of the major causes of water quality deterioration. Based on the analysis of the spatial discharge characteristics and intensity of major pollutants from the agricultural pollution source, the establishment of spatial management subzones for controlling agricultural non-point pollution and a design of a plan for total load control of pollutants from each subzone is an important way to improve the efficiency of control measures. In this paper the Four Lake basin in Hubei Province is adopted as the research case region and a systematic research of the control countermeasures of agricultural non-point pollution based on the catchment scale is carried out. The results shows that in the Four Lake basin, the COD, total nitrogen, total phosphorus and ammonia nitrogen load of the water environment are mainly caused by agricultural non-point pollution. These four kinds of non-point source pollutants respectively account for 67.6%, 82.2%, 84.7% and 50.9% of the total pollutant discharge amount in the basin. The analysis of the spatial discharge characteristics of non-point source pollutants in the Four Lake basin shows that the major contributor source regions of non-point source pollutant in the basin are the four counties, including Honghu, Jianli, Qianjiang and Shayang where the aquatic and livestock production are relatively developed. According to the spatial discharge characteristics of the pollutants and the evaluation of the discharge intensity of pollutants, the Four Lake basin is divided into three agricultural non-point pollution management subzones, which including Changhu upstream aquatic and livestock production pollution control subzone, Four-lake trunk canal rural non-point source pollution control subzone and Honghu aquatic production pollution control subzone. Specific pollution control measures are put forward for each subzone. With a comprehensive consideration of the water quality amelioration and the

  10. [Spatial discharge characteristics and total load control of non-point source pollutants based on the catchment scale].

    PubMed

    Wang, Xia-Hui; Lu, Jun; Zhang, Qing-Zhong; Wang, Bo; Yao, Rui-Hua; Zhang, Hui-Yuan; Huang, Feng

    2011-09-01

    Agricultural non-point source pollution is one of the major causes of water quality deterioration. Based on the analysis of the spatial discharge characteristics and intensity of major pollutants from the agricultural pollution source, the establishment of spatial management subzones for controlling agricultural non-point pollution and a design of a plan for total load control of pollutants from each subzone is an important way to improve the efficiency of control measures. In this paper the Four Lake basin in Hubei Province is adopted as the research case region and a systematic research of the control countermeasures of agricultural non-point pollution based on the catchment scale is carried out. The results shows that in the Four Lake basin, the COD, total nitrogen, total phosphorus and ammonia nitrogen load of the water environment are mainly caused by agricultural non-point pollution. These four kinds of non-point source pollutants respectively account for 67.6%, 82.2%, 84.7% and 50.9% of the total pollutant discharge amount in the basin. The analysis of the spatial discharge characteristics of non-point source pollutants in the Four Lake basin shows that the major contributor source regions of non-point source pollutant in the basin are the four counties, including Honghu, Jianli, Qianjiang and Shayang where the aquatic and livestock production are relatively developed. According to the spatial discharge characteristics of the pollutants and the evaluation of the discharge intensity of pollutants, the Four Lake basin is divided into three agricultural non-point pollution management subzones, which including Changhu upstream aquatic and livestock production pollution control subzone, Four-lake trunk canal rural non-point source pollution control subzone and Honghu aquatic production pollution control subzone. Specific pollution control measures are put forward for each subzone. With a comprehensive consideration of the water quality amelioration and the

  11. [Nitrogen non-point source pollution identification based on ArcSWAT in Changle River].

    PubMed

    Deng, Ou-Ping; Sun, Si-Yang; Lü, Jun

    2013-04-01

    The ArcSWAT (Soil and Water Assessment Tool) model was adopted for Non-point source (NPS) nitrogen pollution modeling and nitrogen source apportionment for the Changle River watershed, a typical agricultural watershed in Southeast China. Water quality and hydrological parameters were monitored, and the watershed natural conditions (including soil, climate, land use, etc) and pollution sources information were also investigated and collected for SWAT database. The ArcSWAT model was established in the Changle River after the calibrating and validating procedures of the model parameters. Based on the validated SWAT model, the contributions of different nitrogen sources to river TN loading were quantified, and spatial-temporal distributions of NPS nitrogen export to rivers were addressed. The results showed that in the Changle River watershed, Nitrogen fertilizer, nitrogen air deposition and nitrogen soil pool were the prominent pollution sources, which contributed 35%, 32% and 25% to the river TN loading, respectively. There were spatial-temporal variations in the critical sources for NPS TN export to the river. Natural sources, such as soil nitrogen pool and atmospheric nitrogen deposition, should be targeted as the critical sources for river TN pollution during the rainy seasons. Chemical nitrogen fertilizer application should be targeted as the critical sources for river TN pollution during the crop growing season. Chemical nitrogen fertilizer application, soil nitrogen pool and atmospheric nitrogen deposition were the main sources for TN exported from the garden plot, forest and residential land, respectively. However, they were the main sources for TN exported both from the upland and paddy field. These results revealed that NPS pollution controlling rules should focus on the spatio-temporal distribution of NPS pollution sources. PMID:23798104

  12. Modeling the contribution of point sources and non-point sources to Thachin River water pollution.

    PubMed

    Schaffner, Monika; Bader, Hans-Peter; Scheidegger, Ruth

    2009-08-15

    Major rivers in developing and emerging countries suffer increasingly of severe degradation of water quality. The current study uses a mathematical Material Flow Analysis (MMFA) as a complementary approach to address the degradation of river water quality due to nutrient pollution in the Thachin River Basin in Central Thailand. This paper gives an overview of the origins and flow paths of the various point- and non-point pollution sources in the Thachin River Basin (in terms of nitrogen and phosphorus) and quantifies their relative importance within the system. The key parameters influencing the main nutrient flows are determined and possible mitigation measures discussed. The results show that aquaculture (as a point source) and rice farming (as a non-point source) are the key nutrient sources in the Thachin River Basin. Other point sources such as pig farms, households and industries, which were previously cited as the most relevant pollution sources in terms of organic pollution, play less significant roles in comparison. This order of importance shifts when considering the model results for the provincial level. Crosschecks with secondary data and field studies confirm the plausibility of our simulations. Specific nutrient loads for the pollution sources are derived; these can be used for a first broad quantification of nutrient pollution in comparable river basins. Based on an identification of the sensitive model parameters, possible mitigation scenarios are determined and their potential to reduce the nutrient load evaluated. A comparison of simulated nutrient loads with measured nutrient concentrations shows that nutrient retention in the river system may be significant. Sedimentation in the slow flowing surface water network as well as nitrogen emission to the air from the warm oxygen deficient waters are certainly partly responsible, but also wetlands along the river banks could play an important role as nutrient sinks. PMID:19501876

  13. Pollutant runoff from non-point sources and its estimation by runoff models.

    PubMed

    Noguchi, M; Hiwatashi, T; Mizuno, Y; Minematsu, M

    2002-01-01

    In order to attain a sound and sustainable water environment, it is important to carry out the environmental management of the watershed. For this purpose, knowledge on the pollutant runoff mechanism from non-point sources becomes very important especially under rainy conditions. At Isahaya, Nagasaki, Japan, a big project of construction of sea-dyke and reclamation is now going on, so reducing the pollutant runoff, especially from non-point sources, becomes more important. Some runoff models of rainwater are developed to predict the rate of pollutant loads from the non-point sources, and their results are compared with each other to investigate the accuracy of prediction. In this paper, runoff analysis of both rainwater and pollutants has been carried out using three models: the tank model, the kinematic wave (K-W) model, and a model using the digital elevation model (DEM). For precise estimation, it becomes necessary to identify the parameters included in these models. Here, total nitrogen has been considered as pollutants, and detachment rates are evaluated, correlated with a class of land use, soil type, and moisture content. Finally, it has been shown that pollutant runoff from non-point sources can be predicted fairly well, identifying the model parameter appropriately.

  14. HYDROLOGY AND SEDIMENT MODELING USING THE BASINS NON-POINT SOURCE MODEL

    EPA Science Inventory

    The Non-Point Source Model (Hydrologic Simulation Program-Fortran, or HSPF) within the EPA Office of Water's BASINS watershed modeling system was used to simulate streamflow and total suspended solids within Contentnea Creek, North Carolina, which is a tributary of the Neuse Rive...

  15. [Characteristics of non-point source pollution in Tiaoxi watershed and related affecting factors].

    PubMed

    Jin, Jing-liang; Wang, Fei-er; Dai, Lu-ying; Tian, Ping; Zhang, Zhi-jian

    2011-08-01

    By using soil and water assessment tool (SWAT) model, this paper simulated the surface runoff intensity and the export loadings of sediment particulates and nutrients via non-point source hydrological pathway in Tiaoxi watershed, and integrated with the simulation results, analyzed the temporal and spatial distribution characteristics of non-point source pollution in the watershed in 2008. In the study area, the per unit area non-point source pollution was stronger in northern region than in southern region and in eastern region than in western region, and the weakest in central region. Among the land utilization types, farmland had the biggest contribution to the sediment loading. There were significantly positive correlations between the loadings of surface runoff and associated sediment particulates and the rainfall intensity. The export loadings of nutrients through surface runoff were higher in rainy season (from June to September) than in dry season (from December to next March), and there existed significant correlations between the surface runoff loadings of sediment particulates, organic nitrogen, and nitrate and the average gradient of lands.

  16. Point and non-point microbial source pollution: A case study of Delhi

    NASA Astrophysics Data System (ADS)

    Jamwal, Priyanka; Mittal, Atul K.; Mouchel, Jean-Marie

    The present study identifies major point and non-point sources of microbial pollution during dry and wet weather in Delhi watershed which is the first prerequisite for planning and management of water quality of the river Yamuna. Fecal coliforms (FC) and fecal streptococci (FS) levels were determined from two types of sources - point source (effluent from sewage treatment plants) and non-point source (stormwater runoff during dry and wet weather). FC and FS levels in the river Yamuna were also monitored, which is an ultimate sink for all microbial loads in Delhi watershed. Effluent from sewage treatment plants (STPs) employing different treatment technologies were evaluated. FC and FS levels greater than the effluent discharge standard (1000 MPN/100 ml) were observed in the effluents from all STPs except “oxidation pond Timarpur”. This study also involved field program for characterization of urban runoff from different land-uses. Results indicated that the microbial quality of urban runoff produced during wet weather from different land-uses was similar to that of raw sewage. Sewage overflows along with human and animal sources were responsible for high FC and FS levels in the runoff samples. Wet weather FC and FS levels in river Yamuna were higher as compared to the dry weather levels suggesting that dilution of the river water during wet weather does not affect its microbiological quality. Thus on the basis of this study it was found that urban runoff also contributes to the microbial quality of the river Yamuna.

  17. [Quantification of non-point sources phosphorus pollution in key protection area of Taihu Lake].

    PubMed

    Guo, Hongyan; Wang, Xiaorong; Zhu, Jianguo

    2004-01-01

    The distribution of various kinds of non-point sources phosphorus pollution in Xueyan Town, Wujin city, Taihu area was researched through field experiments and local investigation during rice growth season. The results showed that of all kinds of phosphorus pollution, about 56.2% (1313 kg P) was from farmland, 22.2% (518 kg P) was from town residents, 18.9% (442 kg P) was from village residents, and 2.7% (62 kg P) was from livestock. Besides the strict control of the phosphorus pollution from farmland, attention should also be paid on the control of domestic water pollution from towns and villages. PMID:15139206

  18. Uncertainty Analysis of non-point source pollution control facilities design techniques in Korea

    NASA Astrophysics Data System (ADS)

    Lee, J.; Okjeong, L.; Gyeong, C. B.; Park, M. W.; Kim, S.

    2015-12-01

    The design of non-point sources control facilities in Korea is divided largely by the stormwater capture ratio, the stormwater load capture ratio, and the pollutant reduction efficiency of the facility. The stormwater capture ratio is given by a design formula as a function of the water quality treatment capacity, the greater the capacity, the more the amount of stormwater intercepted by the facility. The stormwater load capture ratio is defined as the ratio of the load entering the facility of the total pollutant load generated in the target catchment, and is given as a design formula represented by a function of the stormwater capture ratio. In order to estimate the stormwater capture ratio and load capture ratio, a lot of quantitative analysis of hydrologic processes acted in pollutant emission is required, but these formulas have been applied without any verification. Since systematic monitoring programs were insufficient, verification of these formulas was fundamentally impossible. However, recently the Korean ministry of Environment has conducted an long-term systematic monitoring project, and thus the verification of the formulas became possible. In this presentation, the stormwater capture ratio and load capture ratio are re-estimated using actual TP data obtained from long-term monitoring program at Noksan industrial complex located in Busan, Korea. Through the re-estimated process, the uncertainty included in the design process that has been applied until now will be shown in a quantitative extent. In addition, each uncertainty included in the stormwater capture ratio estimation and in the stormwater load capture ratio estimation will be expressed to quantify the relative impact on the overall non-point pollutant control facilities design process. Finally, the SWMM-Matlab interlocking module for model parameters estimation will be introduced. Acknowledgement This subject is supported by Korea Ministry of Environment as "The Eco Innovation Project : Non-point

  19. Assessment of the relationship between rural non-point source pollution and economic development in the Three Gorges Reservoir Area.

    PubMed

    Zhang, Tong; Ni, Jiupai; Xie, Deti

    2016-04-01

    This study investigates the relationship between rural non-point source (NPS) pollution and economic development in the Three Gorges Reservoir Area (TGRA) by using the Environmental Kuznets Curve (EKC) hypothesis for the first time. Five types of pollution indicators, namely, fertilizer input density (FD), pesticide input density (PD), agricultural film input density (AD), grain residues impact (GI), and livestock manure impact (MI), were selected as rural NPS pollutant variables. Rural net income per capita was used as the indicator of economic development. Pollution load was generated by agricultural inputs (consumption of fertilizer, pesticide, and agricultural film) and economic growth with invert U-shaped features. The predicted turning points for FD, PD, and AD were at rural net income per capita levels of 6167.64, 6205.02, and 4955.29 CNY, respectively, which were all surpassed. However, the features between agricultural waste outputs (grain residues and livestock manure) and economic growth were inconsistent with the EKC hypothesis, which reflected the current trends of agricultural economic structure in the TGRA. Given that several other factors aside from economic development level could influence the pollutant generation in rural NPS, a further examination with long-run data support should be performed to understand the relationship between rural NPS pollution and income level. PMID:26936476

  20. Assessment of the relationship between rural non-point source pollution and economic development in the Three Gorges Reservoir Area.

    PubMed

    Zhang, Tong; Ni, Jiupai; Xie, Deti

    2016-04-01

    This study investigates the relationship between rural non-point source (NPS) pollution and economic development in the Three Gorges Reservoir Area (TGRA) by using the Environmental Kuznets Curve (EKC) hypothesis for the first time. Five types of pollution indicators, namely, fertilizer input density (FD), pesticide input density (PD), agricultural film input density (AD), grain residues impact (GI), and livestock manure impact (MI), were selected as rural NPS pollutant variables. Rural net income per capita was used as the indicator of economic development. Pollution load was generated by agricultural inputs (consumption of fertilizer, pesticide, and agricultural film) and economic growth with invert U-shaped features. The predicted turning points for FD, PD, and AD were at rural net income per capita levels of 6167.64, 6205.02, and 4955.29 CNY, respectively, which were all surpassed. However, the features between agricultural waste outputs (grain residues and livestock manure) and economic growth were inconsistent with the EKC hypothesis, which reflected the current trends of agricultural economic structure in the TGRA. Given that several other factors aside from economic development level could influence the pollutant generation in rural NPS, a further examination with long-run data support should be performed to understand the relationship between rural NPS pollution and income level.

  1. The removal of nutrients from non-point source wastewater by a hybrid bioreactor.

    PubMed

    Wu, Yonghong; Hu, Zhengyi; Yang, Linzhang; Graham, Bruce; Kerr, Philip G

    2011-02-01

    The aim of this project was to establish an economical and environmentally benign biotechnology for removing nutrients from non-point source wastewater. The proposal involves a hybrid bioreactor comprised of sequential anaerobic, anoxic and aerobic (A(2)/O) processes and an eco-ditch being constructed and applied in a suburban area, Kunming, south-western China, where wastewater was discharged from an industrial park and suburban communities. The results show that the hybrid bioreactor fosters heterotrophic and autotrophic microorganisms. When the hydraulic load is 200 m(3) per day with the running mode in 12h cycles, the removal efficiencies of the nutrients were 81% for TP, 74% for TDP, 82% for TN, 79% for NO(3)-N and 86% for NH(4)-N. The improved bacterial community structure and bacterial habitats further implied enhanced water quality and indicates that the easily-deployed, affordable and environmentally-friendly hybrid bioreactor is a promising bio-measure for removing high loadings of nutrients from non-point source wastewater. PMID:21093255

  2. Isotopic Tracers for Delineating Non-Point Source Pollutants in Surface Water

    SciTech Connect

    Davisson, M L

    2001-03-01

    This study tested whether isotope measurements of surface water and dissolved constituents in surface water could be used as tracers of non-point source pollution. Oxygen-18 was used as a water tracer, while carbon-14, carbon-13, and deuterium were tested as tracers of DOC. Carbon-14 and carbon-13 were also used as tracers of dissolved inorganic carbon, and chlorine-36 and uranium isotopes were tested as tracers of other dissolved salts. In addition, large databases of water quality measurements were assembled for the Missouri River at St. Louis and the Sacramento-San Joaquin Delta in California to enhance interpretive results of the isotope measurements. Much of the water quality data has been under-interpreted and provides a valuable resource to investigative research, for which this report exploits and integrates with the isotope measurements.

  3. Discriminating between point and non-point sources of atrazine contamination of a sandy aquifer.

    PubMed

    Leterme, Bertrand; Vanclooster, Marnik; Rounsevell, Mark D A; Bogaert, Patrick

    2006-06-01

    This study analyses the sources of atrazine contamination in the Brusselian sandy aquifer of central Belgium. Atrazine has in the past been used for both agricultural and non-agricultural applications, but it is difficult to distinguish the contamination originating from these two sources. The spatial and temporal covariance of atrazine concentrations was studied by fitting semi-variogram models to monitoring data. Correlation ranges were found to be 600 m and 600-700 days, respectively. The results were used to apply a declustering algorithm before examining the distribution of atrazine concentrations measured in groundwater. Monitoring data appeared to follow a pseudo-lognormal distribution, as a lognormality test was negative. An inflexion point on the cumulative density function was thought to indicate the two different pollution processes, i.e., agricultural and non-agricultural contamination sources. A non-parametric one-way analysis of variance suggested that the vast majority of atrazine in groundwater was from non-agricultural, point sources. This was supported by the strong relationship between mean concentrations and land use, whilst other environmental variables, such as soil organic matter or groundwater depth, produced less meaningful results.

  4. Non-point pollution of groundwater from agricultural activities in Mediterranean Spain: the Balearic Islands case study

    NASA Astrophysics Data System (ADS)

    Candela, L.; Wallis, K. J.; Mateos, R. M.

    2008-04-01

    Mediterranean Spain is a region with intensive agricultural production combined with an important seasonal water demand for water supply. High application rates of inorganic nitrogen fertiliser, input of plant protection products and intensive irrigation, sometimes with treated wastewater, is a common practice. As a result, most aquifers show nitrate contamination problems of agricultural origin. Data on pesticide residues is scarce, as systematic monitoring is not currently done. In Majorca Island, values up to 700 mg/l of nitrate in groundwater have been observed. To analyse the current situation derived from non-point pollution, several actions have been taken at different scales: declaration of a nitrate vulnerable zone, field experiments to evaluate nitrogen transport to the aquifer and the development of a GIS-simulation model to generate nitrate risk maps.

  5. Introduction: Assessing non-point source pollution in the vadose zone with advanced information technologies

    NASA Astrophysics Data System (ADS)

    Corwin, Dennis L.; Loague, Keith; Ellsworth, Timothy R.

    The information age has ushered in a global awareness of complex environmental problems that do not respect political or physical boundaries: climatic change, ozone layer depletion, deforestation, desertification, and non-point source (NPS) pollution. Among these global environmental problems, NPS pollutants represent a perfect example of a complex multidisciplinary problem that exists over multiple scales with tremendous spatial and temporal complexity. To address the NPS problem, specific to the vadose zone, advanced information technologies must be applied in a spatial context. An integrated system of advanced information technologies (i.e., global positioning, geographic information system, geostatistics, remote sensing, solute transport modeling, neural networks, transfer functions, fuzzy logic, hierarchical theory, and uncertainty analysis) provides a framework from which real-time and/or simulated assessments of NPS pollution can be made. The ability to accurately assess present and future NPS-pollution impacts on ecosystems ranging from local to global scales provides a powerful tool for environmental stewardship and guiding future human activities.

  6. Pollution of surface waters by metalaxyl and nitrate from non-point sources.

    PubMed

    Bermúdez-Couso, Alipio; Fernández-Calviño, David; Álvarez-Enjo, Manuel Ali; Simal-Gándara, Jesús; Nóvoa-Muñoz, Juan Carlos; Arias-Estévez, Manuel

    2013-09-01

    The mobility of contaminants in soil is highly dependent upon the characteristics of the contaminant chemical and the properties of the soil. In order to explore these relationships, the district of A Limia (Galicia, NW Spain) was selected as the study area--a cropland devoted to growing potatoes, where the soil had been managed intensively over the last 50 years. The soil was characterised by low slopes with the water table located very close to the soil surface. Our aim was to study the influence of high and intensive crop production on the water bodies and non-point source contamination, with a particular focus on metalaxyl and nitrate. The highest concentrations of metalaxyl occurred when rainfalls were low and in zones of the study area where natural hydrology was significantly altered by numerous drainage canals. The spatial and temporal distributions of the nitrate also showed a high variability, with the interaction between seasons and sampling area being the most significant factor in explaining the levels found.

  7. Integrated watershed approach in controlling point and non-point source pollution within Zelivka drinking water reservoir.

    PubMed

    Holas, J; Hrncir, M

    2002-01-01

    An agricultural watershed involves manipulation of soil, water and other natural resources and it has profound impacts on ecosystems. To manage these complex issues, we must understand causes and consequences and interactions-related transport of pollutants, quality of the environment, mitigation measures and policy measures. A ten year period of economic changes has been analysed with respect to sustainable development concerning Zelivka drinking water reservoir and its watershed, where agriculture and forestry are the main human activities. It is recommended that all land users within a catchment area should receive payments for their contribution to water cycle management. Setting up the prevention principles and best management practices financially subsidized by a local water company has been found very effective in both point and non-point source pollution abatement, and the newly prepared Clean Water Programme actively involves local municipal authorities as well. The first step based on systems analysis was to propose effective strategies and select alternative measures and ways for their financing. Long term monitoring of nutrient loads entering the reservoir and hazardous events statistics resulted in maps characterising the territory including vulnerable zones and risk factors. Financing involves providing annual payments to farmers, who undertake to manage specified areas of their land in a particular way and one-off payments to realise proposed issues ensuring soil conservation and watershed ecosystem benefits.

  8. Modeling Links Between Hydrology and Non Point Source Pollution in a Data Scarce Environment, Inner Mongolia, China

    NASA Astrophysics Data System (ADS)

    Runkle, B. R.; Liang, X.; Hao, F.

    2005-12-01

    Hydrological behavior is a central factor in deciding the fate of agricultural pollutants, yet the exact functions of hydrology and the scales at which they are most important are understudied. A physically based hydrological model was developed to examine the transport of common agricultural pollutants (nitrogen, phosphorus, pesticides) and problems of soil salinity. This model looks to uncover the effects of different spatial and temporal scales on the dynamics of non-point source pollution loading, transport, and distribution. The principal geochemical and physical transport mechanisms such as dissolution, adsorption, advection and mass transfer from pore water to overland flow will be characterized as functions of irrigation input and soil moisture. The model is used to examine emergent behaviors at different scales and to determine which hydrological processes and conditions are most sensitive for pollutant transport. The model will be validated by comparison with data in the Inner Mongolia Irrigation District, a 5000 km2 region along the north bank of the Yellow River in northern China. The region receives very little (<200 mm) rainfall and relies heavily on irrigation water from the Yellow River and groundwater. Polluted drainage water is threatening the ecology of nearby Wuliangsuhai Lake, a wetlands ecosystem important for bird habitat. This project is supported in part by the National Natural Science Foundation of China.

  9. A Validation Framework for Non-Point Source Simulation Models: Application to the Southern California Central Valley with Spatio-Temporally Heterogenous Source Rates

    NASA Astrophysics Data System (ADS)

    Kourakos, G.; Harter, T.

    2013-12-01

    Non-point source pollution on groundwater of agricultural regions is an alarming issue of global importance. The very large response times of contaminants which may vary from decades to centuries, require mitigation measures to be based on reliable modeling. Here we present a novel computational framework to assess and evaluate the dynamic, spatio-temporally distributed linkages between non-point sources above a groundwater basin and groundwater discharges to wells, streams, or other compliance discharge surfaces (CDSs) within a groundwater basin. The modeling framework allows for efficient evaluation of NPS pollution scenarios and of their short- and long-term effects on pollutant exceedance probabilities in CDSs. We apply the model to simulate 100 years of nitrate pollution at high resolution in a 2 million hectare semi-arid, irrigated agricultural region with a large diversity of crops, but also natural lands and urban areas, and highly heterogeneous, temporally variable loading landscape in the Southern California Central Valley. Results show that the timing of nitrate breakthrough in wells is significantly controlled by aquifer recharge and pumping rates in NPS areas and by the effective porosity of the aquifer system. MLast the model predictions are compared against a highly heterogeneous, spatio-temporally varying in space and time database of historic nitrate records and an attempt is made to compute the spatial distribution of nitrate half-life due to denitrification.

  10. Integrated watershed economic model for non-point source pollution management in Upper Big Walnut Creek Watershed, OH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Today, non-point source pollution (NPS) is one of the major sources of water quality impairments globally (UNEP, 2007). In the US, nutrient pollution is the leading cause of water quality issues in lakes and estuaries (USEPA, 2002). The maximum concentration of nutrients in streams is found to be in...

  11. Simulation of spatial and temporal distributions of non-point source pollution load in the Three Gorges Reservoir Region.

    PubMed

    Shen, Zhenyao; Qiu, Jiali; Hong, Qian; Chen, Lei

    2014-09-15

    Non-point source (NPS) pollution has become the largest threat to water quality in recent years. Major pollutants, particularly from agricultural activities, which include nitrogen, phosphorus and sediment that have been released into aquatic environments, have caused a range of problems in the Three Gorges Reservoir Region (TGRR), China. It is necessary to identify the spatial and temporal distributions of NPS pollutants and the highly polluted areas for the purpose of watershed management. In this study, the NPS pollutant load was simulated using the Soil and Water Assessment Tool (SWAT) and the small-scale watershed extended method (SWEM). The simulation results for four typical small catchments were extended to the entire watershed leading to estimates of the NPS load from 2001 to 2009. The results demonstrated that the NPS pollution load in the western area was the highest and that agricultural land was the primary pollutant source. The similar annual variation trends of runoff and sediment loads demonstrated that the sediment load was closely related to runoff. The loads of total nitrogen (TN) and total phosphorus (TP) were relatively stable from 2001 to 2007, except for high loads in 2006. The increase in pollution source strength was an important reason for the significant upward trend of TN and TP loads from 2008 to 2009. The rainfall from April to October contributed to the largest amount of runoff, sediment and nutrient loads for the year. The NPS load intensities in each sub-basin reveal large variations in the spatial distribution of different pollutants. It was shown that the temporal and spatial distributions of pollutant loads were positively correlated with the annual rainfall amounts and with human activities. Furthermore, this finding illustrates that conservation practices and nutrient management should be implemented in specific sites during special periods for the purpose of NPS pollution control in the TGRR.

  12. Evaluation of a non-point source pollution model, AnnAGNPS, in a tropical watershed

    USGS Publications Warehouse

    Polyakov, V.; Fares, A.; Kubo, D.; Jacobi, J.; Smith, C.

    2007-01-01

    Impaired water quality caused by human activity and the spread of invasive plant and animal species has been identified as a major factor of degradation of coastal ecosystems in the tropics. The main goal of this study was to evaluate the performance of AnnAGNPS (Annualized Non-Point Source Pollution Model), in simulating runoff and soil erosion in a 48 km2 watershed located on the Island of Kauai, Hawaii. The model was calibrated and validated using 2 years of observed stream flow and sediment load data. Alternative scenarios of spatial rainfall distribution and canopy interception were evaluated. Monthly runoff volumes predicted by AnnAGNPS compared well with the measured data (R2 = 0.90, P < 0.05); however, up to 60% difference between the actual and simulated runoff were observed during the driest months (May and July). Prediction of daily runoff was less accurate (R2 = 0.55, P < 0.05). Predicted and observed sediment yield on a daily basis was poorly correlated (R2 = 0.5, P < 0.05). For the events of small magnitude, the model generally overestimated sediment yield, while the opposite was true for larger events. Total monthly sediment yield varied within 50% of the observed values, except for May 2004. Among the input parameters the model was most sensitive to the values of ground residue cover and canopy cover. It was found that approximately one third of the watershed area had low sediment yield (0-1 t ha-1 y-1), and presented limited erosion threat. However, 5% of the area had sediment yields in excess of 5 t ha-1 y-1. Overall, the model performed reasonably well, and it can be used as a management tool on tropical watersheds to estimate and compare sediment loads, and identify "hot spots" on the landscape. ?? 2007 Elsevier Ltd. All rights reserved.

  13. Assessing the effects of non-point source pollution on American Samoa's coral reef communities.

    PubMed

    Houk, Peter; Didonato, Guy; Iguel, John; Van Woesik, Robert

    2005-08-01

    Surveys were completed on Tutuila Island, American Samoa, to characterize reef development and assess the impacts of non-point source pollution on adjacent coral reefs at six sites. Multivariate analyses of benthic and coral community data found similar modern reef development at three locations; Aoa, Alofau, and Leone. These sites are situated in isolated bays with gentle sloping foundations. Aoa reefs had the highest estimates of crustose coralline algae cover and coral species richness, while Leone and Alofau showed high abundances of macroalgae and Porites corals. Aoa has the largest reef flat between watershed discharge and the reef slope, and the lowest human population density. Masefau and Fagaalu have a different geomorphology consisting of cemented staghorn coral fragments and steep slopes, however, benthic and coral communities were not similar. Benthic data suggest Fagaalu is heavily impacted compared with all other sites. Reef communities were assessed as bio-criteria indicators for waterbody health, using the EPA aquatic life use support designations of (1) fully supportive, (2) partially supportive, and (3) non-supportive for aquatic life. All sites resulted in a partially supportive ranking except Fagaalu, which was non-supportive. The results of this rapid assessment based upon relative benthic community measures are less desirable than long-term dataset analyses from monitoring programs, however it fills an important role for regulatory agencies required to report annual waterbody assessments. Future monitoring sites should be established to increase the number of replicates within each geological and physical setting to allow for meaningful comparisons along a gradient of hypothesized pollution levels.

  14. A Spatial and Temporal Assessment of Non-Point Groundwater Pollution Sources, Tutuila Island, American Samoa

    NASA Astrophysics Data System (ADS)

    Shuler, C. K.; El-Kadi, A. I.; Dulaiova, H.; Glenn, C. R.; Fackrell, J.

    2015-12-01

    The quality of municipal groundwater supplies on Tutuila, the main island in American Samoa, is currently in question. A high vulnerability for contamination from surface activities has been recognized, and there exists a strong need to clearly identify anthropogenic sources of pollution and quantify their influence on the aquifer. This study examines spatial relationships and time series measurements of nutrients and other tracers to identify predominant pollution sources and determine the water quality impacts of the island's diverse land uses. Elevated groundwater nitrate concentrations are correlated with areas of human development, however, the mixture of residential and agricultural land use in this unique village based agrarian setting makes specific source identification difficult using traditional geospatial analysis. Spatial variation in anthropogenic impact was assessed by linking NO3- concentrations and δ15N(NO3) from an extensive groundwater survey to land-use types within well capture zones and groundwater flow-paths developed with MODFLOW, a numerical groundwater model. Land use types were obtained from high-resolution GIS data and compared to water quality results with multiple-regression analysis to quantify the impact that different land uses have on water quality. In addition, historical water quality data and new analyses of δD and δ18O in precipitation, groundwater, and mountain-front recharge waters were used to constrain the sources and mechanisms of contamination. Our analyses indicate that groundwater nutrient levels on Tutuila are controlled primarily by residential, not agricultural activity. Also a lack of temporal variation suggests that episodic pollution events are limited to individual water sources as opposed to the entire aquifer. These results are not only valuable for water quality management on Tutuila, but also provide insight into the sustainability of groundwater supplies on other islands with similar hydrogeology and land

  15. Modeling non-point source pollutants in the vadose zone: Back to the basics

    NASA Astrophysics Data System (ADS)

    Corwin, Dennis L.; Letey, John, Jr.; Carrillo, Marcia L. K.

    More than ever before in the history of scientific investigation, modeling is viewed as a fundamental component of the scientific method because of the relatively recent development of the computer. No longer must the scientific investigator be confined to artificially isolated studies of individual processes that can lead to oversimplified and sometimes erroneous conceptions of larger phenomena. Computer models now enable scientists to attack problems related to open systems such as climatic change, and the assessment of environmental impacts, where the whole of the interactive processes are greater than the sum of their isolated components. Environmental assessment involves the determination of change of some constituent over time. This change can be measured in real time or predicted with a model. The advantage of prediction, like preventative medicine, is that it can be used to alter the occurrence of potentially detrimental conditions before they are manifest. The much greater efficiency of preventative, rather than remedial, efforts strongly justifies the need for an ability to accurately model environmental contaminants such as non-point source (NPS) pollutants. However, the environmental modeling advances that have accompanied computer technological development are a mixed blessing. Where once we had a plethora of discordant data without a holistic theory, now the pendulum has swung so that we suffer from a growing stockpile of models of which a significant number have never been confirmed or even attempts made to confirm them. Modeling has become an end in itself rather than a means because of limited research funding, the high cost of field studies, limitations in time and patience, difficulty in cooperative research and pressure to publish papers as quickly as possible. Modeling and experimentation should be ongoing processes that reciprocally enhance one another with sound, comprehensive experiments serving as the building blocks of models and models

  16. Influence of non-point source pollution on riverine fish assemblages in South West France.

    PubMed

    Ibarra, Alonso Aguilar; Dauba, Francis; Lim, Puy

    2005-07-01

    The relationship between non-point source pollution (NSP) and fish assemblages in the Garonne basin, SW France was studied. Two independent data sets were coupled, one containing 20 physico-chemical variables and another containing 40 fish species in 84 study sites. Species were classified in guilds according to their feeding habitat and their diet composition. The physico-chemical variables were log-transformed and standardized for a factor analysis in which they were grouped into four factors which accounted for 80% of the total variability. These were named according to factor loadings (i.e. a measure of the variance of a given variable) whose absolute values were larger than 0.5. Hence, the first factor (F1) was formed by variables linked to NSP, most notably by sodium, chloride, potassium, orthophosphates, nitrites and chemical oxygen demand. The second factor (F2) was related to alkalinity (i.e. bicarbonates, calcium, conductivity and pH). The third factor (F3) included oxygen saturation rate and dissolved oxygen, and F4 combined both temperature and flow. Factor scores (i.e. weighted sums of the original variables) were then introduced in stepwise multiple regression models as explanatory variables of log-transformed fish species richness of trophic guilds. The NSP factor was significant (p < 0.05) for the following models: benthic omnivores (r2 = 0.66), all species (r2 = 0.65), total benthic species (r2 = 0.63), total water-column species (r2 = 0.57), benthic invertivores (r2 = 0.32) and water-column invertivores (r2 = 0.16). The guilds for which NSP was not significant were water-column omnivores, water-column piscivores and benthic detritivores. Thus, there was evidence of an inversely proportional association, though not causation, of NSP with species richness of riverine fish trophic guilds on a large spatio-temporal scale. Fish assemblages may respond in different ways to NSP depending on their species composition, on the region and on the scale, and

  17. Metabolomics for in situ environmental monitoring of surface waters impacted by contaminants from both point and non-point sources

    EPA Science Inventory

    We investigated the efficacy of metabolomics for field-monitoring of fish exposed to waste water treatment plant (WWTP) effluents and non-point sources of chemical contamination. Lab-reared male fathead minnows (Pimephales promelas, FHM) were held in mobile monitoring units and e...

  18. ASSESSING NON-POINT SOURCES OF NITROGEN TO SMALL STREAMS IN THE SOUTH FORK BROAD RIVER WATERSHED (GEORGIA, USA)

    EPA Science Inventory

    The National Land Cover Data (NLCD) is a land cover classification derived from Landsat Thematic Mapper satellite data collected in the early to mid-1990s. In this work, land use coverages calculated from the NLCD database are used to assess the impact of non-point sources on the...

  19. An Experimental Study on Using Rare Earth Elements to Trace Non-point source Phosphorous LossA

    NASA Astrophysics Data System (ADS)

    Liang, T.

    2011-12-01

    Controlling phosphorous (P) inputs through management of its sources and transport is critical for limiting freshwater eutrophication. Rare earth elements (REEs) have been successfully used in the analysis of soil erosion and pollutant sources, as well as in the analysis of mineral genesis. To better understand the potential for REE use in tracing non-point sources of P, we examined the combined fate of REEs and P in Chinese soils amended with REEs and documented the formation of REE-P compounds. Laboratory leaching experiments and artificial simulated rainfall experiments were conducted. Vertical leaching transfers of REEs and P were relatively small, with transport depths less than 6 cm for most REEs and P. Export of applied REEs in leachate accounted for less that 5% of inputs. The vertical mobility order of REEs and P in Chinese soils was greatest for purple soil, followed by terra nera soil, then red soil, followed by cinnamon soil, and finally loess soil. Losses of rare earth elements and P in surface runoff exhibited a parabolic relationship to simulated rainfall intensity. With greater exogenous La application, the amount of water soluble P, bicarbonate-extractable P and hydroxide-extractable P decreased significantly, while acid-extractable and residual forms of P increased significantly. In addition, characteristics of exogenous rare earth elements (REEs) and P and their losses with surface runoff (both in the water and sediments) during simulated rainfall experiments (83 mm h-1) were investigated. The results revealed that most REEs (La, 94%; Nd, 93%; Sm, 96%) and P (96%) transported with sediments in the runoff. The total amounts of losses of REEs and P in the runoff were significantly correlated, suggesting the possibility of using REEs to trace the fate of agricultural nonpoint P losses.

  20. Validation and future predictions based on a new Non-Point Source Assessment Toolbox, applied to the Central Valley, California

    NASA Astrophysics Data System (ADS)

    Kourakos, G.; Harter, T.

    2011-12-01

    Groundwater is a major irrigation water source in semi-arid regions. It is also vulnerable to Non-Point Source (NPS) contamination, particularly from nitrate (NO3-) as a result of agricultural practices. To support sound policy decisions we developed a physically based flow and transport model framework to understand and predict the fate of contaminants within regional aquifer systems. In large aquifers, the total source area of pollutants typically cover several thousand square kilometers, whilst individual sources typically do not exceed a few hundred square meters. The large contrast in these scenarios result in NPS modeling tasks that are computationally demanding, and the classical 3D models that solve the Advection-Dispersion Equation (ADE) are often not applicable due to computer memory limitations, numerical dispersion and numerical instabilities. Here, we developed and employed a number of numerical techniques to assemble a Non-Point Source Assessment Toolbox (NPSAT). The NPSAT is a quasi-3D model, combining a flow model and a streamline transport model. The flow model solves the groundwater flow equation using very fine discretization. For very large groundwater basins, a simplistic decomposition method is applied, splitting the aquifer into several overlapping sub-domains and solving to produce a high resolution velocity field. This velocity field is subsequently utilized within the transport model, where backward particle tracking links contamination sources with discharge surfaces using a large number of streamlines. For each streamline the 1D ADE is solved, assuming a unit pulse loading at the source side and a free exit boundary condition at the discharge surface side. From this, a Unit Response Function (URF) is obtained at the discharge surface side. Subsequently, actual Breakthrough Curves (BTCs) can be quickly computed from actual or hypothetical loading histories, by convoluting the URFs with real loading functions. The URFs are stored into a

  1. Impacts of DEM uncertainties on critical source areas identification for non-point source pollution control based on SWAT model

    NASA Astrophysics Data System (ADS)

    Xu, Fei; Dong, Guangxia; Wang, Qingrui; Liu, Lumeng; Yu, Wenwen; Men, Cong; Liu, Ruimin

    2016-09-01

    The impacts of different digital elevation model (DEM) resolutions, sources and resampling techniques on nutrient simulations using the Soil and Water Assessment Tool (SWAT) model have not been well studied. The objective of this study was to evaluate the sensitivities of DEM resolutions (from 30 m to 1000 m), sources (ASTER GDEM2, SRTM and Topo-DEM) and resampling techniques (nearest neighbor, bilinear interpolation, cubic convolution and majority) to identification of non-point source (NPS) critical source area (CSA) based on nutrient loads using the SWAT model. The Xiangxi River, one of the main tributaries of Three Gorges Reservoir in China, was selected as the study area. The following findings were obtained: (1) Elevation and slope extracted from the DEMs were more sensitive to DEM resolution changes. Compared with the results of the 30 m DEM, 1000 m DEM underestimated the elevation and slope by 104 m and 41.57°, respectively; (2) The numbers of subwatersheds and hydrologic response units (HRUs) were considerably influenced by DEM resolutions, but the total nitrogen (TN) and total phosphorus (TP) loads of each subwatershed showed higher correlations with different DEM sources; (3) DEM resolutions and sources had larger effects on CSAs identifications, while TN and TP CSAs showed different response to DEM uncertainties. TN CSAs were more sensitive to resolution changes, exhibiting six distribution patterns at all DEM resolutions. TP CSAs were sensitive to source and resampling technique changes, exhibiting three distribution patterns for DEM sources and two distribution patterns for DEM resampling techniques. DEM resolutions and sources are the two most sensitive SWAT model DEM parameters that must be considered when nutrient CSAs are identified.

  2. [Multiple time scales analysis of spatial differentiation characteristics of non-point source nitrogen loss within watershed].

    PubMed

    Liu, Mei-bing; Chen, Xing-wei; Chen, Ying

    2015-07-01

    Identification of the critical source areas of non-point source pollution is an important means to control the non-point source pollution within the watershed. In order to further reveal the impact of multiple time scales on the spatial differentiation characteristics of non-point source nitrogen loss, a SWAT model of Shanmei Reservoir watershed was developed. Based on the simulation of total nitrogen (TN) loss intensity of all 38 subbasins, spatial distribution characteristics of nitrogen loss and critical source areas were analyzed at three time scales of yearly average, monthly average and rainstorms flood process, respectively. Furthermore, multiple linear correlation analysis was conducted to analyze the contribution of natural environment and anthropogenic disturbance on nitrogen loss. The results showed that there were significant spatial differences of TN loss in Shanmei Reservoir watershed at different time scales, and the spatial differentiation degree of nitrogen loss was in the order of monthly average > yearly average > rainstorms flood process. TN loss load mainly came from upland Taoxi subbasin, which was identified as the critical source area. At different time scales, land use types (such as farmland and forest) were always the dominant factor affecting the spatial distribution of nitrogen loss, while the effect of precipitation and runoff on the nitrogen loss was only taken in no fertilization month and several processes of storm flood at no fertilization date. This was mainly due to the significant spatial variation of land use and fertilization, as well as the low spatial variability of precipitation and runoff. PMID:26710649

  3. [Multiple time scales analysis of spatial differentiation characteristics of non-point source nitrogen loss within watershed].

    PubMed

    Liu, Mei-bing; Chen, Xing-wei; Chen, Ying

    2015-07-01

    Identification of the critical source areas of non-point source pollution is an important means to control the non-point source pollution within the watershed. In order to further reveal the impact of multiple time scales on the spatial differentiation characteristics of non-point source nitrogen loss, a SWAT model of Shanmei Reservoir watershed was developed. Based on the simulation of total nitrogen (TN) loss intensity of all 38 subbasins, spatial distribution characteristics of nitrogen loss and critical source areas were analyzed at three time scales of yearly average, monthly average and rainstorms flood process, respectively. Furthermore, multiple linear correlation analysis was conducted to analyze the contribution of natural environment and anthropogenic disturbance on nitrogen loss. The results showed that there were significant spatial differences of TN loss in Shanmei Reservoir watershed at different time scales, and the spatial differentiation degree of nitrogen loss was in the order of monthly average > yearly average > rainstorms flood process. TN loss load mainly came from upland Taoxi subbasin, which was identified as the critical source area. At different time scales, land use types (such as farmland and forest) were always the dominant factor affecting the spatial distribution of nitrogen loss, while the effect of precipitation and runoff on the nitrogen loss was only taken in no fertilization month and several processes of storm flood at no fertilization date. This was mainly due to the significant spatial variation of land use and fertilization, as well as the low spatial variability of precipitation and runoff.

  4. Managing natural processes in drainage for non-point source nitrogen control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In watersheds dominated by agriculture, artificial drainage systems can efficiently and quickly transport excess water from agricultural soils. The application of more nitrogen (N) than a crop uses creates a surplus in the soil and increases the risk of N loss to the environment. We examine issues a...

  5. Identifying non-point source critical source areas based on multi-factors at a basin scale with SWAT

    NASA Astrophysics Data System (ADS)

    Liu, Ruimin; Xu, Fei; Zhang, Peipei; Yu, Wenwen; Men, Cong

    2016-02-01

    The identification of critical source areas (CSAs) is a precondition for non-point source (NPS) pollution control at a basin scale, especially in areas with limited resources. Based on the Soil and Water Assessment Tool (SWAT), nutrient loads coupled with population density and water quality requirements are regarded as multi-factors for CSAs identification in Xiangxi river watershed, the first tributary of the Yangtze River. The results based on the calibrated model found that the subbasins heavily and seriously polluted by nutrient loads were different from the subbasins identified as CSAs, demonstrating integrating socio-economic factors like population density and water quality requirements to identify CSAs is of much necessity. The CSAs occupied 19.7% of the total subbasins, and accounted for 53% total nitrogen loads, 54% total phosphorus loads and 36% of the total population. Considering the model calibration and validation will take a long time as well as data deficiency in some subbasins, the influence of uncalibrated SWAT on CSAs identifications was discussed. The comparative results between CSAs identification with calibrated and uncalibrated SWAT model revealed that model calibration had little effect on nutrients distribution and CSAs locations in the study area. Uncalibrated SWAT model may be applied when the research objective is less related to model calibration. The results will be greatly effective for CSAs identification and NPS pollution control at a basin scale.

  6. Multi-angle Indicators System of Non-point Pollution Source Assessment in Rural Areas: A Case Study Near Taihu Lake

    NASA Astrophysics Data System (ADS)

    Huang, Lei; Ban, Jie; Han, Yu Ting; Yang, Jie; Bi, Jun

    2013-04-01

    This study aims to identify key environmental risk sources contributing to water eutrophication and to suggest certain risk management strategies for rural areas. The multi-angle indicators included in the risk source assessment system were non-point source pollution, deficient waste treatment, and public awareness of environmental risk, which combined psychometric paradigm methods, the contingent valuation method, and personal interviews to describe the environmental sensitivity of local residents. Total risk values of different villages near Taihu Lake were calculated in the case study, which resulted in a geographic risk map showing which village was the critical risk source of Taihu eutrophication. The increased application of phosphorus (P) and nitrogen (N), loss vulnerability of pollutant, and a lack of environmental risk awareness led to more serious non-point pollution, especially in rural China. Interesting results revealed by the quotient between the scores of objective risk sources and subjective risk sources showed what should be improved for each study village. More environmental investments, control of agricultural activities, and promotion of environmental education are critical considerations for rural environmental management. These findings are helpful for developing targeted and effective risk management strategies in rural areas.

  7. Instream Attenuation of Nitrogen and Phosphorus in Non-Point Source Dominated Streams: Hydrologic and Biogeochemical Controls

    NASA Astrophysics Data System (ADS)

    Bray, E. N.; Chen, X.; Keller, A. A.

    2010-12-01

    Non-point source inputs of total nitrogen (TN) and total phosphorus (TP) in rivers are the leading causes of water quality degradation in the United States (Turner and Rabalais, 2003; Broussard and Turner, 2009). Yet it remains a challenge to adequately quantify the relative role and influence of physical hydrological processes versus biogeochemical processes on the attenuation of TN and TP for individual river reaches. A watershed-scale study of instream dynamics and attenuation of TN and TP in northeastern U.S. headwater streams demonstrates that physical and hydrological processes exert greater control over nutrient removal than biogeochemical processes. To explore these interactions under various attenuation scenarios, we developed the watershed-scale model (WARMF) for 97 catchments to simulate watershed processes, hydrology, and diffuse source loads of nutrients. We simulated a hypothetical nutrient release at a rate of 1 kg/d of TN (50% as ammonium and 50% as nitrate) and TP (100% as phosphate) to predict response lengths of downstream catchments. Resulting attenuation factors are presented as the change in mean load at a given location, normalized to the change in the catchment in which the load is applied. Results indicate that for most catchments, the TN and TP load increase is attenuated from the stream within a few tens of kilometers. Fifty percent attenuation occurs across length scales ranging from a few hundreds of meters to kilometers if the load is introduced in the headwaters, indicating the most rapid nutrient removal occurs in the smallest headwater streams but generally decreases with distance downstream. There are some differences in the attenuation factors for TN and TP, although the pattern of attenuation is the same. Sensitivity analyses highlight five hydrological parameters of paramount importance to concentrations of N and P, namely precipitation, evaporation coefficients (magnitude and skewness), soil layer thickness, soil saturated

  8. The precipitation driven correlation based mapping method (PCM) for identifying the critical source areas of non-point source pollution

    NASA Astrophysics Data System (ADS)

    Huang, Jinhui Jeanne; Lin, Xiaojuan; Wang, Jianhua; Wang, Hao

    2015-05-01

    Critical source areas (CSAs) are the areas that are relatively more erosion-prone and contribute significantly more pollutants per unit area. They have been widely recognized as optimal locations for the control of non-point source (NPS) pollution. Modeling approach has been frequently used to identify the CSAs of NPS pollution on a basin scale. In previous studies, CSAs were identified based on the simulated average annual nutrient yields for the simulation period at the levels of sub-basin or hydrologic response unit (HRU). However, this method did not consider the impact of uneven spatial distribution of precipitation, which is considered to be the driven force of NPS pollution. In many cases, due to limited length of qualified monitoring data collected, the simulation period may not cover a full spectrum of the precipitation characteristics so that some potential CSAs may be missed. In the present study, the precipitation driven correlation based mapping method (PCM) was proposed, which can reduce the impact of uncertain spatial-temporal distribution of precipitation and identify the CSAs of NPS pollution with a better coverage. This method was applied to the Zhang River Basin, a watershed in North China that occupies an area of 18,072 km2. The SWAT (Soil and Water Assessment Tool) was used for simulation purposes. By using PCM, the maps of CSAs for controlling total nitrogen (TN) and total phosphorus (TP) were produced. This study has found that the monthly precipitation is highly correlated with the TN and TP yields. It was observed that TN yields have slightly higher correlation value with the precipitation than TP yields. Hence, the precipitation has more impacts on TN yields than TP yields. The impact is more substantial in urban areas than other areas.

  9. Anthropogenic point-source and non-point-source nitrogen inputs into Huai River basin and their impacts on riverine ammonia-nitrogen flux

    NASA Astrophysics Data System (ADS)

    Zhang, W. S.; Swaney, D. P.; Li, X. Y.; Hong, B.; Howarth, R. W.; Ding, S. H.

    2015-07-01

    This study provides a new approach to estimate both anthropogenic non-point-source and point-source nitrogen (N) inputs to the landscape, and determines their impacts on riverine ammonia-nitrogen (AN) flux, providing a foundation for further exploration of anthropogenic effects on N pollution. Our study site is Huai River basin of China, a water-shed with one of the highest levels of N input in the world. Multi-year average (2003-2010) inputs of N to the watershed are 27 200 ± 1100 kg N km-2 yr-1. Non-point sources comprised about 98 % of total N input, and only 2 % of inputs are directly added to the aquatic ecosystem as point sources. Fertilizer application was the largest non-point source of new N to the Huai River basin (69 % of net anthropogenic N inputs), followed by atmospheric deposition (20 %), N fixation in croplands (7 %), and N content of imported food and feed (2 %). High N inputs showed impacts on riverine AN flux: fertilizer application, point-source N input, and atmospheric N deposition were proved as more direct sources to riverine AN flux. Modes of N delivery and losses associated with biological denitrification in rivers, water consumption, interception by dams may influence the extent of export of riverine AN flux from N sources. Our findings highlight the importance of anthropogenic N inputs from both point sources and non-point sources in heavily polluted watersheds, and provide some implications for AN prediction and management.

  10. Preliminary study on using rare earth elements to trace non-point source phosphorous loss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The environmental fate of phosphorus (P) is of concern as P is a primary cause of freshwater eutrophication. Rare earth elements (REEs) have been successfully used in the analysis of soil erosion and pollutant sources, as well as in the analysis of mineral genesis. To better understand the potential...

  11. Stochastic Analysis of Non Point Source Loading of Fecal Bacteria in a Shallow Heterogeneous Aquifer

    NASA Astrophysics Data System (ADS)

    Cook, S. J.; Li, X.; Atwill, R.; Packman, A. I.; Harter, T.

    2011-12-01

    Manure and wastewater irrigation (MWI) presents a microbiological risk to shallow groundwater quality. Particularly vulnerable are domestic wells in rural areas where treatment systems may be limited or unreliable. However, despite multiple and persistent sources of fecal contamination, cross sectional monitoring of fecal bacteria in groundwater indicates a high degree of variability in both prevalence and measured concentrations. Apparently random variation occurs both between wells and samples at individual wells. In contrast, deliberate longitudinal studies of MWIs, particularly in the laboratory, tend to exhibit relatively smooth breakthrough curves consistent with colloid filtration theory. To better characterize potential sources of variability in observed field data, a 3D stochastic groundwater modeling approach representative of irrigation applications to vulnerable alluvial aquifers was developed. Heterogeniety is assessed by incorporating multiple loading functions and hydrostratigraphic representations of a heterogeneous alluvial aquifer. Simulations indicate that irrigation water breakthroughs to wells are generally limited to shallow depths, suggesting limited risk to domestic wells screened several tens of meters below the water table. Whilst the presence of aquifer heterogeneity significantly extends the transport distance and tailing of breakthrough curves, owing to macro-dispersion and in-well mixing, simulated breakthrough curves are relatively smooth and consistent with observed longitudinal studies. This suggests that the highly erratic and variable nature of microorganism detection may be due to highly transient processes, including but not limited to spatio-temporal variations in source variability and limitations in infrequent monitoring programs to properly determine variability.

  12. Using NASA and Earth Science Products to Improve EPA Non-point Source Water Quality Modeling for the Chesapeake Bay

    NASA Astrophysics Data System (ADS)

    Toll, D.; Engman, T.; Edward, P.; Magness, A.; Townsend, P.; N-Meister, W.; Nigro, J.; Lee, S.

    2007-12-01

    The Environmental Protection Agency (EPA) estimates that over 20,000 bodies of water throughout the country do not meet water quality standards. Nonpoint sources -- pollution from urban, agricultural, and forest land that is transported by runoff -- typically cause 90 percent of impairments. EPA has developed the BASINS (Better Assessment Science Integrating Point and Nonpoint Sources) modeling system for performing numerous water quality studies. The key to this suite of models is the Hydrological Simulation Program - Fortran (HSPF), which calculates daily stream flow rates and the corresponding pollutant concentrations at the watershed outlet. EPA has partnered with NASA to use high spatial and temporal hydrological variables (e.g., precipitation, evaporation, etc.) from the NASA Land Information System (LIS) and land cover/vegetative indices derived from primarily MODIS and Landsat satellite data non-point source water quality for the Chesapeake Bay Basin. For the precipitation and evaporation data, EPA-based BASINS-HSPF streamflow runs were conducted on seven study watersheds in the Chesapeake Bay Basin. Sets of runs using precipitation from default weather stations, the NASA LIS 1/8th degree precipitation, NOAA Stage IV precipitation, NASA LIS Noah land surface model evapotranspiration datasets were conducted for each watershed. The output statistics summarized reveal that for 74% of the runs, the NASA LIS 1/8th degree and Stage IV precipitation-based runs performed better than when using only the default EPA precipitation station data. In addition, an automatic calibration method ('PEST') and Noah land surface model evapotranspiration (ET) being further incorporated. The empirical ability of generalized spectral indices and land cover derived from Landsat and MODIS was tested for predicting stream water nitrogen export from predominately forested watersheds undergoing disturbance. The disturbance index, a summary index that is easily computed from Landsat

  13. [Analysis on nitrogen and phosphorus loading of non-point sources in Shiqiao river watershed based on L-THIA model].

    PubMed

    Li, Kai; Zeng, Fan-Tang; Fang, Huai-Yang; Lin, Shu

    2013-11-01

    Based on the Long-term Hydrological Impact Assessment (L-THIA) model, the effect of land use and rainfall change on nitrogen and phosphorus loading of non-point sources in Shiqiao river watershed was analyzed. The parameters in L-THIA model were revised according to the data recorded in the scene of runoff plots, which were set up in the watershed. The results showed that the distribution of areas with high pollution load was mainly concentrated in agricultural land and urban land. Agricultural land was the biggest contributor to nitrogen and phosphorus load. From 1995 to 2010, the load of major pollutants, namely TN and TP, showed an obviously increasing trend with increase rates of 17.91% and 25.30%, respectively. With the urbanization in the watershed, urban land increased rapidly and its area proportion reached 43.94%. The contribution of urban land to nitrogen and phosphorus load was over 40% in 2010. This was the main reason why pollution load still increased obviously while the agricultural land decreased greatly in the past 15 years. The rainfall occurred in the watershed was mainly concentrated in the flood season, so the nitrogen and phosphorus load of the flood season was far higher than that of the non-flood season and the proportion accounting for the whole year was over 85%. Pearson regression analysis between pollution load and the frequency of different patterns of rainfall demonstrated that rainfall exceeding 20 mm in a day was the main rainfall type causing non-point source pollution.

  14. Evaluation and management of non-point source pollutants in the Lake Tahoe watershed

    SciTech Connect

    Lee, G.F.; Jones-Lee, A.

    1994-12-31

    Lake Tahoe, California-Nevada, one of the most oligotrophic lakes in the world, is experiencing decreased water clarity and increased periphyton growth, and water supplies drawing from the lake are experiencing increased algal-related tastes and odors. The growth of algae in Lake Tahoe is primarily limited by the nitrogen (nitrate and ammonia) loads to the lake, which have been increasing over the years. The nitrogen that is causing the increased fertilization of the lake is primarily derived from atmospheric sources through precipitation onto the lake`s surface. A potentially highly significant source of atmospheric nitrogen in the Lake Tahoe Basin is automobile, bus, and truck engine exhaust discharge of NOx. The fertilization of lawns and other shrubbery, including golf courses, within the Lake Tahoe Basin is also leading to significant growths of attached algae in the nearshore waters of the lake. The fertilizers are transported via groundwater to the nearshore areas of the lake. In order to prevent further deterioration of Lake Tahoe`s eutrophication-related water quality, there is immediate need to control atmospheric input of nitrate and ammonia to the lake`s surface, and to control use of fertilizers on lawns, shrubbery, and golf courses in the watershed. The states of California and Nevada, and the Tahoe Regional Planning Authority need to focus considerable attention on the determination of whether restricting NOx emissions from vehicular traffic within the basin would have a significant beneficial impact on Lake Tahoe`s water clarity.

  15. Modelling of point and non-point source pollution of nitrate with SWAT in the river Dill, Germany

    NASA Astrophysics Data System (ADS)

    Pohlert, T.; Huisman, J. A.; Breuer, L.; Frede, H.-G.

    2005-12-01

    We used the Soil and Water Assessment Tool (SWAT) to simulate point and non-point source pollution of nitrate in a mesoscale mountainous catchment. The results show that the model efficiency for daily discharge is 0.81 for the calibration period (November 1990 to December 1993) and 0.56 for the validation period (April 2000 to January 2003). The model efficiency for monthly nitrate load is 0.66 and 0.77 for the calibration period (April 2000 to March 2002) and validation period (April 2002 to January 2003), respectively. However, the model efficiency for daily loads is low (0.15), which cannot only be attributed to the quality of input data of point source effluents. An analysis of the internal fluxes and cycles of nitrogen pointed out considerable weaknesses in the models conceptualisation of the nitrogen modules which will be improved in future research.

  16. Search for the northwest passage: the assignation of NSP (non-point source pollution) rights in nutrient trading programs.

    PubMed

    Collentine, D

    2002-01-01

    The search for solutions to the problem of non-point source pollution (NSP) includes alternatives based on theories associated with the use of tradable pollution permits. Tradable permit programs have received significant support as a promising policy for the reduction of effluent discharges but programs in practice have not been regarded as successful. The lack of success is ascribed to the design of the programs. However, this may be a design problem which is insurmountable due to the nature of the NSP problem. Tradable permit solutions are based on an assumption that the assignation of quantifiable rights to both point and nonpoint sources, based on some predetermined ambient water quality measure, is possible. The conclusion here is that there are significant features particular to NSP that hinder the introduction of rights and significantly decrease the utility of tradable permit solutions. PMID:12079107

  17. Search for the northwest passage: the assignation of NSP (non-point source pollution) rights in nutrient trading programs.

    PubMed

    Collentine, D

    2002-01-01

    The search for solutions to the problem of non-point source pollution (NSP) includes alternatives based on theories associated with the use of tradable pollution permits. Tradable permit programs have received significant support as a promising policy for the reduction of effluent discharges but programs in practice have not been regarded as successful. The lack of success is ascribed to the design of the programs. However, this may be a design problem which is insurmountable due to the nature of the NSP problem. Tradable permit solutions are based on an assumption that the assignation of quantifiable rights to both point and nonpoint sources, based on some predetermined ambient water quality measure, is possible. The conclusion here is that there are significant features particular to NSP that hinder the introduction of rights and significantly decrease the utility of tradable permit solutions.

  18. Presence of Pathogens and Indicator Microbes at a Non-Point Source Subtropical Recreational Marine Beach ▿ †

    PubMed Central

    Abdelzaher, Amir M.; Wright, Mary E.; Ortega, Cristina; Solo-Gabriele, Helena M.; Miller, Gary; Elmir, Samir; Newman, Xihui; Shih, Peter; Bonilla, J. Alfredo; Bonilla, Tonya D.; Palmer, Carol J.; Scott, Troy; Lukasik, Jerzy; Harwood, Valerie J.; McQuaig, Shannon; Sinigalliano, Chris; Gidley, Maribeth; Plano, Lisa R. W.; Zhu, Xiaofang; Wang, John D.; Fleming, Lora E.

    2010-01-01

    Swimming in ocean water, including ocean water at beaches not impacted by known point sources of pollution, is an increasing health concern. This study was an initial evaluation of the presence of indicator microbes and pathogens and the association among the indicator microbes, pathogens, and environmental conditions at a subtropical, recreational marine beach in south Florida impacted by non-point sources of pollution. Twelve water and eight sand samples were collected during four sampling events at high or low tide under elevated or reduced solar insolation conditions. The analyses performed included analyses of fecal indicator bacteria (FIB) (fecal coliforms, Escherichia coli, enterococci, and Clostridium perfringens), human-associated microbial source tracking (MST) markers (human polyomaviruses [HPyVs] and Enterococcus faecium esp gene), and pathogens (Vibrio vulnificus, Staphylococcus aureus, enterovirus, norovirus, hepatitis A virus, Cryptosporidium spp., and Giardia spp.). The enterococcus concentrations in water and sand determined by quantitative PCR were greater than the concentrations determined by membrane filtration measurement. The FIB concentrations in water were below the recreational water quality standards for three of the four sampling events, when pathogens and MST markers were also generally undetectable. The FIB levels exceeded regulatory guidelines during one event, and this was accompanied by detection of HPyVs and pathogens, including detection of the autochthonous bacterium V. vulnificus in sand and water, detection of the allochthonous protozoans Giardia spp. in water, and detection of Cryptosporidium spp. in sand samples. The elevated microbial levels were detected at high tide and under low-solar-insolation conditions. Additional sampling should be conducted to further explore the relationships between tidal and solar insolation conditions and between indicator microbes and pathogens in subtropical recreational marine waters impacted

  19. Evaluation of non-point source pollution reduction by applying best management practices using a SWAT model and QuickBird high resolution satellite imagery.

    PubMed

    Lee, MiSeon; Park, GeunAe; Park, MinJi; Park, JongYoon; Lee, JiWan; Kim, SeongJoon

    2010-01-01

    This study evaluated the reduction effect of non-point source pollution by applying best management practices (BMPs) to a 1.21 km2 small agricultural watershed using a SWAT (Soil and Water Assessment Tool) model. Two meter QuickBird land use data were prepared for the watershed. The SWAT was calibrated and validated using daily streamflow and monthly water quality (total phosphorus (TP), total nitrogen (TN), and suspended solids (SS)) records from 1999 to 2000 and from 2001 to 2002. The average Nash and Sutcliffe model efficiency was 0.63 for the streamflow and the coefficients of determination were 0.88, 0.72, and 0.68 for SS, TN, and TP, respectively. Four BMP scenarios viz. the application of vegetation filter strip and riparian buffer system, the regulation of Universal Soil Loss Equation P factor, and the fertilizing control amount for crops were applied and analyzed.

  20. Analysis of non-point and point source pollution in China: case study in Shima Watershed in Guangdong Province

    NASA Astrophysics Data System (ADS)

    Fang, Huaiyang; Lu, Qingshui; Gao, Zhiqiang; Shi, Runhe; Gao, Wei

    2013-09-01

    China economy has been rapidly increased since 1978. Rapid economic growth led to fast growth of fertilizer and pesticide consumption. A significant portion of fertilizers and pesticides entered the water and caused water quality degradation. At the same time, rapid economic growth also caused more and more point source pollution discharge into the water. Eutrophication has become a major threat to the water bodies. Worsening environment problems forced governments to take measures to control water pollution. We extracted land cover from Landsat TM images; calculated point source pollution with export coefficient method; then SWAT model was run to simulate non-point source pollution. We found that the annual TP loads from industry pollution into rivers are 115.0 t in the entire watershed. Average annual TP loads from each sub-basin ranged from 0 to 189.4 ton. Higher TP loads of each basin from livestock and human living mainly occurs in the areas where they are far from large towns or cities and the TP loads from industry are relatively low. Mean annual TP loads that delivered to the streams was 246.4 tons and the highest TP loads occurred in north part of this area, and the lowest TP loads is mainly distributed in middle part. Therefore, point source pollution has much high proportion in this area and governments should take measures to control point source pollution.

  1. Calculation and analysis of the non-point source pollution in the upstream watershed of the Panjiakou Reservoir, People's Republic of China

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Tang, L.

    2007-05-01

    Panjiakou Reservoir is an important drinking water resource in Haihe River Basin, Hebei Province, People's Republic of China. The upstream watershed area is about 35,000 square kilometers. Recently, the water pollution in the reservoir is becoming more serious owing to the non-point pollution as well as point source pollution on the upstream watershed. To effectively manage the reservoir and watershed and develop a plan to reduce pollutant loads, the loading of non-point and point pollution and their distribution on the upstream watershed must be understood fully. The SWAT model is used to simulate the production and transportation of the non-point source pollutants in the upstream watershed of the Panjiakou Reservoir. The loadings of non-point source pollutants are calculated for different hydrologic years and the spatial and temporal characteristics of non-point source pollution are studied. The stream network and topographic characteristics of the stream network and sub-basins are all derived from the DEM by ArcGIS software. The soil and land use data are reclassified and the soil physical properties database file is created for the model. The SWAT model was calibrated with observed data of several hydrologic monitoring stations in the study area. The results of the calibration show that the model performs fairly well. Then the calibrated model was used to calculate the loadings of non-point source pollutants for a wet year, a normal year and a dry year respectively. The time and space distribution of flow, sediment and non-point source pollution were analyzed depending on the simulated results. The comparison of different hydrologic years on calculation results is dramatic. The loading of non-point source pollution in the wet year is relatively larger but smaller in the dry year since the non-point source pollutants are mainly transported through the runoff. The pollution loading within a year is mainly produced in the flood season. Because SWAT is a

  2. Minimizing agricultural nonpoint-source impacts: A symposium overview

    SciTech Connect

    Sharpley, A.; Meyer, M.

    1994-01-01

    This paper provides a brief overview of agricultural non-point pollution source issues and options. The need to identify critical sources for pollution control, target specific controls for different wter quality objectives within watersheds, and evaluate and implement cost effective management practices that minimize the pollution to ground water and surface waters are key issues.

  3. SIMPLE: assessment of non-point phosphorus pollution from agricultural land to surface waters by means of a new methodology.

    PubMed

    Schoumans, O F; Mol-Dijkstra, J; Akkermans, L M W; Roest, C W J

    2002-01-01

    In the past, environmental Phosphorus (P) parameters like soil P indices have been used to catogorize the potential risk of P losses from agricultural land. In order to assess the actual risk of P pollution of groundwater and surface waters, dynamic process oriented soil and water quality models have been frequently used. Recently, an approximating model for phosphorus, called SIMPLE, has been developed. This model approximates the output from a complex dynamic water quality model. The approximating model is called a metamodel. This simple P-model proves to be a powerful tool for quick assessment of the risk of P pollution from agricultural land to surface waters. PMID:12079100

  4. [Impact of the land-use change on the non-point source nitrogen load in Yunmeng Lake watershed].

    PubMed

    Meng, Xiao-Yun; Yu, Xing-Xiu; Pan, Xue-Qin

    2012-06-01

    Take potable water sources in Linyi City Yunmeng Lake watershed as a case study, it obtains the nutrient export coefficient of land use by the export coefficient model and simulative rainfall experiment. On the basis of GIS and RS, it analyses the effect of the non-point source (NPS) pollution load because of the land-use change during the past 25 years. The result indicates that the TN increased from 3.77 x 10(3) t in 1986, to 4.45 x 10(3) t in 1995, to 5.5 x 10(3) t in 2010; As far as land-use type is concerned, the TN from farm-land increased year by year, the contribution rate is 80.11% in 1986, 82.60% in 1995 and 85.59% in 2010, the forestland and the grass-land load have a little change, but the contribution rate decreased gradually, the residential load increased by a large margin, however, the contribution rate is very little. As for the sub-basin, the higher the proportion of the farm-land is, the more the TN load increased. There is a significant positive correlation between the farm-land and the nitrogen (TN) load, so the farm-land is the sources of the nitrogen. Conversely, there are negative correlations between the forest-land, grass-land and the TN load; therefore, the forest-land and grass-land are the sinks of the nitrogen. Therefore, it can adjust the land-use structure to reduce and control the TN loss to water environmental pollution.

  5. The Behavior of Organic Phosphorus under Non-Point Source Wastewater in the Presence of Phototrophic Periphyton

    PubMed Central

    Lu, Haiying; Yang, Linzhang; Zhang, Shanqing; Wu, Yonghong

    2014-01-01

    To understand the role of ubiquitous phototrophic periphyton in aquatic ecosystem on the biogeochemical cycling of organic phosphorus, the conversion and removal kinetic characteristics of organic phosphorus (Porg) such as adenosine triphosphate (ATP) were investigated in the presence of the periphyton cultured in artificial non-point source wastewater. The preliminary results showed that the periphyton was very powerful in converting Porg evidenced by the fact that inorganic phosphorus (Pinorg) content in solution increased from about 0.7 to 14.3 mg P L−1 in 48 hours in the presence of 0.6 g L−1 periphyton. This was because the periphyton could produce abundant phosphatases that benefited the conversion of Porg to Pinrog. Moreover, this conversion process was described more suitable by the pseudo-first-order kinetic model. The periphyton was also effective in removing Porg, which showed that the Porg can be completely removed even when the initial Porg concentration was as high as 13 mg P L−1 in 48 hours in the presence of 1.6 g L−1 periphyton. Furthermore, it was found that biosorption dominated the Porg removal process and exhibited the characteristics of physical adsorption. However, this biosorption process by the periphyton was significantly influenced by biomass (absorbent dosage) and temperature. This work provides insights into Porg biogeochemical circulation of aquatic ecosystem that contained the periphyton or similar microbial aggregates. PMID:24465782

  6. Estimating a societal value of earth science information in the assessment of non-point source pollutants

    NASA Astrophysics Data System (ADS)

    Bernknopf, Richard L.; Allison Lenkeit, K.; Dinitz, Laura B.; Loague, Keith

    The availability of potable groundwater supplies is a major environmental-quality concern throughout the U.S. Remediation measures exist as one possible means of "cleaning up" groundwater-contamination problems. An alternative preventive approach to mitigate future contamination incidents is regional-scale non-point source (NPS) vulnerability assessments. The method of assessing groundwater vulnerability in this study is founded on the Retardation Factor (RF), a screening index which is based on Earth Science information. In this chapter the RF index is used as the core of a risk-based regulation to permit the application of specific pesticides in specific soils to avoid future contamination. An integrated Earth Science-Economics model is developed to estimate the benefits of an ex ante informational approach to decision making in a regulatory framework. The RF-based preventive measure is then compared in a cost-effectiveness analysis to a wellhead treatment program in a hypothetical case study for the Hawaiian island of Oahu. The comparison demonstrates that an RF-based regulation has positive net benefits and under certain circumstance can be more efficient than the example wellhead treatment program.

  7. Influencing factor analysis of phosphorus loads from non-point source: a case study in central China.

    PubMed

    Zhuang, Yanhua; Hong, Song; Zhan, F Benjamin; Zhang, Liang

    2015-11-01

    The influence factor analysis for non-point source (NPS) pollution is very important to taking effective water pollution control measures. In this study, the self-organizing map (SOM) and linear model analysis were used to analyze the relationships between total phosphorus (TP) loads and influencing factors, both qualitatively and quantitatively. The land-use type, topography, and vegetation coverage were the main factors influencing the export of TP loads in Tangxun watershed. Slope and normalized difference vegetation index (NDVI) were chosen as characteristic indices of topography and vegetation coverage, respectively. For the whole watershed, the high TP loads were mainly distributed in areas with high slope and low vegetation coverage for a specific land-use type. For different land types, the slope significantly influenced the export of TP loads in waste/bare land and forest/green land while NDVI influenced the export of TP loads in forest/green land and farmland. In terms of multi-factor analysis, the comprehensive influence of slope and NDVI on TP loads showed as waste/bare land>forest/green land>farmland>rural/urban construction land. PMID:26514801

  8. Influencing factor analysis of phosphorus loads from non-point source: a case study in central China.

    PubMed

    Zhuang, Yanhua; Hong, Song; Zhan, F Benjamin; Zhang, Liang

    2015-11-01

    The influence factor analysis for non-point source (NPS) pollution is very important to taking effective water pollution control measures. In this study, the self-organizing map (SOM) and linear model analysis were used to analyze the relationships between total phosphorus (TP) loads and influencing factors, both qualitatively and quantitatively. The land-use type, topography, and vegetation coverage were the main factors influencing the export of TP loads in Tangxun watershed. Slope and normalized difference vegetation index (NDVI) were chosen as characteristic indices of topography and vegetation coverage, respectively. For the whole watershed, the high TP loads were mainly distributed in areas with high slope and low vegetation coverage for a specific land-use type. For different land types, the slope significantly influenced the export of TP loads in waste/bare land and forest/green land while NDVI influenced the export of TP loads in forest/green land and farmland. In terms of multi-factor analysis, the comprehensive influence of slope and NDVI on TP loads showed as waste/bare land>forest/green land>farmland>rural/urban construction land.

  9. [Empirical study on non-point sources pollution based on landscape pattern & ecological processes theory: a case of soil water loss on the Loess Plateau in China].

    PubMed

    Suo, An-ning; Wang, Tian-ming; Wang, Hui; Yu, Bo; Ge, Jian-ping

    2006-12-01

    Non-point sources pollution is one of main pollution modes which pollutes the earth surface environment. Aimed at soil water loss (a typical non-point sources pollution problem) on the Losses Plateau in China, the paper applied a landscape patternevaluation method to twelve watersheds of Jinghe River Basin on the Loess Plateau by means of location-weighted landscape contrast index(LCI) and landscape slope index(LSI). The result showed that LSI of farm land, low density grass land, forest land and LCI responded significantly to soil erosion modulus and responded to depth of runoff, while the relationship between these landscape index and runoff variation index and erosion variation index were not statistically significant. This tell us LSI and LWLCI are good indicators of soil water loss and thus have big potential in non-point source pollution risk evaluation.

  10. Non-point source analysis of a railway bridge area using statistical method: case study of a concrete road-bed.

    PubMed

    Gil, Kyungik; Im, Jiyeol

    2014-06-01

    In an effort to protect the quality of the water system, interest in non-point source pollution is increasing. Recently, studies of non-point sources pollution are continuing in relation to various land-use areas, but such studies have not been fully conducted in railway facility sites. Using monitoring data of railway bridge area with concrete road-bed, the runoff characteristics, pollutant unit loads, and first flush criteria were assessed. Railway bridge area with concrete road-bed typically show the first flush effect, and the pollutant unit load was determined to be higher than other public facilities areas. Further, the first flush criteria show an effective rainfall amount of 7 mm. In other words, from the runoff of railway facilities, considerable amounts of non-point source pollutants are occurred, indicating the need to create best management practices which are adequate for railway facility sites.

  11. DISCRIMINATION OF NATURAL AND NON-POINT SOURCE EFFECTS FROM ANTHROGENIC EFFECTS AS REFLECTED IN BENTHIC STATE IN THREE ESTUARIES IN NEW ENGLAND

    EPA Science Inventory

    In order to protect estuarine resources, managers must be able to discern the effects of natural conditions and non-point source effects, and separate them from multiple anthropogenic point source effects. Our approach was to evaluate benthic community assemblages, riverine nitro...

  12. Parameter uncertainty analysis of the non-point source pollution in the Daning River watershed of the Three Gorges Reservoir Region, China.

    PubMed

    Shen, Zhenyao; Hong, Qian; Yu, Hong; Liu, Ruimin

    2008-11-01

    The generation and formation of non-point source pollution involves great uncertainty, and this uncertainty makes monitoring and controlling pollution very difficult. Understanding the main parameters that affect non-point source pollution uncertainty is necessary to provide the basis for the planning and design of control measures. In this study, three methods were adopted to do the parameter uncertainty analysis with the Soil and Water Assessment Tool (SWAT). Based on the results of parameter sensitivity analysis by the Morris screening method, the ten parameters that most affect runoff, sediment, organic N, nitrate, and total phosphorous (TP) were chosen for further uncertainty analysis. First-order error analysis (FOEA) and the Monte Carlo method (MC) were used to analyze the effect of parameter uncertainty on model outputs. FOEA results showed that only a few parameters had significantly affected the uncertainty of the final simulation results, and many parameters had little or no effect. The SCS curve number was the parameter with significant uncertainty impact on runoff, sediment, organic N, nitrate and TP, and it showed that the runoff process was mainly responsible for the uncertainty of non-point source pollution load. The uncertainty of sediment was the biggest among the five model output results described above. MC results indicated that neglecting the parameter uncertainty of the model would underestimate the non-point source pollution load, and that the relationship between model input and output was non-linear. The uncertainty of non-point source pollution exhibited a temporal pattern: It was greater in summer than in winter. The uncertainty of runoff was smaller compared to that of sediment, organic N, nitrate, and TP, and the source of uncertainty was mainly affected by parameters associated with runoff. PMID:18639918

  13. Respective contributions of point and non-point sources of E. coli and enterococci in a large urbanized watershed (the Seine river, France).

    PubMed

    Garcia-Armisen, T; Servais, P

    2007-03-01

    Because the large rivers of the Seine watershed have a low microbiological water quality, the main sources of fecal contamination were investigated in the present study. The inputs of the point (wastewater treatment plants (WWTPs) effluents) and non-point sources (surface runoff and soil leaching) of fecal bacteria were quantified for Escherichia coli and intestinal enteroccoci used as bacterial indicators. In order to assess the contamination through non-point sources, fecal indicators abundance was estimated in samples collected in small streams located in rural areas upstream from all point sources; these small rivers were characterized by the land use of their watershed. Bacterial indicator numbers were also measured in effluents of WWTPs, some using classical treatment (settling followed by activated sludge process) and some using an additional disinfection stage (UV irradiation). These data were used to estimate the respective importance of each type of source at the scale of the whole Seine river watershed taking into account the land use and the population density. It shows the predominant importance of the point sources of fecal indicator bacteria at the scale of the whole watershed. In a scenario in which activated sludge treatment would be complemented with UV in all WWTPs located in this watershed, the non-point sources of fecal indicator bacteria would be dominant.

  14. Synergistic impacts of land-use change and soil property variation on non-point source nitrogen pollution in a freeze-thaw area

    NASA Astrophysics Data System (ADS)

    Ouyang, Wei; Huang, Haobo; Hao, Fanghua; Guo, Bobo

    2013-07-01

    Quantifying the non-point source (NPS) nitrogen pollution response to the varied land-use and soil properties in highly agricultural regions is critical for the proper management of NPS pollution. This study simulated the NPS nitrogen loading responses to variations of land-use and soil from 1979 to 2009. The Soil and Water Assessment Tool (SWAT) was used to model the NPS organic nitrogen and nitrate loading in a freeze-thaw area in northeast China. The temporal-spatial simulations of land-use in four periods indicated that the NPS nitrogen loading responded to the disappearance of wetlands and the conversion of uplands to paddy rice. After updating the soil data, the watershed NPS nitrogen loading decreased, and the spatial distribution of the loading indicated that the NPS organic nitrogen was more sensitive than was the nitrate to soil variation. F-tests were employed to assess the significance of each of the predictor variables in five types of scenarios. Overall, the results indicate that the watershed NPS nitrogen loading is sensitive to changes of soil and land-use, but soil changes have a more significant impact. The results of this study also suggest that temperature has significant effects on NPS nitrogen yield and that it caused the twin peaks in the temporal scale. Increasing the temperature above zero in April caused a temporal shift in soil water movement and transported nitrogen pollution earlier in the year, causing an increased loading in water before the summer irrigation, which is advantageous for NPS nitrogen pollution control.

  15. Assessing groundwater transport of non-point source pollutants to surface waters and wells: Nitrates in the Maurice Watershed, New Jersey

    NASA Astrophysics Data System (ADS)

    Abrams, D. B.; Haitjema, H. M.

    2010-12-01

    Future changes in agricultural land use will alter input concentrations of non-point source pollutants (e.g. nitrates) to a watershed. While the water quality of surface waters within the watershed may begin to respond very quickly to land use changes due to surface runoff and other fast transport pathways, some of the pollutants may enter groundwater, which moves slowly through an aquifer. Thus, the impacts of land use change on surface water quality may take years to fully manifest, creating the need for a tool that will assess the long term response of contaminants reaching a stream based on changes in contaminant applications. Current modeling methods for groundwater contaminant transport, however, are intensive and require many site specific data. We propose an exponential lumped parameter model which only uses generally available field data to provide a quick assessment of the long term impacts of land use change on surface water quality. The exponential lumped parameter model was applied to the Maurice River watershed in New Jersey to estimate nitrate response in the river. Despite the complex hydrology of the Maurice watershed, the long term nitrate response generated by the lumped parameter model is very similar to the nitrate responses generated by both a more intensive MODFLOW model and field data. Furthermore, this study demonstrates that the same exponential lumped parameter model can be used to generate nitrate responses for high capacity pumping wells. Based on the Maurice watershed results, we will also discuss the validity of the exponential lumped parameter model under various factors, including weak sinks (sinks which do not draw water from the entire depth of the aquifer), seasonal recharge rates, spatially variable nitrate application rates, and subsurface denitrification.

  16. Trends of nitrogen and phosphorus input into Lake Neusiedl from wastewater treatment plants and non-point sources

    NASA Astrophysics Data System (ADS)

    Kinner, Paul; Heiss, Gerhard; Soja, Gerhard

    2013-04-01

    Lake Neusiedl (Austria) is a mesotrophic to eutrophic shallow steppe lake. Due to its low water volume and the lack of a natural outflow, excessive nutrient input is a special risk for this lake. In recent years, improved waste water treatment technologies have reduced the N and P loads of the inflows although all municipalities surrounding Lake Neusiedl (with one exception) and the cities and municipalities within the catchment area of the river Wulka discharge their (treated) wastewater into Lake Neusiedl. The amount of wastewater in 2010 was more than 22 x 106 m3. Although the amount of wastewater increased by more than 70 % in the last 30 years, it was possible to reduce the ammonium load from 38 t/a to 8 t/a (as NH4-N), the nitrate load from 83 t/a to 34 t/a (as NO3-N), the phosphate load from 8 t/a to 3 t/a (as PO4-P) and the total phosphorus load from 11 t/a to 6 t/a (comparison of the average annual loads of 1982 and 2010). Another environmental risk for Lake Neusiedl is the nitrogen input due to agricultural activities. Therefore a pilot action within the EULAKES-project focused on the nitrate levels during annual cycles (2011-2012) in groundwater as well as in selected rivers, channels and ditches discharging into Lake Neusiedl. The monitoring programme demonstrated clearly that the major contribution of the total nitrogen load discharged by surface water into Lake Neusiedl originated from River Wulka. For a general assessment of the influence of surface water discharge into Lake Neusiedl it is necessary to investigate the data of River Wulka for a longer period. Therefore data at the monitoring station Schützen were analysed for the period 1992-2010. Evaluation of the monitoring data showed that due to the higher nitrogen concentrations at higher average annual discharges the inorganic nitrogen load was about 6.5 times higher in 2010 (average discharge of Wulka 2.1 m3/s) than in the year 2001 (average discharge of Wulka 0.56 m3/s). The total inorganic

  17. The simulation research of dissolved nitrogen and phosphorus non-point source pollution in Xiao-Jiang watershed of Three Gorges Reservoir area.

    PubMed

    Wu, Lei; Long, Tian-Yu; Li, Chong-Ming

    2010-01-01

    Xiao-jiang, with a basin area of almost 5,276 km(2) and a length of 182.4 km, is located in the center of the Three Gorges Reservoir Area, and is the largest tributary of the central section in Three Gorges Reservoir Area, farmland accounts for a large proportion of Xiao-jiang watershed, and the hilly cropland of purple soil is much of the farmland of the watershed. After the second phase of water storage in the Three Gorges Reservoir, the majority of sub-rivers in the reservoir area experienced eutrophication phenomenon frequently, and non-point source (NPS) pollution has become an important source of pollution in Xiao-jiang Watershed. Because dissolved nitrogen and phosphorus non-point source pollution are related to surface runoff and interflow, using climatic, topographic and land cover data from the internet and research institutes, the Semi-Distributed Land-use Runoff Process (SLURP) hydrological model was introduced to simulate the complete hydrological cycle of the Xiao-jiang Watershed. Based on the SLURP distributed hydrological model, non-point source pollution annual output load models of land use and rural residents were respectively established. Therefore, using GIS technology, considering the losses of dissolved nitrogen and phosphorus in the course of transport, a dissolved non-point source pollution load dynamic model was established by the organic coupling of the SLURP hydrological model and land-use output model. Through the above dynamic model, the annual dissolved non-point source nitrogen and phosphorus pollution output as well as the load in different types were simulated and quantitatively estimated from 2001 to 2008, furthermore, the loads of Xiao-jiang Watershed were calculated and expressed by temporal and spatial distribution in the Three Gorges Reservoir Area. The simulation results show that: the temporal changes of dissolved nitrogen and phosphorus load in the watershed are close to the inter-annual changes of rainfall runoff, and the

  18. Modeling the effects of point and non-point source pollution on a diversion channel from Yellow River to an artificial lake in China.

    PubMed

    Gao, X P; Li, G N; Li, G R; Zhang, C

    2015-01-01

    The Dragon lake diversion channel (DLDC) is the only river that recharges Dragon Lake, an artificial lake in China. This paper examines the main factors influencing water quality by investigating point source and non-point source pollutants along the main route. Based on the complicated system of rivers and desilting basins, a three-dimensional water quality model using environmental fluid dynamics code (EFDC) was developed. The model of DLDC was calibrated and verified using observed data. The error ranges of river water level, total phosphorus, total nitrogen and chemical oxygen demand were within 5%, 10%, 16% and 20%, respectively, all of which meet the precision requirement. The model was employed to predict the concentrations of pollutants in the main stream under current pollution loads within a year and a flood lasting for 24 hours. The results revealed that the main pollution sources that influence the water quality of waterways were the point sources followed by the non-point pollution sources. Water quality improved when large water quantities were delivered and this trend can be described as dilution. The water quality of the Dongfeng main channel meets the requirement; however, the water quality of the Dongfeng River is somewhat poor, and the water quality of the Wei River is seriously contaminated. To address these problems, we suggest that the Dongfeng River and Wei River adopt a culvert under its riverbeds.

  19. Utilizing water characteristics and sediment nitrogen isotopic features to identify non-point nitrogen pollution sources at watershed scale in Liaoning Province, China.

    PubMed

    Ma, Jian; Chen, Xin; Huang, Bin; Shi, Yi; Chi, Guangyu; Lu, Caiyan

    2015-02-01

    Identifying nitrogen (N) pollution sources is the fundamental work of non-point source pollution load reduction from watersheds, but is hard due to complex N transport and transformation within spatially heterogenized huge areas. During September 2011, we measured water characteristics and sediment N stable isotope in four tributaries of the upper reach of the Hun River, an important water source of the Dahuofang Reservoir, a large drinking water source in Northeast China. Results showed that spatial changes in SO4 (2-) and Cl(-) contents in the tributaries were consisted with the changes in density of the population living along the tributaries. Sediment δ(15)N from all tributaries showed a downstream increasing trend in line with the land use change, which is characterized as more farmlands and more people around the outlet area of each tributary. Principal component analysis indicated the population density had a strong impact on N in these tributaries in the low-flow period. Tributaries and villages close to the Dahuofang Reservoir should be the major N load control objects in reduction of non-point source nitrogen load from the upper reach of the Hun River.

  20. Incorporation of Complex Hydrological and Socio-economic Factors for Non-point Source Pollution Control: A Case Study at the Yincungang Canal, the Lake Tai Basin of China

    NASA Astrophysics Data System (ADS)

    Yang, X.; Luo, X.; Zheng, Z.

    2012-04-01

    It is increasingly realized that non-point pollution sources contribute significantly to water environment deterioration in China. Compared to developed countries, non-point source pollution in China has the unique characteristics of strong intensity and composition complexity due to its special socioeconomic conditions. First, more than 50% of its 1.3 billion people are rural. Sewage from the majority of the rural households is discharged either without or only with minimal treatment. The large amount of erratic rural sewage discharge is a significant source of water pollution. Second, China is plagued with serious agricultural pollution due to widespread improper application of fertilizers and pesticides. Finally, there lack sufficient disposal and recycling of rural wastes such as livestock manure and crop straws. Pollutant loads from various sources have far exceeded environmental assimilation capacity in many parts of China. The Lake Tai basin is one typical example. Lake Tai is the third largest freshwater lake in China. The basin is located in the highly developed and densely populated Yangtze River Delta. While accounting for 0.4% of its land area and 2.9% of its population, the Lake Tai basin generates more than 14% of China's Gross Domestic Production (GDP), and the basin's GDP per capita is 3.5 times as much as the state average. Lake Tai is vital to the basin's socio-economic development, providing multiple services including water supply for municipal, industrial, and agricultural needs, navigation, flood control, fishery, and tourism. Unfortunately, accompanied with the fast economic development is serious water environment deterioration in the Lake Tai basin. The lake is becoming increasingly eutrophied and has frequently suffered from cyanobacterial blooms in recent decades. Chinese government has made tremendous investment in order to mitigate water pollution conditions in the basin. Nevertheless, the trend of deteriorating water quality has yet to

  1. Detection of spatial fluctuations of non-point source fecal pollution in coral reef surrounding waters in southwestern Puerto Rico using PCR-based assays.

    PubMed

    Bonkosky, M; Hernández-Delgado, E A; Sandoz, B; Robledo, I E; Norat-Ramírez, J; Mattei, H

    2009-01-01

    Human fecal contamination of coral reefs is a major cause of concern. Conventional methods used to monitor microbial water quality cannot be used to discriminate between different fecal pollution sources. Fecal coliforms, enterococci, and human-specific Bacteroides (HF183, HF134), general Bacteroides-Prevotella (GB32), and Clostridium coccoides group (CP) 16S rDNA PCR assays were used to test for the presence of non-point source fecal contamination across the southwestern Puerto Rico shelf. Inshore waters were highly turbid, consistently receiving fecal pollution from variable sources, and showing the highest frequency of positive molecular marker signals. Signals were also detected at offshore waters in compliance with existing microbiological quality regulations. Phylogenetic analysis showed that most isolates were of human fecal origin. The geographic extent of non-point source fecal pollution was large and impacted extensive coral reef systems. This could have deleterious long-term impacts on public health, local fisheries and in tourism potential if not adequately addressed.

  2. Seasonal change of non-point source pollution-induced bioavailable phosphorus loss: A case study of Southwestern China

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Zhu, Bo; Wang, Tao; Wang, Yafeng

    2012-02-01

    SummaryBioavailable phosphorus (P) losses due to agriculture activity in a purple soil watershed in the Sichuan Basin of Southwestern China were monitored to define the hydrological controls of P transport. Our results indicate that the proportion of P that was transported in particulate form increased in the rainy season, and that the mass of total bioavailable P (BAP) loads exhibited seasonal fluctuations, wherein the majority (over 90%) was observed to have been exported between June and September. The proportion of bioavailable dissolved P (BDP) in the BAP discharge budget in the watershed varied between 11% and 15% during the monitoring period. The bioavailable particulate P (BPP) and BDP concentrations of stream water under rainstorm events increased by over 40% in comparison to their annual mean concentrations, and the annual BAP load was primarily dominated by the loads that occurred during rainstorm events in the study year. BAP concentration in groundwater significantly fluctuated with the seasons, and the ratio of total BAP in groundwater to that in surface water gradually increased during the rainy season. Thus, the impact of agriculture on the water quality of this watershed becomes clearly evident.

  3. Runoff characteristics and non-point source pollution analysis in the Taihu Lake Basin: a case study of the town of Xueyan, China.

    PubMed

    Zhu, Q D; Sun, J H; Hua, G F; Wang, J H; Wang, H

    2015-10-01

    Non-point source pollution is a significant environmental issue in small watersheds in China. To study the effects of rainfall on pollutants transported by runoff, rainfall was monitored in Xueyan town in the Taihu Lake Basin (TLB) for over 12 consecutive months. The concentrations of different forms of nitrogen (N) and phosphorus (P), and chemical oxygen demand, were monitored in runoff and river water across different land use types. The results indicated that pollutant loads were highly variable. Most N losses due to runoff were found around industrial areas (printing factories), while residential areas exhibited the lowest nitrogen losses through runoff. Nitrate nitrogen (NO3-N) and ammonia nitrogen (NH4-N) were the dominant forms of soluble N around printing factories and hotels, respectively. The levels of N in river water were stable prior to the generation of runoff from a rainfall event, after which they were positively correlated to rainfall intensity. In addition, three sites with different areas were selected for a case study to analyze trends in pollutant levels during two rainfall events, using the AnnAGNPS model. The modeled results generally agreed with the observed data, which suggests that AnnAGNPS can be used successfully for modeling runoff nutrient loading in this region. The conclusions of this study provide important information on controlling non-point source pollution in TLB.

  4. Runoff characteristics and non-point source pollution analysis in the Taihu Lake Basin: a case study of the town of Xueyan, China.

    PubMed

    Zhu, Q D; Sun, J H; Hua, G F; Wang, J H; Wang, H

    2015-10-01

    Non-point source pollution is a significant environmental issue in small watersheds in China. To study the effects of rainfall on pollutants transported by runoff, rainfall was monitored in Xueyan town in the Taihu Lake Basin (TLB) for over 12 consecutive months. The concentrations of different forms of nitrogen (N) and phosphorus (P), and chemical oxygen demand, were monitored in runoff and river water across different land use types. The results indicated that pollutant loads were highly variable. Most N losses due to runoff were found around industrial areas (printing factories), while residential areas exhibited the lowest nitrogen losses through runoff. Nitrate nitrogen (NO3-N) and ammonia nitrogen (NH4-N) were the dominant forms of soluble N around printing factories and hotels, respectively. The levels of N in river water were stable prior to the generation of runoff from a rainfall event, after which they were positively correlated to rainfall intensity. In addition, three sites with different areas were selected for a case study to analyze trends in pollutant levels during two rainfall events, using the AnnAGNPS model. The modeled results generally agreed with the observed data, which suggests that AnnAGNPS can be used successfully for modeling runoff nutrient loading in this region. The conclusions of this study provide important information on controlling non-point source pollution in TLB. PMID:26002368

  5. Evaluation of conventional and alternative monitoring methods for a recreational marine beach with non-point source of fecal contamination

    PubMed Central

    Shibata, Tomoyuki; Solo-Gabriele, Helena M.; Sinigalliano, Christopher D.; Gidley, Maribeth L.; Plano, Lisa R.W.; Fleisher, Jay M.; Wang, John D.; Elmir, Samir M.; He, Guoqing; Wright, Mary E.; Abdelzaher, Amir M.; Ortega, Cristina; Wanless, David; Garza, Anna C.; Kish, Jonathan; Scott, Troy; Hollenbeck, Julie; Backer, Lorraine C.; Fleming, Lora E.

    2010-01-01

    The objectives of this study were to compare enterococci (ENT) measurements based on the membrane filter, ENT(MF) with alternatives that can provide faster results including alternative enterococci methods (e.g. chromogenic substrate (CS), and quantitative polymerase chain reaction (qPCR)), and results from regression models based upon environmental parameters that can be measured in real-time. ENT(MF) were also compared to source tracking markers (Staphylococcus aureus, Bacteroidales human and dog markers, and Catellicoccus gull marker) in an effort to interpret the variability of the signal. Results showed that concentrations of enterococci based upon MF (< 2 to 3,320 CFU/100mL) were significantly different from the CS and qPCR methods (p < 0.01). The correlations between MF and CS (r=0.58, p<0.01) were stronger than between MF and qPCR (r≤0.36, p<0.01). Enterococci levels by MF, CS, and qPCR methods were positively correlated with turbidity and tidal height. Enterococci by MF and CS were also inversely correlated with solar radiation but enterococci by qPCR was not. The regression model based on environmental variables provided fair qualitative predictions of enterococci by MF in real-time, for daily geometric mean levels, but not for individual samples. Overall, ENT(MF) was not significantly correlated with source tracking markers with the exception of samples collected during one storm event. The inability of the regression model to predict ENT(MF) levels for individual samples is likely due to the different sources of ENT impacting the beach at any given time, making it particularly difficult to for environmental parameters to predict short-term variability of ENT(MF). PMID:20925349

  6. Monitoring coastal marine waters for spore-forming bacteria of faecal and soil origin to determine point from non-point source pollution.

    PubMed

    Fujioka, R S

    2001-01-01

    The US Environmental Protection Agency (USEPA) and the World Health Organization (WHO) have established recreational water quality standards limiting the concentrations of faecal indicator bacteria (faecal coliform, E. coli, enterococci) to ensure that these waters are safe for swimming. In the application of these hygienic water quality standards, it is assumed that there are no significant environmental sources of these faecal indicator bacteria which are unrelated to direct faecal contamination. However, we previously reported that these faecal indicator bacteria are able to grow in the soil environment of humid tropical island environments such as Hawaii and Guam and are transported at high concentrations into streams and storm drains by rain. Thus, streams and storm drains in Hawaii contain consistently high concentrations of faecal indicator bacteria which routinely exceed the EPA and WHO recreational water quality standards. Since, streams and storm drains eventually flow out to coastal marine waters, we hypothesize that all the coastal beaches which receive run-off from streams and storm drains will contain elevated concentrations of faecal indicator bacteria. To test this hypothesis, we monitored the coastal waters at four beaches known to receive water from stream or storm drains for salinity, turbidity, and used the two faecal indicator bacteria (E. coli, enterococci) to establish recreational water quality standards. To determine if these coastal waters are contaminated with non-point source pollution (streams) or with point source pollution (sewage effluent), these same water samples were also assayed for spore-forming bacteria of faecal origin (Cl. perfringens) and of soil origin (Bacillus species). Using this monitoring strategy it was possible to determine when coastal marine waters were contaminated with non-point source pollution and when coastal waters were contaminated with point source pollution. The results of this study are most likely

  7. [Accumulation of non-point source pollutants in ditch wetland and their uptake and purification by plants].

    PubMed

    Jiang, Cuiling; Fan, Xiaoqiu; Zhang, Yibing

    2005-07-01

    The study on the vertical and horizontal distribution of organic matters and total nitrogen (TN) in the sediment of ditch wetland naturally grown with reed (Phragmites communis) and wild rice (Zizania latifolia) showed that the sediment below 40 cm depth had a significant effectiveness in retaining and accumulating organic matters and TN, but in its surface layer, this effectiveness varied largely with seasons, and the maximum was more than twofold of the minimum. TN was highly correlated with organic matters, the correlation coefficient being 0.9876 in reed wetland and 0.9335 in wild rice wetland, and in water phase, it was positively related to NH4+ -N and NO3-N, indicating that the main composition of TN was organic N, and the mineralization of organic N was the sources of inorganic N. The harvest of reed in each autumn could take away 818 kg x hm(-2) of N and 103.6 kg x hm(-2) of P, and that of wild rice could take away 131 kg x hm(-2) of N and 28.9 kg x hm(-2) of P. Zizania caduci flora had a high assimilation ability of nutrients. Its cultivation in ditch wetland to replace wild helophytes would be a good approach to attain higher absorbing ability of N and P, and to resolve the secondary pollution problem of emerged plants, because farmers could harvest it voluntarily. PMID:16252882

  8. [Ecological mechanisms of the effects of vegetation restoration on the controls of non-point source pollution on barren tableland in Dianchi Watershed of China].

    PubMed

    Wang, Zhen-Hong; Wu, Xue-Can; Li, Ying-Nan

    2006-01-01

    Surface runoff, soil erosion and the leaching of the different forms of nitrogen and phosphorus were observed and the hygroscopic volume of branch and leaves of all plant species and soil penetration were determined to understand the ecological mechanisms of the effects of vegetation restoration on the controls of non-point source pollution on barren tableland in Dianchi Watershed of China. Results indicated that there were significantly relationships between surface runoff volume and the output of non-point pollution matters. The different manmade vegetation systems, consisted respectively of A. nepalensis, A. mearnsii, R. pseudoacacia and V. zizanioides clump, had shown the different potentials to control the leaching of TN, TP, soluble TP, soluble TN. Strong hygroscopic functions of leaves and branch was able to promote the interception of rainfalls and give rise to the less of surface runoff. The leaves, that were small, with low water content, no leathery and have rough face and epidermal wools, were able to got the highly ratio of the hygroscopic volume to above ground fresh standing crops and strengthened the interception of forest canopy. Preparing soil, growth of root system of plant and the natural recovery of vegetation at the gap of trees enhanced surface runoff penetration, as lightened the surface runoff leaching the different forms of nitrogen, phosphorus of soil on the stands. The leaching of different forms of nitrogen and phosphorus went down with the controls of surface runoff in different stands as well.

  9. Combination system of full-scale constructed wetlands and wetland paddy fields to remove nitrogen and phosphorus from rural unregulated non-point sources.

    PubMed

    Sun, Haijun; Zhang, Hailin; Yu, Zhimin; Wu, Jiasen; Jiang, Peikun; Yuan, Xiaoyan; Shi, Weiming

    2013-12-01

    Constructed wetlands (CWs) have been used effectively to remove nitrogen (N) and phosphorus (P) from non-point sources. Effluents of some CWs were, however, still with high N and P concentrations and remained to be pollution sources. Widely distributed paddy fields can be exploited to alleviate this concern. We were the first to investigate a combination system of three-level CWs with wetland paddy fields in a full scale to remove N and P from rural unregulated non-point sources. The removal efficiencies (REs) of CWs reached 57.3 % (37.4-75.1 %) for N and 76.3 % (62.0-98.4 %) for P. The CWs retained about 1,278 kg N ha(-1) year(-1) and 121 kg P ha(-1) year(-1). There was a notable seasonal change in REs of N and P, and the REs were different in different processing components of CWs. The removal rates of wetland paddy fields adopt "zero-drainage" water management according to local rainfall forecast and physiological water demand of crop growth reached 93.2 kg N ha(-1) year(-1) and 5.4 kg P ha(-1) year(-1). The rice season had higher potential in removing N and P than that in the wheat season. The whole combined system (0.56 ha CWs and 5.5 ha wetland paddy fields) removed 1,790 kg N year(-1) and 151 kg P year(-1), which were higher than those from CWs functioned alone. However, another 4.7-ha paddy fields were needed to fully remove the N and P in the effluents of CWs. The combination of CWs and paddy fields proved to be a more efficient nutrient removal system.

  10. Combination system of full-scale constructed wetlands and wetland paddy fields to remove nitrogen and phosphorus from rural unregulated non-point sources.

    PubMed

    Sun, Haijun; Zhang, Hailin; Yu, Zhimin; Wu, Jiasen; Jiang, Peikun; Yuan, Xiaoyan; Shi, Weiming

    2013-12-01

    Constructed wetlands (CWs) have been used effectively to remove nitrogen (N) and phosphorus (P) from non-point sources. Effluents of some CWs were, however, still with high N and P concentrations and remained to be pollution sources. Widely distributed paddy fields can be exploited to alleviate this concern. We were the first to investigate a combination system of three-level CWs with wetland paddy fields in a full scale to remove N and P from rural unregulated non-point sources. The removal efficiencies (REs) of CWs reached 57.3 % (37.4-75.1 %) for N and 76.3 % (62.0-98.4 %) for P. The CWs retained about 1,278 kg N ha(-1) year(-1) and 121 kg P ha(-1) year(-1). There was a notable seasonal change in REs of N and P, and the REs were different in different processing components of CWs. The removal rates of wetland paddy fields adopt "zero-drainage" water management according to local rainfall forecast and physiological water demand of crop growth reached 93.2 kg N ha(-1) year(-1) and 5.4 kg P ha(-1) year(-1). The rice season had higher potential in removing N and P than that in the wheat season. The whole combined system (0.56 ha CWs and 5.5 ha wetland paddy fields) removed 1,790 kg N year(-1) and 151 kg P year(-1), which were higher than those from CWs functioned alone. However, another 4.7-ha paddy fields were needed to fully remove the N and P in the effluents of CWs. The combination of CWs and paddy fields proved to be a more efficient nutrient removal system. PMID:23703587

  11. Long-term variation (1960-2003) and causal factors of non-point-source nitrogen and phosphorus in the upper reach of the Yangtze River.

    PubMed

    Shen, Zhenyao; Chen, Lei; Ding, Xiaowen; Hong, Qian; Liu, Ruimin

    2013-05-15

    The knowledge of long-term variation and causal factors of non-point source (NPS) pollution in large-scale watersheds is helpful in the development of water quality control programs. In this study, the Improved Export Coefficient Model and the Revised Universal Soil Loss Equation were combined to estimate the temporal and spatial variations (1960-2003) of NPS pollution in the upper reach of the Yangtze River (URYR). Two change points for NPS pollution were successfully detected. In the URYR, the dissolved nitrogen (DN) and dissolved phosphorus (DP) increased before 2000 and decreased after 2000, whereas the inflection points from increase to decline were around 1980 for the adsorbed N (AN) and adsorbed P (AP). The results also indicated that the dissolved pollutants were mainly contributed by the anthropogenic factors, while the adsorbed pollutants were primarily exported by the natural factors. By comparing the load intensities from each source, it revealed that for the dissolved pollutants, the major source of the high load intensity transferred from urban land to dry land after 1980. Simultaneously, the high load intensity areas of the adsorbed pollutants transferred from forest to orchard around 1980, which was mainly attributed to the increasing fertilizer application. These results may be useful for planning and management of the URYR and other large-scale watersheds.

  12. Spatial-temporal characteristics of phosphorus in non-point source pollution with grid-based export coefficient model and geographical information system.

    PubMed

    Liu, Ruimin; Dong, Guangxia; Xu, Fei; Wang, Xiujuan; He, Mengchang

    2015-01-01

    In this paper, the spatial changes and trends in non-point source (NPS) total phosphorus (TP) pollution were analyzed by land and non-land uses in the Songliao River Basin from 1986 to 2000 (14 years). A grid-based export coefficient model was used in the process of analysis based on to a geographic information system. The Songliao Basin is divided in four regions: Liaoning province, Jilin province (JL), Heilongjiang province and the eastern part of the Inner Mongolia (IM) Autonomous Region. Results indicated that the NPS phosphorus load caused by land use and non-land use increased steadily from 3.11×10(4) tons in 1986 to 3.49×10(4) tons in 2000. The southeastern region of the Songliao Plain was the most important NPS pollution contributor of all the districts. Although the TP load caused by land use decreased during the studied period in the Songliao River Basin, the contribution of land use to the TP load was dominant compared to non-land uses. The NPS pollution caused by non-land use steadily increased over the studied period. The IM Autonomous Region and JL province had the largest mean annual rate of change among all districts (more than 30%). In this area, livestock and poultry breeding had become one of the most important NPS pollution sources. These areas will need close attention in the future.

  13. Sensitivity analysis of non-point sources in a water quality model applied to a dammed low-flow-reach river.

    PubMed

    Silva, Nayana G M; von Sperling, Marcos

    2008-01-01

    Downstream of Capim Branco I hydroelectric dam (Minas Gerais state, Brazil), there is the need of keeping a minimum flow of 7 m3/s. This low flow reach (LFR) has a length of 9 km. In order to raise the water level in the low flow reach, the construction of intermediate dikes along the river bed was decided. The LFR has a tributary that receives the discharge of treated wastewater. As part of this study, water quality of the low-flow reach was modelled, in order to gain insight into its possible behaviour under different scenarios (without and with intermediate dikes). QUAL2E equations were implemented in FORTRAN code. The model takes into account point-source pollution and diffuse pollution. Uncertainty analysis was performed, presenting probabilistic results and allowing identification of the more important coefficients in the LFR water-quality model. The simulated results indicate, in general, very good conditions for most of the water quality parameters The variables of more influence found in the sensitivity analysis were the conversion coefficients (without and with dikes), the initial conditions in the reach (without dikes), the non-point incremental contributions (without dikes) and the hydraulic characteristics of the reach (with dikes).

  14. A novel approach combining self-organizing map and parallel factor analysis for monitoring water quality of watersheds under non-point source pollution.

    PubMed

    Zhang, Yixiang; Liang, Xinqiang; Wang, Zhibo; Xu, Lixian

    2015-11-03

    High content of organic matter in the downstream of watersheds underscored the severity of non-point source (NPS) pollution. The major objectives of this study were to characterize and quantify dissolved organic matter (DOM) in watersheds affected by NPS pollution, and to apply self-organizing map (SOM) and parallel factor analysis (PARAFAC) to assess fluorescence properties as proxy indicators for NPS pollution and labor-intensive routine water quality indicators. Water from upstreams and downstreams was sampled to measure dissolved organic carbon (DOC) concentrations and excitation-emission matrix (EEM). Five fluorescence components were modeled with PARAFAC. The regression analysis between PARAFAC intensities (Fmax) and raw EEM measurements indicated that several raw fluorescence measurements at target excitation-emission wavelength region could provide similar DOM information to massive EEM measurements combined with PARAFAC. Regression analysis between DOC concentration and raw EEM measurements suggested that some regions in raw EEM could be used as surrogates for labor-intensive routine indicators. SOM can be used to visualize the occurrence of pollution. Relationship between DOC concentration and PARAFAC components analyzed with SOM suggested that PARAFAC component 2 might be the major part of bulk DOC and could be recognized as a proxy indicator to predict the DOC concentration.

  15. A novel approach combining self-organizing map and parallel factor analysis for monitoring water quality of watersheds under non-point source pollution

    PubMed Central

    Zhang, Yixiang; Liang, Xinqiang; Wang, Zhibo; Xu, Lixian

    2015-01-01

    High content of organic matter in the downstream of watersheds underscored the severity of non-point source (NPS) pollution. The major objectives of this study were to characterize and quantify dissolved organic matter (DOM) in watersheds affected by NPS pollution, and to apply self-organizing map (SOM) and parallel factor analysis (PARAFAC) to assess fluorescence properties as proxy indicators for NPS pollution and labor-intensive routine water quality indicators. Water from upstreams and downstreams was sampled to measure dissolved organic carbon (DOC) concentrations and excitation-emission matrix (EEM). Five fluorescence components were modeled with PARAFAC. The regression analysis between PARAFAC intensities (Fmax) and raw EEM measurements indicated that several raw fluorescence measurements at target excitation-emission wavelength region could provide similar DOM information to massive EEM measurements combined with PARAFAC. Regression analysis between DOC concentration and raw EEM measurements suggested that some regions in raw EEM could be used as surrogates for labor-intensive routine indicators. SOM can be used to visualize the occurrence of pollution. Relationship between DOC concentration and PARAFAC components analyzed with SOM suggested that PARAFAC component 2 might be the major part of bulk DOC and could be recognized as a proxy indicator to predict the DOC concentration. PMID:26526140

  16. Evaluating the Effects of Land Use Planning for Non-Point Source Pollution Based on a System Dynamics Approach in China

    PubMed Central

    Kuai, Peng; Li, Wei; Liu, Nianfeng

    2015-01-01

    Urbanization is proceeding rapidly in several developing countries such as China. This accelerating urbanization alters the existing land use types in a way that results in more Non-Point Source (NPS) pollution to local surface waters. Reasonable land use planning is necessary. This paper compares seven planning scenarios of a case study area, namely Wulijie, China, from the perspective of NPS pollution. A System Dynamics (SD) model was built for the comparison to adequately capture the planning complexity. These planning scenarios, which were developed by combining different land use intensities (LUIs) and construction speeds (CSs), were then simulated. The results show that compared to scenario S1 (business as usual) all other scenarios will introduce more NPS pollution (with an incremental rate of 22%-70%) to Wulijie. Scenario S6 was selected as the best because it induced relatively less NPS pollution while simultaneously maintaining a considerable development rate. Although LUIs represent a more critical factor compared to CSs, we conclude that both LUIs and CSs need to be taken into account to make the planning more environmentally friendly. Considering the power of SD in decision support, it is recommended that land use planning should take into consideration findings acquired from SD simulations. PMID:26267482

  17. A novel approach combining self-organizing map and parallel factor analysis for monitoring water quality of watersheds under non-point source pollution

    NASA Astrophysics Data System (ADS)

    Zhang, Yixiang; Liang, Xinqiang; Wang, Zhibo; Xu, Lixian

    2015-11-01

    High content of organic matter in the downstream of watersheds underscored the severity of non-point source (NPS) pollution. The major objectives of this study were to characterize and quantify dissolved organic matter (DOM) in watersheds affected by NPS pollution, and to apply self-organizing map (SOM) and parallel factor analysis (PARAFAC) to assess fluorescence properties as proxy indicators for NPS pollution and labor-intensive routine water quality indicators. Water from upstreams and downstreams was sampled to measure dissolved organic carbon (DOC) concentrations and excitation-emission matrix (EEM). Five fluorescence components were modeled with PARAFAC. The regression analysis between PARAFAC intensities (Fmax) and raw EEM measurements indicated that several raw fluorescence measurements at target excitation-emission wavelength region could provide similar DOM information to massive EEM measurements combined with PARAFAC. Regression analysis between DOC concentration and raw EEM measurements suggested that some regions in raw EEM could be used as surrogates for labor-intensive routine indicators. SOM can be used to visualize the occurrence of pollution. Relationship between DOC concentration and PARAFAC components analyzed with SOM suggested that PARAFAC component 2 might be the major part of bulk DOC and could be recognized as a proxy indicator to predict the DOC concentration.

  18. Evaluating the Effects of Land Use Planning for Non-Point Source Pollution Based on a System Dynamics Approach in China.

    PubMed

    Kuai, Peng; Li, Wei; Liu, Nianfeng

    2015-01-01

    Urbanization is proceeding rapidly in several developing countries such as China. This accelerating urbanization alters the existing land use types in a way that results in more Non-Point Source (NPS) pollution to local surface waters. Reasonable land use planning is necessary. This paper compares seven planning scenarios of a case study area, namely Wulijie, China, from the perspective of NPS pollution. A System Dynamics (SD) model was built for the comparison to adequately capture the planning complexity. These planning scenarios, which were developed by combining different land use intensities (LUIs) and construction speeds (CSs), were then simulated. The results show that compared to scenario S1 (business as usual) all other scenarios will introduce more NPS pollution (with an incremental rate of 22%-70%) to Wulijie. Scenario S6 was selected as the best because it induced relatively less NPS pollution while simultaneously maintaining a considerable development rate. Although LUIs represent a more critical factor compared to CSs, we conclude that both LUIs and CSs need to be taken into account to make the planning more environmentally friendly. Considering the power of SD in decision support, it is recommended that land use planning should take into consideration findings acquired from SD simulations.

  19. Application of modified export coefficient method on the load estimation of non-point source nitrogen and phosphorus pollution of soil and water loss in semiarid regions.

    PubMed

    Wu, Lei; Gao, Jian-en; Ma, Xiao-yi; Li, Dan

    2015-07-01

    Chinese Loess Plateau is considered as one of the most serious soil loss regions in the world, its annual sediment output accounts for 90 % of the total sediment loads of the Yellow River, and most of the Loess Plateau has a very typical characteristic of "soil and water flow together", and water flow in this area performs with a high sand content. Serious soil loss results in nitrogen and phosphorus loss of soil. Special processes of water and soil in the Loess Plateau lead to the loss mechanisms of water, sediment, nitrogen, and phosphorus are different from each other, which are greatly different from other areas of China. In this study, the modified export coefficient method considering the rainfall erosivity factor was proposed to simulate and evaluate non-point source (NPS) nitrogen and phosphorus loss load caused by soil and water loss in the Yanhe River basin of the hilly and gully area, Loess Plateau. The results indicate that (1) compared with the traditional export coefficient method, annual differences of NPS total nitrogen (TN) and total phosphorus (TP) load after considering the rainfall erosivity factor are obvious; it is more in line with the general law of NPS pollution formation in a watershed, and it can reflect the annual variability of NPS pollution more accurately. (2) Under the traditional and modified conditions, annual changes of NPS TN and TP load in four counties (districts) took on the similar trends from 1999 to 2008; the load emission intensity not only is closely related to rainfall intensity but also to the regional distribution of land use and other pollution sources. (3) The output structure, source composition, and contribution rate of NPS pollution load under the modified method are basically the same with the traditional method. The average output structure of TN from land use and rural life is about 66.5 and 17.1 %, the TP is about 53.8 and 32.7 %; the maximum source composition of TN (59 %) is farmland; the maximum source

  20. Spatio-temporal variation of erosion-type non-point source pollution in a small watershed of hilly and gully region, Chinese Loess Plateau.

    PubMed

    Wu, Lei; Liu, Xia; Ma, Xiao-Yi

    2016-06-01

    Loss of nitrogen and phosphorus in the hilly and gully region of Chinese Loess Plateau not only decreases the utilization rate of fertilizer but also is a potential threat to aquatic environments. In order to explore the process of erosion-type non-point source (NPS) pollution in Majiagou watershed of Loess Plateau, a distributed, dynamic, and integrated NPS pollution model was established to investigate impacts of returning farmland on erosion-type NPS pollution load from 1995 to 2012. Results indicate that (1) the integrated model proposed in this study was verified to be reasonable; the general methodology is universal and can be applicable to the hilly and gully region, Loess Plateau; (2) the erosion-type NPS total nitrogen (TN) and total phosphorus (TP) load showed an overall decreasing trend; the average nitrogen and phosphorus load modulus in the last four years (2009-2012) were 1.23 and 1.63 t/km(2) · a, respectively, which were both decreased by about 35.4 % compared with the initial treatment period (1995-1998); and (3) The spatial variations of NPS pollution are closely related to spatial characteristics of rainfall, topography, and soil and land use types; the peak regions of TN and TP loss mainly occurred along the main river banks of the Yanhe River watershed from northeast to southeast, and gradually decreased with the increase of distance to the left and right river banks, respectively. Results may provide scientific basis for the watershed-scale NPS pollution control of the Loess Plateau. PMID:26898934

  1. Contingent Valuation of Residents' Attitudes and Willingness-to-Pay for Non-point Source Pollution Control: A Case Study in AL-Prespa, Southeastern Albania.

    PubMed

    Grazhdani, Dorina

    2015-07-01

    Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods--dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was 6.4. The survey revealed that residents' yearly income and education level were the main factors affecting residents' willingness-to-pay for NPS pollution control in this area, and there was no significant correlation between residents' yearly income and their education level. The current study would lay a solid foundation on decision-making in further NPS pollution control and public participation through community-based watershed management policies in AL-Prespa watershed and similar areas. PMID:25860594

  2. Spatio-temporal variation of erosion-type non-point source pollution in a small watershed of hilly and gully region, Chinese Loess Plateau.

    PubMed

    Wu, Lei; Liu, Xia; Ma, Xiao-Yi

    2016-06-01

    Loss of nitrogen and phosphorus in the hilly and gully region of Chinese Loess Plateau not only decreases the utilization rate of fertilizer but also is a potential threat to aquatic environments. In order to explore the process of erosion-type non-point source (NPS) pollution in Majiagou watershed of Loess Plateau, a distributed, dynamic, and integrated NPS pollution model was established to investigate impacts of returning farmland on erosion-type NPS pollution load from 1995 to 2012. Results indicate that (1) the integrated model proposed in this study was verified to be reasonable; the general methodology is universal and can be applicable to the hilly and gully region, Loess Plateau; (2) the erosion-type NPS total nitrogen (TN) and total phosphorus (TP) load showed an overall decreasing trend; the average nitrogen and phosphorus load modulus in the last four years (2009-2012) were 1.23 and 1.63 t/km(2) · a, respectively, which were both decreased by about 35.4 % compared with the initial treatment period (1995-1998); and (3) The spatial variations of NPS pollution are closely related to spatial characteristics of rainfall, topography, and soil and land use types; the peak regions of TN and TP loss mainly occurred along the main river banks of the Yanhe River watershed from northeast to southeast, and gradually decreased with the increase of distance to the left and right river banks, respectively. Results may provide scientific basis for the watershed-scale NPS pollution control of the Loess Plateau.

  3. Contingent Valuation of Residents' Attitudes and Willingness-to-Pay for Non-point Source Pollution Control: A Case Study in AL-Prespa, Southeastern Albania

    NASA Astrophysics Data System (ADS)

    Grazhdani, Dorina

    2015-07-01

    Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods—dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was €6.4. The survey revealed that residents' yearly income and education level were the main factors affecting residents' willingness-to-pay for NPS pollution control in this area, and there was no significant correlation between residents' yearly income and their education level. The current study would lay a solid foundation on decision-making in further NPS pollution control and public participation through community-based watershed management policies in AL-Prespa watershed and similar areas.

  4. Contingent Valuation of Residents' Attitudes and Willingness-to-Pay for Non-point Source Pollution Control: A Case Study in AL-Prespa, Southeastern Albania.

    PubMed

    Grazhdani, Dorina

    2015-07-01

    Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods--dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was 6.4. The survey revealed that residents' yearly income and education level were the main factors affecting residents' willingness-to-pay for NPS pollution control in this area, and there was no significant correlation between residents' yearly income and their education level. The current study would lay a solid foundation on decision-making in further NPS pollution control and public participation through community-based watershed management policies in AL-Prespa watershed and similar areas.

  5. Evaluation of Land Use, Land Management and Soil Conservation Strategies to Reduce Non-Point Source Pollution Loads in the Three Gorges Region, China

    NASA Astrophysics Data System (ADS)

    Strehmel, Alexander; Schmalz, Britta; Fohrer, Nicola

    2016-11-01

    The construction of the Three Gorges Dam in China and the subsequent impoundment of the Yangtze River have induced a major land use change in the Three Gorges Reservoir Region, which fosters increased inputs of sediment and nutrients from diffuse sources into the water bodies. Several government programs have been implemented to mitigate high sediment and nutrient loads to the reservoir. However, institutional weaknesses and a focus on economic development have so far widely counteracted the effectiveness of these programs. In this study, the eco-hydrological model soil and water assessment tool is used to assess the effects of changes in fertilizer amounts and the conditions of bench terraces in the Xiangxi catchment in the Three Gorges Reservoir Region on diffuse matter releases. With this, the study aims at identifying efficient management measures, which should have priority. The results show that a reduction of fertilizer amounts cannot reduce phosphorus loads considerably without inhibiting crop productivity. The condition of terraces in the catchment has a strong impact on soil erosion and phosphorus releases from agricultural areas. Hence, if economically feasible, programmes focusing on the construction and maintenance of terraces in the region should be implemented. Additionally, intercropping on corn fields as well as more efficient fertilization schemes for agricultural land were identified as potential instruments to reduce diffuse matter loads further. While the study was carried out in the Three Gorges Region, its findings may also beneficial for the reduction of water pollution in other mountainous areas with strong agricultural use.

  6. The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOCS) to shallow groundwater

    USGS Publications Warehouse

    Pankow, J.F.; Thomson, N.R.; Johnson, R.L.; Baehr, A.L.; Zogorski, J.S.

    1997-01-01

    all no- net recharge cases. The mechanism responsible for this effect was the dispersion acting on each downward infiltration event, and also on the ET-induced flow. The ability of MTBE to reach groundwater in cases 2-5 is taken as evidence of the potential importance of urban air as a non-point source for VOCs in shallow urban groundwater. Two subcases were run for both case 4 and case 5: subcase a (water and VOCs move with ET) and subcase b (water only moves with ET).Numerical simulations were conducted using a 1-D model domain set in medium sand to provide a test of whether methyl-tert-butyl ether (MTBE) and other atmospheric volatile organic compounds could move to shallow groundwater within the 10-15 y time frame over which MTBE was used in large amounts. The gasoline additive MTBE is of special interest because of its: current levels in some urban air; strong partitioning from air into water; resistance to degradation; use as an octane-booster since the 1970s; rapidly increasing use in the 1990s to reduce CO and O3 in urban air; and its frequent detection at low microgram per liter levels in shallow urban groundwater.

  7. Impacts of climate and land-use changes on the migration of non-point source nitrogen and phosphorus during rainfall-runoff in the Jialing River Watershed, China

    NASA Astrophysics Data System (ADS)

    Wu, Lei; Long, Tian-yu; Liu, Xia; Guo, Jin-song

    2012-12-01

    SummaryThe loss of nitrogen and phosphorus via non-point source (NPS) pollution in the Jialing River Watershed has become the main pollution sources of river waters in the Three Gorges reservoir area in the past decades, while climatic conditions and human activities directly affect changes of rainfall-runoff and land use types which are closely related to NPS pollution. This study is to assess the impact of climate change on hydrological behavior considering future land-use types and rural residential area and their propagation to NPS pollution loads. An integrated pollution load model composed of regional climate, the Semi-distributed Land Use based Runoff Processes (SLURPs) hydrological model and the improved export coefficient approach within a single framework was explored and developed to assess impacts of climate and land-use changes on NPS pollution load. Climate data for the Special Report on Emissions Scenarios (SRESs) future scenario B2 from Met Office Hadley center were generated and used as the input data for the runoff and NPS load evaluation of the Jialing River Watershed and the Markov process was used to forecast changes of land use types, respectively. Simulations of present and future regional NPS pollution from land use, livestock and poultry breeding, and agricultural population over the Jialing River Watershed were performed to investigate the potential impacts of global climate change on river water quality using the established model. Results demonstrate that: (1) Annual pollution load would obviously change due to variations of runoff and livestock and poultry breeding, the largest growth months in one year for total nitrogen (TN) and total phosphorus (TP) load are both in June, which is in accordance with changes of rainfall amount. (2) The impacts of global climate change on pollution load are relatively greater when compared to the impacts of future livestock and poultry breeding increase or agricultural population reduction; the effects

  8. Non-Point Source Pollutant Load Variation in Rapid Urbanization Areas by Remote Sensing, Gis and the L-THIA Model: A Case in Bao'an District, Shenzhen, China

    NASA Astrophysics Data System (ADS)

    Li, Tianhong; Bai, Fengjiao; Han, Peng; Zhang, Yuanyan

    2016-11-01

    Urban sprawl is a major driving force that alters local and regional hydrology and increases non-point source pollution. Using the Bao'an District in Shenzhen, China, a typical rapid urbanization area, as the study area and land-use change maps from 1988 to 2014 that were obtained by remote sensing, the contributions of different land-use types to NPS pollutant production were assessed with a localized long-term hydrologic impact assessment (L-THIA) model. The results show that the non-point source pollution load changed significantly both in terms of magnitude and spatial distribution. The loads of chemical oxygen demand, total suspended substances, total nitrogen and total phosphorus were affected by the interactions between event mean concentration and the magnitude of changes in land-use acreages and the spatial distribution. From 1988 to 2014, the loads of chemical oxygen demand, suspended substances and total phosphorus showed clearly increasing trends with rates of 132.48 %, 32.52 % and 38.76 %, respectively, while the load of total nitrogen decreased by 71.52 %. The immigrant population ratio was selected as an indicator to represent the level of rapid urbanization and industrialization in the study area, and a comparison analysis of the indicator with the four non-point source loads demonstrated that the chemical oxygen demand, total phosphorus and total nitrogen loads are linearly related to the immigrant population ratio. The results provide useful information for environmental improvement and city management in the study area.

  9. Evaluating the risk of non-point source pollution from biosolids: integrated modelling of nutrient losses at field and catchment scales

    NASA Astrophysics Data System (ADS)

    Whitehead, P. G.; Heathwaite, A. L.; Flynn, N. J.; Wade, A. J.; Quinn, P. F.

    2007-01-01

    A semi-distributed model, INCA, has been developed to determine the fate and distribution of nutrients in terrestrial and aquatic systems. The model simulates nitrogen and phosphorus processes in soils, groundwaters and river systems and can be applied in a semi-distributed manner at a range of scales. In this study, the model has been applied at field to sub-catchment to whole catchment scale to evaluate the behaviour of biosolid-derived losses of P in agricultural systems. It is shown that process-based models such as INCA, applied at a wide range of scales, reproduce field and catchment behaviour satisfactorily. The INCA model can also be used to generate generic information for risk assessment. By adjusting three key variables: biosolid application rates, the hydrological connectivity of the catchment and the initial P-status of the soils within the model, a matrix of P loss rates can be generated to evaluate the behaviour of the model and, hence, of the catchment system. The results, which indicate the sensitivity of the catchment to flow paths, to application rates and to initial soil conditions, have been incorporated into a Nutrient Export Risk Matrix (NERM).

  10. Development and application of a coupled bio-geochmical and hydrological model for point and non-point source river water pollution

    NASA Astrophysics Data System (ADS)

    Pohlert, T.

    2007-12-01

    The aim of this paper is to present recent developments of an integrated water- and N-balance model for the assessment of land use changes on water and N-fluxes for meso-scale river catchments. The semi-distributed water-balance model SWAT was coupled with algorithms of the bio-geochemical model DNDC as well as the model CropSyst. The new model that is further denoted as SWAT-N was tested with leaching data from a long- term lysimeter experiment as well as results from a 5-years sampling campaign that was conducted at the outlet of the meso-scale catchment of the River Dill (Germany). The model efficiency for N-load as well as the spatial representation of N-load along the river channel that was tested with results taken from longitudinal profiles show that the accuracy of the model has improved due to the integration of the aforementioned process-oriented models. After model development and model testing, SWAT-N was then used for the assessment of the EU agricultural policy (CAP reform) on land use change and consequent changes on N-fluxes within the Dill Catchment. giessen.de/geb/volltexte/2007/4531/

  11. A novel modelling framework to prioritize estimation of non-point source pollution parameters for quantifying pollutant origin and discharge in urban catchments.

    PubMed

    Fraga, I; Charters, F J; O'Sullivan, A D; Cochrane, T A

    2016-02-01

    Stormwater runoff in urban catchments contains heavy metals (zinc, copper, lead) and suspended solids (TSS) which can substantially degrade urban waterways. To identify these pollutant sources and quantify their loads the MEDUSA (Modelled Estimates of Discharges for Urban Stormwater Assessments) modelling framework was developed. The model quantifies pollutant build-up and wash-off from individual impervious roof, road and car park surfaces for individual rain events, incorporating differences in pollutant dynamics between surface types and rainfall characteristics. This requires delineating all impervious surfaces and their material types, the drainage network, rainfall characteristics and coefficients for the pollutant dynamics equations. An example application of the model to a small urban catchment demonstrates how the model can be used to identify the magnitude of pollutant loads, their spatial origin and the response of the catchment to changes in specific rainfall characteristics. A sensitivity analysis then identifies the key parameters influencing each pollutant load within the stormwater given the catchment characteristics, which allows development of a targeted calibration process that will enhance the certainty of the model outputs, while minimizing the data collection required for effective calibration. A detailed explanation of the modelling framework and pre-calibration sensitivity analysis is presented. PMID:26613353

  12. [Catchment scale risk assessment and critical source area identification of agricultural phosphorus loss].

    PubMed

    Li, Qi; Chen, Li-Ding; Qi, Xin; Zhang, Xin-Yu; Ma, Yan

    2007-09-01

    Agricultural non-point source phosphorus pollution is a severe problem for rural water bodies in China, but hard to control directly because of its special characteristics. In this paper, an approach on the catchment scale risk assessment and critical source area identification of agricultural phosphorus loss in northern China was made, based on the catchment scale phosphorus ranking scheme and the method proposed by Gburek et al. Eight factors were selected and weighed in the modified catchment scale phosphorus ranking scheme, and the phosphorus loss risk rating of each factor was adjusted based on the current professional standards and the actual circumstances in China. The areas with ' high' risk rating of phosphorus loss in definite catchment were the critical source areas for non-point source phosphorous pollution control in that catment. The availability of obtained data and the quantification of the assessment were taken into account in the new scheme, and GIS technique and geostatistics were used for confirming the factors. Therefore, the new scheme had definite operability and practicability. PMID:18062300

  13. Inferring non-point pollution from land cover analysis

    NASA Astrophysics Data System (ADS)

    Hyde, Richard F.

    Best Management Practices (BMP's) in farming were found to significantly reduce agricultural non-point water pollution in Central Indiana. Through the implementation of systems of conservation tillage practices and structural measures at the farm level, reductions in runoff were achieved, thereby minimizing erosion and subsequent sedimentation and pollution of the surface water system. These conclusions resulted from a three and one-half year study entitled, ``The Indiana Heartland Model Implementation Project'' administered by the Indiana Heartland Coordinating Commission, involving cooperation and coordination of farmers, citizens, and a multi-agency, multi-disciplinary team comprised of four universities and numerous governmental agencies. The U.S. Environmental Protection Agency funded research, while the U.S. Department of Agriculture provided cost share monies for BMP implementation. A comprehensive geographically encoded computer-aided data base was constructed which included information on land cover, elevation, slope, aspect, soils, etc. Land cover map files were compiled through remote sensing including Landsat MSS digital data and low altitude color infrared aerial photography sources. This digital data base was suited for spatial and statistical analyses and transferred easily as input to Purdue University's ANSWERS Model for further watershed assessment. The ANSWERS Model is a distributed deterministic model which simulates the monitored reaction of subwatersheds to actual storm events. Through this model inferences were made as to the expected water quality improvements, given BMP's were implemented at critical areas for erosion throughout both watersheds.

  14. The sources of deforestation - implications for sustainable agriculture in Brazil

    SciTech Connect

    Torres-Zorrilla, J.; Arnode, C.

    1992-12-01

    Agricultural equilibrium conditions are used to identify the sources of deforestation in Brazil. The rate which forestland can be converted into agricultural land and meet agricultural and environmental goals is calculated. This serves the task of determining how long agricultural land growth can be maintained until environmental targets are violated.

  15. Modeling Agricultural Nonpoint Source Pollution Using a Geographic Information System Approach

    NASA Astrophysics Data System (ADS)

    Emili, Lisa A.; Greene, Richard P.

    2013-01-01

    Agricultural non-point source (NPS) pollution, primarily sediment and nutrients, is the leading source of water-quality impacts to surface waters in North America. The overall goal of this study was to develop geographic information system (GIS) protocols to facilitate the spatial and temporal modeling of changes in soils, hydrology, and land-cover change at the watershed scale. In the first part of this article, we describe the use of GIS to spatially integrate watershed scale data on soil erodibility, land use, and runoff for the assessment of potential source areas within an intensively agricultural watershed. The agricultural non-point source pollution (AGNPS) model was used in the Muddy Creek, Ontario, watershed to evaluate the effectiveness of management strategies in decreasing sediment and nutrient [phosphorus (P)] pollution. This analysis was accompanied by the measurement of water-quality parameters (dissolved oxygen, pH, hardness, alkalinity, and turbidity) as well as sediment and P loadings to the creek. Practices aimed at increasing year-round soil cover would be most effective in decreasing sediment and P losses in this watershed. In the second part of this article, we describe a method for characterizing land-cover change in a dynamic urban fringe watershed. The GIS method we developed for the Blackberry Creek, Illinois, watershed will allow us to better account for temporal changes in land use, specifically corn and soybean cover, on an annual basis and to improve on the modeling of watershed processes shown for the Muddy Creek watershed. Our model can be used at different levels of planning with minimal data preprocessing, easily accessible data, and adjustable output scales.

  16. Modeling agricultural nonpoint source pollution using a geographic information system approach.

    PubMed

    Emili, Lisa A; Greene, Richard P

    2013-01-01

    Agricultural non-point source (NPS) pollution, primarily sediment and nutrients, is the leading source of water-quality impacts to surface waters in North America. The overall goal of this study was to develop geographic information system (GIS) protocols to facilitate the spatial and temporal modeling of changes in soils, hydrology, and land-cover change at the watershed scale. In the first part of this article, we describe the use of GIS to spatially integrate watershed scale data on soil erodibility, land use, and runoff for the assessment of potential source areas within an intensively agricultural watershed. The agricultural non-point source pollution (AGNPS) model was used in the Muddy Creek, Ontario, watershed to evaluate the effectiveness of management strategies in decreasing sediment and nutrient [phosphorus (P)] pollution. This analysis was accompanied by the measurement of water-quality parameters (dissolved oxygen, pH, hardness, alkalinity, and turbidity) as well as sediment and P loadings to the creek. Practices aimed at increasing year-round soil cover would be most effective in decreasing sediment and P losses in this watershed. In the second part of this article, we describe a method for characterizing land-cover change in a dynamic urban fringe watershed. The GIS method we developed for the Blackberry Creek, Illinois, watershed will allow us to better account for temporal changes in land use, specifically corn and soybean cover, on an annual basis and to improve on the modeling of watershed processes shown for the Muddy Creek watershed. Our model can be used at different levels of planning with minimal data preprocessing, easily accessible data, and adjustable output scales.

  17. The impact of the U.S. biofuels expansion on non-point source pollution from nitrogen in a marginal agricultural area

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Energy Independence Security Act aims to increase the production of renewable fuels in order to improve the energy efficiency of the United States. The goal of this legislation is to produce 36 billion gallons of biofuel, primarily corn ethanol, by 2022. A bioeconomic model is employed, includin...

  18. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils.

    PubMed

    Huang, Ying; Li, Tingqiang; Wu, Chengxian; He, Zhenli; Japenga, Jan; Deng, Meihua; Yang, Xiaoe

    2015-12-15

    Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74-100% and 0-24% of the total Hg input, while road dusts and solid wastes contributed for 0-80% and 19-100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions. PMID:26257294

  19. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils.

    PubMed

    Huang, Ying; Li, Tingqiang; Wu, Chengxian; He, Zhenli; Japenga, Jan; Deng, Meihua; Yang, Xiaoe

    2015-12-15

    Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74-100% and 0-24% of the total Hg input, while road dusts and solid wastes contributed for 0-80% and 19-100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions.

  20. Evaluation of the AnnAGNPS model for predicting runoff and sediment yield in a small Mediterranean agricultural watershed in Navarre (Spain)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    AnnAGNPS (Annualized Agricultural Non-Point Source Pollution Model) is a system of computer models developed to predict non-point source pollutant loadings within agricultural watersheds. It contains a daily time step distributed parameter continuous simulation surface runoff model designed to assis...

  1. Ammonia emissions from non-agricultural sources in the UK

    NASA Astrophysics Data System (ADS)

    Sutton, M. A.; Dragosits, U.; Tang, Y. S.; Fowler, D.

    A detailed literature review has been undertaken of the magnitude of non-agricultural sources of ammonia (NH 3) in the United Kingdom. Key elements of the work included estimation of nitrogen (N) excreted by different sources (birds, animals, babies, human sweat), review of miscellaneous combustion sources, as well as identification of industrial sources and use of NH 3 as a solvent. Overall the total non-agricultural emission of NH 3 from the UK in 1996 is estimated here as 54 (27-106) kt NH 3-N yr -1, although this includes 11 (6-23) kt yr -1 from agriculture related sources (sewage sludge spreading, biomass burning and agro-industry). Compared with previous estimates for 1990, component source magnitudes have changed both because of revised average emissions per source unit (emission factors) and changes in the source activity between 1990 and 1996. Sources with larger average emission factors than before include horses, wild animals and sea bird colonies, industry, sugar beet processing, household products and non-agricultural fertilizer use, with the last three sources being included for the first time. Sources with smaller emission factors than before include: land spreading of sewage sludge, direct human emissions (sweat, breath, smoking, infants), pets (cats and dogs) and fertilizer manufacture. Between 1990 and 1996 source activities increased for sewage spreading (due to reduced dumping at sea) and transport (due to increased use of catalytic converters), but decreased for coal combustion. Combined with the current UK estimates of agricultural NH 3 emissions of 229 kt N yr -1 (1996), total UK NH 3 emissions are estimated at 283 kt N yr -1. Allowing for an import of reduced nitrogen (NH x) of 30 kt N yr -1 and deposition of 230 kt N yr -1, these figures imply an export of 83 kt NH 3-N yr -1. Although export is larger than previously estimated, due to the larger contribution of non-agricultural NH 3 emissions, it is still insufficient to balance the UK

  2. Using Microbial Source Tracking to Enhance Environmental Stewardship of Agriculture

    NASA Astrophysics Data System (ADS)

    Martin, Sherry; Rose, Joan; Flood, Matthew; Aw, Tiong; Hyndman, David

    2016-04-01

    Large scale agriculture relies on the application of chemical fertilizers and animal manure. It is well known that nutrients in excess of a plant's uptake and soil retention capacity can travel to nearby waterways via surface run-off and groundwater pathways, indirectly fertilizing these aquatic ecosystems. It has not yet been possible to distinguish water quality impacts of fertilizer from those derived from human and animal waste sources. However, new microbial source tracking (MST) tools allow specific identification of fecal pollution. Our objective was to examine pollution risks at the regional scale using MST, mapping and classification and regression tree analysis. We present results Bovine M2 genetic marker data from three flow regimes (baseflow, snow melt, and post-planting rain). Key landscape characteristics were related to the presence of the bovine markers and appear to be related to fate and transport. Impacts at this regional watershed scale will be discussed. Our research aims to identify the impacts of agricultural management practices on water quality by linking nutrient concentrations with fecal pollution sources. We hope that our research will provide guidance that will help improve water quality through agricultural best management practices to reduce pathogen contamination.

  3. Tracing crop-specific sediment sources in agricultural catchments

    NASA Astrophysics Data System (ADS)

    Blake, William H.; Ficken, Katherine J.; Taylor, Philip; Russell, Mark A.; Walling, Desmond E.

    2012-02-01

    A Compound Specific Stable Isotope (CSSI) sediment tracing approach is evaluated for the first time in an agricultural catchment setting against established geochemical fingerprinting techniques. The work demonstrates that novel CSSI techniques have the potential to provide important support for soil resource management policies and inform sediment risk assessment for the protection of aquatic habitats and water resources. Analysis of soil material from a range of crop covers in a mixed land-use agricultural catchment shows that the carbon CSSI signatures of particle-reactive fatty acids label surface agricultural soil with distinct crop-specific signatures, thus permitting sediment eroded from each land-cover to be tracked downstream. High resolution sediment sampling during a storm event and analysis for CSSI and conventional geochemical fingerprints elucidated temporal patterns of sediment mobilisation under different crop regimes and the specific contribution that each crop type makes to downstream sediment load. Pasture sources (65% of the catchment area) dominated the sediment load but areal yield (0.13 ± 0.02 t ha - 1 ) was considerably less than that for winter wheat (0.44 ± 0.15 t ha - 1 ). While temporal patterns in crop response matched runoff and erosion response predictions based on plot-scale rainfall simulation experiments, comparison of biomarker and geochemical fingerprinting data indicated that the latter overestimated cultivated land inputs to catchment sediment yield due to inability to discriminate temporary pasture (in rotation) from cultivated land. This discrepancy, however, presents an opportunity since combination of the two datasets revealed the extremely localised nature of erosion from permanent pasture fields in this system (estimated at up to 0.5 t ha - 1 ). The novel use of CSSI and geochemical tracers in tandem provided unique insights into sediment source dynamics that could not have been derived from each method alone. Research

  4. [Non-point loads of soluble cadmium by in situ field experiment with different landuses, in central Hunan province mining area].

    PubMed

    Liu, Xiao-li; Zeng, Zhao-xia; Chen, Zhe; Tie, Bai-qing; Chen, Qiu-wen; Ye, Chang-cheng

    2013-09-01

    Non-point source loads of heavy metals from contaminated soil has increasingly become the major cause of heavy metal concentrations of rivers and lakes surpassed the limitation value, while only few studies had focused on quantitative monitoring of soil heavy metal transportation to water, in situ field conditions. As reported, agricultural farmland heavy metal contamination was the major contamination problem, especially for cadmium (Cd) pollution in middle and downstream of Xiangjiang River. This study selected the typical Cd polluted agricultural watershed for a case study, three typical landuse types of rice, dry farmland and unused grassland with three replicate quadrates were carried out for natural rainfall runoff hydrology processes monitoring, from 2011-2012. Results showed that, precipitation pH value increased from spring to summer, soluble Cd concentration of spring runoff was significantly higher than that of summer rainfall runoff, which presented an obviously seasonal heterogeneity and had a negative correlation with rainfall pH value, and rainfall pH value can obviously impact soil soluble Cd transportation into surface runoff charge. In the same rainfall event, soluble Cd concentration and non-point load of rice were significantly lower than those of dry land and unused grassland, while no obviously seasonal trend was found for non-point load of Cd from three typical landuse types because of the rainfall depth variance, which needs more researches and concerns in the future. These results can provide valuable data and scientific supports for watershed scale's heavy metal non-point source load quantitative estimation and water environment management and water quality diagnosis and early warning.

  5. Dissolved organic carbon source integration in an agricultural watershed

    NASA Astrophysics Data System (ADS)

    Hernes, P. J.; Spencer, R. G.; Dyda, R. Y.; Pellerin, B. A.; Bachand, P. A.; Bergamaschi, B. A.

    2012-12-01

    The dissolved organic carbon (DOC) chemistry and concentration at the mouth of a watershed represents an integrated signal of all sources and process that occur upstream of the mouth, however, the relative contributions of all those sources and processes to the chemistry and concentration is not equal. We sampled an agricultural watershed in the Sacramento River valley in California synoptically on multiple occasions in order to better identify the most important contributors to DOC chemistry. Our samples included headwater samples from native grasslands in three sub-catchments, samples within the agricultural portions of those sub-watersheds, samples near the conjunctions, and irrigation field inputs and outputs. DOC concentrations increase considerably in the agricultural portion of the watershed, demonstrating the impacts of anthropogenic disturbance of landscapes as well as the potential for local landscapes to contribute significantly to the overall DOC concentration and chemistry. The central sub-catchment in particular had significantly greater DOC concentrations, which appears to correspond to the much greater proportion of flood irrigation land management in this portion, as our field runoff measurements indicate much higher added DOC during flood irrigation than during furrow irrigation. Flow-weighted averaging of the three sub-catchment DOC concentrations does not replicate concentrations at the mouth (1-6 km downstream of the confluences), indicating the importance of in-stream processing and/or source inputs from riparian zones even along the mainstem. Optical characterization of DOC demonstrates changing chemistry from season to season, and differences in chemistry from different areas of the catchment. The storm-influenced spring sampling yielded higher carbon-specific UV absorbance at 254 nm (SUVA254), indicating a higher proportion of aromaticity, while the southern sub-catchment consistently yielded the highest spectral slope values, which

  6. Source Units Developed as Part of an Internship Program in Agriculture/Agribusiness.

    ERIC Educational Resources Information Center

    Mannebach, Alfred J., Ed.

    This guide includes 12 source units of instruction developed by teachers of vocational agriculture who participated in an internship program in agriculture/agribusiness, which was designed to up-date the knowledge and skills of teachers of vocational agriculture in their areas of teaching specialization and to develop source units of instruction…

  7. Nonpoint Source Pollution.

    PubMed

    Ahmad, Zaki Uddin; Sakib, Salman; Gang, Daniel Dianchen

    2016-10-01

    Research advances on non-point source pollution in the year 2015 have been depicted in this review paper. Nonpoint source pollution is mainly caused by agricultural runoff, urban stormwater, and atmospheric deposition. Modeling techniques of NPS with different tools are reviewed in this article.

  8. Nonpoint Source Pollution.

    PubMed

    Ahmad, Zaki Uddin; Sakib, Salman; Gang, Daniel Dianchen

    2016-10-01

    Research advances on non-point source pollution in the year 2015 have been depicted in this review paper. Nonpoint source pollution is mainly caused by agricultural runoff, urban stormwater, and atmospheric deposition. Modeling techniques of NPS with different tools are reviewed in this article. PMID:27620104

  9. Sole-Source Lighting for Controlled-Environment Agriculture

    NASA Technical Reports Server (NTRS)

    Mitchell.Cary; Stutte, Gary W.

    2015-01-01

    Since plants on Earth evolved under broad-spectrum solar radiation, anytime they are grown exclusively under electric lighting that does not contain all wavelengths in similar proportion to those in sunlight, plant appearance and size could be uniquely different. Nevertheless, plants have been grown for decades under fluorescent (FL) (1) + incandescent (IN) (2) lamps as a sole source of lighting (SSL), and researchers have become comfortable that, in certain proportions of FL + IN for a given species, plants can appear "normal" relative to their growth outdoors. The problem with using such traditional SSLs for commercial production typically is short lamp lifespans and not obtaining enough photosynthetically active radiation (PAR, 400-700 nm) when desired. These limitations led to supplementation of FL + IN lamp outputs with longer-lived, high-intensity discharge (HID) lamps in growth chambers (3). As researchers became comfortable that mixes of orange-biased high-pressure sodium (HPS) and blue-biased metal halide (MH) HIDs together also could give normal plant growth at higher intensities, growth chambers and phytotrons subsequently were equipped mainly with HID lamps, with their intense thermal output filtered out by ventilated light caps or thermal-controlled water barriers. For the most part, IN and HID lamps have found a home in commercial protected horticulture, usually for night-break photoperiod lighting (IN) or for seasonal supplemental lighting (mostly HPS) in greenhouses. However, lack of economically viable options for SSL have held back aspects of year-round indoor agriculture from taking off commercially.

  10. Potential alternative fuel sources for agricultural crops and plant components

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The changing landscape of agricultural production is placing unprecedented demands on farmers as they face increasing global competition and greater natural resource conservation challenges. However, shrinking profit margins due to increasing input costs, particularly of fuel and fertilizer, can res...

  11. ASSESSMENT OF RISK REDUCTION STRATEGIES FOR THE MANAGEMENT OF AGRICULTURAL NONPOINT SOURCE PESTICIDE RUNOFF IN ESTUARINE ECOSYSTEMS

    EPA Science Inventory

    Agricultural nonpoint source (NPS) runoff may result in significant discharges of pesticides, suspended sediments, and fertilizers into estuarine habitats adjacent to agricultural areas or downstream from agricultural watersheds. Exposure of estuarine fin fish and shellfish to to...

  12. Food and agricultural waste: Sources of carbon for ethanol production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the past, wastes derived from agriculture products have met with limited success in the production of biofuels. Our objective in this report is to showcase a new and meaningful concept (called “avoidance”), to measure the environmental importance of converting these waste streams into energy. Agr...

  13. Reference Sources in Science, Engineering, Medicine, and Agriculture.

    ERIC Educational Resources Information Center

    Malinowsky, H. Robert

    This document is a bibliographic guide of over 2,400 titles in science, engineering, medicine and agriculture. This book is intended for use by librarians for reference updates, researchers and students who need to access information but who are unfamiliar with the particular discipline, and for information science students learning about the…

  14. Evaluating Urbanization Impacts from Non-Point Stormwater Runoff using Geospatial Analysis

    NASA Astrophysics Data System (ADS)

    Zivkovich, B. R.; Mays, D. C.

    2015-12-01

    Sediments, nutrients and other chemical impairments caused by urbanization continue to deteriorate natural ecosystem processes, resulting in the current degraded state of urban surface waters. Understanding non-point source impacts on these natural ecosystems has become a prevalent topic in sustainable urban infrastructure design as efforts to restore the urban hydrologic regime continue to drive engineers, planners, and environmentalists to develop optimal design practices for rapidly expanding built environments. To best understand how and where these impairments are received, the U.S. Environmental Protection Agency and other organizations have adopted urban runoff programs to identify contributions from non-point sources. This presentation provides a geospatial analysis method for identifying non-point source watersheds, and associated sub-basins, that contribute the highest loads of pollutants to receiving urban streams and lakes. This method, using a form of linear matrix inversion, is an area-averaged weighting method for non-point pollutants that corresponds to a geospatial land cover analysis. This two-phase analysis can be used to aid all parties in understanding how different land use types affect urban stream systems and processes. Optimal locations for water quality features (i.e., best management practices) can be evaluated in order to reduce, capture, and treat stormwater runoff as close to the source as possible. These best management practices have the ability to operate most effectively when located properly, because their ability to act as a minor treatment and prevention system is of great important for the restoration of the urban hydrologic regime.

  15. Management of agricultural nonpoint source pollution in China: current status and challenges.

    PubMed

    Wang, Xiaoyan

    2006-01-01

    Water quality in China shows an overall trend of deterioration in recent years. Nonpoint source pollution from agricultural and rural regions is the leading source of water pollution. The agricultural nonpoint source pollutants are mainly from fertilization of cropland, excessive livestock and poultry breeding and undefined disposal of daily living wastes in rural areas. Agricultural nonpoint sources contribute the main source of pollution to most watersheds in China, but they are ignored in management strategy and policy. Due to the lack of full understanding of water pollution control and management and the lack of perfect water quality standard systems and practical legislative regulations, agricultural nonpoint source pollution will become one of the biggest challenges to the sustainable development of rural areas and to society as a whole. The system for agricultural nonpoint source pollution control in China should include an appropriate legislation and policy framework, financing mechanisms, monitoring system, and technical guidelines and standards. The management of agricultural nonpoint source pollution requires multidisciplinary approaches that will involve a range of government departments, institutions and the public.

  16. Management of agricultural nonpoint source pollution in China: current status and challenges.

    PubMed

    Wang, Xiaoyan

    2006-01-01

    Water quality in China shows an overall trend of deterioration in recent years. Nonpoint source pollution from agricultural and rural regions is the leading source of water pollution. The agricultural nonpoint source pollutants are mainly from fertilization of cropland, excessive livestock and poultry breeding and undefined disposal of daily living wastes in rural areas. Agricultural nonpoint sources contribute the main source of pollution to most watersheds in China, but they are ignored in management strategy and policy. Due to the lack of full understanding of water pollution control and management and the lack of perfect water quality standard systems and practical legislative regulations, agricultural nonpoint source pollution will become one of the biggest challenges to the sustainable development of rural areas and to society as a whole. The system for agricultural nonpoint source pollution control in China should include an appropriate legislation and policy framework, financing mechanisms, monitoring system, and technical guidelines and standards. The management of agricultural nonpoint source pollution requires multidisciplinary approaches that will involve a range of government departments, institutions and the public. PMID:16594318

  17. Agricultural Science Teachers' Barriers, Roles, and Information Source Preferences for Teaching Biotechnology Topics

    ERIC Educational Resources Information Center

    Mowen, Diana L.; Wingenbach, Gary J.; Roberts, T. Grady; Harlin, Julie F.

    2007-01-01

    The purpose of this study was to determine barriers, roles, and information source preferences for teaching agricultural biotechnology topics. Agricultural science teachers were described primarily as 37 year-old males who had taught for 12 years, had bachelor's degrees, and had lived or worked on a farm or ranch. Equipment was perceived as the…

  18. Economic Analysis of Nitrate Source Reductions in California Agriculture

    NASA Astrophysics Data System (ADS)

    Medellin-Azuara, J.; Howitt, R.; Rosenstock, T.; Harter, T.; Pettygrove, S. G.; Dzurella, K.; Lund, J. R.

    2011-12-01

    We present an analytical approach to assess the economic impact of improving nitrogen management practices in California agriculture. We employ positive mathematical programming to calibrate crop production to base input information. The production function representation is a nested constant elasticity of substitution with two nests: one for applied water and one for applied nitrogen. The first nest accounts for the tradeoffs between irrigation efficiency and capital investments in irrigation technology. The second nest represents the tradeoffs between nitrogen application efficiency and the marginal costs of improving nitrogen efficiency. In the production function nest, low elasticities of substitution and water and nitrogen stress constraints keep agricultural crop yields constant despite changes in nitrogen management practices. We use the Tulare Basin, and the Salinas Valley in California's Central Valley and Central Coast respectively as our case studies. Preliminary results show that initial reductions of 25% in nitrogen loads to groundwater may not impose large costs to agricultural crop production as substitution of management inputs results in only small declines in net revenue from farming and total land use. Larger reductions in the nitrogen load to groundwater of 50% imposes larger marginal costs for better nitrogen management inputs and reductions in the area of lower valued crops grown in the study areas. Despite the shortage of data on quantitative effects of improved nitrogen efficiency; our results demonstrate the potential of combining economic and agronomic data into a model that can reflect differences in cost and substitutabilty in nitrogen application methods, that can be used to reduce the quantity of nitrogen leaching into groundwater.

  19. Emissions from Combustion of Open Area Sources: Prescribed Forest and Agricultural Burns

    EPA Science Inventory

    Emissions from wildfires and prescribed forest and agricultural burns generate a variety of emissions that can cause adverse health effects for humans, contribute to climate change, and decrease visibility. Only limited pollutant data are available for these sources, particularly...

  20. Non-agricultural sources of groundwater nitrate: a review and case study.

    PubMed

    Wakida, Fernando T; Lerner, David N

    2005-01-01

    Nitrate is often seen as an agricultural pollutant of groundwater and so is expected to be at higher concentrations in the groundwaters surrounding a city than in those beneath it. However the difference between rural and urban nitrate concentrations is often small, due to the non-agricultural sources of nitrogen that are concentrated in cities. This paper illustrates the source and significance of non-agricultural nitrogen for groundwater and presents a case study of nitrate loading in the city of Nottingham. Major sources of nitrogen in urban aquifers are related to wastewater disposal (on-site systems and leaky sewers), solid waste disposal (landfills and waste tips). The major sources of nitrogen in the Nottingham area are mains leakage and contaminated land with approximately 38% each of a total load of 21 kg N ha(-1) year(-1).

  1. Research Orientations and Sources of Influence: Agricultural Scientists in the U.S. Land-Grant System.

    ERIC Educational Resources Information Center

    Goldberger, Jessica R.

    2001-01-01

    Uses data from a 1995-96 national survey of agricultural scientists at land-grant universities to investigate the relative importance of 19 sources of influence on agricultural scientists engaged in six areas of agricultural research: productionist-oriented, sustainable agriculture, environmental, basic, consumer-oriented, and rural…

  2. Critical source times for nutrient loss in agricultural catchment streams

    NASA Astrophysics Data System (ADS)

    Melland, Alice; Shore, Mairead; Mellander, Per-Erik; McDonald, Noeleen; Shortle, Ger; Murphy, Paul; Jordan, Phil

    2014-05-01

    Identifying periods of the year when there is a high risk of incidental nutrient loss from farms via runoff to streams underpins current nutrient management legislation in Europe. This research explored high-temporal resolution nutrient transfer patterns relative to the time that manure and fertiliser are prohibited from being spread (the mandatory spreading 'closed' period) in five Irish agricultural catchments. Catchment nutrient losses during the 12 week closed periods in 2009-10, 2010-11 and 2011-12 were compared with losses during the remainder of the year, and with losses in the two week 'shoulder' periods immediately before and after the closed period. The closed period losses were assumed to be residual from soil nutrient stores and the 'shoulder' periods were considered to also include incidental losses. Nutrient loss was measured at sub-hourly frequency as total phosphorus (P) and total oxidised nitrogen (mostly nitrate-N) fluxes in streamflow. The streamflow fluxes showed that the proportion of the annual nitrate-N loss occurring during the closed periods (33-61%) was high compared with the remainder of the year. Six to ten times more nitrate-N loss occurred in the two weeks after, compared with the two weeks before, the closed period. These two week 'shoulder' period losses were, on average, less than or equal to 2.5 kg nitrate-N/ha and 9% of total annual nitrate-N loss in streamflow. On average, 40-53% of the annual P loss occurred during the closed periods but in a runoff-prone catchment in a year with a wet summer, the closed period was the less risky period. Similar to nitrate-N, two to twenty times more P loss occurred in the two weeks after, compared with the two weeks before, the closed period. These shoulder period losses were, on average, less than or equal to 0.027 kg/ha and 4.2% of total annual P loss in streamflow. The proportion of the shoulder period loss that could be attributed to recently spread nutrients was not known but can be

  3. Interrelationships between Mass Media Use and Interpersonal Source Use in Agricultural Development: The Case of the Dominican Republic.

    ERIC Educational Resources Information Center

    Abbott, Eric A.; de Leon, Cesar Amado Martinez

    A study examined (1) how the use of interpersonal information sources, the use of print media sources, and the use of radio sources are interrelated for agricultural decisions, and (2) which patterns of media use or interpersonal source use are most closely associated with knowing recommendations made by agricultural extension services and with…

  4. From "connecting the dots" to "threading the needle:" The challenges ahead in managing agricultural landscapes for environmental quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non point source pollution from agriculture is one of the most challenging problems facing society. In this book chapter, we briefly review the development of “landscape thinking” in agriculture and how this has been incorporated into the USDA Conservation Effects Assessment Program (CEAP). We pre...

  5. Horse paddocks - an emerging source of agricultural water pollution

    NASA Astrophysics Data System (ADS)

    Masud Parvage, Mohammed; Ulén, Barbro; Kirchmann, Holger

    2015-04-01

    Horse farms occupy about 4% of the total agricultural land in the EU but are not well investigated with regard to their impact on water quality. Horse paddocks commonly hold horses on a limited space and the animal density often exceeds the recommended density. Therefore, paddock soils receive significant amounts of phosphorus (P) and nitrogen (N) through feed residues and deposition of faeces and urine, which can lead to nutrient build-up in the soil and subsequent losses to aquatic systems. This study characterized the potential risk of phosphorus (P) and nitrogen (N) leaching losses from Swedish horse paddocks through three stage examination of soil and water P and N status. The experiment began with a pilot study where surface soil P status and eight years of drainage P data were examined from a paddock catchment and an adjacent arable catchment both receiving similar amount of P and N over years. Results showed that there were no signi?cant differences in water-soluble P (WSP) or total P data in soils but the drainage water P concentrations, being higher in the paddock catchment (0.33 mg P l-1, mainly in dissolved reactive form) than the arable catchment (0.10 mg P l-1). In the second experiment, soil P and N status were examined in different parts of horse paddocks (feeding, grazing, and excretion areas) to identify existence of any potential hotspots for losses within the paddock. In total, seven horse farms, covering different grazing densities and soil textures representative of Swedish horse paddocks were examined. The results showed that concentrations of WSP, plant available P or P-AL (P extracted in ammonium acetate lactate solution at pH 3.75), and total N were highest in feeding and excretion areas within the paddocks. It was also observed that the WSP concentration in the paddocks was strongly correlated with horse density (R2 = 0.80, p < 0.001) and P-AL with years of paddock management (R2 = 0.78, p < 0.001). In the final experiment, topsoil

  6. Potential pollutant sources in a Choptank River subwatershed: Influence of agricultural and residential land use and aqueous and atmospheric sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agriculture and animal feeding operations have been implicated as sources of water pollution along the Choptank River, an estuary and tributary of the Chesapeake Bay. This study examined a subwatershed within the Choptank River watershed for effects of land use on water quality. Water and sediment...

  7. Mitigation strategies for methane emissions from agricultural sources

    SciTech Connect

    Duxbury, J.M.

    1993-12-31

    Anthropogenic emissions of CH{sub 4} account for 70% of total global emissions of this greenhouse gas. Current anthropogenic emissions of CH{sub 4} in the US are estimated to be between 24-30 Tg CH{sub 4} or 7-9% of the global anthropogenic total. By comparison the US is responsible for 27% of anthropogenic emissions of CO{sub 2} from fossil fuel use. Table 1 shows that the major anthropogenic sources of CH{sub 4} in the US are landfills (37%), domestic livestock and livestock waste (31%) and the coal mining/natural gas/petroleum industries (28%). On a global basis it is estimated that US landfills contribute 30% to the global landfill total, whereas livestock (including waste) and the coal mining/natural gas/petroleum industries each contribute about 8% to their respective global totals. The US is an insignificant contributor (< 1%) to global emissions of CH{sub 4} from rice paddies.

  8. Sediment fingerprinting in agricultural catchments: A critical re-examination of source discrimination and data corrections

    NASA Astrophysics Data System (ADS)

    Smith, Hugh G.; Blake, William H.

    2014-01-01

    Fine sediment source fingerprinting techniques have been widely applied in agricultural river catchments. Successful source discrimination in agricultural environments depends on the key assumption that land-use source signatures imprinted on catchment soils are decipherable from those due to other landscape factors affecting soil and sediment properties. In this study, we re-examine this critical assumption by investigating (i) the physical and chemical basis for source discrimination and (ii) potential factors that may confound source un-mixing in agricultural catchments, including particle size and organic matter effects on tracer properties. The study is situated in the River Tamar, a predominantly agricultural catchment (920 km2) in south-west England that has also been affected by mining. Source discrimination focused on pasture and cultivated land uses and channel banks. Monthly, time-integrated suspended sediment samples were collected across seven catchments for a 12-month period. Physical and chemical properties measured in source soils and sediment included fallout radionuclides (137Cs, excess 210Pb), major and minor element geochemical constituents, total organic carbon and particle size. Source discrimination was entirely dependent on differences in tracer property concentrations between surface and sub-surface soils. This is based on fallout radionuclide concentrations that are surface-elevated, while many geochemical properties are surface-depleted due to weathering and pedogenetic effects, although surface soil contamination can reverse this trend. However, source discrimination in the study catchments was limited by (i) rotation of cultivated and pasture fields resulting in reduced differences between these two sources, and (ii) the cultivated source signature resembling a mix of the pasture and channel bank sources for many tracer properties. Furthermore, a combination of metal pollution from abandoned historic mines and organic enrichment of

  9. Agroforestry buffers for nonpoint source pollution reductions from agricultural watersheds.

    PubMed

    Udawatta, Ranjith P; Garrett, Harold E; Kallenbach, Robert

    2011-01-01

    Despite increased attention and demand for the adoption of agroforestry practices throughout the world, rigorous long-term scientific studies confirming environmental benefits from the use of agroforestry practices are limited. The objective was to examine nonpoint-source pollution (NPSP) reduction as influenced by agroforestry buffers in watersheds under grazing and row crop management. The grazing study consists of six watersheds in the Central Mississippi Valley wooded slopes and the row crop study site consists of three watersheds in a paired watershed design in Central Claypan areas. Runoff water samples were analyzed for sediment, total nitrogen (TN), and total phosphorus (TP) for the 2004 to 2008 period. Results indicate that agroforestry and grass buffers on grazed and row crop management sites significantly reduce runoff, sediment, TN, and TP losses to streams. Buffers in association with grazing and row crop management reduced runoff by 49 and 19%, respectively, during the study period as compared with respective control treatments. Average sediment loss for grazing and row crop management systems was 13.8 and 17.9 kg ha yr, respectively. On average, grass and agroforestry buffers reduced sediment, TN, and TP losses by 32, 42, and 46% compared with the control treatments. Buffers were more effective in the grazing management practice than row crop management practice. These differences could in part be attributed to the differences in soils, management, and landscape features. Results from this study strongly indicate that agroforestry and grass buffers can be designed to improve water quality while minimizing the amount of land taken out of production.

  10. Evaluation of agricultural nonpoint source pollution potential risk over China with a Transformed-Agricultural Nonpoint Pollution Potential Index method.

    PubMed

    Yang, Fei; Xu, Zhencheng; Zhu, Yunqiang; He, Chansheng; Wu, Genyi; Qiu, Jin Rong; Fu, Qiang; Liu, Qingsong

    2013-01-01

    Agricultural nonpoint source (NPS) pollution has been the most important threat to water environment quality. Understanding the spatial distribution of NPS pollution potential risk is important for taking effective measures to control and reduce NPS pollution. A Transformed-Agricultural Nonpoint Pollution Potential Index (T-APPI) model was constructed for evaluating the national NPS pollution potential risk in this study; it was also combined with remote sensing and geographic information system techniques for evaluation on the large scale and at 1 km2 spatial resolution. This model considers many factors contributing to the NPS pollution as the original APPI model, summarized as four indicators of the runoff, sediment production, chemical use and the people and animal load. These four indicators were analysed in detail at 1 km2 spatial resolution throughout China. The T-APPI model distinguished the four indicators into pollution source factors and transport process factors; it also took their relationship into consideration. The studied results showed that T-APPI is a credible and convenient method for NPS pollution potential risk evaluation. The results also indicated that the highest NPS pollution potential risk is distributed in the middle-southern Jiangsu province. Several other regions, including the North China Plain, Chengdu Basin Plain, Jianghan Plain, cultivated lands in Guangdong and Guangxi provinces, also showed serious NPS pollution potential. This study can provide a scientific reference for predicting the future NPS pollution risk throughout China and may be helpful for taking reasonable and effective measures for preventing and controlling NPS pollution.

  11. [GIS and L-THIA based analysis on variations of non-point pollution in the Guanlan River watershed, Shenzhen].

    PubMed

    Bai, Feng-jiao; Li, Tian-hong

    2012-08-01

    In order to reveal the influence of land use change, on the non-point source pollution load during the rapid urbanization process in the Guanlan River watershed, Shenzhen, Guangdong, with the support of GIS, L-THIA model was used to analyze the changes in spatial distribution of non-point source pollution load in the river watershed from 1996 to 2008. The parameters in L-THIA model were revised according to the environmental conditions of the study region. The results showed that during the urbanization from 1996 to 2008, the load of major pollutants, namely TN, TP and COD, showed an obviously increasing trend with increase rates being 62.78%, 59.73% and 55.40%, respectively, and the distribution of areas with high pollution load was expanding along the river and the main roads, and then connected into large areas. The total load of SS was decreased by 7.59%. This was caused by the reduction of land for development, which was the land use pattern with high SS output. Therefore, in order to control the non-point pollution effectively, the Guanlan River watershed could be divided into four pollution control areas according to the distribution of pollution load and different land use patterns. The results of this research would provide scientific references for non-point source pollution control in the Guanlan River watershed.

  12. Sources of fine sediment stored in agricultural lowland streams, Midwest, USA

    NASA Astrophysics Data System (ADS)

    Lamba, Jasmeet; Thompson, A. M.; Karthikeyan, K. G.; Fitzpatrick, Faith A.

    2015-05-01

    Agricultural activities can accelerate the offsite transport of productive soil from fields leading to stream water quality degradation. Identification of the nature and relative contribution of different sources to fine-grained sediment (e.g., silts, clays) in streams is important to effectively focus agricultural best management practices in watersheds. Sediment fingerprinting techniques through the use of geochemical tracers are commonly used to differentiate relative contribution from various sources. Research was conducted in lowland streams in the Pleasant Valley watershed in South Central Wisconsin (USA) to identify provenance of fine-grained sediment deposits and evaluate the impact of land use on relative contributions from the following potential sources: cropland, pasture, woodland, and eroding stream banks. Results show that both agriculture (croplands and pastures) and eroding stream banks are primary sources to fine sediment deposits on the stream bed with contributions ranging from 19 to 100% and 0 to 81%, respectively. The increase in area under agricultural land use within a subwatershed results in greater contribution from agriculture (R2 = 0.846, p = 0.0034). Relative contributions from eroding stream banks increased with increasing area under grasslands and woodlands within a subwatershed (R2 = 0.814, p = 0.0055). Subwatersheds with greater mass of fine sediment deposited on the stream bed per unit area should be prioritized for best management practices. The conservation practices should be targeted to stream banks or croplands depending on the dominant source of fine sediment within a subwatershed. Site specific changes in relative contributions from different sources to fine-grained sediment in this watershed highlights the complexities involved in sediment transport dynamics. The nested sampling sites helped determine that sediment dynamics at the subwatershed scale need to be considered for application of targeted conservation techniques.

  13. How Do Washington's Newspaper Editors Evaluate Their Sources of Agricultural News?--A Survey.

    ERIC Educational Resources Information Center

    Sampson, M. W.

    This report presents the results of a questionnaire sent to the daily and weekly newspaper editors in Washington to evaluate their sources of agricultural news. Responses were obtained from 16 of 21 daily newspaper editors queried and 63 of 140 weekly editors. The questionnaire was designed to check the accuracy of newspapers' mailing addresses,…

  14. Evaluating analytic and risk assessment tools to estimate sediment and nutrients losses from agricultural lands in the southern region of the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-point source pollution from agricultural fields is a critical problem associated with water quality impairment in the USA and a low-oxygen environment in the Gulf of Mexico. The use, development and enhancement of qualitative and quantitative models or tools for assessing agricultural runoff qua...

  15. GCAM 3.0 Agriculture and Land Use: Data Sources and Methods

    SciTech Connect

    Kyle, G. Page; Luckow, Patrick; Calvin, Katherine V.; Emanuel, William R.; Nathan, Mayda; Zhou, Yuyu

    2011-12-12

    This report presents the data processing methods used in the GCAM 3.0 agriculture and land use component, starting from all source data used, and detailing all calculations and assumptions made in generating the model inputs. The report starts with a brief introduction to modeling of agriculture and land use in GCAM 3.0, and then provides documentation of the data and methods used for generating the base-year dataset and future scenario parameters assumed in the model input files. Specifically, the report addresses primary commodity production, secondary (animal) commodity production, disposition of commodities, land allocation, land carbon contents, and land values.

  16. Identification of groundwater contamination sources of nitrate and sulfate in shallow alluvial aquifers using a dual-isotope approach in an agricultural area

    NASA Astrophysics Data System (ADS)

    Kaown, D.; Koh, D.; Mayer, B.; Hyun, Y.; Bae, G.; Lee, K.

    2007-12-01

    The elevated level of nitrate in groundwater is a serious problem in Korean agricultural areas. Yupori, a small agricultural area in Chuncheon (Korea), shows a rising level of NO3-N and displays multiple NO3-N sources from non-point and point sources in shallow aquifer groundwater. Numerous vegetable fields are located in the western part of the study area and fruit orchards dominate the landscape with only few vegetable fields in the eastern part of the study area. The source identification of groundwater contamination from overburden agricultural area was undertaken by analyzing hydrochemical data and stable isotopic compositions of dissolved nitrate and sulfate (¥ä15N-NO3-, ¥ä18O-NO3-, ¥ä34S-SO42-, and ¥ä18O-SO42-). The measurements of ¥ä15N- NO3- are in the range of 7.1 to 14.4¢¶ and the values of ¥ä18O-NO3- are in the range of -1.8 to 6.5¢¶. High ¥ä15N-NO3- values shown at low concentrations of nitrate in the eastern Yupori are characteristics of manure- derived nitrate and organic soil. The values of ¥ä34S-SO4-2 ranged from 2.9 to 9.9¢¶ and ¥ä18O-SO42- ranged from 2.5 to 4.7¢¶. At high concentrations of SO42- in the western Yupori, the value of ¥ä34S-SO42- are low around 3-4¢¶. The value of ¥ä34S-SO42- increased with decreasing SO42- concentration in the eastern Yupori. Groundwater quality and stable isotopic compositions of dissolved nitrate and sulfate seem to be significantly affected by agricultural land use pattern of the study site.

  17. Landscape planning for agricultural nonpoint source pollution reduction I: a geographical allocation framework.

    PubMed

    Diebel, Matthew W; Maxted, Jeffrey T; Nowak, Peter J; Vander Zanden, M Jake

    2008-11-01

    Agricultural nonpoint source pollution remains a persistent environmental problem, despite the large amount of money that has been spent on its abatement. At local scales, agricultural best management practices (BMPs) have been shown to be effective at reducing nutrient and sediment inputs to surface waters. However, these effects have rarely been found to act in concert to produce measurable, broad-scale improvements in water quality. We investigated potential causes for this failure through an effort to develop recommendations for the use of riparian buffers in addressing nonpoint source pollution in Wisconsin. We used frequency distributions of phosphorus pollution at two spatial scales (watershed and field), along with typical stream phosphorus (P) concentration variability, to simulate benefit/cost curves for four approaches to geographically allocating conservation effort. The approaches differ in two ways: (1) whether effort is aggregated within certain watersheds or distributed without regard to watershed boundaries (dispersed), and (2) whether effort is targeted toward the most highly P-polluting fields or is distributed randomly with regard to field-scale P pollution levels. In realistic implementation scenarios, the aggregated and targeted approach most efficiently improves water quality. For example, with effort on only 10% of a model landscape, 26% of the total P load is retained and 25% of watersheds significantly improve. Our results indicate that agricultural conservation can be more efficient if it accounts for the uneven spatial distribution of potential pollution sources and the cumulative aspects of environmental benefits.

  18. Identification of nitrogen sources to four small lakes in the agricultural region of Khorezm, Uzbekistan

    USGS Publications Warehouse

    Shanafield, M.; Rosen, M.; Saito, L.; Chandra, S.; Lamers, J.; Nishonov, Bakhriddin

    2010-01-01

    Pollution of inland waters by agricultural land use is a concern in many areas of the world, and especially in arid regions, where water resources are inherently scarce. This study used physical and chemical water quality and stable nitrogen isotope (δ15N) measurements from zooplankton to examine nitrogen (N) sources and concentrations in four small lakes of Khorezm, Uzbekistan, an arid, highly agricultural region, which is part of the environmentally-impacted Aral Sea Basin. During the 2-year study period, ammonium concentrations were the highest dissolved inorganic N species in all lakes, with a maximum of 3.00 mg N l−1 and an average concentration of 0.62 mg N l−1. Nitrate levels were low, with a maximum concentration of 0.46 mg N l−1 and an average of 0.05 mg N l−1 for all four lakes. The limited zooplankton δ15N values did not correlate with the high loads of synthetic fertilizer applied to local croplands during summer months. These results suggest that the N cycles in these lakes may be more influenced by regional dynamics than agricultural activity in the immediate surroundings. The Amu-Darya River, which provides the main source of irrigation water to the region, was identified as a possible source of the primary N input to the lakes.

  19. U and Sr Isotope Tracers of Agricultural Salinity Sources to the Lower Rio Grande River

    NASA Astrophysics Data System (ADS)

    Nyachoti, S. K.; Ma, L.; Szynkiewicz, A.; Jin, L.; McIntosh, J. C.

    2014-12-01

    Elevated salinity of the lower Rio Grande River deteriorates water quality and limits domestic and agricultural water use. Both natural and anthropogenic processes contribute salts in the Rio Grande. Previous studies have focused on natural salt contributions with less emphasis on anthropogenic sources of salinity in the Rio Grande. Using (234U/238U) activity ratios (UAR), 87Sr/86Sr isotope ratios, and major element concentrations, we aim to trace and quantify the salt loads in the Lower Rio Grande watershed which is greatly impacted by agricultural activities. Between 2009 and 2010, we sampled the Rio Grande stretch and irrigation return flows between the Elephant Butte Reservoir, New Mexico and El Paso, Texas. Furthermore, we monitored in monthly intervals the temporal changes of chemical and isotopic compositions of the Rio Grande at Canutillo, Tx. Our results show higher U and Sr fluxes in the Rio Grande during the irrigation season as compared to the non-irrigation season. The UAR (1.62 to 2.13) and 87Sr/86Sr ratios (0.7099 to 0.7138) were higher in the non-irrigation season compared to the irrigation season (UAR: 1.69 to 1.77; 87Sr/86Sr: 0.7100 to 0.7106). These variations of UAR and 87Sr/86Sr ratios imply multiple sources of U and Sr in the Rio Grande. In contrast, the agricultural return flows show a narrow range of UAR (1.31 to 1.37) and 87Sr/86Sr ratios (0.7091 to 0.7099) in the studied seasons. This is consistent with salinity contributions from agricultural sources. Rio Grande at Canutillo shows low UAR (1.62 to 1.77) and 87Sr/86Sr ratios (0.7104 to 0.7105) during the irrigation season as compared to the non-irrigation season (UAR: 2.04 to 2.24; 87Sr/86Sr: 0.7105 to 0.7109). The low U and Sr signature at Canutillo during the irrigation season is close to that of the agricultural return flows, indicative of agricultural salinity sources. These results provide useful elemental and isotopic constraints for future mass balance calculations of salinity

  20. MANAGEMENT OF DIFFUSE POLLUTION IN AGRICULTURAL WATERSHEDS: LESSONS FROM THE MINNESOTA RIVER BASIN. (R825290)

    EPA Science Inventory

    Abstract

    The Minnesota River (Minnesota, USA) receives large non-point source pollutant loads. Complex interactions between agricultural, state agency, environmental groups, and issues of scale make watershed management difficult. Subdividing the basin's 12 major water...

  1. Contamination, source, and input route of polycyclic aromatic hydrocarbons in historic wastewater-irrigated agricultural soils.

    PubMed

    Wang, Ning; Li, Hong-Bo; Long, Jin-Lin; Cai, Chao; Dai, Jiu-Lan; Zhang, Juan; Wang, Ren-Qing

    2012-12-01

    Contamination by polycyclic aromatic hydrocarbons (PAHs) of historic wastewater-irrigated agricultural topsoil (0-5 cm) and the contribution of groundwater irrigation and atmospheric deposition to soil PAHs were studied in a typical agricultural region, i.e. Hunpu region, Liaoning, China. Concentrations of total PAHs ranged from 0.43 to 2.64 mg kg⁻¹ in topsoil, being lower than those found in other wastewater-irrigated areas. The levels of PAHs in soil declined as the distance from a water source increased. Concentrations of individual PAHs were generally higher in upland than in paddy topsoils. The calculated nemerow composite index showed that agricultural soil in the region was "polluted" by PAHs. A human health risk assessment based on the total toxic equivalent concentration showed that the presence of elevated concentrations of PAHs in the soil might pose a great threat to the health of local residents. Ratios of pairs of PAHs and principal component analysis (PCA) showed that pyrogenesis, such as coal combustion, was the main source of PAHs, while petroleum, to some extent, also had a strong influence on PAHs contamination in upland soil. The distribution patterns of individual PAHs and composition of PAHs differed between irrigation groundwater and topsoil, but were similar between atmospheric deposition and topsoil. There were significant linear correlations (r = 0.90; p < 0.01) between atmospheric deposition rates and average concentrations of the 16 individual PAHs in soils, while no significant relationships were observed between irrigation groundwater and topsoil in levels of PAHs. These suggested that PAHs in agricultural soils were mainly introduced from atmospheric deposition, rather than from groundwater irrigation after the phasing out of wastewater irrigation in the region since 2002. This study provides a reference to ensure agricultural product safety, pollution control, and proper soil management.

  2. Selection and application of agricultural wastes as solid carbon sources and biofilm carriers in MBR.

    PubMed

    Yang, Xiao-Li; Jiang, Qi; Song, Hai-Liang; Gu, Tian-Tian; Xia, Ming-Qian

    2015-01-01

    This paper examined the feasibility of agricultural wastes used as solid carbon sources and the effect of determined agricultural wastes on improving denitrification. Eight agricultural wastes were evaluated in MBR tests to find out their carbon release capacity, denitrification potential, leaching elements and surface properties. The results showed that retinervus luffae fructus, wheat straw, corncob and rice straw had higher carbon release capacity with COD of 13.17-21.07 mg g(-1)day(-1), BOD5 of 3.33-7.33 mg g(-1)day(-1) and respirable carbon of 8.64-10.71 mg g(-1)day(-1). Correspondingly, they displayed a good denitrification potential of 105.3-140.1mg NO3(-)-Ng(-1). Rice straw, retinervus luffae fructus and corncob were then applied in MBRs. These three agricultural wastes were found to be effective in enhancing the denitrification process, where the TN removal increased from 43.44% (control MBR) to 82.34, 68.92 and 62.97%, respectively.

  3. Evaluating agricultural nonpoint-source pollution programs in two Lake Erie tributaries.

    PubMed

    Forster, D Lynn; Rausch, Jonathan N

    2002-01-01

    During the past three decades, numerous government programs have encouraged Lake Erie basin farmers to adopt practices that reduce water pollution. The first section of this paper summarizes these state and federal government agricultural pollution abatement programs in watersheds of two prominent Lake Erie tributaries, the Maumee River and Sandusky River. Expenditures are summarized for each program, total expenditures in each county are estimated, and cost effectiveness of program expenditures (i.e., cost per metric ton of soil saved) are analyzed. Farmers received nearly $143 million as incentive payments to implement agricultural nonpoint source pollution abatement programs in the Maumee and Sandusky River watersheds from 1987 to 1997. About 95% of these funds was from federal sources. On average, these payments totaled about $7000 per farm or about $30 per farm acre (annualized equivalent of $2 per acre) within the watersheds. Our analysis raises questions about how efficiently these incentive payments were allocated. The majority of Agricultural Conservation Program (ACP) funds appear to have been spent on less cost-effective practices. Also, geographic areas with relatively low (high) soil erosion rates received relatively large (small) funding.

  4. Stream sediment sources in midwest agricultural basins with land retirement along channel

    USGS Publications Warehouse

    Williamson, Tanja N.; Christensen, Victoria G.; Richardson, William B.; Frey, Jeffrey W.; Gellis, Allen C.; Kieta, K. A.; Fitzpatrick, Faith A.

    2014-01-01

    Documenting the effects of agricultural land retirement on stream-sediment sources is critical to identifying management practices that improve water quality and aquatic habitat. Particularly difficult to quantify are the effects from conservation easements that commonly are discontinuous along channelized streams and ditches throughout the agricultural midwestern United States. Our hypotheses were that sediment from cropland, retired land, stream banks, and roads would be discernible using isotopic and elemental concentrations and that source contributions would vary with land retirement distribution along tributaries of West Fork Beaver Creek in Minnesota. Channel-bed and suspended sediment were sampled at nine locations and compared with local source samples by using linear discriminant analysis and a four-source mixing model that evaluated seven tracers: In, P, total C, Be, Tl, Th, and Ti. The proportion of sediment sources differed significantly between suspended and channel-bed sediment. Retired land contributed to channel-bed sediment but was not discernible as a source of suspended sediment, suggesting that retired-land material was not mobilized during high-flow conditions. Stream banks were a large contributor to suspended sediment; however, the percentage of stream-bank sediment in the channel bed was lower in basins with more continuous retired land along the riparian corridor. Cropland sediments had the highest P concentrations; basins with the highest cropland-sediment contributions also had the highest P concentrations. Along stream reaches with retired land, there was a lower proportion of cropland material in suspended sediment relative to sites that had almost no land retirement, indicating less movement of nutrients and sediment from cropland to the channel as a result of land retirement.

  5. Stream Sediment Sources in Midwest Agricultural Basins with Land Retirement along Channel.

    PubMed

    Williamson, T N; Christensen, V G; Richardson, W B; Frey, J W; Gellis, A C; Kieta, K A; Fitzpatrick, F A

    2014-09-01

    Documenting the effects of agricultural land retirement on stream-sediment sources is critical to identifying management practices that improve water quality and aquatic habitat. Particularly difficult to quantify are the effects from conservation easements that commonly are discontinuous along channelized streams and ditches throughout the agricultural midwestern United States. Our hypotheses were that sediment from cropland, retired land, stream banks, and roads would be discernible using isotopic and elemental concentrations and that source contributions would vary with land retirement distribution along tributaries of West Fork Beaver Creek in Minnesota. Channel-bed and suspended sediment were sampled at nine locations and compared with local source samples by using linear discriminant analysis and a four-source mixing model that evaluated seven tracers: In, P, total C, Be, Tl, Th, and Ti. The proportion of sediment sources differed significantly between suspended and channel-bed sediment. Retired land contributed to channel-bed sediment but was not discernible as a source of suspended sediment, suggesting that retired-land material was not mobilized during high-flow conditions. Stream banks were a large contributor to suspended sediment; however, the percentage of stream-bank sediment in the channel bed was lower in basins with more continuous retired land along the riparian corridor. Cropland sediments had the highest P concentrations; basins with the highest cropland-sediment contributions also had the highest P concentrations. Along stream reaches with retired land, there was a lower proportion of cropland material in suspended sediment relative to sites that had almost no land retirement, indicating less movement of nutrients and sediment from cropland to the channel as a result of land retirement. PMID:25603248

  6. COMPARATIVE DIVERSITY OF FECAL BACTERIA IN AGRICULTURALLY SIGNIFICANT ANIMALS TO IDENTIFY ALTERNATIVE TARGETS FOR MICROBIAL SOURCE TRACKING

    EPA Science Inventory

    Animals of agricultural significance contribute a large percentage of fecal pollution to waterways via runoff contamination. The premise of microbial source tracking is to utilize fecal bacteria to identify target populations which are directly correlated to specific animal feces...

  7. Using Strontium Isotopes in Arid Agricultural Soils to Determine a Sink or Source of CO2

    NASA Astrophysics Data System (ADS)

    Ortiz, A. C.; Jin, L.

    2014-12-01

    Arid and semi-arid regions of the world are predicted to continue to expand through land degradation and prolonged drought events. Agricultural practices in these drylands degrade soils through elevated salinity, sodicity and alkalinity. Indeed, flood irrigation loads salts onto the soils including carbonate minerals in the form of calcite. Alfalfa and Pecan are salt tolerant and commonly grown in the arid El Paso region, but need irrigation using Rio Grande water with little to no contribution from local ground waters. We hypothesize that the irrigation is loading extra Ca and bicarbonate to soils and anthropogenically enhancing the precipitation of carbonates. We intend to monitor soil CO2 efflux after irrigation, characterize soil minerals, and combine them to isotopic data of soil, irrigation, and drainage waters to link the sources of Ca and C, kinetics of calcite precipitation, to irrigation events. This will include strontium isotopic analysis to determine the source of calcium in the agricultural fields, U-disequilibrium isotopes to estimate the carbonate ages, and CO2 efflux to monitor atmosphere-soil exchange. Carbon dioxide emissions are expected to change during flood irrigation when soils are saturated. After irrigation events, evaporative effects increase Ca and dissolved inorganic carbon concentration in soil waters leading to precipitation of calcite and thus elevated CO2efflux. Preliminary measurements in the pecan field show a marginally significant difference in CO2 fluxes before and after irrigation (p=0.07, t-test). Carbon dioxide emissions are lower during moist conditions (0.6 g m-2hr-1 CO2) than those in dry conditions (1.0 g m-2hr-1 CO2). Future C isotope data are needed to identify the source of extra CO2, biogenic or calcite-precipitation related. A water leachable extraction of alfalfa soils shows 87Sr/86Sr ratios ranged from 0.7101 to 0.7103, indicating Rio Grande river as a dominant calcium source. Further Sr isotopic analysis of

  8. Wetlands and Agriculture in Africa: Major Sources of N2O?

    NASA Astrophysics Data System (ADS)

    Gettel, G. M.

    2015-12-01

    Papyrus wetlands in East Africa are rapidly being converted to agricultural production in an effort to increase food security. This conversion is often seasonal, with wetlands being used for grazing and crop production of maize, sugarcane, and rice during dry seasons, and flooding occurring during wet seasons. An important question with respect to greenhouse gas production is whether wetland conversion to agriculture increases N2O fluxes. This trend has been shown in temperate regions where increased N2O fluxes are positively related to low soil C:N ratios, especially when soil moisture content remains high. In order to examine whether denitrification contributes to N2O flux, we measured potential denitrification rates (PDR by acetylene block method) in intact papyrus wetlands and agricultural converted wetlands in Kenya, Tanzania, Uganda, and Rwanda, and also performed multivariate analysis to relate soil characteristics to PDR. Agricultural land-cover types included maize, sugarcane, rice, and grazing. Results showed that intact wetlands are potentially important sources of N2O, as PDR in papyrus vegetation were consistently the highest (p<0.05; 128 - 601 μg N2O g DW-1 hour-1) while grazing sites showed the lowest (0.1 - 0.5 μg N2O g DW-1 hour-1). Rates were second highest in rice fields (2.3 - 303 μg N2O g DW-1 hour-1), and intermediate in maize and sugarcane (6.5 - 75 μmg N2O g DW-1 hour-1 and 5 - 30 μg N2O g DW-1 hour-1 respectively). PDR across all sites was inversely related to soil C:N ratio, with nitrate consistently limiting PDR in the wetland sites while soil carbon limited PDR in agricultural sites. This is seemingly in contrast with other findings that show that lower C:N ratios result in high N2O fluxes from drained wetland sites. However, flux measurements along with more realistic process-based measurements of denitrification are urgently needed to more fully understand the effect of agricultural conversion of wetlands in East Africa.

  9. An investigation of element ratios for assessing suspended-sediment sources in small agricultural basins

    USGS Publications Warehouse

    Juracek, K.

    2012-01-01

    Various sediment properties previously have been investigated for the purpose of determining sources of suspended sediment. A remaining research need is an assessment of element ratios for the determination of suspended-sediment sources in different terrestrial environments. In this study, 253 element ratios were assessed to determine which, if any, were potentially useful for sediment-source determinations in six small agricultural basins in northeastern Kansas, USA. Samples of surface soils (cropland and grassland), channel banks, and reservoir bottom sediments were collected, analyzed for 23 elements, and compared. Of the 253 element ratios assessed, only the Co/Pb and Co/Zn ratios were substantially and consistently different between the channel banks and surface soils for all six basins. For three of four reservoirs for which data were available, sediment-source estimates provided by Co/Pb ratios were in agreement with estimates previously provided using 137Cs. For two of the four reservoirs, sediment-source estimates provided by Co/Zn ratios were consistent with the 137Cs estimates. Thus, the Co/Pb ratio potentially may be more useful. Additional research is needed to ascertain whether or not the use of Co/Pb and Co/Zn ratios as tracers is widely applicable or restricted to specific terrestrial environments.

  10. Chloride Sources and Losses in Two Tile-Drained Agricultural Watersheds.

    PubMed

    David, Mark B; Mitchell, Corey A; Gentry, Lowell E; Salemme, Ronald K

    2016-01-01

    Chloride is a relatively unreactive plant nutrient that has long been used as a biogeochemical tracer but also can be a pollutant causing aquatic biology impacts when concentrations are high, typically from rock salt applications used for deicing roads. Chloride inputs to watersheds are most often from atmospheric deposition, road salt, or agricultural fertilizer, although studies on agricultural watersheds with large fertilizer inputs are few. We used long-term (21 and 17 yr) chloride water quality data in two rivers of east-central Illinois to better understand chloride biogeochemistry in two agricultural watersheds (Embarras and Kaskaskia), the former with a larger urban land use and both with extensive tile drainage. During our sampling period, the average chloride concentration was 23.7 and 20.9 mg L in the Embarras and Kaskaskia Rivers, respectively. Annual fluxes of chloride were 72.5 and 61.2 kg ha yr in the Embarras and Kaskaskia watersheds, respectively. In both watersheds, fertilizer chloride was the dominant input (∼49 kg ha yr), with road salt likely the other major source (23.2 and 7.2 kg ha yr for the Embarras and Kaskaskia watersheds, respectively). Combining our monitoring data with earlier published data on the Embarras River showed an increase in chloride concentrations as potash use increased in Illinois during the 1960s and 1970s with a lag of about 2 to 6 yr to changes in potash inputs based on a multiple-regression model. In these agricultural watersheds, riverine chloride responds relatively quickly to potash fertilization as a result of tile-drainage.

  11. Chloride Sources and Losses in Two Tile-Drained Agricultural Watersheds.

    PubMed

    David, Mark B; Mitchell, Corey A; Gentry, Lowell E; Salemme, Ronald K

    2016-01-01

    Chloride is a relatively unreactive plant nutrient that has long been used as a biogeochemical tracer but also can be a pollutant causing aquatic biology impacts when concentrations are high, typically from rock salt applications used for deicing roads. Chloride inputs to watersheds are most often from atmospheric deposition, road salt, or agricultural fertilizer, although studies on agricultural watersheds with large fertilizer inputs are few. We used long-term (21 and 17 yr) chloride water quality data in two rivers of east-central Illinois to better understand chloride biogeochemistry in two agricultural watersheds (Embarras and Kaskaskia), the former with a larger urban land use and both with extensive tile drainage. During our sampling period, the average chloride concentration was 23.7 and 20.9 mg L in the Embarras and Kaskaskia Rivers, respectively. Annual fluxes of chloride were 72.5 and 61.2 kg ha yr in the Embarras and Kaskaskia watersheds, respectively. In both watersheds, fertilizer chloride was the dominant input (∼49 kg ha yr), with road salt likely the other major source (23.2 and 7.2 kg ha yr for the Embarras and Kaskaskia watersheds, respectively). Combining our monitoring data with earlier published data on the Embarras River showed an increase in chloride concentrations as potash use increased in Illinois during the 1960s and 1970s with a lag of about 2 to 6 yr to changes in potash inputs based on a multiple-regression model. In these agricultural watersheds, riverine chloride responds relatively quickly to potash fertilization as a result of tile-drainage. PMID:26828190

  12. Identifying diffused nitrate sources in a stream in an agricultural field using a dual isotopic approach.

    PubMed

    Ding, Jingtao; Xi, Beidou; Gao, Rutai; He, Liansheng; Liu, Hongliang; Dai, Xuanli; Yu, Yijun

    2014-06-15

    Nitrate (NO3(-)) pollution is a severe problem in aquatic systems in Taihu Lake Basin in China. A dual isotope approach (δ(15)NNO3(-) and δ(18)ONO3(-)) was applied to identify diffused NO3(-) inputs in a stream in an agricultural field at the basin in 2013. The site-specific isotopic characteristics of five NO3(-) sources (atmospheric deposition, AD; NO3(-) derived from soil organic matter nitrification, NS; NO3(-) derived from chemical fertilizer nitrification, NF; groundwater, GW; and manure and sewage, M&S) were identified. NO3(-) concentrations in the stream during the rainy season [mean±standard deviation (SD)=2.5±0.4mg/L] were lower than those during the dry season (mean±SD=4.0±0.5mg/L), whereas the δ(18)ONO3(-) values during the rainy season (mean±SD=+12.3±3.6‰) were higher than those during the dry season (mean±SD=+0.9±1.9‰). Both chemical and isotopic characteristics indicated that mixing with atmospheric NO3(-) resulted in the high δ(18)O values during the rainy season, whereas NS and M&S were the dominant NO3(-) sources during the dry season. A Bayesian model was used to determine the contribution of each NO3(-) source to total stream NO3(-). Results showed that reduced N nitrification in soil zones (including soil organic matter and fertilizer) was the main NO3(-) source throughout the year. M&S contributed more NO3(-) during the dry season (22.4%) than during the rainy season (17.8%). AD generated substantial amounts of NO3(-) in May (18.4%), June (29.8%), and July (24.5%). With the assessment of temporal variation of diffused NO3(-) sources in agricultural field, improved agricultural management practices can be implemented to protect the water resource and avoid further water quality deterioration in Taihu Lake Basin. PMID:24686140

  13. Basic biogenic aerosol precursors: Agricultural source attribution of volatile amines revised

    NASA Astrophysics Data System (ADS)

    Kuhn, U.; Sintermann, J.; Spirig, C.; Jocher, M.; Ammann, C.; Neftel, A.

    2011-08-01

    Despite recent evidence on an important role of volatile amines in the nucleation of particulate matter, very scarce information is available on their atmospheric abundance and source distribution. Previous measurements in animal housings had identified livestock husbandry as the main amine source, with trimethylamine (TMA) being the key component. This has led to the assumption that the agricultural sources for amines are similar as for ammonia, emitted throughout the cascade of animal excretion, storage and application in the field. In this study, we present the first micrometeorological flux measurements as well as dynamic enclosure experiments showing that the amine source strength from stored slurry is negligible, implying significant consequences for the global amine emission inventory. In the case of cattle, amine production is attributed to the animal's rumination activity and exhalation is suggested to be an important emission pathway, similar to the greenhouse gas methane. Fodder like hay and silage also emits volatile amines, potentially assigning these alkaloid compounds a key function in enhancing particle formation in remote areas.

  14. Potential sources of and ecological risks from heavy metals in agricultural soils, Daye City, China.

    PubMed

    Du, Ping; Xie, Yunfeng; Wang, Shijie; Zhao, Huanhuan; Zhang, Zhuo; Wu, Bin; Li, Fasheng

    2015-03-01

    Concentrations of eight heavy metals (arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn)) were measured in 92 topsoil samples collected from agricultural areas in Daye City to (1) assess the distribution of these heavy metals, (2) discriminate natural and anthropic contributions, and (3) identify possible sources of pollution. Mean concentrations of As, Cd, Cu, and Zn in the investigated soils were 23.8, 1.41, 105, and 159 mg kg(-1), respectively. These values were higher, in some cases by several orders of magnitude, than their corresponding background values. Estimated ecological risks, based on contamination factors and potential ecological risk indexes, were mostly low, but were considerable for As and Cd. A range of basic and multivariate statistical analyses (Pearson's correlation analysis, hierarchical cluster analysis, and principal component analysis) clearly revealed two distinct metal groups, comprising As/Cd/Cu/Zn and Cr/Ni/Hg/Pb, whose concentrations were closely associated with the distribution and pollution characteristics of industries in and around the city. Results demonstrated that As/Cd/Cu/Zn were indicators of anthropic pollution, while Cr/Hg/Ni/Pb were from parent materials. Maps of pollutant distribution compiled for the entire arable area further indicated that non-ferrous metal smelting and mining is the main source of diffuse pollution, and also showed the contribution of point source pollution to metal concentrations in agricultural topsoil. Results of this study will be useful for planning, risk assessment, and decision making by environmental managers in this region. PMID:25242589

  15. Potential sources of and ecological risks from heavy metals in agricultural soils, Daye City, China.

    PubMed

    Du, Ping; Xie, Yunfeng; Wang, Shijie; Zhao, Huanhuan; Zhang, Zhuo; Wu, Bin; Li, Fasheng

    2015-03-01

    Concentrations of eight heavy metals (arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn)) were measured in 92 topsoil samples collected from agricultural areas in Daye City to (1) assess the distribution of these heavy metals, (2) discriminate natural and anthropic contributions, and (3) identify possible sources of pollution. Mean concentrations of As, Cd, Cu, and Zn in the investigated soils were 23.8, 1.41, 105, and 159 mg kg(-1), respectively. These values were higher, in some cases by several orders of magnitude, than their corresponding background values. Estimated ecological risks, based on contamination factors and potential ecological risk indexes, were mostly low, but were considerable for As and Cd. A range of basic and multivariate statistical analyses (Pearson's correlation analysis, hierarchical cluster analysis, and principal component analysis) clearly revealed two distinct metal groups, comprising As/Cd/Cu/Zn and Cr/Ni/Hg/Pb, whose concentrations were closely associated with the distribution and pollution characteristics of industries in and around the city. Results demonstrated that As/Cd/Cu/Zn were indicators of anthropic pollution, while Cr/Hg/Ni/Pb were from parent materials. Maps of pollutant distribution compiled for the entire arable area further indicated that non-ferrous metal smelting and mining is the main source of diffuse pollution, and also showed the contribution of point source pollution to metal concentrations in agricultural topsoil. Results of this study will be useful for planning, risk assessment, and decision making by environmental managers in this region.

  16. Evaluating nitrate sources in nested agricultural sub-basins using nitrate stable isotopes

    NASA Astrophysics Data System (ADS)

    Chang, C. C.; Frey, J. W.; Kim, M.; Kendall, C.

    2005-05-01

    Nutrient enrichment is the second leading cause of drinking water contamination in the United States. To provide environmental managers with nutrient source and transport information, the U.S. Geological Survey' s National Water-Quality Assessment (NAWQA) Program conducted a multi-component study in Sugar Creek Basin, Indiana, in which major nutrients, cations, anions, and pesticides were analyzed. Land use at Sugar Creek (246 square km basin) is dominated by row crop agriculture, primarily corn and soybeans. The soils are largely heavy clay, glacial till in origin, and require tile drains to move excess water and make the land farmable. As one component of the study, stable isotopes of nitrate (N-15 and O-18) were used to examine nitrate sources and transport, and possible transformations of nitrate. Water samples were collected in 2003 and 2004 from major environmental compartments involved with the movement of nutrients into the creek, (precipitation, tile drain, and overland flow). Samples were also collected from Leary-Weber Ditch, a 6.2 square km basin is nested within Sugar Creek. Collection times bracketing four distinct periods of the agricultural cycle: pre-application of fertilizer, post-application of fertilizer, growing season, and post-harvest periods. Nutrient samples (nitrate, phosphate, ammonia) were also collected several times between storm events during baseflow conditions. Preliminary nutrient and pesticide data indicate that tile drains are the primary pathway into streams. Little interaction occurs between the ground water and surface water interface. Nitrate stable isotopes will enable us to determine the relative contribution of nitrate sources feeding in from the tile drains, into Leary-Weber Ditch and Sugar Creek.

  17. Nonpoint Source Pollution: Agriculture, Forestry, and Mining. Instructor Guide. Working for Clean Water: An Information Program for Advisory Groups.

    ERIC Educational Resources Information Center

    Buskirk, E. Drannon, Jr.

    Nonpoint sources of pollution have diffuse origins and are major contributors to water quality problems in both urban and rural areas. Addressed in this instructor's manual are the identification, assessment, and management of nonpoint source pollutants resulting from mining, agriculture, and forestry. The unit, part of the Working for Clean Water…

  18. Financing alternatives for agricultural nonpoint source pollution control programs. Final report

    SciTech Connect

    Braden, J.B.; Farnsworth, R.L.; Seitz, W.D.; Uchtmann, D.L.

    1988-10-01

    The study examines mechanisms for increasing state and local spending for abatement of nonpoint source pollution from agriculture. Emphasis is on the legal feasibility and economic consequences of various funding options. The state and local funding mechanisms considered include income or sales taxes, an income tax checkoff, property taxes, special property assessments, water taxes, recreation license fees or surcharges, recreational equipment and fuel excise taxes, recreational access fees, erosion taxes, and farm chemicals taxes. Rated most highly are: property taxes or special assessments and water taxes at the local level; and water taxes and increased recreation fees at the state level. These mechanisms have a clear connection to the objective of improved water quality, would yield substantial revenues, and would be easy to administer. The remaining funding mechanisms would be too difficult to administer or have limited revenue potential.

  19. Impacts of input parameter spatial aggregation on an agricultural nonpoint source pollution model

    NASA Astrophysics Data System (ADS)

    FitzHugh, T. W.; Mackay, D. S.

    2000-09-01

    The accuracy of agricultural nonpoint source pollution models depends in part on how well model input parameters describe the relevant characteristics of the watershed. The spatial extent of input parameter aggregation has previously been shown to have a substantial impact on model output. This study investigates this problem using the Soil and Water Assessment Tool (SWAT), a distributed-parameter agricultural nonpoint source pollution model. The primary question addressed here is: how does the size or number of subwatersheds used to partition the watershed affect model output, and what are the processes responsible for model behavior? SWAT was run on the Pheasant Branch watershed in Dane County, WI, using eight watershed delineations, each with a different number of subwatersheds. Model runs were conducted for the period 1990-1996. Streamflow and outlet sediment predictions were not seriously affected by changes in subwatershed size. The lack of change in outlet sediment is due to the transport-limited nature of the Pheasant Branch watershed and the stable transport capacity of the lower part of the channel network. This research identifies the importance of channel parameters in determining the behavior of SWAT's outlet sediment predictions. Sediment generation estimates do change substantially, dropping by 44% between the coarsest and the finest watershed delineations. This change is primarily due to the sensitivity of the runoff term in the Modified Universal Soil Loss Equation to the area of hydrologic response units (HRUs). This sensitivity likely occurs because SWAT was implemented in this study with a very detailed set of HRUs. In order to provide some insight on the scaling behavior of the model two indexes were derived using the mathematics of the model. The indexes predicted SWAT scaling behavior from the data inputs without a need for running the model. Such indexes could be useful for model users by providing a direct way to evaluate alternative models

  20. Source and transport factors influencing storm phosphorus losses in agricultural catchments

    NASA Astrophysics Data System (ADS)

    Shore, Mairead; Jordan, Phil; Mellander, Per-Erik; kelly-quinn, Mary; Wall, David; Murphy, Paul; Melland, Alice

    2014-05-01

    The relative risk of diffuse phosphorus (P) loss from agricultural land was assessed in a well-drained arable catchment and a poorly-drained grassland catchment and in two nested basins within each catchment. This research investigated the relative control of hydrology and soil P on P losses between basins. Quick flow (QF) P losses (defined here as both concentrations and loads), monitored in stream flow during four storm events, were compared with a dynamic metric of transport risk (QF magnitude) and a static metric of critical source area (CSA) risk (extent of highly-connected poorly-drained soils with excess plant-available soil P). The potential for static transport metrics of soil connectivity and soil drainage class, to predict relative QF magnitudes and P losses between basins was also investigated. In basins with similar CSA risk but with contrasting QF magnitudes, mean TRP (total molybdate-reactive P) losses were consistently higher in the basins which had the highest QF magnitudes. This suggests that basin hydrology, rather than hydrology of high-P soils only, determined relative TRP losses between hydrologically contrasting basins. Furthermore, static transport metrics of soil connectivity and soil drainage class reliably discerned relative QF magnitudes and TRP losses between these basins. However, for two of the storm events (both occurring during the hydrologically active season), PP (particulate P) concentrations were frequently higher in basins which had the lowest QF magnitudes and may be attributed to a higher proportion of bare soil in these basins at these times as a result of their predominantly arable nature. In basins with similar hydrology, relative TRP and PP losses did not reflect trends in CSA risk or QF magnitude. The dynamics of TRP and PP losses and QF magnitude between these basins varied across storms, thus could not be predicted using static metrics. Where differences in hydrological dynamics were large, storm TRP losses were well

  1. Nitrate behaviors and source apportionment in an aquatic system from a watershed with intensive agricultural activities.

    PubMed

    Lu, Lu; Cheng, Hongguang; Pu, Xiao; Liu, Xuelian; Cheng, Qianding

    2015-01-01

    Nitrate pollution in aquatic systems caused by intensive agricultural activities is a serious problem in the Sanjiang Plain. In this study, a dual isotope approach (δ(15)N-NO3(-) and δ(18)O-NO3(-)) was employed to identify potential nitrate sources (atmospheric deposition, AD; NO3(-) derived from soil organic matter nitrification, NS; NO3(-) derived from chemical fertilizer nitrification, NF; and manure and sewage, M&S) and transformation processes occurring in the Abujiao River watershed located in the Sanjiang Plain. The Bayesian model (stable isotope analysis in R, SIAR) was utilized to apportion the contribution of the potential sources. In this watershed, the nitrate concentrations in the surface water were low (mean ± SD = 1.15 ± 0.84 mg L(-1)), and were greatly influenced by precipitation and land use conditions during the two sampling periods (the high flow period, September; the low flow period, November). On the contrary, in the ground water, high NO3(-) concentrations were observed (7.84 ± 5.83 mg L(-1)) and no significant temporal variation in NO3(-) was found during the sampling periods. The sampled water δ(18)O-NO3(-) values suggest that the nitrification process was not the main N cycling process, because most of the measured δ(18)O-NO3(-) values were above the expected δ(18)O-NO3(-) from nitrification throughout the sampling periods. Both the chemical and isotopic characteristics indicated that the signs of de-nitrification were absent in the surface water. However, significant de-nitrification processes were observed in the ground water for all sample periods. Results from the SIAR model showed that source contributions differed significantly during the two sampling periods. During the high flow period, chemical fertilizers and soil N fertilizer equally contributed to the major sources of nitrate in the surface water. In contrast, manure and sewage sources dominated the source contribution during the low flow period (November). This study

  2. The Use of LiDAR Elevation Data and Satellite Imagery to Locate Critical Source Areas to Diffuse Pollution in Agricultural Watersheds

    NASA Astrophysics Data System (ADS)

    Drouin, Ariane; Michaud, Aubert; Thériault, Georges; Beaudin, Isabelle; Rodrigue, Jean-François; Denault, Jean-Thomas; Desjardins, Jacques; Côté, Noémi

    2013-04-01

    In Quebec / Canada, water quality improvement in rural areas greatly depends on the reduction of diffuse pollution. Indeed, point source pollution has been reduced significantly in Canada in recent years by creating circumscribed pits for manure and removing animals from stream. Diffuse pollution differs from point source pollution because it is spread over large areas. In agricultural areas, sediment loss by soil and riverbank erosion along with loss of nutrients (phosphorus, nitrogen, etc.) and pesticides from fields represent the main source of non-point source pollution. The factor mainly responsible for diffuse pollution in agricultural areas is surface runoff occurring in poorly drained areas in fields. The presence of these poorly drained areas is also one of the most limiting factors in crop productivity. Thus, a reconciliation of objectives at the farm (financial concern for farmers) and off-farm concerns (environmental concern) is possible. In short, drainage, runoff, erosion, water quality and crop production are all interconnected issues that need to be tackled together. Two complementary data sources are mainly used in the diagnosis of drainage, surface runoff and erosion : elevation data and multispectral satellite images. In this study of two watersheds located in Québec (Canada), LiDAR elevation data and satellite imagery (QuickBird, Spot and Landsat) were acquired. The studied territories have been partitioned in hydrologic response units (HRUs) according to sub-basins, soils, elevation (topographic index) and land use. These HRUs are afterwards used in a P index software (P-Edit) that calculates the quantities of sediments and phosphorus exported from each HRUs. These exports of sediments and phosphorus are validated with hydrometric and water quality data obtain in two sub-basins and are also compared to soil brightness index derived from multispectral images. This index is sensitive to soil moisture and thus highlights areas where the soil is

  3. Landscape planning for agricultural nonpoint source pollution reduction III: Assessing phosphorus and sediment reduction potential

    USGS Publications Warehouse

    Diebel, M.W.; Maxted, J.T.; Robertson, D.M.; Han, S.; Vander Zanden, M. J.

    2009-01-01

    Riparian buffers have the potential to improve stream water quality in agricultural landscapes. This potential may vary in response to landscape characteristics such as soils, topography, land use, and human activities, including legacies of historical land management. We built a predictive model to estimate the sediment and phosphorus load reduction that should be achievable following the implementation of riparian buffers; then we estimated load reduction potential for a set of 1598 watersheds (average 54 km2) in Wisconsin. Our results indicate that land cover is generally the most important driver of constituent loads in Wisconsin streams, but its influence varies among pollutants and according to the scale at which it is measured. Physiographic (drainage density) variation also influenced sediment and phosphorus loads. The effect of historical land use on present-day channel erosion and variation in soil texture are the most important sources of phosphorus and sediment that riparian buffers cannot attenuate. However, in most watersheds, a large proportion (approximately 70%) of these pollutants can be eliminated from streams with buffers. Cumulative frequency distributions of load reduction potential indicate that targeting pollution reduction in the highest 10% of Wisconsin watersheds would reduce total phosphorus and sediment loads in the entire state by approximately 20%. These results support our approach of geographically targeting nonpoint source pollution reduction at multiple scales, including the watershed scale. ?? 2008 Springer Science+Business Media, LLC.

  4. Modeling of land use and reservoir effects on nonpoint source pollution in a highly agricultural basin

    USGS Publications Warehouse

    Wu, Yiping; Liu, Shu-Guang

    2012-01-01

    Nonpoint source (NPS) pollution is tightly linked to land use activities that determine the sources and magnitudes of pollutant loadings to stream water. The pollutant loads may also be alleviated within reservoirs because of the physical interception resulting from changed hydrological regimes and other biochemical processes. It is important but challenging to assess the NPS pollution processes with human effects due to the measurement limitations. The objective of this study is to evaluate the effects of human activities such as land uses and reservoir operation on the hydrological and NPS pollution processes in a highly agricultural area-the Iowa River Basin-using the Soil and Water Assessment Tool (SWAT). The evaluation of model performance at multiple sites reveals that SWAT can consistently simulate the daily streamflow, and monthly/annual sediment and nutrient loads (nitrate nitrogen and mineral phosphorus) in the basin. We also used the calibrated model to estimate the trap efficiencies of sediment (~78%) and nutrients (~30%) in the Coralville Reservoir within the basin. These non-negligible effects emphasize the significance of incorporating the sediment and nutrient removal mechanisms into watershed system studies. The spatial quantification of the critical NPS pollution loads can help identify hot-spot areas that are likely locations for the best management practices.

  5. Landscape planning for agricultural nonpoint source pollution reduction III: assessing phosphorus and sediment reduction potential.

    PubMed

    Diebel, Matthew W; Maxted, Jeffrey T; Robertson, Dale M; Han, Seungbong; Vander Zanden, M Jake

    2009-01-01

    Riparian buffers have the potential to improve stream water quality in agricultural landscapes. This potential may vary in response to landscape characteristics such as soils, topography, land use, and human activities, including legacies of historical land management. We built a predictive model to estimate the sediment and phosphorus load reduction that should be achievable following the implementation of riparian buffers; then we estimated load reduction potential for a set of 1598 watersheds (average 54 km(2)) in Wisconsin. Our results indicate that land cover is generally the most important driver of constituent loads in Wisconsin streams, but its influence varies among pollutants and according to the scale at which it is measured. Physiographic (drainage density) variation also influenced sediment and phosphorus loads. The effect of historical land use on present-day channel erosion and variation in soil texture are the most important sources of phosphorus and sediment that riparian buffers cannot attenuate. However, in most watersheds, a large proportion (approximately 70%) of these pollutants can be eliminated from streams with buffers. Cumulative frequency distributions of load reduction potential indicate that targeting pollution reduction in the highest 10% of Wisconsin watersheds would reduce total phosphorus and sediment loads in the entire state by approximately 20%. These results support our approach of geographically targeting nonpoint source pollution reduction at multiple scales, including the watershed scale.

  6. Modeling of land use and reservoir effects on nonpoint source pollution in a highly agricultural basin.

    PubMed

    Wu, Yiping; Liu, Shuguang

    2012-09-01

    Nonpoint source (NPS) pollution is tightly linked to land use activities that determine the sources and magnitudes of pollutant loadings to stream water. The pollutant loads may also be alleviated within reservoirs because of the physical interception resulting from changed hydrological regimes and other biochemical processes. It is important but challenging to assess the NPS pollution processes with human effects due to the measurement limitations. The objective of this study is to evaluate the effects of human activities such as land uses and reservoir operation on the hydrological and NPS pollution processes in a highly agricultural area-the Iowa River Basin-using the Soil and Water Assessment Tool (SWAT). The evaluation of model performance at multiple sites reveals that SWAT can consistently simulate the daily streamflow, and monthly/annual sediment and nutrient loads (nitrate nitrogen and mineral phosphorus) in the basin. We also used the calibrated model to estimate the trap efficiencies of sediment (∼78%) and nutrients (∼30%) in the Coralville Reservoir within the basin. These non-negligible effects emphasize the significance of incorporating the sediment and nutrient removal mechanisms into watershed system studies. The spatial quantification of the critical NPS pollution loads can help identify hot-spot areas that are likely locations for the best management practices.

  7. Modeling of land use and reservoir effects on nonpoint source pollution in a highly agricultural basin.

    PubMed

    Wu, Yiping; Liu, Shuguang

    2012-09-01

    Nonpoint source (NPS) pollution is tightly linked to land use activities that determine the sources and magnitudes of pollutant loadings to stream water. The pollutant loads may also be alleviated within reservoirs because of the physical interception resulting from changed hydrological regimes and other biochemical processes. It is important but challenging to assess the NPS pollution processes with human effects due to the measurement limitations. The objective of this study is to evaluate the effects of human activities such as land uses and reservoir operation on the hydrological and NPS pollution processes in a highly agricultural area-the Iowa River Basin-using the Soil and Water Assessment Tool (SWAT). The evaluation of model performance at multiple sites reveals that SWAT can consistently simulate the daily streamflow, and monthly/annual sediment and nutrient loads (nitrate nitrogen and mineral phosphorus) in the basin. We also used the calibrated model to estimate the trap efficiencies of sediment (∼78%) and nutrients (∼30%) in the Coralville Reservoir within the basin. These non-negligible effects emphasize the significance of incorporating the sediment and nutrient removal mechanisms into watershed system studies. The spatial quantification of the critical NPS pollution loads can help identify hot-spot areas that are likely locations for the best management practices. PMID:22790209

  8. Watershed Management Tool for Selection and Spacial Allocation of Non-Point Source Pollution Control Practices

    EPA Science Inventory

    Distributed-parameter watershed models are often utilized for evaluating the effectiveness of sediment and nutrient abatement strategies through the traditional {calibrate→ validate→ predict} approach. The applicability of the method is limited due to modeling approximations. In ...

  9. A Tale of Three Watersheds: Non-point Source Pollution and Conservation Practices Across Iowa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research was conducted as part of a Conservation Effects Assessment Project (CEAP) - Watershed Assessment Study supported by USDA-CSREES. The objectives of the project are to evaluate the effects of watershed conservation practices on water quality, with a focus on understanding how the suite o...

  10. [Adsorbed non-point source pollution load of Jialing River basin].

    PubMed

    Long, Tian-Yu; Li, Ji-Cheng; Liu, La-Mei

    2008-07-01

    Based on the American Universal Soil Loss Equation, focused on the two main factors that are hydrology condition and land management practice which can influence the soil loss in the watershed change yearly, and took into account the sediment transport process which can effect the soil loss differ spatially, a new sediment load evaluation method was put forward which can reflect the yearly change process of soil loss. Took Jialing River basin as a research example and validated the new evaluation method. Furthermore, according to the correlation between the sediment load and adsorbed nitrogen and phosphorus pollution load, established a yearly load evaluation model of the adsorbed nitrogen and phosphorus pollution. By virtue of the geographical information technology, the yearly load and spatial distribution of the adsorbed nitrogen and phosphorus pollution due to soil erosion in the Jialing River basin from 1990 to 2005 have been studied by the established model. The results show that adsorbed phase of nitrogen and phosphorus pollution are quite seriously in the subbasin of Bailong River and Xihanshui River. In recent years, adsorbed nitrogen and phosphorus pollution loads have declined year by year because of the conservation practices of soil and water in this basin. The average loads of adsorbed nitrogen and phosphorus pollution are 34 423 t/a and 1 848 t/a respectively in the past five years, which have reduced by about 60% from 1990.

  11. A Description and Source Listing of Curriculum Materials in Agricultural Education, 1969-1970.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Agricultural Education Div.

    The purpose of this annotated bibliography is to provide teachers of vocational agriculture, agricultural supervisors, and agricultural teacher educators with information on current curriculum materials available to them. Classified according to the AGDEX filing system, the 163 references are grouped under the headings: (1) Field Crops, (2)…

  12. A Description and Source Listing of Curriculum Materials in Agricultural Education. 1972-73.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Agricultural Education Div.

    Listed are 246 curriculum material items in ten categories: field crops, horticulture, forestry, animal science, soils, diseases and pests, agricultural engineering, agricultural economics, agricultural occupations, and professional. Most materials are annotated and all are classified according to the AGPEX filing system. Bibliographic and…

  13. A Description and Source Listing of Curriculum Materials in Agricultural Education, 1970-1971.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Agricultural Education Div.

    To provide teachers of vocational agriculture, agricultural supervisors, and agricultural teacher educators with information on current curriculum materials available to them, this annotated bibliography presents 207 references classified according to the AGDEX filing system. Topics are: (1) Field Crops, (2) Horticulture, (3) Forestry, (4) Animal…

  14. Contribution of base flow to nonpoint source pollution loads in an agricultural watershed

    USGS Publications Warehouse

    Schilling, K.E.; Wolter, C.F.

    2001-01-01

    Nonpoint source pollution of surface water from overland flow, drainage tiles, and ground water discharge is a major cause of water quality impairment in Iowa. Nonpoint source pollution from base flow ground water was estimated in the Walnut Creek watershed by measuring chemical loads of atrazine, nitrate, chloride, and sulfate at 18 tributary creeks and 19 tiles. Loads were measured during a stable base flow period at creeks and files that discharged into Walnut Creek between two stream gauges. Chemical concentrations of atrazine (< 0.1-12 ??g/L), nitrate (0.1 to 15 mg/L, and chloride (1.5 to 26 mg/L) in water were similar for creek and tile samples. Water draining predominantly agricultural row crop areas had much higher concentrations than water draining restored prairie areas. Three methods were used to estimate base flow discharge in the watershed: (1) Darcy flux; (2) watershed discharge budget; and (3) discharge-drainage area; each yielded similar results (31.2 L/s to 62.3 L/s). Base flow loads to the main channel were estimated by subtracting the loads from the upstream gauge; creeks and tiles, from the total load measured at the downstream gauge station. Base flow concentration for atrazine ranged from 0.15 to 0.29 ??g/L and sulfate concentration ranged from 32 to 64 mg/L, whereas concentrations for nitrate and chloride were negative (-1 to -4 mg/L). Calculated base flow concentrations of atrazine and sulfate appeared to be reasonable estimates, but negative concentrations of nitrate and chloride imply either loss of chemical mass in the stream from upstream to downstream sampling points or measurement error. Load data suggest little contribution from base flow pollutants to Walnut Creek water quality, with most of the pollutant load derived from major tributary creeks. Results from this study have implications for determining total maximum daily loads in agricultural watersheds where contributions from point sources (creeks and tiles) can he used to

  15. Application of Potential Non-Point Pollution Index For An Urban Watershed: Istanbul, Kucukcekmece Lagoon

    NASA Astrophysics Data System (ADS)

    Musaoglu, N.; Dikerler, T.; Seker, D. Z.; Ustun, B.

    2011-12-01

    Istanbul is a major city with more than 15 million population and limited water resources. Besides, its urbanized area has been rapidly expanding for more than 30 years. Küçükçekmece Lagoon, as a potential RAMSAR site with its rich natural diversity and housing asset for birds, has been suffering from urbanization and industrial stress. With Sazlidere Dam constructed on the Lagoon's most important creek which supplies fresh water, Küçükçekmece Basin has almost 600 km2 wide area. Due to dam operation which cuts fresh water input down, water quality of the Küçükçekmece Lagoon has been deteriorating, as well as other antropogenic impacts. Potential non-point pollution index (or PNPI) is based on land use, soil and topographic data and aims to highlight the potentially polluting areas in a watershed. Denoting those areas, PNPI puts an assessment of the pressure exerted on the water bodies by different land uses. This index calculates different layers in order to represent run-off, land cover effect, and the distance of each polluting source (or pixels) in the study area. By the multiplication of those layers under GIS, a new data layer is produced showing the polluting potential of each pixel on the study area. For by Küçükçekmece Basin, Landsat ETM satellite images have been taken and its land use produced by unsupervised classification. Using this updated data, land use - land cover indicator has been calculated for the basin. Topography is another fact that is needed to produce both run-off indicator and distance indicator and it is generated by elevation data with 5m resolution. By integrating these indicator layers, PNPI analysis layer has been produced for Küçükçekmece Lagoon watershed.

  16. Nonpoint-source agricultural hazard index: a case study of the province of cremona, Italy.

    PubMed

    Trevisan, M; Padovani, L; Capri, E

    2000-11-01

    This paper reports the results of a study aimed at the evaluation of the hazard level of farming activities in the province of Cremona, Italy, with particular reference to groundwater. The applied methodology employs a parametric approach based on the definition of potential hazard indexes (nonpoint-source agricultural hazard indexes, NPSAHI). Two categories of parameters were considered: the hazard factors (HF), which represent all farming activities that cause or might cause an impact on groundwater (use of fertilizers and pesticides, application of livestock and poultry manure, food industry wastewater, and urban sludge), and the control factors (CF), which adapt the hazard factor to the characteristics of the site (geographical location, slope, agronomic practices, and type of irrigation). The hazard index (HI) can be calculated multiplying the hazard factors by the control factors and, finally, the NPSAHI are obtained dividing HI into classes on a percentile basis using a scale ranging from 1 to 10. Organization, processing, and display of all data layers were performed using the geographical information system (GIS) ArcView and its Spatial Analyst extension. Results show that the potential hazard of groundwater pollution by farming activities in the province of Cremona falls mainly in the fifth class (very low hazard).

  17. Unaccounted variability in NH3 agricultural sources detected by IASI contributing to European spring haze episode

    NASA Astrophysics Data System (ADS)

    Fortems-Cheiney, A.; Dufour, G.; Hamaoui-Laguel, L.; Foret, G.; Siour, G.; Van Damme, M.; Meleux, F.; Coheur, P.-F.; Clerbaux, C.; Clarisse, L.; Favez, O.; Wallasch, M.; Beekmann, M.

    2016-05-01

    Ammonia (NH3), whose main source in the troposphere is agriculture, is an important gaseous precursor of atmospheric particulate matter (PM). We derived daily ammonia emissions using NH3 total columns measured from the Infrared Atmospheric Sounding Interferometer (IASI) on board Metop-A, at a relatively high spatial resolution (grid cell of 0.5° × 0.5°). During the European spring haze episodes of 24-31 March 2012 and 8-15 March 2014, IASI reveals NH3 total column magnitudes highlighting higher NH3 emissions over central Europe (especially over Germany, Czech Republic, and eastern France) from the ones provided by the European reference European Monitoring and Evaluation Programme inventory. These ammonia emissions exhibit in addition a large day-to-day variability, certainly due to spreading practices. The increase of NH3 emissions in the model, that reaches +300% locally, leads to an increase of both NH3 and PM2.5 surface concentrations and allows for a better comparison with independent measurements (in terms of bias, root-mean-square error, and correlation). This study suggests that there are good prospects for better quantifying NH3 emissions by atmospheric inversions.

  18. Developing unique tracers to distinguish nutrient contributions from agriculture and wastewater sources in the Choptank River and Anacostia River watersheds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eutrophication is a major problem for the Chesapeake Bay ecosystem. The efficacy of the restoration efforts implemented is restricted by the inability to differentiate nutrient sources. This study assessed the use of stable tracers in order to discriminate between urban and agricultural nutrient sou...

  19. Studies by the U.S. Geological Survey on sources, transport, and fate of agricultural chemicals

    USGS Publications Warehouse

    Capel, Paul D.; Hamilton, Pixie A.; Erwin, Martha L.

    2004-01-01

    Information from these studies will help with decision-making related to chemical use, conservation, and other farming practices that are used to reduce runoff of agricultural chemicals and sediment from fields. This information also will benefit the U.S. Environmental Protection Agency, the Department of Agriculture, local and regional water managers, and agricultural chemical manufacturers who are involved in managing chemical use and pesticide registration.

  20. Re-examining the basis for source discrimination and data corrections used by sediment fingerprinting studies in agricultural catchments

    NASA Astrophysics Data System (ADS)

    Smith, Hugh; Blake, Will

    2014-05-01

    The sediment fingerprinting technique has been widely used in agricultural catchments to quantify fine sediment contributions from various land use sources. This application of the technique depends on the key assumption that land-use source signatures imprinted on catchment soils are decipherable from those due to other landscape factors affecting soil and sediment properties. We re-examine this key assumption by investigating (i) the physical and chemical basis for source discrimination and (ii) potential factors that may confound source un-mixing in agricultural catchments, including particle size and organic matter effects on tracer properties. The study is situated in the River Tamar, a predominantly agricultural catchment in south-west England that has also been affected by mining. Source discrimination focused on pasture and cultivated land uses and channel banks. Monthly, time-integrated suspended sediment samples were collected across seven catchments for a 12-month period. Physical and chemical properties measured in source soils and sediment included fallout radionuclides, major and minor element geochemical constituents, total organic carbon and particle size. Source discrimination was entirely dependent on differences in tracer property concentrations between surface and sub-surface soils. This is based on fallout radionuclide concentrations that are surface-elevated, while many geochemical properties are surface-depleted due to weathering and pedogenetic effects, although surface soil contamination can reverse this trend. Source discrimination in the study catchments was limited by (i) rotation of cultivated and pasture fields resulting in reduced differences between these two sources and (ii) the cultivated source signature resembling a mix of the pasture and channel bank sources for many tracer properties. Furthermore, metal pollution from abandoned historic mines and organic enrichment of sediment from areas of peaty soil resulted in the non

  1. Quantifying sediment sources in a lowland agricultural catchment pond using (137)Cs activities and radiogenic (87)Sr/(86)Sr ratios.

    PubMed

    Le Gall, Marion; Evrard, Olivier; Foucher, Anthony; Laceby, J Patrick; Salvador-Blanes, Sébastien; Thil, François; Dapoigny, Arnaud; Lefèvre, Irène; Cerdan, Olivier; Ayrault, Sophie

    2016-10-01

    Soil erosion often supplies high sediment loads to rivers, degrading water quality and contributing to the siltation of reservoirs and lowland river channels. These impacts are exacerbated in agricultural catchments where modifications in land management and agricultural practices were shown to accelerate sediment supply. In this study, sediment sources were identified with a novel tracing approach combining cesium ((137)Cs) and strontium isotopes ((87)Sr/(86)Sr) in the Louroux pond, at the outlet of a lowland cultivated catchment (24km(2), Loire River basin, France) representative of drained agricultural areas of Northwestern Europe. Surface soil (n=36) and subsurface channel bank (n=17) samples were collected to characterize potential sources. Deposited sediment (n=41) was sampled across the entire surface of the pond to examine spatial variation in sediment deposits. In addition, a 1.10m sediment core was sampled in the middle of the pond to reconstruct source variations throughout time. (137)Cs was used to discriminate between surface and subsurface sources, whereas (87)Sr/(86)Sr ratios discriminated between lithological sources. A distribution modeling approach quantified the relative contribution of these sources to the sampled sediment. Results indicate that surface sources contributed to the majority of pond (μ 82%, σ 1%) and core (μ 88%, σ 2%) sediment with elevated subsurface contributions modeled near specific sites close to the banks of the Louroux pond. Contributions of the lithological sources were well mixed in surface sediment across the pond (i.e., carbonate sediment contribution, μ 48%, σ 1% and non-carbonate sediment contribution, μ 52%, σ 3%) although there were significant variations of these source contributions modeled for the sediment core between 1955 and 2013. These fluctuations reflect both the progressive implementation of land consolidation schemes in the catchment and the eutrophication of the pond. This original sediment

  2. Quantifying sediment sources in a lowland agricultural catchment pond using (137)Cs activities and radiogenic (87)Sr/(86)Sr ratios.

    PubMed

    Le Gall, Marion; Evrard, Olivier; Foucher, Anthony; Laceby, J Patrick; Salvador-Blanes, Sébastien; Thil, François; Dapoigny, Arnaud; Lefèvre, Irène; Cerdan, Olivier; Ayrault, Sophie

    2016-10-01

    Soil erosion often supplies high sediment loads to rivers, degrading water quality and contributing to the siltation of reservoirs and lowland river channels. These impacts are exacerbated in agricultural catchments where modifications in land management and agricultural practices were shown to accelerate sediment supply. In this study, sediment sources were identified with a novel tracing approach combining cesium ((137)Cs) and strontium isotopes ((87)Sr/(86)Sr) in the Louroux pond, at the outlet of a lowland cultivated catchment (24km(2), Loire River basin, France) representative of drained agricultural areas of Northwestern Europe. Surface soil (n=36) and subsurface channel bank (n=17) samples were collected to characterize potential sources. Deposited sediment (n=41) was sampled across the entire surface of the pond to examine spatial variation in sediment deposits. In addition, a 1.10m sediment core was sampled in the middle of the pond to reconstruct source variations throughout time. (137)Cs was used to discriminate between surface and subsurface sources, whereas (87)Sr/(86)Sr ratios discriminated between lithological sources. A distribution modeling approach quantified the relative contribution of these sources to the sampled sediment. Results indicate that surface sources contributed to the majority of pond (μ 82%, σ 1%) and core (μ 88%, σ 2%) sediment with elevated subsurface contributions modeled near specific sites close to the banks of the Louroux pond. Contributions of the lithological sources were well mixed in surface sediment across the pond (i.e., carbonate sediment contribution, μ 48%, σ 1% and non-carbonate sediment contribution, μ 52%, σ 3%) although there were significant variations of these source contributions modeled for the sediment core between 1955 and 2013. These fluctuations reflect both the progressive implementation of land consolidation schemes in the catchment and the eutrophication of the pond. This original sediment

  3. PROFILE: Comparative Analysis of New Zealand and US Approaches for Agricultural Nonpoint Source Pollution Management.

    PubMed

    Caruso

    2000-01-01

    / Nonpoint source (NPS) pollution from widespread agricultural/pastoral land use in New Zealand can result in receiving water quality problems, but the Resource Management Act of 1991 requires the sustainable management of land and water resources. Many similar types of problems occur in the United States, where the Clean Water Act is the primary legislation addressing NPS pollution and progress has been made on the development and use of a variety of management approaches. However, little evaluation and comparison of approaches or cooperation between the two countries has occurred in the past. This type of analysis could provide information that is useful for more effective management of the problem. The goal of this study is to evaluate and compare approaches used in New Zealand and the United States for management of agricultural NPS pollution.The role of the central government in New Zealand is generally limited to research and policy development, and regional councils are responsible for most monitoring and management of the problem. The role of the federal government in the United States includes research and monitoring, policy development, and regulation. States also have a significant management role. Both countries rely on voluntary approaches for NPS pollution management. Very few national water quality standards exist in New Zealand, whereas standards are widely used in the United States. Loading estimates and modeling are often used in the United States, but not in New Zealand. A wide range of best management practices (BMPs) are used in the United States, including buffer strips and constructed/engineered wetlands. Buffer strips and riparian management have been emphasized and used widely in New Zealand.Many approaches are common to both countries, but management of the problem has only been partly successful. The primary barriers are the inadequacy of the voluntary approach and the lack of scientific tools that are useful to decision-makers. More work

  4. Characterizing the ozone formation potential of agricultural sources in California's San Joaquin Valley: A computational and experimental approach

    NASA Astrophysics Data System (ADS)

    Howard, Cody Jerome

    The global pattern of expanding urban centers and increasing agricultural intensity is leading to more frequent interactions between air pollution emissions from urban and agricultural sources. The confluence of these emissions that traditionally have been separated by hundreds of kilometers is creating new air quality challenges in numerous regions across the United States. An area of particular interest is California's San Joaquin Valley (SJV), which has an agricultural output higher than many countries, a rapidly expanding human population, and ozone concentrations that are already higher than many dense urban areas. New regulations in the SJV restrict emissions of reactive organic gases (ROG) from animal sources in an attempt to meet Federal and State ozone standards designed to protect human health. A transportable "smog" chamber was developed and tested to directly measure the ozone formation potential of a variety of agricultural emissions in representative urban and rural atmospheres. After validation of the experimental procedure, four animal types were examined: beef cattle, dairy cattle, swine, and poultry, as well as six commonly used animal feeds: cereal silage (wheat grain and oat grain), alfalfa silage, corn silage, high moisture ground corn, almond shells, almond hulls, and total mixed ration. The emitted ROG composition was also measured so that the theoretical incremental reactivity could be calculated for a variety of atmospheres and directly compared with the measured ozone formation potential (OFP) under the experimental conditions. A computational model was created based on a modified form of the Caltech Atmospheric Chemistry Mechanism and validated against experimental results. After validation, the computational model was used to predict OFP across a range of NOx and ROG concentrations. The ROG OFP measurements combined with adjusted agricultural ROG emissions inventory estimates were used to predict the actual ozone production in the SJV

  5. Sulphate leaching from diffuse agricultural and forest sources in a large central European catchment during 1900-2010.

    PubMed

    Kopáček, Jiří; Hejzlar, Josef; Porcal, Petr; Posch, Maximilian

    2014-02-01

    Using dynamic, mass budget, and empirical models, we quantified sulphate-sulphur (SO4-S) leaching from soils in a large central European catchment (upper Vltava river, Czech Republic) over a 110-year period (1900-2010). SO4-S inputs to soils with synthetic fertilisers and atmospheric deposition increased in the 1950s-1980s, then rapidly decreased (~80%), and remained low since the middle 1990s. The proportion of drained agricultural land rapidly increased from 4 to 43% between the 1950s and 1990s; then the draining ability of the system slowly decreased due to its ageing. Sulphate concentrations in the Vltava exhibited similar trends as the external SO4-S inputs, suggesting that they could be explained by changes in atmospheric and fertiliser S inputs. The available data and modelling, however, showed that (i) internal SO4-S sources (mineralization of soil organic S in the drained agricultural land), (ii) a hysteresis in SO4-S leaching from forest soils (a net S retention at the high S inputs and then a net release at the lowered inputs), and (iii) hydrology must be taken into account. An empirical model was then employed, based on parameters representing hydrology (discharge), external SO4-S sources (inputs by synthetic fertilisers and atmospheric deposition), and internal SO4-S sources (mineralization related to soil drainage). The model explained 84% of the observed variability in annual SO4-S concentrations in the Vltava river during 1900-2010 and showed that forest soils were a net sink (105 kg ha(-1)) while agricultural land was a net source (55 kg ha(-1)) of SO4-S during 1960-2010. In the late 1980s, forest soils changed from a sink to a source of S, and the present release of SO4-S accumulated in forest soils thus delays recovery of surface waters from acidification, while S losses from agricultural soils increase the risk of future S deficiency in S-demanding crops.

  6. Nitrate-nitrogen and oxygen isotope ratios for identification of nitrate sources and dominant nitrogen cycle processes in a tile-drained dryland agricultural field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural systems are a leading source of reactive nitrogen to aquatic and atmospheric ecosystems. Natural d15Nnitrate and d18Onitrate are used to identify the dominant nitrogen cycle processes and sources of NO3- leached from a tile-drained, dryland agricultural field. Tile-drain water discharge...

  7. PROBABILISTIC ASSESSMENT OF GROUNDWATER VULNERABILITY TO NONPOINT SOURCE POLLUTION IN AGRICULTURAL WATERSHEDS

    EPA Science Inventory

    This paper presents a probabilistic framework for the assessment of groundwater pollution potential by pesticides in two adjacent agricultural watersheds in the Mid-Altantic Coastal Plain. Indices for estimating streams vulnerability to pollutants' load from the surficial aquifer...

  8. National, holistic, watershed-scale approach to understand the sources, transport, and fate of agricultural chemicals

    USGS Publications Warehouse

    Capel, P.D.; McCarthy, K.A.; Barbash, J.E.

    2008-01-01

    This paper is an introduction to the following series of papers that report on in-depth investigations that have been conducted at five agricultural study areas across the United States in order to gain insights into how environmental processes and agricultural practices interact to determine the transport and fate of agricultural chemicals in the environment. These are the first study areas in an ongoing national study. The study areas were selected, based on the combination of cropping patterns and hydrologic setting, as representative of nationally important agricultural settings to form a basis for extrapolation to unstudied areas. The holistic, watershed-scale study design that involves multiple environmental compartments and that employs both field observations and simulation modeling is presented. This paper introduces the overall study design and presents an overview of the hydrology of the five study areas. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  9. Concentrations, distribution, sources, and ecological risk assessment of heavy metals in agricultural topsoil of the Three Gorges Dam region, China.

    PubMed

    Liu, Minxia; Yang, Yuyi; Yun, Xiaoyan; Zhang, Miaomiao; Wang, Jun

    2015-03-01

    Concentrations, distribution, sources, and ecological risk of seven heavy metals including chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), and mercury (Hg) in agricultural topsoil samples of the Three Gorges Dam region, China were investigated in this study. Among seven heavy metals, Zn had the highest mean concentration (149 mg kg(-1)) in the agricultural topsoil, followed by Cr (66 mg kg(-1)), Cu (52.2 mg kg(-1)), Pb (13.0 mg kg(-1)), Ni (8.5 mg kg(-1)), Cd (0.29 mg kg(-1)), and Hg (0.08 mg kg(-1)). Enrichment factor (EF) values of Zn, Cu, Cd, and Hg were higher than 1.5, indicating that Zn, Cu, Cd, and Hg were the major pollutants in this study area. The average potential ecological risk index (RI) value was 147, suggesting that heavy metals in the agricultural topsoil in the study area had a low ecological risk. The result of factor analysis (FA) and correlation analysis showed that long-term use of chemical fertilizer and pesticides, natural rock weathering, and atmospheric deposition were the several main sources of seven heavy metals in agricultural topsoil of the Three Gorges Dam region. Factor analysis-multiple linear regression (FA-MLR) results indicated that the most important source in this area was long-term use of chemical fertilizer and pesticides, which contributed 70 % for Cu and Zn, 62 % for Cd, and 72 % for Hg. More attention must be paid to the extensive use of chemical fertilizers and pesticides containing heavy metals which have been accumulated in the agricultural soil. PMID:25716527

  10. Concentrations, distribution, sources, and ecological risk assessment of heavy metals in agricultural topsoil of the Three Gorges Dam region, China.

    PubMed

    Liu, Minxia; Yang, Yuyi; Yun, Xiaoyan; Zhang, Miaomiao; Wang, Jun

    2015-03-01

    Concentrations, distribution, sources, and ecological risk of seven heavy metals including chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), and mercury (Hg) in agricultural topsoil samples of the Three Gorges Dam region, China were investigated in this study. Among seven heavy metals, Zn had the highest mean concentration (149 mg kg(-1)) in the agricultural topsoil, followed by Cr (66 mg kg(-1)), Cu (52.2 mg kg(-1)), Pb (13.0 mg kg(-1)), Ni (8.5 mg kg(-1)), Cd (0.29 mg kg(-1)), and Hg (0.08 mg kg(-1)). Enrichment factor (EF) values of Zn, Cu, Cd, and Hg were higher than 1.5, indicating that Zn, Cu, Cd, and Hg were the major pollutants in this study area. The average potential ecological risk index (RI) value was 147, suggesting that heavy metals in the agricultural topsoil in the study area had a low ecological risk. The result of factor analysis (FA) and correlation analysis showed that long-term use of chemical fertilizer and pesticides, natural rock weathering, and atmospheric deposition were the several main sources of seven heavy metals in agricultural topsoil of the Three Gorges Dam region. Factor analysis-multiple linear regression (FA-MLR) results indicated that the most important source in this area was long-term use of chemical fertilizer and pesticides, which contributed 70 % for Cu and Zn, 62 % for Cd, and 72 % for Hg. More attention must be paid to the extensive use of chemical fertilizers and pesticides containing heavy metals which have been accumulated in the agricultural soil.

  11. Severe situation of rural nonpoint source pollution and efficient utilization of agricultural wastes in the Three Gorges Reservoir Area.

    PubMed

    Zhang, Tong; Ni, Jiupai; Xie, Deti

    2015-11-01

    Rural nonpoint source (NPS) pollution caused by agricultural wastes has become increasingly serious in the Three Gorges Reservoir Area (TGRA), significantly affecting the reservoir water quality. The grim situation of rural NPS pollution in the TGRA indicated that agrochemicals (chemical fertilizer and pesticide) were currently the highest contributor of rural NPS pollution (50.38%). The harmless disposal rates of livestock excrement, crop straws, rural domestic refuse, and sewage also cause severe water pollution. More importantly, the backward agricultural economy and the poor environmental awareness of farmers in the hinterland of the TGRA contribute to high levels of rural NPS pollution. Over the past decade, researchers and the local people have carried out various successful studies and practices to realize the effective control of rural NPS pollution by efficiently utilizing agricultural wastes in the TGRA, including agricultural waste biogas-oriented utilization, crop straw gasification, decentralized land treatment of livestock excrement technology, and crop straw modification. These technologies have greatly increased the renewable resource utilization of agricultural wastes and improved water quality and ecological environment in the TGRA. PMID:26392092

  12. Severe situation of rural nonpoint source pollution and efficient utilization of agricultural wastes in the Three Gorges Reservoir Area.

    PubMed

    Zhang, Tong; Ni, Jiupai; Xie, Deti

    2015-11-01

    Rural nonpoint source (NPS) pollution caused by agricultural wastes has become increasingly serious in the Three Gorges Reservoir Area (TGRA), significantly affecting the reservoir water quality. The grim situation of rural NPS pollution in the TGRA indicated that agrochemicals (chemical fertilizer and pesticide) were currently the highest contributor of rural NPS pollution (50.38%). The harmless disposal rates of livestock excrement, crop straws, rural domestic refuse, and sewage also cause severe water pollution. More importantly, the backward agricultural economy and the poor environmental awareness of farmers in the hinterland of the TGRA contribute to high levels of rural NPS pollution. Over the past decade, researchers and the local people have carried out various successful studies and practices to realize the effective control of rural NPS pollution by efficiently utilizing agricultural wastes in the TGRA, including agricultural waste biogas-oriented utilization, crop straw gasification, decentralized land treatment of livestock excrement technology, and crop straw modification. These technologies have greatly increased the renewable resource utilization of agricultural wastes and improved water quality and ecological environment in the TGRA.

  13. Characteristic and potential sources of polychlorinated dibenzo-P-dioxins and dibenzofurans in agricultural soils in Beijing, China.

    PubMed

    Li, Wei; Li, Chaoqin; Chen, Zuosheng; Cai, Zongwei

    2014-09-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in 25 background and 80 agricultural soil samples collected from 21 sites in Beijing, China. The levels of PCDD/Fs in the north agricultural soils were low (0.15-0.58 ng international toxic equivalent quantity [I-TEQ]/kg), which were comparable with those of the background soils (0.091-0.35 ng I-TEQ/kg). In the southern agricultural soils, however, concentrations were several times higher (0.27-3.3 ng I-TEQ/kg). Comparison of PCDD/Fs congener compositions between possible sources and samples indicated that agricultural soils in Beijing had not been contaminated by the 3 main PCDD/F contamination sources in China--ferrous and nonferrous metal, waste incineration, and power generation. They had, however, been slightly contaminated by the impurities of some organochlorine pesticides, such as sodium pentachlorophenate, and by open burning of biomass, vehicle exhaust, atmospheric deposition, sediment, and sewage sludge. These results have been supported by the principal components analysis.

  14. Agricultural sources of contaminants of emerging concern and adverse health effects on freshwater fish

    USGS Publications Warehouse

    Tillitt, Donald E.; Buxton, Herbert T.

    2011-01-01

    Agricultural contaminants of emerging concern (CECs) are generally thought of as certain classes of chemicals associated with animal feeding and production facilities. Veterinary pharmaceuticals used in animal food production systems represent one of the largest groups of CECs. In our review, we discuss the extensive increase in use of antibiotics in animal feeding operations (AFOs) around the world. AFOs are a major consumer of antibiotics and other veterinary pharmaceuticals and over the past decade there has been growing information on the occurrence, release, and fate of CECs from animal food production operations, including the application of pharmaceutical-containing manure to agricultural fields and releases from waste lagoons. Concentrations of CECs in surface and ground water in proximity to AFOs correspond to their presence in the AFO wastes. In many cases, the environmental concentrations of agriculturally-derived CECs are below toxicity thresholds. Hormones and hormone replacement compounds are a notable exception, where chemical concentrations near AFOs can exceed concentrations known to cause adverse effects on endocrine-related functions in fish. In addition, some agricultural pesticides, once thought to be safe to non-target organisms, have demonstrated endocrine-related effects that may pose threats to fish populations in agricultural regions. That is, we have pesticides with emerging concerns, thus, the concern is emerging and not necessarily the chemical. In this light, one must consider certain agricultural pesticides to be included in the list of CECs. Even though agricultural pesticides are routinely evaluated in regulatory testing schemes which have been used for decades, the potential hazards of some pesticides have only recently been emerging. Emerging concerns of pesticides in fish include interference with hormone signaling pathways; additive (or more than additive) effects from pesticide mixtures; and adverse population-level effects at

  15. Investigating the sources of sediment in a Canadian agricultural watershed using a colour-based fingerprinting technique

    NASA Astrophysics Data System (ADS)

    Barthod, Louise; Lobb, David; Owens, Philip; Martinez-Carreras, Nuria; Koiter, Alexander; Petticrew, Ellen; McCullough, Gregory

    2014-05-01

    The development of beneficial management practises to minimize adverse impacts of agriculture on soil and water quality requires information on the sources of sediment at the watershed scale. Sediment fingerprinting allows for the determination of sediment sources and apportionment of their contribution within a watershed, using unique physical, radiochemical or biogeochemical properties, or fingerprints, of the potential sediment sources. The use of sediment colour as a fingerprint is an emerging technique that can provide a rapid and inexpensive means of investigating sediment sources. This technique is currently being utilized to determine sediment sources within the South Tobacco Creek Watershed, an agricultural watershed located in the Canadian prairies (south-central Manitoba). Suspended sediment and potential source (topsoil, channel bank and shale bedrock material) samples were collected between 2009 and 2011 at six locations along the main stem of the creek. Sample colour was quantified from diffuse reflectance spectrometry measurements over the visible wavelength range using a spectroradiometer (ASD Field Spec Pro, 400-2500 nm). Sixteen colour coefficients were derived from several colour space models (CIE XYZ, CIE xyY, CIE Lab, CIE Luv, CIE Lch, Landsat RGB, Redness Index). The individual discrimination power of the colour coefficients, after passing several prerequisite tests (e.g., linearly additive behaviour), was assessed using discriminant function analysis. A stepwise discriminant analysis, based on the Wilk's lambda criterion, was then performed in order to determine the best-suited colour coefficient fingerprints which maximized the discrimination between the potential sources. The selected fingerprints classified the source samples in the correct category 86% of the time. The misclassification is due to intra-source variability and source overlap which can lead to higher uncertainty in sediment source apportionment. The selected fingerprints

  16. Agriculture: A source of raw materials for industrial purposes the French strategy

    SciTech Connect

    Mauguin, P.; Gaouyer, J.P.; Labrousse, S.

    1995-11-01

    Creating new value-added products from agricultural and forestry biomass can present opportunities for diversifying industry, preserving agricultural activities and reinvigorating exploitation of forests. Stimulating new markets for agriculture and forestry products is strategically important for France, in order to cushion the effects of the reform of the European Common Policy (CAP), while maintaining the commitments assessed at the Rio Coference. The promotion of new markets should constitute a major vector for rural development, by marking use of agricultural lands no longer needed for food crops due to the glut of foodstuffs on the market. In the next few years, energy uses of biomass should help hold down greenhouse gas emissions, by regulating and storing CO{sub 2}. For each of these markets, whether for energy uses (solid, liquid or gaseous fuels) or for other applications, the first priority is to match prices and specifications of the fossil fuels that are to be deplaced, with minimum impact on the environment. To match these goals, the French government has launched a new research group, Agriculture for Chemicals and Energy (AGRICE). AGRICE has been set up for a renewable five years period. Its members are: Agriculture, Industry, Research and Environment departments; the Institut National de la Recherche Agronomique (INRA), the Institut Francais due Petrole (IFP), the French Agency for Environment and Energy (Ademe); Wheat producers, Beet growers, and oil seed producers; and Rhone Poulenc (chemicals), TOTAL (oil company). In 1995, AGRICE will have a 40 Millions FFrancs from public funds, supplemented by 25 Millions FFrancs from business and trade groups.

  17. Sediment sources in a small agricultural catchment: A composite fingerprinting approach based on the selection of potential sources

    NASA Astrophysics Data System (ADS)

    Zhou, Huiping; Chang, Weina; Zhang, Longjiang

    2016-08-01

    Fingerprinting techniques have been widely used as a reasonable and reliable means for investigating sediment sources, especially in relatively large catchments in which there are significant differences in surface materials. However, the discrimination power of fingerprint properties for small catchments, in which the surface materials are relatively homogeneous and human interference is marked, may be affected by fragmentary or confused source information. Using fingerprinting techniques can be difficult, and there is still a need for further studies to verify the effectiveness of such techniques in these small catchments. A composite fingerprinting approach was used in this study to investigate the main sources of sediment output, as well as their relative contributions, from a small catchment (30 km2) with high levels of farming and mining activities. The impact of the selection of different potential sediment sources on the derivation of composite fingerprints and its discrimination power were also investigated by comparing the results from different combinations of potential source types. The initial source types and several samples that could cause confusion were adjusted. These adjustments improved the discrimination power of the composite fingerprints. The results showed that the composite fingerprinting approach used in this study had a discriminatory efficiency of 89.2% for different sediment sources and that the model had a mean goodness of fit of 0.90. Cultivated lands were the main sediment source. The sediment contribution of the studied cultivated lands ranged from 39.9% to 87.8%, with a mean of 76.6%, for multiple deposited sediment samples. The mean contribution of woodlands was 21.7%. Overall, the sediment contribution from mining and road areas was relatively low. The selection of potential sources is an important factor in the application of fingerprinting techniques and warrants more attention in future studies, as is the case with other

  18. A Description and Source Listing of Curriculum Materials in Agricultural Education, 1971-1972.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Agricultural Education Div.

    Members of the Curriculum Materials Committee collect materials available to them prior to each American Vocational Association Meeting. The resulting bibliography contains current, non-commercial materials developed by persons in vocational education in agriculture for use in that field, but of interest beyond the state in which it was developed.…

  19. A DESCRIPTION AND SOURCE LISTING OF PROFESSIONAL INFORMATION IN AGRICULTURAL EDUCATION, 1963-64.

    ERIC Educational Resources Information Center

    SLEDGE, GEORGE W.; AND OTHERS

    BRIEF ANNOTATIONS ARE GIVEN FOR MANY OF THE 107 REFERENCES LISTED UNDER THE FOLLOWING CATEGORIES -- (1) ADULT EDUCATION, (2) AGRICULTURAL ENGINEERING, (3) ANIMAL SCIENCE, (4) CURRICULUM DEVELOPMENT AND CURRICULUM IN CROPS, ENTOMOLOGY, FARM MANAGEMENT, FARM MECHANICS, AND LIVESTOCK, (5) FARM BUSINESS MANAGEMENT AND MARKETING, (6) FORESTRY, (7)…

  20. Using lidar to characterize particles from point and diffuse sources in an agricultural field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lidar (LIght Detection And Ranging) provides the means to quantitatively evaluate the spatial and temporal variability of particulate emissions from agricultural activities. Aglite is a three-wavelength portable scanning lidar system built at the Energy Dynamics Laboratory (EDL) to measure the spati...

  1. [Estimation of nonpoint source pollutant loads and optimization of the best management practices (BMPs) in the Zhangweinan River basin].

    PubMed

    Xu, Hua-Shan; Xu, Zong-Xue; Liu, Pin

    2013-03-01

    One of the key techniques in establishing and implementing TMDL (total maximum daily load) is to utilize hydrological model to quantify non-point source pollutant loads, establish BMPs scenarios, reduce non-point source pollutant loads. Non-point source pollutant loads under different years (wet, normal and dry year) were estimated by using SWAT model in the Zhangweinan River basin, spatial distribution characteristics of non-point source pollutant loads were analyzed on the basis of the simulation result. During wet years, total nitrogen (TN) and total phosphorus (TP) accounted for 0.07% and 27.24% of the total non-point source pollutant loads, respectively. Spatially, agricultural and residential land with steep slope are the regions that contribute more non-point source pollutant loads in the basin. Compared to non-point source pollutant loads with those during the baseline period, 47 BMPs scenarios were set to simulate the reduction efficiency of different BMPs scenarios for 5 kinds of pollutants (organic nitrogen, organic phosphorus, nitrate nitrogen, dissolved phosphorus and mineral phosphorus) in 8 prior controlled subbasins. Constructing vegetation type ditch was optimized as the best measure to reduce TN and TP by comparing cost-effective relationship among different BMPs scenarios, and the costs of unit pollutant reduction are 16.11-151.28 yuan x kg(-1) for TN, and 100-862.77 yuan x kg(-1) for TP, which is the most cost-effective measure among the 47 BMPs scenarios. The results could provide a scientific basis and technical support for environmental protection and sustainable utilization of water resources in the Zhangweinan River basin.

  2. Interactively Improving Agricultural Field Mapping in Sub-Saharan Africa with Crowd-Sourcing and Active Learning

    NASA Astrophysics Data System (ADS)

    Debats, S. R.; Estes, L. D.; Caylor, K. K.

    2015-12-01

    As satellite imagery becomes increasingly available, management of large image databases becomes more important for efficient image processing. We have developed a computer vision-based classification algorithm to distinguish smallholder agricultural land cover in Sub-Saharan Africa, using a group of high-resolution images from South Africa as a case study. For supervised classification, smallholder agriculture, with ambiguous patterns of small, irregular fields, requires a wide range of training data samples to adequately describe the variability in appearance. We employ crowd-sourcing to obtain new training data to expand the geographic range of our algorithm. A crowd-sourcing user is asked to hand-digitize the boundaries of agricultural fields in an assigned 1 km2 image. Yet random assignment of images to users could result in a highly redundant training data set with limited discriminative power. Furthermore, larger training data sets require a greater number of users to hand-digitize fields, which increases costs through crowd-sourcing engines like Amazon Mechanical Turk, as well as longer algorithm training times, which increases computing costs. Therefore, we employ an active learning approach to interactively select the most informative images to be hand-digitized for training data by crowd-sourcing users, based on changes in algorithm accuracy. We investigate the use of various image similarity measures used in content-based image retrieval systems, which quantify the distance, such as Euclidean distance or Manhattan distance, between a variety of extracted feature spaces to determine how similar the content of two images are. We determine the minimum training data set needed to maximize algorithm accuracy, as well as automate the selection of additional training images to classify a new target image that expands the geographic range of our algorithm.

  3. Reducing fluxes of faecal indicator compliance parameters to bathing waters from diffuse agricultural sources: the Brighouse Bay study, Scotland.

    PubMed

    Kay, D; Aitken, M; Crowther, J; Dickson, I; Edwards, A C; Francis, C; Hopkins, M; Jeffrey, W; Kay, C; McDonald, A T; McDonald, D; Stapleton, C M; Watkins, J; Wilkinson, J; Wyer, M D

    2007-05-01

    The European Water Framework Directive requires the integrated management of point and diffuse pollution to achieve 'good' water quality in 'protected areas'. These include bathing waters, which are regulated using faecal indicator organisms as compliance parameters. Thus, for the first time, European regulators are faced with the control of faecal indicator fluxes from agricultural sources where these impact on bathing water compliance locations. Concurrently, reforms to the European Union (EU) Common Agricultural Policy offer scope for supporting on-farm measures producing environmental benefits through the new 'single farm payments' and the concept of 'cross-compliance'. This paper reports the first UK study involving remedial measures, principally stream bank fencing, designed to reduce faecal indicator fluxes at the catchment scale. Considerable reduction in faecal indicator flux was observed, but this was insufficient to ensure bathing water compliance with either Directive 76/160/EEC standards or new health-evidence-based criteria proposed by WHO and the European Commission.

  4. Economic gains from targeted measures related to non-point pollution in agriculture based on detailed nitrate reduction maps.

    PubMed

    Jacobsen, Brian H; Hansen, Anne Lausten

    2016-06-15

    From 1990 to 2003, Denmark reduced N-leaching from the root zone by 50%. However, more measures are required, and in recent years, the focus has been on how to differentiate measures in order to ensure that they are implemented where the effect on N-loss reductions per ha is the greatest. The purpose of the NiCA project has been to estimate the natural nitrate reduction in the groundwater more precisely than before using a plot size down to 1ha. This article builds on these findings and presents the possible economic gains for the farmer when using this information to reach a given N-loss level. Targeted measures are especially relevant where the subsurface N-reduction varies significantly within the same farm and national analyses have shown that a cost reduction of around 20-25% using targeted measures is likely. The analyses show an increasing potential with increasing variation in N-reduction in the catchment. In this analysis, the knowledge of spatial variation in N-reduction potential is used to place measures like catch crops or set-a-side at locations with the greatest effect on 10 case farms in the Norsminde Catchment, Denmark. The findings suggest that the gains are from 0 to 32€/ha and the average farm would gain approximately 14-21€/ha/year from the targeted measures approach. The analysis indicates that the economic gain is greater than the costs of providing the detailed maps of 5-10€/ha/year. When N-loss reduction requirements are increased, the economic gains are greater. When combined with new measures like mini-wetlands and early sowing the economic advantage is increased further. The paper also shows that not all farms can use the detailed information on N-reduction and there is not a clear link between spatial variation in N-reduction at the farm level and possible economic gains for all these 10 farms. PMID:26974574

  5. Source apportionment of groundwater pollutants in Apulian agricultural sites using multivariate statistical analyses: case study of Foggia province

    PubMed Central

    2012-01-01

    Background Ground waters are an important resource of water supply for human health and activities. Groundwater uses and applications are often related to its composition, which is increasingly influenced by human activities. In fact the water quality of groundwater is affected by many factors including precipitation, surface runoff, groundwater flow, and the characteristics of the catchment area. During the years 2004-2007 the Agricultural and Food Authority of Apulia Region has implemented the project “Expansion of regional agro-meteorological network” in order to assess, monitor and manage of regional groundwater quality. The total wells monitored during this activity amounted to 473, and the water samples analyzed were 1021. This resulted in a huge and complex data matrix comprised of a large number of physical-chemical parameters, which are often difficult to interpret and draw meaningful conclusions. The application of different multivariate statistical techniques such as Cluster Analysis (CA), Principal Component Analysis (PCA), Absolute Principal Component Scores (APCS) for interpretation of the complex databases offers a better understanding of water quality in the study region. Results Form results obtained by Principal Component and Cluster Analysis applied to data set of Foggia province it’s evident that some sampling sites investigated show dissimilarities, mostly due to the location of the site, the land use and management techniques and groundwater overuse. By APCS method it’s been possible to identify three pollutant sources: Agricultural pollution 1 due to fertilizer applications, Agricultural pollution 2 due to microelements for agriculture and groundwater overuse and a third source that can be identified as soil run off and rock tracer mining. Conclusions Multivariate statistical methods represent a valid tool to understand complex nature of groundwater quality issues, determine priorities in the use of ground waters as irrigation water

  6. Comparing source of agricultural contact water and the presence of fecal indicator organisms on the surface of 'juliet' grape tomatoes.

    PubMed

    Pahl, Donna M; Telias, Adriana; Newell, Michael; Ottesen, Andrea R; Walsh, Christopher S

    2013-06-01

    Consumption of fresh tomatoes (Solanum lycopersicum) has been implicated as the cause of several foodborne illness outbreaks in the United States, most notably in cases of salmonellosis. How the levels of fecal indicator organisms (FIOs) in water relate to the counts of these microorganisms on the tomato fruit surface is unknown, although microbial water quality standards exist for agricultural use. This study utilized four types of FIOs currently and historically used in microbial water quality standards (Enterobacteriaceae, total coliforms, fecal coliforms, and Escherichia coli) to monitor the water quality of two surface ponds and a groundwater source. The groundwater tested contained significantly lower counts of all FIOs than the two surface water sources (P < 0.05). Considerable variability in bacterial counts was found in the surface water sources over the course of the season, perhaps explained by environmental variables, such as water temperature, pH, precipitation, and air temperature (R(2) of 0.13 to 0.27). We also monitored the fruit surface of grape tomatoes treated with overhead applications of the different water sources over the 2009 and 2010 growing seasons. The type of water source and time of year significantly affected the populations of FIOs in irrigation water (P < 0.05). Despite up to 5-log differences in fecal coliforms and 3-log differences in E. coli between the water sources, there was little difference in the populations measured in washes taken from tomato fruits. This lack of association between the aforementioned FIOs present in the water samples and on the tomato fruit surface demonstrates the difficulty in developing reliable metrics needed for testing of agricultural water to ensure the effectiveness of food safety programs.

  7. Understanding Multifunctional Agricultural Land by Using Low Cost and Open Source Solutions to Quantify Ecosystem Function and Services

    NASA Astrophysics Data System (ADS)

    Forsmoo, Joel; Anderson, Karen; Brazier, Richard; Macleod, Kit; Wilkinson, Mark

    2016-04-01

    There is a need to advance our understanding of how the spatial structure of farmed landscapes contributes to the provision of functions and services. Agricultural land is of critical importance in NW Europe, covering large parts of NW Europe's temperate land. Moreover, these agricultural areas are primarily intensively managed, with a focus on maximizing food and fibre production. Such landscapes therefore can provide a wealth of ecosystem goods and services (ESs) including regulation of climate, erosion regulation, hydrology, water quality, nutrient cycling and biodiversity conservation. However, it has been shown they are key sources of sediment, phosphorous, nitrogen and storm runoff contributing to flooding, and therefore it is likely that most agricultural landscapes do not maximize the services or benefits that they might provide. The focus of this study is the spatio-temporal assessment of carbon sequestration (particularly through proxies such as above-ground biomass) and hydrological processes on agricultural land. Understanding and quantifying both of these is important to (a) inform payments for ecosystem services frameworks, (b) evaluate and improve carbon sequestration models, (c) manage the flood risk, (d) downstream water security and (e) water quality. Quantifying both of these ESs is dependent on data describing the fine spatial and temporal structure and function of the landscape. Common practice has been to use remote sensing techniques, e.g. satellites, providing coarse spatial resolution (around 30cm at 20° off nadir) and/or temporal resolution (around 5 days revisit time at <20° off nadir). In this paper we will explain how imaging data from lightweight and easily deployed unmanned aerial vehicles (UAVs) can be used to generate structure from motion (SFM) products describing the very fine detailed (<3 cm pixel resolution) structure of the agricultural environment. We will demonstrate how these products can be delivered using advanced free

  8. Understanding the sources and mitigation potential of nitrous oxide in agriculture

    NASA Astrophysics Data System (ADS)

    Horwath, W. R.; Zhu, X.; Doane, T. A.; Burger, M.

    2014-12-01

    More than half of the global warming potential of GHG emissions from agriculture is attributed to nitrous oxide (N2O).. Many factors control the production and release of N2O from soils. In addition to fertilizer N, soil N, moisture and carbon availability control N2O emissions. In addition, a previously overlooked factor, iron, was recently found to be the most significant factor influencing N2O production. Controlled by soil and management factors, N2O production is attributed to multiple pathways, including ammonia oxidation (AO), denitrification, and abiotic chemical reactions. Ammonia oxidation or nitrifier activity N2O production, is a well known pathway, but it significance to total N2O production is also highly debated and soil conditions influencing its production are poorly understood. Studies in a variety of crops in California strongly suggest that this pathway contributes substantially to N2O emissions. It is well established that denitrification primarily occurs under O2- limiting conditions, while N2O produced from AO is also influenced by soil O2 content, with maximum production occurring at low O2 levels (~0.5%). Since emission of N2O can arise from both AO and denitrification activities at low O2 concentrations, it is difficult to discern the importance of each pathway under various soil conditions and management. Furthermore, both the N form and concentration are determinants of nitrifier N2O production. The nitrifier denitrification pathway has been shown to dominate over nitrifier nitrification and nitrification coupled denitrification pathways. Irrigation, rainfall, and fertilization events stimulate microbial activity, including AO and denitrification that produces N2O and although limited, these events contribute to the majority of annual emissions. This uncertainty and complexity surrounding N2O production pathways has hampered the development of practices to reduce N2O emissions. As agricultural production intensifies in developing

  9. Trophic status and assessment of non-point nutrient enrichment of Lake Crescent Olympic National Park

    USGS Publications Warehouse

    Boyle, Terence P.; Beeson, David R.

    1991-01-01

    A limited effort study was conducted in Lake Crescent, Olympic National Park to determine the trophic status and assess whether non-point nutrients were leaching into the lake and affecting biological resources. The concentration of chlorophyll a, total nitrogen concentration, and Secchi disk transparency used as parameters of the Trophic Status Index revealed that Lake Crescent in Olympic National Park was in the oligotrophic range. Evaluation of the nitrogen to phosphorous ration revealed that nitrogen was the nutrient limiting to overall lake productivity. Single species and community bioassays indicated that other nutrients, possibly iron, had some secondary control over community composition of the algal community. Assessment of six near-shore sites for the presence and effects of non-point nutrients revealed that La Poel Point which formerly was the site of a resort had slightly higher algal bioassay and periphyton response than the other sites. No conditions that would require immediate action by resource management of Olympic National Park were identified. The general recommendations for a long term lake monitoring plan are discussed.

  10. Methane and nitrous oxide emissions of China: Sources from agricultural systems and mitigation options

    SciTech Connect

    Lin Erda; Li Yue; Dong Hongmin; Zhou Wennong

    1994-12-31

    This paper reports the estimated results of methane and nitrous oxide emissions from China`s agricultural systems. The results show that the overall methane emissions from paddies and ruminants were 11.335 and 5.796 Tg/y, respectively in 1990. For mitigation options, based on some experiments, a number of options were recommended to reduce methane and nitrous oxide emissions. Several research priority areas were proposed to reduce the uncertainties in estimates they are: (1) improve measurement methods; (2) further identify controlling factors; and (3) develop simulation models.

  11. The organic agricultural waste as a basic source of biohydrogen production

    NASA Astrophysics Data System (ADS)

    Sriwuryandari, Lies; Priantoro, E. Agung; Sintawardani, Neni; Astuti, J. Tri; Nilawati, Dewi; Putri, A. Mauliva Hada; Mamat, Sentana, Suharwadji; Sembiring, T.

    2016-02-01

    Biohydrogen production research was carried out using raw materials of agricultural organic waste that was obtained from markets around the Bandung city. The organic part, which consisted of agricultural waste material, mainly fruit and vegetable waste, was crushed and milled using blender. The sludge that produced from milling process was then used as a substrate for mixed culture microorganism as a raw material to produce biohydrogen. As much as 1.2 kg.day-1 of sludge (4% of total solid) was fed into bioreactor that had a capacity of 30L. Experiment was done under anaerobic fermentation using bacteria mixture culture that maintained at pH in the range of 5.6-6.5 and temperature of 25-30oC on semi-continuous mode. Parameters of analysis include pH, temperature, total solid (TS), organic total solid (OTS), total gas production, and hydrogen gas production. The results showed that from 4% of substrate resulted 897.86 L of total gas, which contained 660.74 L (73.59%) of hydrogen gas. The rate of hydrogen production in this study was 11,063 mol.L-1.h-1.

  12. Fingerprinting Sources of Suspended Sediment in a Canadian Agricultural Watershed Using the MixSIAR Bayesian Unmixing Model

    NASA Astrophysics Data System (ADS)

    Smith, J. P.; Owens, P. N.; Gaspar, L.; Lobb, D. A.; Petticrew, E. L.

    2015-12-01

    An understanding of sediment redistribution processes and the main sediment sources within a watershed is needed to support watershed management strategies. The fingerprinting technique is increasingly being recognized as a method for establishing the source of the sediment transported within watersheds. However, the different behaviour of the various fingerprinting properties has been recognized as a major limitation of the technique, and the uncertainty associated with tracer selection needs to be addressed. There are also questions associated with which modelling approach (frequentist or Bayesian) is the best to unmix complex environmental mixtures, such as river sediment. This study aims to compare and evaluate the differences between fingerprinting predictions provided by a Bayesian unmixing model (MixSIAR) using different groups of tracer properties for use in sediment source identification. We used fallout radionuclides (e.g. 137Cs) and geochemical elements (e.g. As) as conventional fingerprinting properties, and colour parameters as emerging properties; both alone and in combination. These fingerprinting properties are being used (i.e. Koiter et al., 2013; Barthod et al., 2015) to determine the proportional contributions of fine sediment in the South Tobacco Creek Watershed, an agricultural watershed located in Manitoba, Canada. We show that the unmixing model using a combination of fallout radionuclides and geochemical tracers gave similar results to the model based on colour parameters. Furthermore, we show that a model that combines all tracers (i.e. radionuclide/geochemical and colour) gave similar results, showing that sediment sources change from predominantly topsoil in the upper reaches of the watershed to channel bank and bedrock outcrop material in the lower reaches. Barthod LRM et al. (2015). Selecting color-based tracers and classifying sediment sources in the assessment of sediment dynamics using sediment source fingerprinting. J Environ Qual

  13. Seasonal Variation in Hydrology Driving Shifts in Sources of Nitrate in an Agricultural Dominant Semi-arid Watershed

    NASA Astrophysics Data System (ADS)

    Moon Nielsen, L. G.; Orr, C. H.

    2010-12-01

    In the South Fork Palouse River in the semi-arid region of Eastern Washington State, surface water hydrology is driven by seasonal variation in precipitation, with peak surface water flow and highest Nitrate values observed from January to April, and lowest surface flows and corresponding lower Nitrate concentrations observed from June to August. Land-use in the watershed is predominantly non-irrigated cropland (82%) fertilized by synthetic fertilizer, with an additional 8% of land in urban areas. Due to the prevalence of anthropogenically influenced land in the watershed, Nitrate concentrations measured in streams here are chronically elevated above natural levels. Typically in an area that is dominated by agriculture, the source of Nitrate in surface waters draining agricultural land would be predicted to be synthetic fertilizer. However it is important to consider the impacts seasonal hydrological conditions can have upon Nitrate sources and flow paths. We investigated how Nitrate sources in Palouse streams and rivers changed seasonally to address the hypothesis that seasonal variation in precipitation shifts the dominant sources of Nitrate in surface waters. We based our determination of nitrogen source on the results from dual stable isotope analysis of Nitrate using the denitrifier method. Sampling was done at 7 locations of increasing catchment area along the South Fork Palouse River and tributary streams. Sampling site catchment area varied one order of magnitude from 70.9 to 717.4 km2. Surface waters at yearly low flow during the summer season indicated δ15N-Nitrate and δ18O-Nitrate ranging within generally accepted values to indicate Nitrate derived from animal and human waste. These can be attributed to waste water discharge from the urban areas in the watershed. Yearly hydrologic data suggests that during the winter season, increased precipitation causes a shift in δ15N-Nitrate and δ18O-Nitrate to values typically observed in sources derived from

  14. Downstream mixing of sediment and tracers in agricultural catchments: Evidence of changing sediment sources and fluvial processes?

    NASA Astrophysics Data System (ADS)

    Ralph, Timothy; Wethered, Adam; Smith, Hugh; Heijnis, Henk

    2014-05-01

    Land clearance, soil tillage and grazing in agricultural catchments have liberated sediment and altered hydrological connectivity between hillslopes and channels, leading to increased sediment availability, mobilisation and delivery to rivers. The type and amount of sediment supplied to rivers is critical for fluvial geomorphology and aquatic ecosystem health. Contemporary sediment dynamics are routinely investigated using environmental radionuclides such as caesium-137 (Cs-137) and excess lead-210 (Pb-210ex), which can provide information regarding sediment source types and fluvial processes if sediment sources can be distinguished from one another and mixing models applied to representative samples. However, downstream transport, mixing and dilution of radionuclide-labelled sediment (especially from sources with low initial concentrations) can obliterate the tracer signal; sometimes before anything of geomorphological importance happens in the catchment. Can these findings be used as evidence of sediment source variations and fluvial processes when the limits of detection (of Cs-137 in particular) are being exceeded so rapidly downstream? Sediment sources and downstream sediment dynamics were investigated in Coolbaggie Creek, a major supplier of sediment to the Macquarie River in an agricultural catchment with temperate to semi-arid climate in Australia. Radionuclides were used to discriminate between the <63 micron fraction of sediment sources including forested topsoils (Cs-137 11.28 +/- 0.75 Bq/kg; Pb-210ex 181.87 +/- 20.00 Bq/kg), agricultural topsoils (Cs-137 3.21 +/- 0.26 Bq/kg; Pb-210ex 29.59 +/- 10.94 Bq/kg) and sub-soils from channel banks and gullies (Cs-137 1.45 +/- 0.47 Bq/kg; Pb-210ex 4.67 +/- 1.93 Bq/kg). Within the trunk stream, suspended sediment, organic matter and Cs-137 and Pb-210ex concentrations declined downstream. Results from a mixing model suggest that agricultural topsoils account for 95% of fine sediment entering the channel in the

  15. Sources of heavy metal pollution in agricultural soils of a rapidly industrializing area in the Yangtze Delta of China.

    PubMed

    Xu, Xianghua; Zhao, Yongcun; Zhao, Xiaoyan; Wang, Yudong; Deng, Wenjing

    2014-10-01

    The rapid industrialization and urbanization in developing countries have increased pollution by heavy metals, which is a concern for human health and the environment. In this study, 230 surface soil samples (0-20cm) were collected from agricultural areas of Jiaxing, a rapidly industrializing area in the Yangtze Delta of China. Sequential Gaussian simulation (SGS) and multivariate factorial kriging analysis (FKA) were used to identify and explore the sources of heavy metal pollution for eight metals (Cu, Zn, Pb, Cr, Ni, Cd, Hg and As). Localized hot-spots of pollution were identified for Cu, Zn, Pb, Cr, Ni and Cd with area percentages of 0.48 percent, 0.58 percent, 2.84 percent, 2.41 percent, 0.74 percent, and 0.68 percent, respectively. The areas with Hg pollution covered approximately 38 percent whereas no potential pollution risk was found for As. The soil parent material and point sources of pollution had significant influences on Cr, Ni, Cu, Zn and Cd levels, except for the influence of agricultural management practices also accounted for micro-scale variations (nugget effect) for Cu and Zn pollution. Short-range (4km) diffusion processes had a significant influence on Cu levels, although they did not appear to be the dominant sources of Zn and Cd variation. The short-range diffusion pollution arising from current and historic industrial emissions and urbanization, and long-range (33km) variations in soil parent materials and/or diffusion jointly determined the current concentrations of soil Pb. The sources of Hg pollution risk may be attributed to the atmosphere deposition of industrial emission and historical use of Hg-containing pesticides.

  16. Integrating different knowledge sources and disciplines for practical applications in Forest and Agricultural Engineering

    NASA Astrophysics Data System (ADS)

    Guzmán, Gema; Castillo, Carlos; Taguas, Encarnación

    2013-04-01

    One of the aims of 'The Bologna Process' is to promote among the students the acquisition of practical, social and creative skills to face real-life situations and to solve the difficulties they might find during their professional life. It involves an important change in the educational system, from a traditional approach focused on teaching, towards a new one that encourages learning. Under this context, University teaching implies the design of activities addressed to the dissemination of "know-how" to solve different problems associated with two technical disciplines: Forest and Agricultural Engineering. This study presents a preliminary experience where a group of information and communication technologies (ICT) such as, audiovisual resources (videos, reports and photo gallery), virtual visits to blogs and interactive activities have been used to provide a comprehensive knowledge of the environmental and sociocultural components of the landscape in order to facilitate the decision-making process in the engineering project context . With these tools, the students must study and characterize all these aspects in order to justify the chosen solutions and the project design. This approach was followed in the analysis of the limiting factors of practical cases in projects about forestation, landscape restoration and hydrological planning. This communication shows how this methodology has been applied in Forest and Agricultural Engineering and the students' experience with these innovative tools. The use of ICTs involved a friendly framework that stimulated students' interest and made subjects more attractive, since it allowed to assess the complex relationships between landscape, history and economy. Furthermore, this type of activities promotes the interdisciplinary training and the acquisition of creative and autonomous skills which are not included in many cases into the main objectives of the subjects.

  17. Nitrate concentrations under irrigated agriculture

    USGS Publications Warehouse

    Zaporozec, A.

    1983-01-01

    In recent years, considerable interest has been expressed in the nitrate content of water supplies. The most notable toxic effect of nitrate is infant methemoglobinemia. The risk of this disease increases significantly at nitrate-nitrogen levels exceeding 10 mg/l. For this reason, this concentration has been established as a limit for drinking water in many countries. In natural waters, nitrate is a minor ionic constituent and seldom accounts for more than a few percent of the total anions. However, nitrate in a significant concentration may occur in the vicinity of some point sources such as septic tanks, manure pits, and waste-disposal sites. Non-point sources contributing to groundwater pollution are numerous and a majority of them are related to agricultural activities. The largest single anthropogenic input of nitrate into the groundwater is fertilizer. Even though it has not been proven that nitrogen fertilizers are responsible for much of nitrate pollution, they are generally recognized as the main threat to groundwater quality, especially when inefficiently applied to irrigated fields on sandy soils. The biggest challenge facing today's agriculture is to maintain the balance between the enhancement of crop productivity and the risk of groundwater pollution. ?? 1982 Springer-Verlag New York Inc.

  18. Agricultural Wastes.

    ERIC Educational Resources Information Center

    Jewell, W. J.; Switzenbaum, M. S.

    1978-01-01

    Presents a literature review of agricultural wastes, covering publications of 1976-77. Some of the areas covered are: (1) water characteristics and impacts; (2) waste treatment; (3) reuse of agricultural wastes; and (4) nonpoint pollution sources. A list of 150 references is also presented. (HM)

  19. Using Radioactive Fallout Cesium (137Cs) to Distinguish Sediment Sources in an Agricultural Watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Radioactive fallout Cesium (Cs-137) has been used for quantifying sources of accumulating sediment in water bodies and to determine the rates and pattern of soil erosion. The objectives of this research are to use Cs-137 as a tracer to determine patterns of soil erosion and deposition of eroding soi...

  20. Organic matter source and degradation as revealed by molecular biomarkers in agricultural soils of Yuanyang terrace

    PubMed Central

    Li, Fangfang; Pan, Bo; Zhang, Di; Yang, Xiaolei; Li, Hao; Liao, Shaohua; Ghaffar, Abdul; Peng, Hongbo; Xing, Baoshan

    2015-01-01

    Three soils with different tillage activities were collected and compared for their organic matter sources and degradation. Two soils (TD and TP) with human activities showed more diverse of chemicals in both free lipids and CuO oxidation products than the one (NS) without human activities. Branched alkanoic acids only accounted for less than 5% of lipids, indicating limited microbial inputs in all three investigated soils. The degradation of lignin in NS and TD was relatively higher than TP, probably because of the chemical degradation, most likely UV light-involved photodegradation. Lignin parameters obtained from CuO oxidation products confirmed that woody gymnosperm tissue (such as pine trees) may be the main source for NS, while angiosperm tissues from vascular plant may be the predominant source for the lignins in TD and TP. Analysis of BPCAs illustrated that BC in NS may be mainly originated from soot or other fossil carbon sources, whereas BC in TD and TP may be produced during corn stalk and straw burning. BC was involved in mineral interactions for TD and TP. The dynamics of organic matter needs to be extensively examined for their nonideal interactions with contaminants. PMID:26046574

  1. Organic matter source and degradation as revealed by molecular biomarkers in agricultural soils of Yuanyang terrace

    NASA Astrophysics Data System (ADS)

    Li, Fangfang; Pan, Bo; Zhang, Di; Yang, Xiaolei; Li, Hao; Liao, Shaohua; Ghaffar, Abdul; Peng, Hongbo; Xing, Baoshan

    2015-06-01

    Three soils with different tillage activities were collected and compared for their organic matter sources and degradation. Two soils (TD and TP) with human activities showed more diverse of chemicals in both free lipids and CuO oxidation products than the one (NS) without human activities. Branched alkanoic acids only accounted for less than 5% of lipids, indicating limited microbial inputs in all three investigated soils. The degradation of lignin in NS and TD was relatively higher than TP, probably because of the chemical degradation, most likely UV light-involved photodegradation. Lignin parameters obtained from CuO oxidation products confirmed that woody gymnosperm tissue (such as pine trees) may be the main source for NS, while angiosperm tissues from vascular plant may be the predominant source for the lignins in TD and TP. Analysis of BPCAs illustrated that BC in NS may be mainly originated from soot or other fossil carbon sources, whereas BC in TD and TP may be produced during corn stalk and straw burning. BC was involved in mineral interactions for TD and TP. The dynamics of organic matter needs to be extensively examined for their nonideal interactions with contaminants.

  2. The role of hydrology in connecting agricultural phosphorus sources to surface water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Minimizing the risk of phosphorus (P) loss from land to water represents one of the most important priorities of nutrient management in the Chesapeake Bay watershed. Simply put, for P to pose a water quality problem, there must be a source of P that can readily be connected to surface water by hydro...

  3. Stream nitrogen sources apportionment and pollution control scheme development in an agricultural watershed in eastern China.

    PubMed

    Chen, Dingjiang; Lu, Jun; Huang, Hong; Liu, Mei; Gong, Dongqin; Chen, Jiabo

    2013-08-01

    A modeling system that couples a land-usebased export coefficient model, a stream nutrient transport equation, and Bayesian statistics was developed for stream nitrogen source apportionment. It divides a watershed into several sub-catchments, and then considers the major landuse categories as stream nitrogen sources in each subcatchment. The runoff depth and stream water depth are considered as the major factors influencing delivery of nitrogen from land to downstream stream node within each sub-catchment. The nitrogen sources and delivery processes are lumped into several constant parameters that were calibrated using Bayesian statistics from commonly available stream monitoring and land-use datasets. This modeling system was successfully applied to total nitrogen (TN) pollution control scheme development for the ChangLe River watershed containing six sub-catchments and four land-use categories. The temporal (across months and years) and spatial (across sub-catchments and land-use categories) variability of nonpoint source (NPS) TN export to stream channels and delivery to the watershed outlet were assessed. After adjustment for in-stream TNretention, the time periods and watershed areas with disproportionately high-TN contributions to the stream were identified. Aimed at a target stream TN level of 2 mg L-1, a quantitative TN pollution control scheme was further developed to determine which sub-catchments, which land-use categories in a sub-catchment, which time periods, and how large of NPS TN export reduction were required. This modeling system provides a powerful tool for stream nitrogen source apportionment and pollution control scheme development at the watershed scale and has only limited data requirements.

  4. [Mechanism of contour hedgerow's control for non-point pollution in the semiarid region in northwest Hebei Province].

    PubMed

    Tang, Z; Cai, Q; Xu, F; Li, S; Wang, Z

    2001-11-01

    Slope nutrient loss is an important type of non-point pollution. The mechanism of non-point pollution control by using plenty of natural observed data in Hilly Loess region in Northwest Hebei Province, as well as combating with the large-scale artificial simulation rainfall in the field slope was analyzed. The study results show that the critical slope length was 10-15 m on the condition of rainstorm, which led to the generation of rill and made the erosion amount went up obviously. The study show that the nutrient loss in sediment was the main type of non-point pollution, the contour hedgerow the process of non-point pollution by controlling the nutrient loss in sediment, then the study got the erosion control model of the contour hedgerow.

  5. Mapping hazard from urban non-point pollution: a screening model to support sustainable urban drainage planning.

    PubMed

    Mitchell, Gordon

    2005-01-01

    Non-point sources of pollution are difficult to identify and control, and are one of the main reasons that urban rivers fail to reach the water quality objectives set for them. Whilst sustainable drainage systems (SuDS) are available to help combat this diffuse pollution, they are mostly installed in areas of new urban development. However, SuDS must also be installed in existing built areas if diffuse loadings are to be reduced. Advice on where best to locate SuDS within existing built areas is limited, hence a semi-distributed stochastic GIS-model was developed to map small-area basin-wide loadings of 18 key stormwater pollutants. Load maps are combined with information on surface water quality objectives to permit mapping of diffuse pollution hazard to beneficial uses of receiving waters. The model thus aids SuDS planning and strategic management of urban diffuse pollution. The identification of diffuse emission 'hot spots' within a water quality objectives framework is consistent with the 'combined' (risk assessment) approach to pollution control advocated by the EU Water Framework Directive. PMID:15572076

  6. Source identification of nitrate in groundwater using stable isotopes and Cl/Br ratios in an agricultural area

    NASA Astrophysics Data System (ADS)

    Koh, D.; Mayer, B.

    2009-12-01

    Sources of nitrate in groundwater were investigated in an agricultural area with natural area at higher altitude, upland at hilly terrains and residential areas at low-lying lands using δ15N and δ18O of nitrate and Cl/Br ratios. The NO3- concentration in groundwater was as high as 49 mg/L, with an average of 6.0 mg/L and a median value of 4.4 mg/L as NO3-N, and, 22% of the groundwater samples exceeded the DWS of South Korea, which is 10 mg/L for NO3-N. Nitrate sources were consistently identified in residential and upland areas using stable isotopes of nitrate and Cl/Br ratios which showed that the higher δ15N-NO3- and Cl/Br ratios in residential area and lower δ15N-NO3- and Cl/Br ratios in upland Meanwhile, contribution of atmospheric nitrate in natural area was not readily observable due to resetting of δ18O-NO3- in the soil zone. The higher δ15N-NO3- values in residential area was consistent with higher Cl/Br ratios indicating the effect of domestic wastewater including sewage and septic effluents. Upland area had δ15N-NO3- corresponding to soil organic nitrogen which seems resulted from mixed sources of mineralized fertilizer and manure with higher contribution of the latter. The lower Cl/Br ratios of upland area compared to residential area indicates higher contribution of agrochemicals including fertilizers and pesticides. Statistical comparison of chemical and isotopic parameters according to land-use groups revealed that nitrate concentrations and Cl/Br ratios were distinctive between four land uses considered whereas stable isotopes of nitrate were not significantly different between anthropogenic land uses indicating Cl/Br ratio is a more efficient tracer for impact of land-uses on groundwater quality in agricultural areas.

  7. Evaluating agricultural nonpoint-source pollution using integrated geographic information systems and hydrologic/water quality model

    SciTech Connect

    Tim, U.S.; Jolly, R.

    1994-01-01

    Considerable progress has been made in developing physically based, distributed parameter, hydrologic/water quality (HIWQ) models for planning and control of nonpoint-source pollution. The widespread use of these models is often constrained by the excessive and time-consuming input data demands and the lack of computing efficiencies necessary for iterative simulation of alternative management strategies. Recent developments in geographic information systems (GIS) provide techniques for handling large amounts of spatial data for modeling nonpoint-source pollution problems. Because a GIS can be used to combine information from several sources to form an array of model input data and to examine any combinations of spatial input/output data, it represents a highly effective tool for HiWQ modeling. This paper describes the integration of a distributed-parameter model (AGNPS) with a GIS (ARC/INFO) to examine nonpoint sources of pollution in an agricultural watershed. The ARC/INFO GIS provided the tools to generate and spatially organize the disparate data to support modeling, while the AGNPS model was used to predict several water quality variables including soil erosion and sedimentation within a watershed. The integrated system was used to evaluate the effectiveness of several alternative management strategies in reducing sediment pollution in a 417-ha watershed located in southern Iowa. The implementation of vegetative filter strips and contour buffer (grass) strips resulted in a 41 and 47% reduction in sediment yield at the watershed outlet, respectively. In addition, when the integrated system was used, the combination of the above management strategies resulted in a 71% reduction in sediment yield. In general, the study demonstrated the utility of integrating a simulation model with GIS for nonpoini-source pollution control and planning. Such techniques can help characterize the diffuse sources of pollution at the landscape level. 52 refs., 6 figs., 1 tab.

  8. Agricultural waste as a source for the production of silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Vaibhav, Vineet; Vijayalakshmi, U.; Roopan, S. Mohana

    2015-03-01

    The major interest of the paper deals with the extraction of silica from four natural sources such as rice husk, bamboo leaves, sugarcane bagasse and groundnut shell. These waste materials in large quantities can create a serious environmental problem. Hence, there is a need to adopt proper strategy to reduce the waste. In the present investigation, all the waste materials are subjected to moisture removal in a hot plate and sintered at 900 °C for 7 h. The sintered powder was treated with 1 M NaOH to form sodium silicate and then with 6 M H2SO4 to precipitate silica. The prepared silica powders were characterized by FT-IR, XRD and SEM-EDAX analysis. The silica recovered from different sources was found to vary between 52% and 78%. Magnesium substituted silica was formed from the groundnut waste and further treatment is required to precipitate silica.

  9. [Mechanism of stomatal regulation by root sourced signaling and its agricultural signficance].

    PubMed

    Guo, Anhong; Li, Zhaoxiang; Liu, Gengshan; Yang, Yuanyan; An, Shunqing

    2004-06-01

    Under soil drought condition, root sourced signal abcisic acid (ABA) plays an important role in the long distance signaling process, and can be a measurement of soil water availability. ABA is also an effective stomatal closing agent, and acts to reduce transpiration and canopy water loss. This paper briefly introduced the physiological mechanism and theoretical model about the stomatal regulation by root sourced signaling, and indicated that the combination of this model with root water absorption model and stomatal conductance model could be more effective in depicting the response of plant to soil drying and atmospheric drought. In addition, some effective irrigation approaches, such as regulated deficit irrigation (RDI), partial root-zone drying (PRD) and controlled alternative irrigation (CAI) were profited from the mechanism of plant water use regulation by the root sourced signaling. These irrigation measures favored to reasonably distribute available soil water in root-zone. Root signaling system also played important role in regulating root growth and its development, retarding shoot growth to adjusting root shoot ratio, and optimizing assimilation allocation to favor to improve reproductive development. These processes hold substantial promise for enhancing crop water use efficiency. PMID:15362642

  10. Poultry litter ash as a potential phosphorus source for agricultural crops.

    PubMed

    Codling, Eton E; Chaney, Rufus L; Sherwell, John

    2002-01-01

    Maryland will impose restrictions on poultry litter application to soils with excessive P by the year 2005. Alternative uses for poultry litter are being considered, including burning as a fuel to generate electricity. The resulting ash contains high levels of total P, but the availability for crop uptake has not been reported. Our objective was to compare the effectiveness of poultry litter ash (PLA) and potassium phosphate (KP) as a P source for wheat (Triticum aestivum L.) in acidic soils, without and with limestone application. Two acidic soils (pH 4.25 and 4.48) were studied, unlimed or limed to pH 6.5 before cropping. The PLA and KP were applied at 0, 39, and 78 kg P ha(-1), after which wheat was grown. Limestone significantly increased wheat yield, but the P sources without limestone did not. The two P sources were not significantly different as P fertilizer. At the 78 kg P ha(-1) rate, wheat shoot-P concentrations were 1.10 and 1.12 g kg(-1) for the PLA treatment compared with 0.90 and 0.89 g kg(-1) for KP in the nonlimed and limed soils, respectively. Trace element concentrations in wheat shoots from the PLA treatment were less than or equal to KP and the control. The low levels of water-soluble P and metals in the soils and the low metal concentrations in wheat suggest that PLA is an effective P fertilizer. Further studies are needed to determine the optimum application rate of PLA as a P fertilizer.

  11. Targeting allergenic fungi in agricultural environments aids the identification of major sources and potential risks for human health.

    PubMed

    Weikl, F; Radl, V; Munch, J C; Pritsch, K

    2015-10-01

    Fungi are, after pollen, the second most important producers of outdoor airborne allergens. To identify sources of airborne fungal allergens, a workflow for qPCR quantification from environmental samples was developed, thoroughly tested, and finally applied. We concentrated on determining the levels of allergenic fungi belonging to Alternaria, Cladosporium, Fusarium, and Trichoderma in plant and soil samples from agricultural fields in which cereals were grown. Our aims were to identify the major sources of allergenic fungi and factors potentially influencing their occurrence. Plant materials were the main source of the tested fungi at and after harvest. Amounts of A. alternata and C. cladosporioides varied significantly in fields under different management conditions, but absolute levels were very high in all cases. This finding suggests that high numbers of allergenic fungi may be an inevitable side effect of farming in several crops. Applied in large-scale studies, the concept described here may help to explain the high number of sensitization to airborne fungal allergens.

  12. Tracing sources of suspended sediment in a Canadian agricultural watershed using a Bayesian model: Testing different groups of fingerprinting properties

    NASA Astrophysics Data System (ADS)

    Gaspar, Leticia; Owens, Philip; Petticrew, Ellen; Lobb, David; Koiter, Alexander; Reiffarth, Dominic; Barthod, Louise; Liu, Kui; Martinez-Carreras, Nuria

    2015-04-01

    An understanding of sediment redistribution processes and the main sediment sources within a watershed is needed to support catchment management strategies, to control soil erosion processes, and to preserve water quality and ecological status. The fingerprinting technique is increasingly recognised as a method for establishing the source of the sediment transported within a catchment. However, the different behaviour of the various fingerprinting properties has been recognised as a major limitation of the technique, and the uncertainty associated with tracer selection has to be addressed. Do the different properties give similar results? Can we combine different groups of tracers? This study aims to compare and evaluate the differences between fingerprinting predictions provided by a Bayesian mixing model using different groups of tracer properties for use in sediment source identification. We are employing fallout radionuclides (137Cs, 210Pbex) and geochemical elements as conventional fingerprinting properties, and colour parameters and compound-specific stable isotopes (CSSIs) as emerging properties; both alone and in combination. These fingerprinting properties are being used to determine the proportional contributions of fine sediment in the South Tobacco Creek Watershed, an agricultural catchment located in south-central Manitoba in Canada. We present preliminary results to evaluate the use of different statistical procedures to increase the accuracy of fingerprinting outputs and establish protocols for the selection of appropriate fingerprint properties.

  13. Targeting allergenic fungi in agricultural environments aids the identification of major sources and potential risks for human health.

    PubMed

    Weikl, F; Radl, V; Munch, J C; Pritsch, K

    2015-10-01

    Fungi are, after pollen, the second most important producers of outdoor airborne allergens. To identify sources of airborne fungal allergens, a workflow for qPCR quantification from environmental samples was developed, thoroughly tested, and finally applied. We concentrated on determining the levels of allergenic fungi belonging to Alternaria, Cladosporium, Fusarium, and Trichoderma in plant and soil samples from agricultural fields in which cereals were grown. Our aims were to identify the major sources of allergenic fungi and factors potentially influencing their occurrence. Plant materials were the main source of the tested fungi at and after harvest. Amounts of A. alternata and C. cladosporioides varied significantly in fields under different management conditions, but absolute levels were very high in all cases. This finding suggests that high numbers of allergenic fungi may be an inevitable side effect of farming in several crops. Applied in large-scale studies, the concept described here may help to explain the high number of sensitization to airborne fungal allergens. PMID:26022406

  14. Assessment of groundwater vulnerability to nitrates from agricultural sources using a GIS-compatible logic multicriteria model.

    PubMed

    Rebolledo, Boris; Gil, Antonia; Flotats, Xavier; Sánchez, José Ángel

    2016-04-15

    In the present study an overlay method to assess groundwater vulnerability is proposed. This new method based on multicriteria decision analysis (MCDA) was developed and validated using an appropriate case study in Aragon area (NE Spain). The Vulnerability Index to Nitrates from Agricultural Sources (VINAS) incorporates a novel Logic Scoring of Preferences (LSP) approach, and it has been developed using public geographic information from the European Union. VINAS-LSP identifies areas with five categories of vulnerability, taking into account the hydrogeological and environmental characteristics of the territory as a whole. The resulting LSP map is a regional screening tool that can provide guidance on the potential risk of nitrate pollution, as well as highlight areas where specific research and farming planning policies are required. PMID:26874616

  15. Assessment of groundwater vulnerability to nitrates from agricultural sources using a GIS-compatible logic multicriteria model.

    PubMed

    Rebolledo, Boris; Gil, Antonia; Flotats, Xavier; Sánchez, José Ángel

    2016-04-15

    In the present study an overlay method to assess groundwater vulnerability is proposed. This new method based on multicriteria decision analysis (MCDA) was developed and validated using an appropriate case study in Aragon area (NE Spain). The Vulnerability Index to Nitrates from Agricultural Sources (VINAS) incorporates a novel Logic Scoring of Preferences (LSP) approach, and it has been developed using public geographic information from the European Union. VINAS-LSP identifies areas with five categories of vulnerability, taking into account the hydrogeological and environmental characteristics of the territory as a whole. The resulting LSP map is a regional screening tool that can provide guidance on the potential risk of nitrate pollution, as well as highlight areas where specific research and farming planning policies are required.

  16. From deposition to erosion: Spatial and temporal variability of sediment sources, storage, and transport in a small agricultural watershed

    NASA Astrophysics Data System (ADS)

    Florsheim, J. L.; Pellerin, B. A.; Oh, N. H.; Ohara, N.; Bachand, P. A. M.; Bachand, S. M.; Bergamaschi, B. A.; Hernes, P. J.; Kavvas, M. L.

    2011-09-01

    The spatial and temporal variability of sediment sources, storage, and transport were investigated in a small agricultural watershed draining the Coast Ranges and Sacramento Valley in central California. Results of field, laboratory, and historical data analysis in the Willow Slough fluvial system document changes that transformed a transport-limited depositional system to an effective erosion and transport system, despite a large sediment supply. These changes were caused by a combination of factors: (i) an increase in transport capacity, and (ii) hydrologic alteration. Alteration of the riparian zone and drainage network pattern during the past ~ 150 years included a twofold increase in straightened channel segments along with a baselevel change from excavation that increased slope, and increased sediment transport capacity by ~ 7%. Hydrologic alteration from irrigation water contributions also increased transport capacity, by extending the period with potential for sediment transport and erosion by ~ 6 months/year. Field measurements document Quaternary Alluvium as a modern source of fine sediment with grain size distributions characterized by 5 to 40% fine material. About 60% of an upland and 30% of a lowland study reach incised into this deposit exhibit bank erosion. During this study, the wet 2006 and relatively dry 2007 water years exhibited a range of total annual suspended sediment load spanning two orders of magnitude: ~ 108,500 kg/km 2/year during 2006 and 5,950 kg/km 2/year during 2007, only 5% of that during the previous year. Regional implications of this work are illustrated by the potential for a small tributary such as Willow Slough to contribute sediment - whereas large dams limit sediment supply from larger tributaries - to the Sacramento River and San Francisco Bay Delta and Estuary. This work is relevant to lowland agricultural river-floodplain systems globally in efforts to restore aquatic and riparian functions and where water quality

  17. From deposition to erosion: spatial and temporal variability of sediment sources, storage, and transport in a small agricultural watershed

    USGS Publications Warehouse

    Florsheim, J.L.; Pellerin, B.A.; Oh, N.H.; Ohara, N.; Bachand, P.A.M.; Bachand, Sandra M.; Bergamaschi, B.A.; Hernes, P.J.; Kavvas, M.L.

    2011-01-01

    The spatial and temporal variability of sediment sources, storage, and transport were investigated in a small agricultural watershed draining the Coast Ranges and Sacramento Valley in central California. Results of field, laboratory, and historical data analysis in the Willow Slough fluvial system document changes that transformed a transport-limited depositional system to an effective erosion and transport system, despite a large sediment supply. These changes were caused by a combination of factors: (i) an increase in transport capacity, and (ii) hydrologic alteration. Alteration of the riparian zone and drainage network pattern during the past ~ 150 years included a twofold increase in straightened channel segments along with a baselevel change from excavation that increased slope, and increased sediment transport capacity by ~ 7%. Hydrologic alteration from irrigation water contributions also increased transport capacity, by extending the period with potential for sediment transport and erosion by ~ 6 months/year. Field measurements document Quaternary Alluvium as a modern source of fine sediment with grain size distributions characterized by 5 to 40% fine material. About 60% of an upland and 30% of a lowland study reach incised into this deposit exhibit bank erosion. During this study, the wet 2006 and relatively dry 2007 water years exhibited a range of total annual suspended sediment load spanning two orders of magnitude: ~ 108,500 kg/km2/year during 2006 and 5,950 kg/km2/year during 2007, only 5% of that during the previous year. Regional implications of this work are illustrated by the potential for a small tributary such as Willow Slough to contribute sediment – whereas large dams limit sediment supply from larger tributaries – to the Sacramento River and San Francisco Bay Delta and Estuary. This work is relevant to lowland agricultural river–floodplain systems globally in efforts to restore aquatic and riparian functions and where water quality

  18. Nitrate sinks and sources as controls of spatio-temporal water quality dynamics in an agricultural headwater catchment

    NASA Astrophysics Data System (ADS)

    Schuetz, Tobias; Gascuel-Odoux, Chantal; Durand, Patrick; Weiler, Markus

    2016-02-01

    Several controls are known to affect water quality of stream networks during flow recession periods, such as solute leaching processes, surface water-groundwater interactions as well as biogeochemical in-stream turnover processes. Throughout the stream network, combinations of specific water and solute export rates and local in-stream conditions overlay the biogeochemical signals from upstream sections. Therefore, upstream sections can be considered functional units which could be distinguished and ordered regarding their relative contribution to nutrient dynamics at the catchment outlet. Based on snapshot sampling of flow and nitrate concentrations along the stream in an agricultural headwater during the summer flow recession period, we determined spatial and temporal patterns of water quality for the whole stream. A data-driven, in-stream-mixing-and-removal model was developed and applied for analysing the spatio-temporal in-stream retention processes and their effect on the spatio-temporal fluxes of nitrate from subcatchments. Thereby, we have been able to distinguish quantitatively between nitrate sinks, sources per stream reaches, and subcatchments, and thus we could disentangle the overlay of nitrate sink and source signals. For nitrate sources, we determined their permanent and temporal impact on stream water quality and for nitrate sinks, we found increasing nitrate removal efficiencies from upstream to downstream. Our results highlight the importance of distinct nitrate source locations within the watershed for in-stream concentrations and in-stream removal processes, respectively. Thus, our findings contribute to the development of a more dynamic perception of water quality in streams and rivers concerning ecological and sustainable water resource management.

  19. Phosphorus Recycling from an Unexplored Source by Polyphosphate Accumulating Microalgae and Cyanobacteria-A Step to Phosphorus Security in Agriculture.

    PubMed

    Mukherjee, Chandan; Chowdhury, Rajojit; Ray, Krishna

    2015-01-01

    Phosphorus (P), an essential element required for crop growth has no substitute. The global food security depends on phosphorus availability in soil for crop production. World phosphorus reserves are fast depleting and with an annual increase of 2.3% in phosphorus demand, the current reserves will be exhausted in coming 50-100 years. India and other Western countries are forced to import phosphorus fertilizers at high costs to meet their agricultural demands due to uneven distribution of phosphate rocks on earth. The present study from India, aims to draw attention to an unnoticed source of phosphorus being wasted as parboiled rice mill effluent and subsequent bio-recovery of the valuable element from this unconventional source. The research was conducted in West Bengal, India, a state with the highest number of parboiled rice mills where its effluent carries on an average ~40 mg/L of soluble phosphorus. Technology to recover and recycle this wastewater P in India in a simple, inexpensive mode is yet to be optimized. Our strategy to use microalgae, Chlorella sp. and cyanobacteria, Cyanobacterium sp., Lyngbya sp., and Anabaena sp. to sequester the excess phosphorus from the effluent as polyphosphate inclusions and its subsequent recycling as slow and moderate release phosphorus biofertilizers to aid plant growth, preventing phosphorus loss and pollution, is a contemporary venture to meet the need of the hour. These polyphosphate accumulating microorganisms play a dual role of remediation and recovery of phosphorus, preliminarily validated in laboratory scale. PMID:26733966

  20. Dioxins, furans, biphenyls, arsenic, thorium and uranium in natural and anthropogenic sources of phosphorus and calcium used in agriculture.

    PubMed

    Avelar, A C; Ferreira, W M; Pemberthy, D; Abad, E; Amaral, M A

    2016-05-01

    The aim of this study was to assess the presence of dioxins, furans and biphenyls, and the inorganic contaminants such as arsenic (As), thorium (Th) and uranium (U) in three main products used in Agriculture in Brazil: feed grade dicalcium phosphate, calcined bovine bone meal and calcitic limestone. The first two are anthropogenic sources of phosphorus and calcium, while calcitic limestone is a natural unprocessed mineral. Regarding to dioxin-like substances, all samples analyzed exhibited dioxins (PCDD) and furans (PCDF) and dioxin-like polychlorinated biphenyls (dl-PCBs) concentrations below limit of detection (LOD). In general, achieved is in accordance with regulation in Brazil where is established a maximum limit in limestone used in the citric pulp production (0.50pg WHO-TEQ g(-1)). In addition, reported data revealed very low levels for limestone in comparison with similar materials reported by European legislation. As result for toxic metals, achieved data were obtained using Instrumental Neutron Activation Analysis (INAA). On one hand, limestone sample exhibits the largest arsenic concentration. On another hand, dicalcium phosphate exhibited the largest uranium concentration, which represents a standard in animal nutrition. Therefore, it is phosphorus source in the animal feed industry can be a goal of concern in the feed field. PMID:26901743

  1. Dioxins, furans, biphenyls, arsenic, thorium and uranium in natural and anthropogenic sources of phosphorus and calcium used in agriculture.

    PubMed

    Avelar, A C; Ferreira, W M; Pemberthy, D; Abad, E; Amaral, M A

    2016-05-01

    The aim of this study was to assess the presence of dioxins, furans and biphenyls, and the inorganic contaminants such as arsenic (As), thorium (Th) and uranium (U) in three main products used in Agriculture in Brazil: feed grade dicalcium phosphate, calcined bovine bone meal and calcitic limestone. The first two are anthropogenic sources of phosphorus and calcium, while calcitic limestone is a natural unprocessed mineral. Regarding to dioxin-like substances, all samples analyzed exhibited dioxins (PCDD) and furans (PCDF) and dioxin-like polychlorinated biphenyls (dl-PCBs) concentrations below limit of detection (LOD). In general, achieved is in accordance with regulation in Brazil where is established a maximum limit in limestone used in the citric pulp production (0.50pg WHO-TEQ g(-1)). In addition, reported data revealed very low levels for limestone in comparison with similar materials reported by European legislation. As result for toxic metals, achieved data were obtained using Instrumental Neutron Activation Analysis (INAA). On one hand, limestone sample exhibits the largest arsenic concentration. On another hand, dicalcium phosphate exhibited the largest uranium concentration, which represents a standard in animal nutrition. Therefore, it is phosphorus source in the animal feed industry can be a goal of concern in the feed field.

  2. Phosphorus Recycling from an Unexplored Source by Polyphosphate Accumulating Microalgae and Cyanobacteria—A Step to Phosphorus Security in Agriculture

    PubMed Central

    Mukherjee, Chandan; Chowdhury, Rajojit; Ray, Krishna

    2015-01-01

    Phosphorus (P), an essential element required for crop growth has no substitute. The global food security depends on phosphorus availability in soil for crop production. World phosphorus reserves are fast depleting and with an annual increase of 2.3% in phosphorus demand, the current reserves will be exhausted in coming 50–100 years. India and other Western countries are forced to import phosphorus fertilizers at high costs to meet their agricultural demands due to uneven distribution of phosphate rocks on earth. The present study from India, aims to draw attention to an unnoticed source of phosphorus being wasted as parboiled rice mill effluent and subsequent bio-recovery of the valuable element from this unconventional source. The research was conducted in West Bengal, India, a state with the highest number of parboiled rice mills where its effluent carries on an average ~40 mg/L of soluble phosphorus. Technology to recover and recycle this wastewater P in India in a simple, inexpensive mode is yet to be optimized. Our strategy to use microalgae, Chlorella sp. and cyanobacteria, Cyanobacterium sp., Lyngbya sp., and Anabaena sp. to sequester the excess phosphorus from the effluent as polyphosphate inclusions and its subsequent recycling as slow and moderate release phosphorus biofertilizers to aid plant growth, preventing phosphorus loss and pollution, is a contemporary venture to meet the need of the hour. These polyphosphate accumulating microorganisms play a dual role of remediation and recovery of phosphorus, preliminarily validated in laboratory scale. PMID:26733966

  3. Investigating the Sources and Dynamics of Dissolved Organic Matter in an Agricultural Watershed in California (U.S.A.)

    NASA Astrophysics Data System (ADS)

    Dyda, R. Y.; Hernes, P. J.; Spencer, R. G.; Ingrum, T. D.; Pellerin, B. A.; Bergamaschi, B. A.

    2007-12-01

    Dissolved organic matter (DOM) is ubiquitous and plays critical roles in nutrient cycling, aquatic food webs and numerous other biogeochemical processes. Furthermore, various factors control the quality and quantity of DOM, including land use, soil composition, in situ production, microbial uptake and assimilation and hydrology. As a component of DOM, dissolved organic carbon (DOC) has been recently identified as a drinking water constituent of concern due to its propensity to form EPA-regulated carcinogenic compounds when disinfected for drinking water purposes. Therefore, understanding the sources, cycling and modification of DOC across various landscapes is of direct relevance to a wide range of studies. The Willow Slough watershed is located in the Central Valley of California (U.S.A.) and is characterized by both diverse geomorphology as well as land use. The watershed drains approximately 425 km2 and is bordered by Cache and Putah Creeks to the north and south. The study area in the watershed includes the eastern portion of the foothills of the inner Coast Range and the alluvial plain and encompasses diverse land uses, including orchards, viticulture, dairy, pasture and natural grasslands. The Willow Slough watershed represents a unique opportunity to examine DOC dynamics through multiple land uses and hydrologic flow paths that are common throughout California. Preliminary data show that DOC concentrations at the watershed mouth peak during winter storms and also increase gradually throughout the summer months during the agricultural irrigation season. The increasing DOC concentrations during the summer months may result from agricultural runoff and/or primary production in channel. In addition, initial results using the chromophoric DOM (CDOM) absorption coefficient and spectral slope parameters indicate seasonal differences in the composition of the DOM. Spectral slopes decreased during both the summer irrigation season and winter storms relative to winter

  4. A lighting assembly based on red and blue light-emitting diodes as a lighting source for space agriculture

    NASA Astrophysics Data System (ADS)

    Avercheva, Olga; Berkovich, Yuliy A.; Smolyanina, Svetlana; Bassarskaya, Elizaveta; Zhigalova, Tatiana; Ptushenko, Vasiliy; Erokhin, Alexei

    Light-emitting diodes (LEDs) are a promising lighting source for space agriculture due to their high efficiency, longevity, safety, and other factors. Assemblies based on red and blue LEDs have been recommended in literature, although not all plants show sufficient productivity in such lighting conditions. Adding of green LEDs proposed in some works was aimed at psychological support for the crew, and not at the improvement of plant growth. We studied the growth and the state of the photosynthetic apparatus in Chinese cabbage (Brassica chinensis L.) plants grown under red (650 nm) and blue (470 nm) light-emitting diodes (LEDs). Plants grown under a high-pressure sodium lamp (HPS lamp) were used as a control. The plants were illuminated with two photosynthetic photon flux levels: nearly 400 µE and about 100 µE. Plants grown under LEDs with 400 µE level, as compared to control plants, showed lower fresh weight, edible biomass, growth rate, and sugar content. The difference in fresh weight and edible biomass was even more pronounced in plants grown with 100 µE level; the data indicate that the adaptability of the test plants to insufficient lighting decreased. Under LEDs, we observed the decreasing of root growth and the absence of transition to the flowering stage, which points to a change in the hormonal balance in plants grown in such lighting conditions. We also found differences in the functioning of the photosynthetic apparatus and its reaction to a low lighting level. We have concluded that a lighting assembly with red and blue LEDs only is insufficient for the plant growth and productivity, and can bring about alterations in their adaptive and regulatory mechanisms. Further studies are needed to optimize the lighting spectrum for space agriculture, taking into account the photosynthetic, phototropic and regulatory roles of light. Using white LEDs or adding far-red and green LEDs might be a promising approach.

  5. Application of strontium isotope measurements to trace sediment sources in an upstream agricultural catchment (Loire River basin, France)

    NASA Astrophysics Data System (ADS)

    Le Gall, Marion; Evrard, Olivier; Thil, François; Foucher, Anthony; Salvador-Blanes, Sébastien; Cerdan, Olivier; Ayrault, Sophie

    2015-04-01

    Soil erosion is recognized as one of the main processes of land degradation in agricultural areas. It accelerates the supply of sediment to the rivers and degrades water quality. To limit those impacts and optimize management programs in such areas, sources of sediment need to be identified and sediment transport to be controlled. Here, we determined the sources of suspended sediment in the Louroux (24 km², French Loire River basin), a small catchment representative of lowland cultivated environments of Northwestern Europe. In this catchment, channels have been reshaped and 220 tile drain outlets have been installed over the last several decades. As a result, soil erosion and sediment fluxes have increased drastically. The variation of 87Sr/86Sr ratios, driven by the weathering of rocks with different ages and chemical composition, may reflect the mixing of different sediment sources. Strontium isotopic ratios (87Sr/86Sr) were therefore determined in potential soil sources, suspended particulate matter (SPM) and a sediment core sampled in the Louroux Pond at the catchment outlet. Soil, SPM and core samples displayed significantly different isotopic signatures. 87Sr/86Sr ratios in soil samples varied from 0.712763 to 0.724631 ± 0.000017 (2σ, n=20). Highest values were observed in silicic parts of the catchment whereas the lower values were identified in a calcareous area close to the Louroux Pond. 87Sr/86Sr ratios in SPM (0.713660 to 0.725749 ± 0.000017, 2σ, n=20) plotted between the soil and sediment core (0.712255 to 0.716415 ± 0.000017, 2σ, n=12), suggesting the presence of particles originating from at least two different lithological sources, i.e. silicic rocks and carbonate material. Variations in 87Sr/86Sr ratios in the outlet core sample were used to reconstruct the sedimentary dynamics in the catchment during the last decades. These results will guide the future implementation of appropriate management practices aiming to reduce erosion in upstream

  6. Anthropogenic and geogenic Cd, Hg, Pb and Se sources of contamination in a brackish aquifer below agricultural fields

    NASA Astrophysics Data System (ADS)

    Mastrocicco, Micòl; Colombani, Nicolò; Di Giuseppe, Dario; Faccini, Barbara; Ferretti, Giacomo; Coltorti, Massimo

    2015-04-01

    Groundwater quality is often threatened by industrial, agricultural and land use practices (anthropogenic input). In deltaic areas is however difficult to distinguish between geogenic and anthropogenic inorganic contaminants pollution, since these phenomena can influence each other and often display a seasonal cycling. The effect of geogenic groundwater ionic strength (>10 g/l) on the mobility of trace elements like Cd, Hg, Pb and Se was studied in combination with the anthropogenic sources of these elements (fertilizers) in a shallow aquifer. The site is located in the Po river plain (Northern Italy) in an agricultural field belonging to a reclaimed deltaic environment, near Codigoro town. It is 6 ha wide and is drained by a subsurface drainage system made of PVC tile drains with a slope of 3‰, which provides gravity drainage towards two ditches that in turn discharge in a main channel. The whole area has been intensively cultivated with cereal rotation since 1960, mainly using synthetic urea as nitrogen fertilizer at an average rate of 180 kg-N/ha/y and pig slurry at an average rate of 60 kg-N/ha/y. The sediments were analyzed for major and trace elements via XRF, while major ions in groundwater were analyzed via IC and trace elements via ICP-MS. Three monitoring wells, with an inner diameter of 2 cm and screened down to 4 m below ground level, were set up in the field and sampled every four month from 2012 to 2014. The use of intensive depth profiles with resolution of 0.5 m in three different locations, gave insights into groundwater and sediment matrix interactions. To characterize the anthropogenic inputs synthetic urea and pig slurry were analyzed for trace elements via ICP-MS. The synthetic urea is a weak source of Cd and Hg (~1 ppb), while Se and Pb are found below detection limits. The pig slurry is a much stronger source of Se (~19 ppb) and Pb (~23 ppb) and a weak source of Cd (~3 ppb) and Hg (~2 ppb). Although, the mass loading rate pig slurry is

  7. Using SWAT, Bacteroidales microbial source tracking markers, and fecal indicator bacteria to predict waterborne pathogen occurrence in an agricultural watershed.

    PubMed

    Frey, Steven K; Topp, Edward; Edge, Thomas; Fall, Claudia; Gannon, Victor; Jokinen, Cassandra; Marti, Romain; Neumann, Norman; Ruecker, Norma; Wilkes, Graham; Lapen, David R

    2013-10-15

    Developing the capability to predict pathogens in surface water is important for reducing the risk that such organisms pose to human health. In this study, three primary data source scenarios (measured stream flow and water quality, modelled stream flow and water quality, and host-associated Bacteroidales) are investigated within a Classification and Regression Tree Analysis (CART) framework for classifying pathogen (Escherichia coli 0157:H7, Salmonella, Campylobacter, Cryptosporidium, and Giardia) presence and absence (P/A) for a 178 km(2) agricultural watershed. To provide modelled data, a Soil Water Assessment Tool (SWAT) model was developed to predict stream flow, total suspended solids (TSS), total N and total P, and fecal indicator bacteria loads; however, the model was only successful for flow and total N and total P simulations, and did not accurately simulate TSS and indicator bacteria transport. Also, the SWAT model was not sensitive to an observed reduction in the cattle population within the watershed that may have resulted in significant reduction in E. coli concentrations and Salmonella detections. Results show that when combined with air temperature and precipitation, SWAT modelled stream flow and total P concentrations were useful for classifying pathogen P/A using CART methodology. From a suite of host-associated Bacteroidales markers used as independent variables in CART analysis, the ruminant marker was found to be the best initial classifier of pathogen P/A. Of the measured sources of independent variables, air temperature, precipitation, stream flow, and total P were found to be the most important variables for classifying pathogen P/A. Results indicate a close relationship between cattle pollution and pathogen occurrence in this watershed, and an especially strong link between the cattle population and Salmonella detections. PMID:24079968

  8. Sustainable Sourcing of Global Agricultural Raw Materials: Assessing Gaps in Key Impact and Vulnerability Issues and Indicators

    PubMed Central

    Springer, Nathaniel P.; Garbach, Kelly; Guillozet, Kathleen; Haden, Van R.; Hedao, Prashant; Hollander, Allan D.; Huber, Patrick R.; Ingersoll, Christina; Langner, Megan; Lipari, Genevieve; Mohammadi, Yaser; Musker, Ruthie; Piatto, Marina; Riggle, Courtney; Schweisguth, Melissa; Sin, Emily; Snider, Sara; Vidic, Nataša; White, Aubrey; Brodt, Sonja; Quinn, James F.; Tomich, Thomas P.

    2015-01-01

    Understanding how to source agricultural raw materials sustainably is challenging in today’s globalized food system given the variety of issues to be considered and the multitude of suggested indicators for representing these issues. Furthermore, stakeholders in the global food system both impact these issues and are themselves vulnerable to these issues, an important duality that is often implied but not explicitly described. The attention given to these issues and conceptual frameworks varies greatly—depending largely on the stakeholder perspective—as does the set of indicators developed to measure them. To better structure these complex relationships and assess any gaps, we collate a comprehensive list of sustainability issues and a database of sustainability indicators to represent them. To assure a breadth of inclusion, the issues are pulled from the following three perspectives: major global sustainability assessments, sustainability communications from global food companies, and conceptual frameworks of sustainable livelihoods from academic publications. These terms are integrated across perspectives using a common vocabulary, classified by their relevance to impacts and vulnerabilities, and categorized into groups by economic, environmental, physical, human, social, and political characteristics. These issues are then associated with over 2,000 sustainability indicators gathered from existing sources. A gap analysis is then performed to determine if particular issues and issue groups are over or underrepresented. This process results in 44 “integrated” issues—24 impact issues and 36 vulnerability issues —that are composed of 318 “component” issues. The gap analysis shows that although every integrated issue is mentioned at least 40% of the time across perspectives, no issue is mentioned more than 70% of the time. A few issues infrequently mentioned across perspectives also have relatively few indicators available to fully represent them

  9. Sustainable Sourcing of Global Agricultural Raw Materials: Assessing Gaps in Key Impact and Vulnerability Issues and Indicators.

    PubMed

    Springer, Nathaniel P; Garbach, Kelly; Guillozet, Kathleen; Haden, Van R; Hedao, Prashant; Hollander, Allan D; Huber, Patrick R; Ingersoll, Christina; Langner, Megan; Lipari, Genevieve; Mohammadi, Yaser; Musker, Ruthie; Piatto, Marina; Riggle, Courtney; Schweisguth, Melissa; Sin, Emily; Snider, Sara; Vidic, Nataša; White, Aubrey; Brodt, Sonja; Quinn, James F; Tomich, Thomas P

    2015-01-01

    Understanding how to source agricultural raw materials sustainably is challenging in today's globalized food system given the variety of issues to be considered and the multitude of suggested indicators for representing these issues. Furthermore, stakeholders in the global food system both impact these issues and are themselves vulnerable to these issues, an important duality that is often implied but not explicitly described. The attention given to these issues and conceptual frameworks varies greatly--depending largely on the stakeholder perspective--as does the set of indicators developed to measure them. To better structure these complex relationships and assess any gaps, we collate a comprehensive list of sustainability issues and a database of sustainability indicators to represent them. To assure a breadth of inclusion, the issues are pulled from the following three perspectives: major global sustainability assessments, sustainability communications from global food companies, and conceptual frameworks of sustainable livelihoods from academic publications. These terms are integrated across perspectives using a common vocabulary, classified by their relevance to impacts and vulnerabilities, and categorized into groups by economic, environmental, physical, human, social, and political characteristics. These issues are then associated with over 2,000 sustainability indicators gathered from existing sources. A gap analysis is then performed to determine if particular issues and issue groups are over or underrepresented. This process results in 44 "integrated" issues--24 impact issues and 36 vulnerability issues--that are composed of 318 "component" issues. The gap analysis shows that although every integrated issue is mentioned at least 40% of the time across perspectives, no issue is mentioned more than 70% of the time. A few issues infrequently mentioned across perspectives also have relatively few indicators available to fully represent them. Issues in the

  10. Effect of hillslope position and manure application rates on the persistence of fecal source tracking indicators in an agricultural soil.

    PubMed

    Piorkowski, Gregory S; Bezanson, Greg S; Jamieson, Rob C; Hansen, Lisbeth Truelstrup; Yost, Chris K

    2014-03-01

    The influence of liquid dairy manure (LDM) application rates (12.5 and 25 kL ha) and soil type on the decay rates of library-independent fecal source tracking markers (host-associated and mitochondrial DNA) and persistent (>58 d) population structure was examined in a field study. The soils compared were an Aquic Haplorthod and a Typic Haplorthod in Nova Scotia, Canada, that differed according to landscape position and soil moisture regime. Soil type and LDM application rate did not influence decay rates (0.045-0.057 d). population structure, in terms of the occurrence of abundance of strain types, varied according to soil type ( = 0.012) but did not vary by LDM application rate ( = 0.121). Decay of ruminant-specific (BacR), bovine-specific (CowM2), and mitochondrial DNA (AcytB) markers was analyzed for 13 d after LDM application. The decay rates of BacR were greater under high-LDM application rates (0.281-0.358 d) versus low-LDM application rates (0.212-0.236 d) but were unaffected by soil type. No decay rates could be calculated for the CowM2 marker because it was undetectable within 6 d after manure application. Decay rates for AcytB were lower for the Aquic Haplorthod (0.088-0.100 d), with higher moisture status compared with the Typic Haplorthod (0.135 d). Further investigation into the decay of fecal source tracking indicators in agricultural field soils is warranted to assess the influence of soil type and agronomic practice on the differential decay of relevant markers and the likelihood of transport in runoff.

  11. Modeling hydrology, groundwater recharge and non-point nitrate loadings in the Himalayan Upper Yamuna basin.

    PubMed

    Narula, Kapil K; Gosain, A K

    2013-12-01

    The mountainous Himalayan watersheds are important hydrologic systems responsible for much of the water supply in the Indian sub-continent. These watersheds are increasingly facing anthropogenic and climate-related pressures that impact spatial and temporal distribution of water availability. This study evaluates temporal and spatial distribution of water availability including groundwater recharge and quality (non-point nitrate loadings) for a Himalayan watershed, namely, the Upper Yamuna watershed (part of the Ganga River basin). The watershed has an area of 11,600 km(2) with elevation ranging from 6300 to 600 m above mean sea level. Soil and Water Assessment Tool (SWAT), a physically-based, time-continuous model, has been used to simulate the land phase of the hydrological cycle, to obtain streamflows, groundwater recharge, and nitrate (NO3) load distributions in various components of runoff. The hydrological SWAT model is integrated with the MODular finite difference groundwater FLOW model (MODFLOW), and Modular 3-Dimensional Multi-Species Transport model (MT3DMS), to obtain groundwater flow and NO3 transport. Validation of various modules of this integrated model has been done for sub-basins of the Upper Yamuna watershed. Results on surface runoff and groundwater levels obtained as outputs from simulation show a good comparison with the observed streamflows and groundwater levels (Nash-Sutcliffe and R(2) correlations greater than +0.7). Nitrate loading obtained after nitrification, denitrification, and NO3 removal from unsaturated and shallow aquifer zones is combined with groundwater recharge. Results for nitrate modeling in groundwater aquifers are compared with observed NO3 concentration and are found to be in good agreement. The study further evaluates the sensitivity of water availability to climate change. Simulations have been made with the weather inputs of climate change scenarios of A2, B2, and A1B for end of the century. Water yield estimates under

  12. Modeling hydrology, groundwater recharge and non-point nitrate loadings in the Himalayan Upper Yamuna basin.

    PubMed

    Narula, Kapil K; Gosain, A K

    2013-12-01

    The mountainous Himalayan watersheds are important hydrologic systems responsible for much of the water supply in the Indian sub-continent. These watersheds are increasingly facing anthropogenic and climate-related pressures that impact spatial and temporal distribution of water availability. This study evaluates temporal and spatial distribution of water availability including groundwater recharge and quality (non-point nitrate loadings) for a Himalayan watershed, namely, the Upper Yamuna watershed (part of the Ganga River basin). The watershed has an area of 11,600 km(2) with elevation ranging from 6300 to 600 m above mean sea level. Soil and Water Assessment Tool (SWAT), a physically-based, time-continuous model, has been used to simulate the land phase of the hydrological cycle, to obtain streamflows, groundwater recharge, and nitrate (NO3) load distributions in various components of runoff. The hydrological SWAT model is integrated with the MODular finite difference groundwater FLOW model (MODFLOW), and Modular 3-Dimensional Multi-Species Transport model (MT3DMS), to obtain groundwater flow and NO3 transport. Validation of various modules of this integrated model has been done for sub-basins of the Upper Yamuna watershed. Results on surface runoff and groundwater levels obtained as outputs from simulation show a good comparison with the observed streamflows and groundwater levels (Nash-Sutcliffe and R(2) correlations greater than +0.7). Nitrate loading obtained after nitrification, denitrification, and NO3 removal from unsaturated and shallow aquifer zones is combined with groundwater recharge. Results for nitrate modeling in groundwater aquifers are compared with observed NO3 concentration and are found to be in good agreement. The study further evaluates the sensitivity of water availability to climate change. Simulations have been made with the weather inputs of climate change scenarios of A2, B2, and A1B for end of the century. Water yield estimates under

  13. Assessing the pollution potential of non-point mine wastes on surface water using a geo-spatial modeling approach

    NASA Astrophysics Data System (ADS)

    Xiao, Huaguo

    Abandoned mine lands (or inactive and abandoned mines) have received increasing concerns because they may cause severe environmental and public health problems. Most of previous studies to characterize mine waste pollution potential were focused on screening-level investigations. The issues related to pollution potential of mine waste were poorly addressed from the perspective of non-point source pollution, and few efforts have been made to study the effect of spatial characteristics of mine wastes on water quality using spatial technology such as GIS, remote sensing and spatial modeling. This research develops a geo-spatial approach to assessing mine waste pollution on surface water, which integrates GIS, remote sensing and watershed modeling techniques in order to effectively address the effects of spatial characteristics of pollutants. The study area is Tri-State Mining District which is located in the conjunction of Missouri, Kansas and Okalahoma. This district was the most important lead and zinc mining area in U.S. The historic mining left behind a huge area of mine wastes. Satellite remote sensing data (Landsat MSS and TM) were acquired, processed and classified in a decadal interval to generate land use/land cover (LULC) data for the entire district. Watersheds within the district were delineated by using USGS DEM data and a newly-developed GIS tool. Water quality indicators were selected and relevant water quality data between 1970 and 2002 was retrieved from USGS and USEPA databases. With the classified LULC data as a data source, landscape metrics (composition and spatial configuration indices) for each water quality station in mine waste-located watersheds were calculated. Statistical analyses were performed to quantify the relationship between landscape and surface water quality and to evaluate the impacts of landscape characteristics on surface water quality. Related GIS data layers were then created and a cell-based watershed modeling was conducted

  14. Application of particle size distributions to total particulate stack samples to estimate PM2.5 and PM10 emission factors for agricultural sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Particle size distributions (PSD) have long been used to more accurately estimate the PM10 fraction of total particulate matter (PM) stack samples taken from agricultural sources. These PSD analyses were typically conducted using a Coulter Counter with 50 micrometer aperture tube. With recent increa...

  15. USING LANDSCAPE ECOLOGY TO MAP WATERSHEDS THAT ARE VULNERABLE TO NON-POINT SOURCE POLLUTION IN THE OZARKS

    EPA Science Inventory

    The U.S. EPA's Office of Research and Development, and U.S. EPA Region 7 have collaborated to map and interpret landscape-scale (i.e. broad-scale) ecological metrics among watershed of the Upper White River, and have produced the first geospatial models of water quality vulnerabi...

  16. Field-deployed Metabolomics for Assessing Surface Waters Impacted by Point and Non-Point Sources of Contamination

    EPA Science Inventory

    Metabolomics has become well-established for studying chemical contaminant-induced alterations to normal biological function. For example, the literature contains a wealth of laboratory-based studies involving analysis of samples from organisms exposed to individual chemical toxi...

  17. In-situ treatment of non-point source pollution part 2: Field results from two different treatment structures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphorus (P) sorbing materials (PSMs) have been used to reduce dissolved P (DP) concentrations in surface runoff and leachate via applications to soils and animal manure. In August, 2006, a P removal structure filled with an aluminum oxide, iron oxide and calcium sulfate/carbonate rich residual d...

  18. Field-deployed Metabolomics for Assessing Waters Impacted by Point and Non-Point Sources of Contamination

    EPA Science Inventory

    Metabolomics is becoming well-established for studying chemical contaminant-induced alterations to normal biological function. For example, the literature contains a wealth of laboratory-based studies involving analysis of samples from organisms exposed to individual chemical tox...

  19. Synthesis and application of lignin-based copolymer LSAA on controlling non-point source pollution resulted from surface runoff.

    PubMed

    Liu, Chen; Wu, Guangxia; Mu, Huanzhen; Yuan, Zonghuan; Tang, Lianyi; Lin, Xiangwei

    2008-01-01

    In this article, alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin, starch, acrylamide, and acrylic acid). Its practical application effect and environmental safety were studied. The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants. The runoff quantity was decreased by 16.67%-47.00% and the loads of total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) were reduced by 17.78%-62.14%, 26.32%-59.91%, 15.25%-47.42%, and 22.18%-52.78%, respectively. The tests on its environmental safety showed that LSAA did no harm the soil. Compared with polyacrylamide (PAM), a dominant product in this field, LSAA exhibited similar effects and cheap cost. Thus, this study not only created a new product for controlling runoff water quality but also offered a beneficial application for industrial paper waste.

  20. LANDSCAPE CHARACTERIZATION & NON-POINT SOURCE NITROGEN MODELING IN SUPPORT OF TMDL DEVELOPMENT IN THE NEUSE RIVER BASIN, NC

    EPA Science Inventory



    Pfesteria-like toxic- blooms have been implicated as the causative agent responsible for numerous outbreaks of fish lesions and fish kills in the Mid-Atlantic and southeastern U.S. An increase in frequency, intensity, and severity of toxic blooms in recent years is though...

  1. Synthesis and application of lignin-based copolymer LSAA on controlling non-point source pollution resulted from surface runoff.

    PubMed

    Liu, Chen; Wu, Guangxia; Mu, Huanzhen; Yuan, Zonghuan; Tang, Lianyi; Lin, Xiangwei

    2008-01-01

    In this article, alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin, starch, acrylamide, and acrylic acid). Its practical application effect and environmental safety were studied. The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants. The runoff quantity was decreased by 16.67%-47.00% and the loads of total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) were reduced by 17.78%-62.14%, 26.32%-59.91%, 15.25%-47.42%, and 22.18%-52.78%, respectively. The tests on its environmental safety showed that LSAA did no harm the soil. Compared with polyacrylamide (PAM), a dominant product in this field, LSAA exhibited similar effects and cheap cost. Thus, this study not only created a new product for controlling runoff water quality but also offered a beneficial application for industrial paper waste. PMID:18814577

  2. USING LANDSCAPE ECOLOGY AND PARTIAL LEAST SQUARES PREDICTIONS TO MAP WATERSHEDS THAT ARE VULNERABLE TO NON-POINT SOURCE POLLUTION

    EPA Science Inventory

    The U.S. Environmental Protection Agency's Office of Research and Development have mapped and interpreted landscape-scale (i.e., broad scale) ecological metrics among watersheds in the upper White River watershed, producing the first geospatial models of water quality vulnerabili...

  3. USING LANDSCAPE ECOLOGY AND PARTIAL LEAST SQUARES PREDICITIONS TO MAP WATERSHEDS THAT ARE VULNERABLE TO NON-POINT SOURCE POLLUTION

    EPA Science Inventory

    The U.S. Environmental Protection Agency¿s Office of Research and Development have mapped and interpreted landscape-scale (i.e., broad scale) ecological metrics among watersheds in the upper White River watershed, producing the first geospatial models of water quality vulnerabili...

  4. Nitrate in aquifers beneath agricultural systems

    USGS Publications Warehouse

    Burkart, M.R.; Stoner, J.D.

    2002-01-01

    Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater vulnerability to nitrate contamination. Analysis of nationally consistent measurements from the U.S. Geological Survey's NAWOA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial and other unconsolidated aquifers are the most vulnerable and shallow carbonate aquifers provide a substantial but smaller contamination risk. Where any of these aquifers are overlain by permeable soils the risk of contamination is larger. Irrigated systems can compound this vulnerability by increasing leaching facilitated by additional recharge and additional nutrient applications. The agricultural system of corn, soybeans, and hogs produced significantly larger concentrations of groundwater nitrate than all other agricultural systems, although mean nitrate concentrations in counties with dairy, poultry, cattle and grains, and horticulture systems were similar. If trends in the relation between increased fertilizer use and groundwater nitrate in the United States are repeated in other regions of the world, Asia may experience increasing problems because of recent increases in fertilizer use. Groundwater monitoring in Western and Eastern Europe as well as Russia over the next decade may provide data to determine if the trend in increased nitrate contamination can be reversed. If the concentrated livestock trend in the United States is global, it may be accompanied by increasing nitrogen contamination in groundwater. Concentrated livestock provide both point sources in the confinement area and intense non-point sources as fields close to facilities are used for manure disposal. Regions where irrigated cropland is expanding, such as in Asia, may experience the greatest impact of

  5. High-frequency monitoring reveals nutrient sources and transport processes in an agriculture-dominated lowland water system

    NASA Astrophysics Data System (ADS)

    van der Grift, Bas; Broers, Hans Peter; Berendrecht, Wilbert; Rozemeijer, Joachim; Osté, Leonard; Griffioen, Jasper

    2016-05-01

    Many agriculture-dominated lowland water systems worldwide suffer from eutrophication caused by high nutrient loads. Insight in the hydrochemical functioning of embanked polder catchments is highly relevant for improving the water quality in such areas or for reducing export loads to downstream water bodies. This paper introduces new insights in nutrient sources and transport processes in a polder in the Netherlands situated below sea level using high-frequency monitoring technology at the outlet, where the water is pumped into a higher situated lake, combined with a low-frequency water quality monitoring programme at six locations within the drainage area. Seasonal trends and short-scale temporal dynamics in concentrations indicated that the NO3 concentration at the pumping station originated from N loss from agricultural lands. The NO3 loads appear as losses via tube drains after intensive rainfall events during the winter months due to preferential flow through the cracked clay soil. Transfer function-noise modelling of hourly NO3 concentrations reveals that a large part of the dynamics in NO3 concentrations during the winter months can be related to rainfall. The total phosphorus (TP) concentration and turbidity almost doubled during operation of the pumping station, which points to resuspension of particulate P from channel bed sediments induced by changes in water flow due to pumping. Rainfall events that caused peaks in NO3 concentrations did not results in TP concentration peaks. The rainfall induced and NO3 enriched quick interflow, may also be enriched in TP but retention of TP due to sedimentation of particulate P then results in the absence of rainfall induced TP concentration peaks. Increased TP concentrations associated with run-off events is only observed during a rainfall event at the end of a freeze-thaw cycle. All these observations suggest that the P retention potential of polder water systems is primarily due to the artificial pumping regime

  6. High-frequency monitoring reveals nutrient sources and transport processes in an agriculture-dominated lowland water system

    NASA Astrophysics Data System (ADS)

    van der Grift, B.; Broers, H. P.; Berendrecht, W. L.; Rozemeijer, J. C.; Osté, L. A.; Griffioen, J.

    2015-08-01

    Many agriculture-dominated lowland water systems worldwide suffer from eutrophication caused by high nutrient loads. Insight in the hydrochemical functioning of embanked polder catchments is highly relevant for improving the water quality in such areas. This paper introduces new insights in nutrient sources and transport processes in a low elevated polder in the Netherlands using high-frequency monitoring technology at the outlet, where the water is pumped into a higher situated lake, combined with a low-frequency water quality monitoring program at six locations within the drainage area. Seasonal trends and short scale temporal dynamics in concentrations indicated that the NO3 concentration at the pumping station originated from N-loss from agricultural lands. The NO3 loads appear as losses with drain water discharge after intensive rainfall events during the winter months due to preferential flow through the cracked clay soil. Transfer function-noise modelling of hourly NO3 concentrations reveals that a large part of the dynamics in NO3 concentrations during the winter months can be related to rainfall. The total phosphorus (TP) concentration almost doubled during operation of the pumping station which points to resuspension of particulate P from channel bed sediments induced by changes in water flow due to pumping. Rainfall events that caused peaks in NO3 concentrations did not results in TP concentration peaks. The by rainfall induced and NO3 enriched quick interflow, may also be enriched in TP but this is then buffered in the water system due to sedimentation of particulate P. Increased TP concentrations associated with run-off events is only observed during a rainfall event at the end of a freeze-thaw cycle. All these observations suggest that the P retention potential of polder water systems is highly due to the artificial pumping regime that buffers high flows. As the TP concentration is affected by operation of the pumping station, timing of sampling

  7. Chemical characteristics and source apportionment of PM2.5 during the harvest season in eastern China's agricultural regions

    NASA Astrophysics Data System (ADS)

    Li, Jianfeng; Song, Yu; Mao, Yi; Mao, Zhichun; Wu, Yusheng; Li, Mengmeng; Huang, Xin; He, Qichao; Hu, Min

    2014-08-01

    To determine the contribution of the open burning of wheat straw residues to local PM2.5 during the harvest season of June 2013, PM2.5 was sampled in an agricultural region in eastern China. The sampling site was approximately 1 km from the nearest wheat field. Chemical compositions were analyzed, and source apportionment was undertaken using the positive matrix factorization model. The average PM2.5 concentration was 110.7 μg/m3, containing 36.4 μg/m3 organics, 7.3 μg/m3 EC, 6.0 μg/m3 potassium (K) and 4.9 μg/m3 chloride ion (Cl-). The sampling period was divided into three phases: the pre-local-burning phase (Phase 1), the local-burning phase (Phase 2) and the post-local-burning phase (Phase 3). In Phase 2, the concentrations of PM2.5 and the organics, EC, K and Cl- in PM2.5 were 163.6 μg/m3, 59.0 μg/m3, 12.2 μg/m3, 11.0 μg/m3 and 10.8 μg/m3, respectively, which were all remarkably higher than in both Phase 1 and Phase 3. Eight sources of PM2.5 were determined, including two types of wheat residue burning sources, which showed a significant difference in Cl- content. The atmospheric relative humidity (RH) and the aging process of PM2.5 might be the causes: only fresh particulate emissions from wheat residue burning could feature high-concentration Cl- under high RH conditions. In Phase 2, wheat residue burning contributed 51.3% of PM2.5, 75.8% of OC, 74.5% of EC, 90.1% of K and 104.1% of Cl-. These percentages were lower in Phases 1 and 3 than in Phase 2. Wheat residue burning caused such severe air pollution that it's necessary to prohibit the open burning of crop residues in order to protect public health and the environment.

  8. Methodology for agricultural and rural NPS pollution in a typical county of the North China Plain.

    PubMed

    Yang, Yong; Chen, Ying; Zhang, Xiaolan; Ongley, Edwin; Zhao, Lei

    2012-09-01

    Agricultural non-point source (NPS) pollution has been recently identified by the Chinese government as a major source of aquatic pollution. Methodologies commonly used to make basin-wide or area-wide assessments are problematic and regional distinctions have not been made relative to rainfall and runoff. Using a typical agricultural county in the Hai River basin of the North China Plan we developed methodology to estimate potential load and delivered load for crops (field crops + rice), animal production, rural living and from atmospheric N input. We use scenarios to allow for uncertainty in delivery to estimate the relative roles of different rural forms of pollution. Livestock raising is the major source of NPS pollution. Despite a 75% rural population, rural living contributes almost nothing to surface water pollution. While over-fertilization is typical, nutrient runoff from crops is low. Our results have implications for policies now under development for NPS control in China.

  9. Descriptions and Source Listings of Professional Information in Agricultural Education, 1966-67, 1967-68, and 1968-69.

    ERIC Educational Resources Information Center

    American Vocational Association, Washington, DC. Professional Information Committee.

    These annotated bibliographies contain a total of 449 references of professional information in agricultural education published annually. References are organized under headings of: (1) Agricultural Mechanics, (2) Animal Science, (3) Conservation and Forestry, (4) Curriculum Development and Course of Study, (5) Farm Business Management and…

  10. Forests on drained agricultural peatland are potentially large sources of greenhouse gases - insights from a full rotation period simulation

    NASA Astrophysics Data System (ADS)

    He, Hongxing; Jansson, Per-Erik; Svensson, Magnus; Björklund, Jesper; Tarvainen, Lasse; Klemedtsson, Leif; Kasimir, Åsa

    2016-04-01

    The CoupModel was used to simulate a Norway Spruce forest on fertile drained peat over 60 years, from planting in 1951 until 2011, describing abiotic, biotic and greenhouse gas (GHG) emissions (CO2 and N2O). By calibrating the model against tree ring derived biomass data and measured 6 year abiotic data we obtained a "reference" model by which we were able to describe the GHG fluxes and controlling factors over the 60 years. The GHG fluxes are composed of two important quantities, the forest carbon (C) uptake, 405 g C m‑2 yr‑1 and the decomposition of peat soil, 396 g C m‑2 yr‑1. N2O emissions contribute to the GHG emissions by 0.5 g N m‑2 yr‑1, corresponding to 56.8 g C m‑2 yr‑1. The 60-year-old Spruce forest has an accumulated biomass of 164 Mg C ha‑1. However, over this period 208 Mg C ha‑1 GHG has been added to the atmosphere, which means a net addition of GHG emissions. The main losses are from the peat soil and, indirectly, from forest thinning products, which we assume have a short lifetime. Model sensitivity analysis by changing initial soil C, drainage depth and initial soil C/N ratio also confirms that forests on drained agricultural peatland are a GHG source. We conclude that after harvest at an age of 80 years, most of the stored biomass carbon is liable to be released, the system having captured C only temporarily and with a cost of disappeared peat, adding both CO2 and N2O to the atmosphere.

  11. Identification of sources and behavior of agricultural contaminants in groundwater using nitorgen and sulfur isootope in Haean basin, Korea

    NASA Astrophysics Data System (ADS)

    Kaown, Dugin; Kim, Heejung; Mayer, Bernard; Hyun, Yunjung; Lee, Jin-Yong; Lee, Kang-Kun

    2013-04-01

    The Haean basin shows a bowl-shaped topographic feature and the drainage system shows a dendritic pattern. The study area is consisted of forests (58.0%), vegetable fields (27.6%), rice paddy fields (11.4%) and fruit fields (0.5%). Most of residents in the study area practice agriculture and paddy rice and vegetables (Chinese radish) are the typical crops grown. The concentration of nitrate in groundwater showed 0.8 ~ 67.3 mg/L in June, 2012 and 2.0 ~ 65.7 mg/L in September, 2012. Hydrogeochemical values and stable isotope ratios of dissolved nitrate and sulfate in groundwater were used to identify contamination sources and transformation processes in shallow groundwater. The δ15N-NO3- values in the study area ranged between +5.2 and +16.9‰ in June and between +4.4 and +13.0‰ in September. The sulfate concentration in groundwater samples obtained from the study area varied from 0.8 to 16.5 mg/L in June and 0 to 19.7 mg/L in September. δ34S-SO42- values ranged from +2.9 to +11.7‰ in June and +1.6 to +8.2‰ in September. The values of δ15N-NO3- and δ34S-SO42- in September were slightly decreased than those of values in June. The chemical composition of groundwater in vegetable and fruit fields showed slightly lower values of δ34S-SO42- and δ15N-NO3- indicated that a mixture of synthetic and organic fertilizers is responsible for groundwater contamination with agro-chemicals. Most groundwater from forests and paddy fields showed slightly higher values of δ15N-NO3- suggested that organic fertilizer is introduced into subsurface.

  12. Forests on drained agricultural peatland are potentially large sources of greenhouse gases - insights from a full rotation period simulation

    NASA Astrophysics Data System (ADS)

    He, Hongxing; Jansson, Per-Erik; Svensson, Magnus; Björklund, Jesper; Tarvainen, Lasse; Klemedtsson, Leif; Kasimir, Åsa

    2016-04-01

    The CoupModel was used to simulate a Norway Spruce forest on fertile drained peat over 60 years, from planting in 1951 until 2011, describing abiotic, biotic and greenhouse gas (GHG) emissions (CO2 and N2O). By calibrating the model against tree ring derived biomass data and measured 6 year abiotic data we obtained a "reference" model by which we were able to describe the GHG fluxes and controlling factors over the 60 years. The GHG fluxes are composed of two important quantities, the forest carbon (C) uptake, 405 g C m-2 yr-1 and the decomposition of peat soil, 396 g C m-2 yr-1. N2O emissions contribute to the GHG emissions by 0.5 g N m-2 yr-1, corresponding to 56.8 g C m-2 yr-1. The 60-year-old Spruce forest has an accumulated biomass of 164 Mg C ha-1. However, over this period 208 Mg C ha-1 GHG has been added to the atmosphere, which means a net addition of GHG emissions. The main losses are from the peat soil and, indirectly, from forest thinning products, which we assume have a short lifetime. Model sensitivity analysis by changing initial soil C, drainage depth and initial soil C/N ratio also confirms that forests on drained agricultural peatland are a GHG source. We conclude that after harvest at an age of 80 years, most of the stored biomass carbon is liable to be released, the system having captured C only temporarily and with a cost of disappeared peat, adding both CO2 and N2O to the atmosphere.

  13. Degradation State, Sources, and Reactivity of Dissolved Organic Matter from an Amino Acid Time Series in an Agricultural Watershed

    NASA Astrophysics Data System (ADS)

    Matiasek, S. J.; Pellerin, B. A.; Spencer, R. G.; Bergamaschi, B. A.; Hernes, P.

    2015-12-01

    A detailed time series of dissolved amino acids was obtained in an agricultural watershed in the northern Central Valley, California, USA to investigate the roles of hydrologic and seasonal changes on the composition of dissolved organic matter (DOM). Total hydrolysable amino acid (THAA) concentrations ranged from 0.55 to 9.96 μM (mean 3.76 ± 1.80 μM) and not only peaked with discharge during winter storms, but also remained elevated throughout the irrigation season when discharge was low. Summer irrigation was a critical hydrologic regime for DOM cycling, since it mobilized DOM similar in concentration and reactivity to DOM released during winter storms for an extended period of time, with the largest amino acid contributions to the dissolved organic carbon (DOC) and the dissolved organic nitrogen (DON) pools (3.4 ‒ 3.7 % DOC-AA, 17.4 ‒ 22.5 % DON-AA), the largest proportion of basic amino acids (B/(B+A) = 0.19 ‒ 0.22), and the largest degradation index values (mean 1.37 ± 0.96). The mole percent of non-protein amino acids, commonly considered as an indicator of microbial degradation, decreased with DOM processing and was highest during summer (mean 4.1 ± 1.1%). A lack of correlation between THAA concentrations and UV-Vis absorbance and fluorescence proxies (including "protein-like" fluorophores B and T) indicated that optical properties may be limited in representing amino acid dynamics in this system. A new parameter for DOM processing derived from trends in individual amino acids demonstrated strong potential for inferring the extent of DOM degradation in freshwater systems. The biogeochemical relevance of irrigation practices is heightened by timing, since the additional export of reactive DOM coincides with enhanced downstream DOM processing in the Sacramento-San Joaquin River Delta, a critical habitat for endangered species serving as water source for 25 million Californians.

  14. Source identification of PCDD/Fs in agricultural soils near to a Chinese MSWI plant through isomer-specific data analysis.

    PubMed

    Xu, Meng-Xia; Yan, Jian-Hua; Lu, Sheng-Yong; Li, Xiao-Dong; Chen, Tong; Ni, Ming-Jiang; Dai, Hui-Fen; Cen, Ke-Fa

    2008-04-01

    Isomer-specific data were investigated in order to identify the sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in agricultural soils, including Fluvo-aquic and paddy soils, in the vicinity of a Chinese municipal solid waste incineration (MSWI) plant. Homologue and isomer profiles of PCDD/Fs in soils were compared with those of potential sources, including combustion sources, i.e., MSWI flue gas and fly ash; and the impurities in agrochemicals, such as the pentachlorophenol (PCP), sodium pentachlorophenate (PCP-Na) and 1,3,5-trichloro-2-(4-nitrophenoxy) benzene (CNP). The results showed that the PCDD/F isomer profiles of combustion sources and agricultural soils were very similar, especially for PCDFs, although their homologue profiles varied, indicating that all the isomers within each homologue behave identically in the air and soil. Moreover, factor analysis of the isomer compositions among 33 soil samples revealed that the contamination of PCDD/Fs in agricultural soils near the MSWI plant were primarily influenced by the combustion sources, followed by the PCP/PCP-Na and CNP sources. This implication is consistent with our previous findings based on chemometric analysis of homologue profiles of soil and flue gas samples, and identifies PCP/PCP-Na as an additional important source of PCDD/Fs in the local area. This makes the similarities and differences of isomer profiles between Fluvo-aquic and paddy soils more explainable. It is, therefore, advisable to use isomer-specific data for PCDD/F source identifications where possible.

  15. Tropical forests were the primary sources of new agricultural land in the 1980s and 1990s

    PubMed Central

    Gibbs, H. K.; Ruesch, A. S.; Achard, F.; Clayton, M. K.; Holmgren, P.; Ramankutty, N.; Foley, J. A.

    2010-01-01

    Global demand for agricultural products such as food, feed, and fuel is now a major driver of cropland and pasture expansion across much of the developing world. Whether these new agricultural lands replace forests, degraded forests, or grasslands greatly influences the environmental consequences of expansion. Although the general pattern is known, there still is no definitive quantification of these land-cover changes. Here we analyze the rich, pan-tropical database of classified Landsat scenes created by the Food and Agricultural Organization of the United Nations to examine pathways of agricultural expansion across the major tropical forest regions in the 1980s and 1990s and use this information to highlight the future land conversions that probably will be needed to meet mounting demand for agricultural products. Across the tropics, we find that between 1980 and 2000 more than 55% of new agricultural land came at the expense of intact forests, and another 28% came from disturbed forests. This study underscores the potential consequences of unabated agricultural expansion for forest conservation and carbon emissions. PMID:20807750

  16. Tropical forests were the primary sources of new agricultural land in the 1980s and 1990s.

    PubMed

    Gibbs, H K; Ruesch, A S; Achard, F; Clayton, M K; Holmgren, P; Ramankutty, N; Foley, J A

    2010-09-21

    Global demand for agricultural products such as food, feed, and fuel is now a major driver of cropland and pasture expansion across much of the developing world. Whether these new agricultural lands replace forests, degraded forests, or grasslands greatly influences the environmental consequences of expansion. Although the general pattern is known, there still is no definitive quantification of these land-cover changes. Here we analyze the rich, pan-tropical database of classified Landsat scenes created by the Food and Agricultural Organization of the United Nations to examine pathways of agricultural expansion across the major tropical forest regions in the 1980s and 1990s and use this information to highlight the future land conversions that probably will be needed to meet mounting demand for agricultural products. Across the tropics, we find that between 1980 and 2000 more than 55% of new agricultural land came at the expense of intact forests, and another 28% came from disturbed forests. This study underscores the potential consequences of unabated agricultural expansion for forest conservation and carbon emissions. PMID:20807750

  17. Tropical forests were the primary sources of new agricultural land in the 1980s and 1990s.

    PubMed

    Gibbs, H K; Ruesch, A S; Achard, F; Clayton, M K; Holmgren, P; Ramankutty, N; Foley, J A

    2010-09-21

    Global demand for agricultural products such as food, feed, and fuel is now a major driver of cropland and pasture expansion across much of the developing world. Whether these new agricultural lands replace forests, degraded forests, or grasslands greatly influences the environmental consequences of expansion. Although the general pattern is known, there still is no definitive quantification of these land-cover changes. Here we analyze the rich, pan-tropical database of classified Landsat scenes created by the Food and Agricultural Organization of the United Nations to examine pathways of agricultural expansion across the major tropical forest regions in the 1980s and 1990s and use this information to highlight the future land conversions that probably will be needed to meet mounting demand for agricultural products. Across the tropics, we find that between 1980 and 2000 more than 55% of new agricultural land came at the expense of intact forests, and another 28% came from disturbed forests. This study underscores the potential consequences of unabated agricultural expansion for forest conservation and carbon emissions.

  18. Agricultural Libraries and Information.

    ERIC Educational Resources Information Center

    Russell, Keith W., Ed.; Pisa, Maria G., Ed.

    1990-01-01

    Eleven articles address issues relating to agricultural libraries and information, including background on agricultural libraries and information, trend management, document delivery, reference services, user needs and library services, collection development, technologies for international information management, information sources,…

  19. Identifying sources of dissolved organic carbon in agriculturally dominated rivers using radiocarbon age dating: Sacramento-San Joaquin River Basin, California

    USGS Publications Warehouse

    Sickman, James O.; DiGiorgio, Carol L.; Davisson, M. Lee; Lucero, Delores M.; Bergamaschi, Brian A.

    2010-01-01

    We used radiocarbon measurements of dissolved organic carbon (DOC) to resolve sources of riverine carbon within agriculturally dominated landscapes in California. During 2003 and 2004, average Δ14C for DOC was -254‰ in agricultural drains in the Sacramento-San Joaquin Delta, -218‰ in the San Joaquin River, -175‰ in the California State Water Project and -152‰ in the Sacramento River. The age of bulk DOC transiting the rivers of California's Central Valley is the oldest reported for large rivers and suggests wide-spread loss of soil organic matter caused by agriculture and urbanization. Using DAX 8 adsorbent, we isolated and measured 14C concentrations in hydrophobic acid fractions (HPOA); river samples showed evidence of bomb-pulse carbon with average Δ14C of 91 and 76‰ for the San Joaquin and Sacramento Rivers, respectively, with older HPOA, -204‰, observed in agricultural drains. An operationally defined non-HPOA fraction of DOC was observed in the San Joaquin River with seasonally computed Δ14C values of between -275 and -687‰; the source of this aged material was hypothesized to be physically protected organic-matter in high clay-content soils and agrochemicals (i.e., radiocarbon-dead material) applied to farmlands. Mixing models suggest that the Sacramento River contributes about 50% of the DOC load in the California State Water Project, and agricultural drains contribute approximately one-third of the load. In contrast to studies showing stabilization of soil carbon pools within one or two decades following land conversion, sustained loss of soil organic matter, occurring many decades after the initial agricultural-land conversion, was observed in California's Central Valley.

  20. Tracing organic and inorganic pollution sources of agricultural crops and water resources in Güzelhisar Basin of the Aegean Region - Turkey

    NASA Astrophysics Data System (ADS)

    Czarnecki, Sezin; Colak Esetlili, Bihter; Esetlili, Tolga; Tepecik, Mahmut; Anac, Dilek; Düring, Rolf-Alexander

    2014-05-01

    The study area Güzelhisar Basin is 6 km far from the city Aliaga, Aegean Region in Turkey which represents a rather industrialized area having five large iron and steel factories, but also areas of agriculture. Steel industry in Aliaga is causing metal pollution. Around Güzelhisar Basin and nearby, the dominant crop fields are cotton, maize, vegetables, olive trees and vineyards. Güzelhisar stream and dam water is used for irrigation of the agricultural land. Due to contamination from metal industry in Aliaga, organic farming is not allowed in this region. Industrial activities in the region present a threat on sustainable agriculture. The region is a multi-impacted area in terms of several pollutant sources affecting soil and water quality. The overall objective of the project is to trace back plant nutrients (N, P, K, Ca, Mg, Na, Fe, Mn, Zn, Cu, and B), hazardous substances (i. e. persistent organic pollutants), radionuclides (40K, 232Th, 226Ra/238U), and metal contents (As, Cd, Cr, Co, Cu, Hg, Mn, Ni, Pb, and Zn) by examining the soils, agricultural crops and natural plants from Güzelhisar Basin and water and sediments from Güzelhisar stream and dam. Spatial distribution of pollution will be evaluated by regionalization methods. For this, an advanced analytical methodology will be applied which provides an understanding of sources and occurrence of the respective substances of concern. An innovative multi-tracer approach comprising organic and inorganic marker substances, will identify and quantitatively assess sources and their impact on water pollution and the pollutant pathways in this agricultural crop production system.

  1. Monthly variability and possible sources of nitrate in ground water beneath mixed agricultural land use, Suwannee and Lafayette Counties, Florida

    USGS Publications Warehouse

    Katz, Brian G.; Böhlke, J.K.

    2000-01-01

    In an area of mixed agricultural land use in Suwannee and Lafayette Counties of northern Florida, water samples were collected monthly from 14 wells tapping the Upper Floridan aquifer during July 1998 through June 1999 to assess hydrologic and land-use factors affecting the variability in nitrate concentrations in ground water. Unusually high amounts of rainfall in September and October 1998 (43.5 centimeters total for both months) resulted in an increase in water levels in all wells in October 1998. This was followed by unusually low amounts of rainfall during November 1998 through May 1999, when rainfall was 40.7 centimeters below 30-year mean monthly values. The presence of karst features (sinkholes, springs, solution conduits) and the highly permeable sands that overlie the Upper Floridan aquifer provide for rapid movement of water containing elevated nitrate concentrations to the aquifer. Nitrate was the dominant form of nitrogen in ground water collected at all sites and nitrate concentrations ranged from less than 0.02 to 22 milligrams per liter (mg/L), as nitrogen. Water samples from most wells showed substantial monthly or seasonal fluctuations in nitrate concentrations. Generally, water samples from wells with nitrate concentrations higher than 10 mg/L showed the greatest amount of monthly fluctuation. For example, water samples from six of eight wells had monthly nitrate concentrations that varied by at least 5 mg/L during the study period. Water from most wells with lower nitrate concentrations (less than 6 mg/L) also showed large monthly fluctuations. For instance, nitrate concentrations in water from four sites showed monthly variations of more than 50 percent. Large fluctuations in nitrate concentrations likely result from seasonal agricultural practices (fertilizer application and animal waste spreading) at a particular site. For example, an increase in nitrate concentrations observed in water samples from seven sites in February or March 1999 most

  2. Nitrate in aquifers beneath agricultural systems

    USGS Publications Warehouse

    Burkart, M.R.; Stoner, J.D.; ,

    2007-01-01

    Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater vulnerability to nitrate contamination. Analysis of nationally consistent measurements from the U.S. Geological Survey's NAWQA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial and other unconsolidated aquifers are the most vulnerable and also shallow carbonate aquifers that provide a substantial but smaller contamination risk. Where any of these aquifers are overlain by permeable soils the risk of contamination is larger. Irrigated systems can compound this vulnerability by increasing leaching facilitated by additional recharge and additional nutrient applications. The system of corn, soybean, and hogs produced significantly larger concentrations of groundwater nitrate than all other agricultural systems because this system imports the largest amount of N-fertilizer per unit production area. Mean nitrate under dairy, poultry, horticulture, and cattle and grains systems were similar. If trends in the relation between increased fertilizer use and groundwater nitrate in the United States are repeated in other regions of the world, Asia may experience increasing problems because of recent increases in fertilizer use. Groundwater monitoring in Western and Eastern Europe as well as Russia over the next decade may provide data to determine if the trend in increased nitrate contamination can be reversed. If the concentrated livestock trend in the United States is global, it may be accompanied by increasing nitrogen contamination in groundwater. Concentrated livestock provide both point sources in the confinement area and intense non-point sources as fields close to facilities are used for manure disposal. Regions where irrigated cropland is expanding, such as

  3. Nitrate in aquifers beneath agricultural systems.

    PubMed

    Burkart, M R; Stoner, J D

    2002-01-01

    Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater vulnerability to nitrate contamination. Analysis of nationally consistent measurements from the U.S. Geological Survey's NAWOA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial and other unconsolidated aquifers are the most vulnerable and shallow carbonate aquifers provide a substantial but smaller contamination risk. Where any of these aquifers are overlain by permeable soils the risk of contamination is larger. Irrigated systems can compound this vulnerability by increasing leaching facilitated by additional recharge and additional concentrations of groundwater nitrate than all other agricultural systems, although mean nitrate concentrations in counties with dairy, poultry, cattle and grains, and horticulture systems were similar. If trends in the relation between increased fertilizer use and groundwater nitrate in the United States are repeated in other regions of the world, Asia may experience increasing problems because of recent increases in fertilizer use. Groundwater monitoring in Western and Eastern Europe as well as Russia over the next decade may provide data to determine if the trend in increased nitrate contamination can be reversed. If the concentrated livestock trend in the United States is global, it may be accompanied by increasing nitrogen contamination in groundwater. Concentrated livestock provide both point sources in the confinement area and intense non-point sources as fields close to facilities are used for manure disposal. Regions where irrigated cropland is expanding, such as in Asia, may experience the greatest impact of this practice.

  4. Nitrate in aquifers beneath agricultural systems.

    PubMed

    Burkart, M R; Stoner, J D

    2007-01-01

    Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater vulnerability to nitrate contamination. Analysis of nationally consistent measurements from the U.S. Geological Survey's NAWQA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial and other unconsolidated aquifers are the most vulnerable and also shallow carbonate aquifers that provide a substantial but smaller contamination risk. Where any of these aquifers are overlain by permeable soils the risk of contamination is larger. Irrigated systems can compound this vulnerability by increasing leaching facilitated by additional recharge and additional nutrient applications. The system of corn, soybean, and hogs produced significantly larger concentrations of groundwater nitrate than all other agricultural systems because this system imports the largest amount of N-fertilizer per unit production area. Mean nitrate under dairy, poultry, horticulture, and cattle and grains systems were similar. If trends in the relation between increased fertilizer use and groundwater nitrate in the United States are repeated in other regions of the world, Asia may experience increasing problems because of recent increases in fertilizer use. Groundwater monitoring in Western and Eastern Europe as well as Russia over the next decade may provide data to determine if the trend in increased nitrate contamination can be reversed. If the concentrated livestock trend in the United States is global, it may be accompanied by increasing nitrogen contamination in groundwater. Concentrated livestock provide both point sources in the confinement area and intense non-point sources as fields close to facilities are used for manure disposal. Regions where irrigated cropland is expanding, such as

  5. Nonpoint-source agricultural chemicals in ground water in Nebraska; preliminary results for six areas of the High Plains Aquifer

    USGS Publications Warehouse

    Chen, Hsiu-Hsiung; Druliner, A.D.

    1987-01-01

    The reconnaissance phase of a study to determine the occurrence of agricultural chemicals from nonpoint sources in groundwater in six areas, which represented the major provinces of the High Plains aquifer in Nebraska is described. In 1984, water from 82 wells in the 6 study areas was analyzed for nitrate, and water from 57 of the 82 wells was analyzed for triazine herbicides. Data for 9 of the 21 independent variables suspected of affecting concentrations of nitrate and triazine herbicides in groundwater were compiled from the 82 well sites. The variables and their ranges are: hydraulic gradient (XI), 0.006-0.0053; hydraulic conductivity (X2), 5-149 ft/day; specific discharge (X3), 0.0128-0.2998 ft/day; depth to water (X4), 3-239 ft; well depth (X5), 40-550 ft; annual precipitation (X6), 12.0-39.3 inches; soil permeability (X7), 0.76-9.0 inches; irrigation well density (X8), 0-8 irrigation wells/ sq mi; and annual nitrogen fertilizer use (X9), 0-260 lbs of nitrogen/acre. Nitrate concentrations ranged from < 0.1 to 45 mg/L as nitrogen. Triazine herbicide concentrations were detected in samples from five of the six study areas in concentrations ranging from < 0.1 to 2.3 mg/L. Statistical tests indicated that there were significant differences in nitrate concentrations among the six study areas, while no significant differences in triazine herbicide concentrations were found. Concentrations of nitrate and triazine herbicide were significantly larger in more intensively irrigated areas. Preliminary correlations with the independent variables and nitrate concentrations indicated significant relations at the 95% confidence level with variables X2, X5, and X8. Correlations with triazine herbicide concentrations indicated significant relations with variables X2 , X3, X5, X6, and X8, and with nitrate concentrations (X10). By using a simple multiple regression technique, variables X5, X8, and X9 explained about 51% of the variation in nitrate concentrations. Variables X3

  6. Towards an improved inventory of N2O from agriculture: Model evaluation of N2O emission factors and N fraction leached from different sources in UK agriculture

    NASA Astrophysics Data System (ADS)

    Cardenas, L. M.; Gooday, R.; Brown, L.; Scholefield, D.; Cuttle, S.; Gilhespy, S.; Matthews, R.; Misselbrook, T.; Wang, J.; Li, C.; Hughes, G.; Lord, E.

    2013-11-01

    National and international requirements for greenhouse gas emissions demand the development of more accurate inventories and mitigation options that are effective in reducing emissions. The UK government set a target for the year 2050 of an 80% reduction in greenhouse gas emissions compared to the 1990 baseline. Estimate of UK national emissions is based on IPCC default methodology and as agriculture contributes about 7% of total GHG emissions of which 60% is N2O, efforts to improve the inventory and assess mitigation options are needed. Models can be used to derive N2O emission factors providing high spatial and temporal resolution. In this study, we used two models, the UK-DNDC, a mechanistic model to estimate N2O emissions from soils and the NITCAT model to estimate the fraction of N applied that is leached and causes indirect emissions, both at county level for the UK. Four mitigation options were assessed and the results showed there were differences in the emission factors according to location. Average emission factors for N2O from soils for inorganic fertiliser did not differ from the IPCC default value but for organic fertiliser the model gave much lower values. FracLEACH for arable land was higher than that for grassland (UK averages of 0.28 and 0.09 respectively) and the national average value was 0.18. For N2O, the most effective mitigation measure was adjusting fertiliser rates to account for crop available manure N. For N leaching, the most effective measure was implementation of a manure closed period.

  7. Study on nitrogen load reduction efficiency of agricultural conservation management in a small agricultural watershed.

    PubMed

    Liu, Xiaoli; Chen, Qiuwen; Zeng, Zhaoxia

    2014-01-01

    Different crops can generate different non-point source (NPS) loads because of their spatial topography heterogeneity and variable fertilization application rates. The objective of this study was to assess nitrogen NPS load reduction efficiency by spatially adjusting crop plantings as an agricultural conservation management (ACM) measure in a typical small agricultural watershed in the black soil region in northeast China. The assessment was undertaken using the Soil and Water Assessment Tool (SWAT). Results showed that lowland crops produce higher nitrogen NPS loads than those in highlands. It was also found that corn gave a comparatively larger NPS load than soybeans due to its larger fertilization demand. The ACM assessed was the conversion of lowland corn crops into soybean crops and highland soybean crops into corn crops. The verified SWAT model was used to evaluate the impact of the ACM action on nitrogen loads. The results revealed that the ACM could reduce NO3-N and total nitrogen loads by 9.5 and 10.7%, respectively, without changing the area of crops. Spatially optimized regulation of crop planting according to fertilizer demand and geological landscapes can effectively decrease NPS nitrogen exports from agricultural watersheds. PMID:24759530

  8. Study on nitrogen load reduction efficiency of agricultural conservation management in a small agricultural watershed.

    PubMed

    Liu, Xiaoli; Chen, Qiuwen; Zeng, Zhaoxia

    2014-01-01

    Different crops can generate different non-point source (NPS) loads because of their spatial topography heterogeneity and variable fertilization application rates. The objective of this study was to assess nitrogen NPS load reduction efficiency by spatially adjusting crop plantings as an agricultural conservation management (ACM) measure in a typical small agricultural watershed in the black soil region in northeast China. The assessment was undertaken using the Soil and Water Assessment Tool (SWAT). Results showed that lowland crops produce higher nitrogen NPS loads than those in highlands. It was also found that corn gave a comparatively larger NPS load than soybeans due to its larger fertilization demand. The ACM assessed was the conversion of lowland corn crops into soybean crops and highland soybean crops into corn crops. The verified SWAT model was used to evaluate the impact of the ACM action on nitrogen loads. The results revealed that the ACM could reduce NO3-N and total nitrogen loads by 9.5 and 10.7%, respectively, without changing the area of crops. Spatially optimized regulation of crop planting according to fertilizer demand and geological landscapes can effectively decrease NPS nitrogen exports from agricultural watersheds.

  9. Near-Channel Sediment Sources Now Dominate in Many Agricultural Landscapes: The Emergence of River-Network Models to Guide Watershed Management

    NASA Astrophysics Data System (ADS)

    Czuba, J. A.; Foufoula-Georgiou, E.; Gran, K. B.; Belmont, P.; Wilcock, P. R.

    2015-12-01

    Detailed sediment budgets for many agricultural watersheds are revealing a surprising story - that sediment is no longer primarily sourced from upland fields, but instead from near-channel sources. This is the case for the Minnesota River Basin (MRB) where an intensification and expansion of agricultural drainage combined with increased precipitation has (1) reduced surface runoff and erosion, (2) amplified streamflows, and (3) accelerated both near-channel sediment generation and sediment transport. Bluffs and streambanks in the MRB are now the dominant sources of sediment, but these features are not easily incorporated into traditional watershed-scale, sediment-transport models. Instead, we are advancing a network-based modeling framework that explicitly considers sediment sources, transport, and storage along a river network. We apply this framework to bed-material sediment transport in the Greater Blue Earth River Basin, the major sediment-generating subbasin of the MRB, where a recent sediment budget has quantified the locations and rates of erosion and deposition of major sediment sources and sinks (i.e., bluffs, streambanks/floodplains, agricultural fields, and ravines) over millennial and decadal timescales. With the river network as the basis of a simple model, inputs of sediment to the network are informed by the sediment budget and these inputs are tracked through the network using process-based time delays that incorporate uniform-flow hydraulics and at-capacity sediment transport. We explore how this sediment might move through the network and affect the variability of bed elevations under cases where the mechanisms of in-channel and floodplain storage are turned on and off. We will discuss timescales of movement of sediment through the system to better inform legacy effects and hysteresis, and also discuss targeted management actions that will most effectively reduce the detrimental effects of excess sediment.

  10. Wastewater Reuse for Agriculture: Development of a Regional Water Reuse Decision-Support Model (RWRM) for Cost-Effective Irrigation Sources.

    PubMed

    Tran, Quynh K; Schwabe, Kurt A; Jassby, David

    2016-09-01

    Water scarcity has become a critical problem in many semiarid and arid regions. The single largest water use in such regions is for crop irrigation, which typically relies on groundwater and surface water sources. With increasing stress on these traditional water sources, it is important to consider alternative irrigation sources for areas with limited freshwater resources. One potential irrigation water resource is treated wastewater for agricultural fields located near urban centers. In addition, treated wastewater can contribute an appreciable amount of necessary nutrients for plants. The suitability of reclaimed water for specific applications depends on water quality and usage requirements. The main factors that determine the suitability of recycled water for agricultural irrigation are salinity, heavy metals, and pathogens, which cause adverse effects on human, plants, and soils. In this paper, we develop a regional water reuse decision-support model (RWRM) using the general algebraic modeling system to analyze the cost-effectiveness of alternative treatment trains to generate irrigation water from reclaimed wastewater, with the irrigation water designed to meet crop requirements as well as California's wastewater reuse regulations (Title 22). Using a cost-minimization framework, least-cost solutions consisting of treatment processes and their intensities (blending ratios) are identified to produce alternative irrigation sources for citrus and turfgrass. Our analysis illustrates the benefits of employing an optimization framework and flexible treatment design to identify cost-effective blending opportunities that may produce high-quality irrigation water for a wide range of end uses. PMID:27499353

  11. Assessment of sources and fate of nitrate in shallow groundwater of an agricultural area by using a multi-tracer approach.

    PubMed

    Pastén-Zapata, Ernesto; Ledesma-Ruiz, Rogelio; Harter, Thomas; Ramírez, Aldo I; Mahlknecht, Jürgen

    2014-02-01

    Nitrate isotopic values are often used as a tool to understand sources of contamination in order to effectively manage groundwater quality. However, recent literature describes that biogeochemical reactions may modify these values. Therefore, data interpretation is difficult and often vague. We provide a discussion on this topic and complement the study using halides as comparative tracers assessing an aquifer underneath a sub-humid to humid region in NE Mexico. Hydrogeological information and stable water isotopes indicate that active groundwater recharge occurs in the 8000km(2) study area under present-day climatic and hydrologic conditions. Nitrate isotopes and halide ratios indicate a diverse mix of nitrate sources and transformations. Nitrate sources include organic waste and wastewater, synthetic fertilizers and soil processes. Animal manure and sewage from septic tanks were the causes of groundwater nitrate pollution within orchards and vegetable agriculture. Dairy activities within a radius of 1,000 m from a sampling point significantly contributed to nitrate pollution. Leachates from septic tanks caused nitrate pollution in residential areas. Soil nitrogen and animal waste were the sources of nitrate in groundwater under shrubland and grassland. Partial denitrification processes helped to attenuate nitrate concentration underneath agricultural lands and grassland, especially during summer months. PMID:24200723

  12. Wastewater Reuse for Agriculture: Development of a Regional Water Reuse Decision-Support Model (RWRM) for Cost-Effective Irrigation Sources.

    PubMed

    Tran, Quynh K; Schwabe, Kurt A; Jassby, David

    2016-09-01

    Water scarcity has become a critical problem in many semiarid and arid regions. The single largest water use in such regions is for crop irrigation, which typically relies on groundwater and surface water sources. With increasing stress on these traditional water sources, it is important to consider alternative irrigation sources for areas with limited freshwater resources. One potential irrigation water resource is treated wastewater for agricultural fields located near urban centers. In addition, treated wastewater can contribute an appreciable amount of necessary nutrients for plants. The suitability of reclaimed water for specific applications depends on water quality and usage requirements. The main factors that determine the suitability of recycled water for agricultural irrigation are salinity, heavy metals, and pathogens, which cause adverse effects on human, plants, and soils. In this paper, we develop a regional water reuse decision-support model (RWRM) using the general algebraic modeling system to analyze the cost-effectiveness of alternative treatment trains to generate irrigation water from reclaimed wastewater, with the irrigation water designed to meet crop requirements as well as California's wastewater reuse regulations (Title 22). Using a cost-minimization framework, least-cost solutions consisting of treatment processes and their intensities (blending ratios) are identified to produce alternative irrigation sources for citrus and turfgrass. Our analysis illustrates the benefits of employing an optimization framework and flexible treatment design to identify cost-effective blending opportunities that may produce high-quality irrigation water for a wide range of end uses.

  13. Assessment of sources and fate of nitrate in shallow groundwater of an agricultural area by using a multi-tracer approach.

    PubMed

    Pastén-Zapata, Ernesto; Ledesma-Ruiz, Rogelio; Harter, Thomas; Ramírez, Aldo I; Mahlknecht, Jürgen

    2014-02-01

    Nitrate isotopic values are often used as a tool to understand sources of contamination in order to effectively manage groundwater quality. However, recent literature describes that biogeochemical reactions may modify these values. Therefore, data interpretation is difficult and often vague. We provide a discussion on this topic and complement the study using halides as comparative tracers assessing an aquifer underneath a sub-humid to humid region in NE Mexico. Hydrogeological information and stable water isotopes indicate that active groundwater recharge occurs in the 8000km(2) study area under present-day climatic and hydrologic conditions. Nitrate isotopes and halide ratios indicate a diverse mix of nitrate sources and transformations. Nitrate sources include organic waste and wastewater, synthetic fertilizers and soil processes. Animal manure and sewage from septic tanks were the causes of groundwater nitrate pollution within orchards and vegetable agriculture. Dairy activities within a radius of 1,000 m from a sampling point significantly contributed to nitrate pollution. Leachates from septic tanks caused nitrate pollution in residential areas. Soil nitrogen and animal waste were the sources of nitrate in groundwater under shrubland and grassland. Partial denitrification processes helped to attenuate nitrate concentration underneath agricultural lands and grassland, especially during summer months.

  14. Assessing the sources of suspended sediments in the streams of an agricultural watershed in the Canadian prairies using caesium-137 as a tracer

    NASA Astrophysics Data System (ADS)

    Koiter, A. J.; Lobb, D. A.; Owens, P. N.; Tiessen, K. H. D.; Li, S.

    2012-04-01

    Sediments adversely impact the quality of surface waters and are a significant source of contaminants such as nutrients and pesticides in agricultural watersheds. The South Tobacco Creek watershed is part of a national project aimed at measuring the economic and water quality impacts of different agricultural practices and is one of nine sites across Canada. This predominantly agricultural watershed extends across the Manitoba Escarpment; its upper reaches lay in undulating glacial tills and its lower reaches lay in the lacustrine sediments of glacial Lake Agassiz. Past studies of soil erosion within fields and sediment delivery from the watershed have produced conflicting results. In 2009, a comprehensive study of the sources of sediments was undertaken using sediment fingerprinting techniques. Suspended sediments were sampled using paired time-integrated samplers fixed to the stream bed. Samples were collected over the course of three years at several locations along the main stem of the creek, ranging from 3rd order (42 ha) to seventh order (7441 ha) drainage basins. Sediment samples were analyzed for caesium-137 content and the values were compared to those measured within the surface soil of field and riparian areas, and streambank profiles. Analysis determined that the majority of suspended sediments being exported from the watershed were coming from the stream channels and not the soils of the uplands.

  15. Historical accumulation of N and P and sources of organic matter and N in sediment in an agricultural reservoir in Northern China.

    PubMed

    Ni, Zhaokui; Wang, Shengrui; Chu, Zhaosheng; Jin, Xiangcan

    2015-07-01

    Agriculture has significantly intensified in Northern China since the 1980s. This intensification has caused a series of simultaneous lake ecological environment problems in this area. However, little is known about the role of agricultural intensification in historical nutrient dynamics and lake eutrophication processes. The Yanghe reservoir, a typical artificial reservoir characterized by high-yield grain production in Northern China, has been suffering from serious eutrophication and water quality deterioration. This study evaluates the effect of agricultural intensification on nutrient retention and source in the sediments using (210)Pb and (137)Cs dating techniques combined with stable C and N isotopes (δ(13)C, δ(15)N) and total organic carbon/total nitrogen, as well as total nitrogen (TN), total phosphorus (TP), and P fractions. Results suggested that agricultural intensification was keys to the accumulation of nutrients and was a source of organic matter (OM) and N in sediment for the past three decades. N and P pollution started in the 1980s and worsened from the 1990s. Good water quality status and steady sedimentary environment with low nutrient content (mean concentrations of TN and TP were 815 and 387 mg kg(-1), respectively) were observed before the 1980s. Sediment OM was primarily derived from aquatic plants, whereas N was primarily derived from soil erosion and aquatic plants. However, water quality began to deteriorate while sediment nutrient content began to increase after the 1980s, with values of 1186 mg kg(-1) for TN and 434 mg kg(-1) for TP in 1989. Sediment OM was primarily derived from C3 (sweet potato) and aquatic plants, and the major sources of N were soil erosion, fertilizer, and sewage, which accompany the rapid development of agriculture in the watershed. Following the further growth of grain production and fertilizers, excessive external nutrient loading has resulted in dramatic water quality and ecosystem deterioration since 1990

  16. Information for Agricultural Development.

    ERIC Educational Resources Information Center

    Kaungamno, E. E.

    This paper describes the major international agricultural information services, sources, and systems; outlines the existing information situation in Tanzania as it relates to problems of agricultural development; and reviews the improvements in information provision resources required to support the process of agricultural development in Tanzania.…

  17. Indicators of the sources and distribution of nitrate in water from shallow domestic wells in agricultural areas of the New Jersey Coastal Plain

    USGS Publications Warehouse

    Vowinkel, Eric F.; Tapper, Robert J.

    1995-01-01

    Previously collected and new water-quality data from shallow wells (screened interval less than 30 meters below the land surface) in predominantly agricultural areas of the New Jersey Coastal Plain were used to determine the relation of nitrate concentrations in shallow ground water to various hydrogeologic and land-use factors in the study area. Information on land use, well construction, hydrogeology, and water quality were used to predict the conditions under which concentrations of nitrate as nitrogen in water from domestic wells in predominantly agricultural areas are most likely to be equal to or larger than the U.S. Environmental Protection Agency maximum contaminant level (MCL) of 10 milligrams per liter. Results of the analyses of water-quality samples collected during 1980-89 from 230 shallow wells in the outcrop areas of the Kirkwood-Cohansey and Potomac-Raritan-Magothy aquifer systems were used to evaluate the regional effects of land use on shallow-ground-water quality. Results of statistical analysis indicate that concentrations of nitrate in shallow ground water are significantly different (p= 0.001) in agricultural areas than in undeveloped areas in both aquifer systems. Concentrations of nitrate nitrogen exceeded the MCL in water from more than 33 percent of the 60 shallow wells in agricultural areas. Concentrations of hitrate in water from shallow wells in agricultural areas increased as the percentage of agricultural land within an 800-meter-radius buffer zone of the wellhead increased (r= 0.81). Concentrations ofhitrate in water from domestic wells in agricultural areas were similar (p= 0.23) to those concentrations in water from irrigation wells. These results indicate that most of the nitrate in water from domestic wells in agricultural areas results from agricultural practices rather than other sources, such as septic systems. Water-quality samples collected from 12 shallow domestic wells in agricultural areas screened in the outcrop areas of

  18. Information technology and innovative drainage management practices for selenium load reduction from irrigated agriculture to provide stakeholder assurances and meet contaminant mass loading policy objectives

    SciTech Connect

    Quinn, N.W.T.

    2009-10-15

    Many perceive the implementation of environmental regulatory policy, especially concerning non-point source pollution from irrigated agriculture, as being less efficient in the United States than in many other countries. This is partly a result of the stakeholder involvement process but is also a reflection of the inability to make effective use of Environmental Decision Support Systems (EDSS) to facilitate technical information exchange with stakeholders and to provide a forum for innovative ideas for controlling non-point source pollutant loading. This paper describes one of the success stories where a standardized Environmental Protection Agency (EPA) methodology was modified to better suit regulation of a trace element in agricultural subsurface drainage and information technology was developed to help guide stakeholders, provide assurances to the public and encourage innovation while improving compliance with State water quality objectives. The geographic focus of the paper is the western San Joaquin Valley where, in 1985, evapoconcentration of selenium in agricultural subsurface drainage water, diverted into large ponds within a federal wildlife refuge, caused teratogenecity in waterfowl embryos and in other sensitive wildlife species. The fallout from this environmental disaster was a concerted attempt by State and Federal water agencies to regulate non-point source loads of the trace element selenium. The complexity of selenium hydrogeochemistry, the difficulty and expense of selenium concentration monitoring and political discord between agricultural and environmental interests created challenges to the regulation process. Innovative policy and institutional constructs, supported by environmental monitoring and the web-based data management and dissemination systems, provided essential decision support, created opportunities for adaptive management and ultimately contributed to project success. The paper provides a retrospective on the contentious planning

  19. Quantifying the dominant sources of sediment in a drained lowland agricultural catchment: The application of a thorium-based particle size correction in sediment fingerprinting

    NASA Astrophysics Data System (ADS)

    Foucher, Anthony; Laceby, Patrick J.; Salvador-Blanes, Sébastien; Evrard, Olivier; Le Gall, Marion; Lefèvre, Irène; Cerdan, Olivier; Rajkumar, Vignesh; Desmet, Marc

    2015-12-01

    Soil erosion is one of the main factors influencing land degradation and water quality at the global scale. Identifying the main sediment sources is therefore essential for the implementation of appropriate soil erosion mitigation measures. Accordingly, caesium-137 (137Cs) concentrations were used to determine the relative contribution of surface and subsurface erosion sources in a lowland drained catchment in France. As 137Cs concentrations are often dependent on particle size, specific surface area (SSA) and novel thorium (Th) based particle size corrections were applied. Surface and subsurface samples were collected to characterize the radionuclide properties of potential sources. Sediment samples were collected during one hydrological year and a sediment core was sampled to represent sediment accumulated over a longer temporal period. Additionally, sediment from tile drains was sampled to determine the radionuclide properties of sediment exported from the drainage network. A distribution modelling approach was used to quantify the relative sediment contributions from surface and subsurface sources. The results highlight a substantial enrichment in fine particles and associated 137Cs concentrations between the sources and the sediment. The application of both correction factors reduced this difference, with the Th correction providing a more accurate comparison of source and sediment samples than the SSA correction. Modelling results clearly indicate the dominance of surface sources during the flood events and in the sediment core. Sediment exported from the drainage network was modelled to originate predominantly from surface sources. This study demonstrates the potential of Th to correct for 137Cs particle size enrichment. More importantly, this research indicates that drainage networks may significantly increase the connectivity of surface sources to stream networks. Managing sediment transferred through drainage networks may reduce the deleterious effects of

  20. Dynamics and sources of reduced sulfur, humic substances and dissolved organic carbon in a temperate river system affected by agricultural practices.

    PubMed

    Marie, Lauriane; Pernet-Coudrier, Benoît; Waeles, Matthieu; Gabon, Marine; Riso, Ricardo

    2015-12-15

    Although reduced organic sulfur substances (RSS) as well as humic substances (HS) are widely suspected to play a role in, for example, metal speciation or used as a model of dissolved organic carbon (DOC) in laboratory studies, reports of their quantification in natural waters are scarce. We have examined the dynamics and sources of reduced sulfur, HS and DOC over an annual cycle in a river system affected by agricultural practices. The new differential pulse cathodic stripping voltammetry was successfully applied to measure glutathione-like compounds (GSHs), thioacetamide-like compounds (TAs) and the liquid chromatography coupled to organic detector to analyze HS and DOC at high frequency in the Penzé River (NW France). The streamflow-concentration patterns, principal components analysis and flux analysis allowed discrimination of the source of each organic compound type. Surprisingly, the two RSS and HS detected in all samples, displayed different behavior. As previously shown, manuring practice is the main source of DOC and HS in this watershed where agricultural activity is predominant. The HS were then transferred to the river systems via runoff, particularly during the spring and autumn floods, which are responsible of >60% of the annual flux. TAs had a clear groundwater source and may be formed underground, whereas GSHs displayed two sources: one aquagenic in spring and summer probably linked to the primary productivity and a second, which may be related to bacterial degradation. High sampling frequency allowed a more accurate assessment of the flux values which were 280 tC y(-1) for DOC representing 20 kg C ha(-1) y(-1). HS, TAs and GSHs fluxes represented 60, 13, and 4% of the total annual DOC export, respectively.

  1. Dynamics and sources of reduced sulfur, humic substances and dissolved organic carbon in a temperate river system affected by agricultural practices.

    PubMed

    Marie, Lauriane; Pernet-Coudrier, Benoît; Waeles, Matthieu; Gabon, Marine; Riso, Ricardo

    2015-12-15

    Although reduced organic sulfur substances (RSS) as well as humic substances (HS) are widely suspected to play a role in, for example, metal speciation or used as a model of dissolved organic carbon (DOC) in laboratory studies, reports of their quantification in natural waters are scarce. We have examined the dynamics and sources of reduced sulfur, HS and DOC over an annual cycle in a river system affected by agricultural practices. The new differential pulse cathodic stripping voltammetry was successfully applied to measure glutathione-like compounds (GSHs), thioacetamide-like compounds (TAs) and the liquid chromatography coupled to organic detector to analyze HS and DOC at high frequency in the Penzé River (NW France). The streamflow-concentration patterns, principal components analysis and flux analysis allowed discrimination of the source of each organic compound type. Surprisingly, the two RSS and HS detected in all samples, displayed different behavior. As previously shown, manuring practice is the main source of DOC and HS in this watershed where agricultural activity is predominant. The HS were then transferred to the river systems via runoff, particularly during the spring and autumn floods, which are responsible of >60% of the annual flux. TAs had a clear groundwater source and may be formed underground, whereas GSHs displayed two sources: one aquagenic in spring and summer probably linked to the primary productivity and a second, which may be related to bacterial degradation. High sampling frequency allowed a more accurate assessment of the flux values which were 280 tC y(-1) for DOC representing 20 kg C ha(-1) y(-1). HS, TAs and GSHs fluxes represented 60, 13, and 4% of the total annual DOC export, respectively. PMID:26278374

  2. Identifying sediment sources in a drained lowland agricultural catchment: the application of a novel thorium-based particle size correction in sediment fingerprinting

    NASA Astrophysics Data System (ADS)

    Laceby, J. P.; Le Gall, M.; Foucher, A.; Salvador-Blanes, S.; Evrard, O.; Lefèvre, I.; Cerdan, O.; Desmet, M.

    2015-12-01

    Soil erosion is one of the main processes influencing land and water degradation at the global scale. Identifying the main sediment sources is therefore essential for effective soil erosion management. Accordingly, caesium-137 (137Cs) concentrations were used to quantify the relative contribution of surface and subsurface erosion sources in a lowland drained catchment in France. As 137Cs concentrations are often dependent on particle size, specific surface area (SSA) and novel Thorium (Th) based particle size corrections were applied. Surface and subsurface samples were collected to characterize the radionuclide properties of potential sources. Sediment samples were collected during one hydrological year and a sediment core was sampled to represent sediment accumulated over a longer temporal period. Additionally, sediment from tile drains was sampled to determine the radionuclide properties of sediment exported from the drainage network. The results highlight a substantial enrichment in fine particles and associated 137Cs concentrations between the sources and the sediment. The application of both correction factors reduced this difference, with the Th correction providing a more accurate comparison of source and sediment samples than the SSA correction. Modelling results clearly indicate the dominance of surface sources during the flood events and in the sediment core. Sediment exported from the drainage network was modelled to originate predominantly from surface sources. This study demonstrates the potential of Th to correct for 137Cs particle size enrichment. More importantly, this research indicates that drainage networks may significantly increase the connectivity of surface sources to stream networks. Managing sediment transferred through drainage networks may reduce the deleterious effects of suspended sediment loads on riverine systems in similar lowland drained agricultural catchments.

  3. Nitrogen fertilization, soil nitrate accumulation, and policy recommendations in several agricultural regions of China.

    PubMed

    Ju, Xiaotang; Liu, Xuejun; Zhang, Fusuo; Roelcke, Marco

    2004-08-01

    Excessive nitrogen (N) fertilization and decreasing N recovery rates by crops have caused dramatic increases in non-point source pollution from agriculture in China. The rate of N fertilization across the country varies widely among regions and crops, depending on the stage of economic development. For example, N application rates in the eastern regions and on cash crops are far higher than in western regions of the country and on cereal crops. Moreover, N application rates in wealthier regions are higher than recommended by the Chinese Academy of Sciences. To successfully achieve environmental protection as well as high crop yields, China must formulate relevant agricultural policies to encourage farmers in economically developed areas to reduce their N fertilization rate while also issuing conventional fertilization recommendations for small-scale farming systems and the expanding cultivation of cash crops. PMID:15387063

  4. Distribution, enrichment and principal component analysis for possible sources of naturally occurring and anthropogenic radionuclides in the agricultural soil of Punjab state, India.

    PubMed

    Kumar, Ajay; Joshi, Vikram M; Mishra, Manish K; Karpe, Rupali; Rout, Sabyasachi; Narayanan, Usha; Tripathi, Raj M; Singh, Jaspal; Kumar, Sanjeev; Hegde, Ashok G; Kushwaha, Hari S

    2012-06-01

    Enrichment factor (EF) of elements including geo-accumulation indices for soil quality and principal component analysis (PCA) were used to identify the contributions of the origin of sources in the studied area. Results of (40)K, (137)Cs, (238)U and (232)Th including their decay series isotopes in the agricultural soil of Mansa and Bathinda districts in the state of Punjab were presented and discussed. The measured mean radioactivity concentrations for (238)U, (232)Th and (40)K in the agricultural soil of the studied area differed from nationwide average crustal abundances by 51, 17 and 43 %, respectively. The sequence of the EFs of radionuclides in soil from the greatest to the least was found to be (238)U > (40)K > (226)Ra > (137)Cs > (232)Th > (228)Ra. Even though the enrichment of naturally occurring radionuclides was found to be higher, they remained to be in I(geo) class of '0', indicating that the soil is uncontaminated with respect to these radionuclides. Among non-metals, N showed the highest EF and belonged to I(geo) class of '2', indicating that soil is moderately contaminated due to intrusion of fertiliser. The resulting data set of elemental contents in soil was also interpreted by PCA, which facilitates identification of the different groups of correlated elements. The levels of the (40)K, (238)U and (232)Th radionuclides showed a significant positive correlation with each other, suggesting a similar origin of their geochemical sources and identical behaviour during transport in the soil system.

  5. [Contribution of Base Flow to Total Nitrogen Loading in Subtropical Agricultural Catchments].

    PubMed

    Ma, Qiu-mei; Li, Wei; Wang, Yi; Liu, Xin-liang; Li, Yong; Wu, Jin-shui

    2016-04-15

    With the fast development of economics and improvement of people's living standard, non-point source pollution of the agricultural catchments in subtropical China has become more and more severe, where water quality deterioration has become a main barrier for sustainable development and ecological restoration. The process of ecohydrology in catchment is greatly influenced by the process of base flow in channel. This study selected the Tuojia and Jianshan catchments located in Changsha County, Hunan Province, to quantify and compare the contribution of base flow to total nitrogen (TN) loading from January 2011 to December 2013, through field observation and model estimation. The results suggested that the Tuojia catchment with higher intensity of rice agriculture had the greater volume of base flow, higher average flow-weighted TN concentration in base flow, and greater monthly TN loading via base flow [15.2 mm · month⁻¹, 4.14 mg · L⁻¹ and 0.54 kg · (hm² · month)⁻¹, respectively] than those in the Jianshan catchment with lower intensity [11.4 mm · month⁻¹, 1.72 mg · L⁻¹ and 0.20 kg · (hm² · month)⁻¹, respectively]. The base flow contribution to TN loading showed an apparently seasonal pattern. During rice-growing seasons, the contributions of base flow to TN loading were 23.2% and 18.6% in the Tuojia and Jianshan catchments, respectively, lower than those in the fallow seasons (46.9% and 40.0% correspondingly. These results suggested that rice agriculture increased the contribution of base flow in the fallow season to TN loading. Therefore, to alleviate the suffering of non-point source pollution in the rice agriculture catchments, reasonable management measure of rice fields should be implemented to decrease contrihution of base flow to TN loading. PMID:27548958

  6. TMDL implementation in agricultural landscapes: a communicative and systemic approach.

    PubMed

    Jordan, Nicholas R; Slotterback, Carissa Schively; Cadieux, Kirsten Valentine; Mulla, David J; Pitt, David G; Olabisi, Laura Schmitt; Kim, Jin-Oh

    2011-07-01

    Increasingly, total maximum daily load (TMDL) limits are being defined for agricultural watersheds. Reductions in non-point source pollution are often needed to meet TMDL limits, and improvements in management of annual crops appear insufficient to achieve the necessary reductions. Increased adoption of perennial crops and other changes in agricultural land use also appear necessary, but face major barriers. We outline a novel strategy that aims to create new economic opportunities for land-owners and other stakeholders and thereby to attract their voluntary participation in land-use change needed to meet TMDLs. Our strategy has two key elements. First, focused efforts are needed to create new economic enterprises that capitalize on the productive potential of multifunctional agriculture (MFA). MFA seeks to produce a wide range of goods and ecosystem services by well-designed deployment of annual and perennial crops across agricultural landscapes and watersheds; new revenue from MFA may substantially finance land-use change needed to meet TMDLs. Second, efforts to capitalize on MFA should use a novel methodology, the Communicative/Systemic Approach (C/SA). C/SA uses an integrative GIS-based spatial modeling framework for systematically assessing tradeoffs and synergies in design and evaluation of multifunctional agricultural landscapes, closely linked to deliberation and design processes by which multiple stakeholders can collaboratively create appropriate and acceptable MFA landscape designs. We anticipate that application of C/SA will strongly accelerate TMDL implementation, by aligning the interests of multiple stakeholders whose active support is needed to change agricultural land use and thereby meet TMDL goals.

  7. Simultaneous Determination of Thermal Conductivity and Thermal Diffusivity of Food and Agricultural Materials Using a Transient Plane-Source Method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal conductivity and thermal diffusivity are two important physical properties essential for designing any food engineering processes. Recently a new transient plane-source method was developed to measure a variety of materials, but its application in foods has not been documented. Therefore, ...

  8. Comparison of Online Agricultural Information Services.

    ERIC Educational Resources Information Center

    Reneau, Fred; Patterson, Richard

    1984-01-01

    Outlines major online agricultural information services--agricultural databases, databases with agricultural services, educational databases in agriculture--noting services provided, access to the database, and costs. Benefits of online agricultural database sources (availability of agricultural marketing, weather, commodity prices, management…

  9. Identifying sources of groundwater nitrate contamination in a large alluvial groundwater basin with highly diversified intensive agricultural production.

    PubMed

    Lockhart, K M; King, A M; Harter, T

    2013-08-01

    Groundwater quality is a concern in alluvial aquifers underlying agricultural areas worldwide. Nitrate from land applied fertilizers or from animal waste can leach to groundwater and contaminate drinking water resources. The San Joaquin Valley, California, is an example of an agricultural landscape with a large diversity of field, vegetable, tree, nut, and citrus crops, but also confined animal feeding operations (CAFOs, here mostly dairies) that generate, store, and land apply large amounts of liquid manure. As in other such regions around the world, the rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (≤150 m deep), of which many have been affected by nitrate. Variability in crops, soil type, and depth to groundwater contribute to large variability in nitrate occurrence across the underlying aquifer system. The role of these factors in controlling groundwater nitrate contamination levels is examined. Two hundred domestic wells were sampled in two sub-regions of the San Joaquin Valley, Stanislaus and Merced (Stan/Mer) and Tulare and Kings (Tul/Kings) Counties. Forty six percent of well water samples in Tul/Kings and 42% of well water samples in Stan/Mer exceeded the MCL for nitrate (10mg/L NO3-N). For statistical analysis of nitrate contamination, 78 crop and landuse types were considered by grouping them into ten categories (CAFO, citrus, deciduous fruits and nuts, field crops, forage, native, pasture, truck crops, urban, and vineyards). Vadose zone thickness, soil type, well construction information, well proximity to dairies, and dominant landuse near the well were considered. In the Stan/Mer area, elevated nitrate levels in domestic wells most strongly correlate with the combination of very shallow (≤21 m) water table and the presence of either CAFO derived animal waste applications or deciduous fruit and nut crops (synthetic fertilizer applications). In Tulare County, statistical data indicate that elevated

  10. Identifying sources of groundwater nitrate contamination in a large alluvial groundwater basin with highly diversified intensive agricultural production

    NASA Astrophysics Data System (ADS)

    Lockhart, K. M.; King, A. M.; Harter, T.

    2013-08-01

    Groundwater quality is a concern in alluvial aquifers underlying agricultural areas worldwide. Nitrate from land applied fertilizers or from animal waste can leach to groundwater and contaminate drinking water resources. The San Joaquin Valley, California, is an example of an agricultural landscape with a large diversity of field, vegetable, tree, nut, and citrus crops, but also confined animal feeding operations (CAFOs, here mostly dairies) that generate, store, and land apply large amounts of liquid manure. As in other such regions around the world, the rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (≤ 150 m deep), of which many have been affected by nitrate. Variability in crops, soil type, and depth to groundwater contribute to large variability in nitrate occurrence across the underlying aquifer system. The role of these factors in controlling groundwater nitrate contamination levels is examined. Two hundred domestic wells were sampled in two sub-regions of the San Joaquin Valley, Stanislaus and Merced (Stan/Mer) and Tulare and Kings (Tul/Kings) Counties. Forty six percent of well water samples in Tul/Kings and 42% of well water samples in Stan/Mer exceeded the MCL for nitrate (10 mg/L NO3-N). For statistical analysis of nitrate contamination, 78 crop and landuse types were considered by grouping them into ten categories (CAFO, citrus, deciduous fruits and nuts, field crops, forage, native, pasture, truck crops, urban, and vineyards). Vadose zone thickness, soil type, well construction information, well proximity to dairies, and dominant landuse near the well were considered. In the Stan/Mer area, elevated nitrate levels in domestic wells most strongly correlate with the combination of very shallow (≤ 21 m) water table and the presence of either CAFO derived animal waste applications or deciduous fruit and nut crops (synthetic fertilizer applications). In Tulare County, statistical data indicate that elevated

  11. Identifying sources of groundwater nitrate contamination in a large alluvial groundwater basin with highly diversified intensive agricultural production.

    PubMed

    Lockhart, K M; King, A M; Harter, T

    2013-08-01

    Groundwater quality is a concern in alluvial aquifers underlying agricultural areas worldwide. Nitrate from land applied fertilizers or from animal waste can leach to groundwater and contaminate drinking water resources. The San Joaquin Valley, California, is an example of an agricultural landscape with a large diversity of field, vegetable, tree, nut, and citrus crops, but also confined animal feeding operations (CAFOs, here mostly dairies) that generate, store, and land apply large amounts of liquid manure. As in other such regions around the world, the rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (≤150 m deep), of which many have been affected by nitrate. Variability in crops, soil type, and depth to groundwater contribute to large variability in nitrate occurrence across the underlying aquifer system. The role of these factors in controlling groundwater nitrate contamination levels is examined. Two hundred domestic wells were sampled in two sub-regions of the San Joaquin Valley, Stanislaus and Merced (Stan/Mer) and Tulare and Kings (Tul/Kings) Counties. Forty six percent of well water samples in Tul/Kings and 42% of well water samples in Stan/Mer exceeded the MCL for nitrate (10mg/L NO3-N). For statistical analysis of nitrate contamination, 78 crop and landuse types were considered by grouping them into ten categories (CAFO, citrus, deciduous fruits and nuts, field crops, forage, native, pasture, truck crops, urban, and vineyards). Vadose zone thickness, soil type, well construction information, well proximity to dairies, and dominant landuse near the well were considered. In the Stan/Mer area, elevated nitrate levels in domestic wells most strongly correlate with the combination of very shallow (≤21 m) water table and the presence of either CAFO derived animal waste applications or deciduous fruit and nut crops (synthetic fertilizer applications). In Tulare County, statistical data indicate that elevated

  12. Agricultural nonpoint source pollution and economic incentive policies. Issues in the reauthorization of the Clean Water Act. Staff report

    SciTech Connect

    Malik, A.S.; Larson, B.A.; Ribaudo, M.

    1992-11-01

    The limited success of command-and-control policies for reducing nonpoint source (NPS) water pollution mandated under the Federal Water Pollution Control Act (FWPCA) has prompted increased interest in economic incentive policies as an alternative control mechanism. No single policy, however, is likely to be effective in reducing all NPS pollution. Economic incentives may be effective in some cases, command-and-control practices in others.

  13. Coherence among different microbial source tracking markers in a small agricultural stream with or without livestock exclusion practices.

    PubMed

    Wilkes, Graham; Brassard, Julie; Edge, Thomas A; Gannon, Victor; Jokinen, Cassandra C; Jones, Tineke H; Marti, Romain; Neumann, Norman F; Ruecker, Norma J; Sunohara, Mark; Topp, Edward; Lapen, David R

    2013-10-01

    Over 1,400 water samples were collected biweekly over 6 years from an intermittent stream protected and unprotected from pasturing cattle. The samples were monitored for host-specific Bacteroidales markers, Cryptosporidium species/genotypes, viruses and coliphages associated with humans or animals, and bacterial zoonotic pathogens. Ruminant Bacteroidales markers did not increase within the restricted cattle access reach of the stream, whereas the ruminant Bacteroidales marker increased significantly in the unrestricted cattle access reach. Human Bacteroidales markers significantly increased downstream of homes where septic issues were documented. Wildlife Bacteroidales markers were detected downstream of the cattle exclusion practice where stream and riparian habitat was protected, but detections decreased after the unrestricted pasture, where the stream and riparian zone was unprotected from livestock. Detection of a large number of human viruses was shown to increase downstream of homes, and similar trends were observed for the human Bacteroidales marker. There was considerable interplay among biomarkers with stream flow, season, and the cattle exclusion practices. There were no to very weak associations with Bacteroidales markers and bacterial, viral, and parasitic pathogens. Overall, discrete sample-by-sample coherence among the different microbial source tracking markers that expressed a similar microbial source was minimal, but spatial trends were physically meaningful in terms of land use (e.g., beneficial management practice) effects on sources of fecal pollution.

  14. Coherence among Different Microbial Source Tracking Markers in a Small Agricultural Stream with or without Livestock Exclusion Practices

    PubMed Central

    Wilkes, Graham; Brassard, Julie; Edge, Thomas A.; Gannon, Victor; Jokinen, Cassandra C.; Jones, Tineke H.; Marti, Romain; Neumann, Norman F.; Ruecker, Norma J.; Sunohara, Mark; Topp, Edward

    2013-01-01

    Over 1,400 water samples were collected biweekly over 6 years from an intermittent stream protected and unprotected from pasturing cattle. The samples were monitored for host-specific Bacteroidales markers, Cryptosporidium species/genotypes, viruses and coliphages associated with humans or animals, and bacterial zoonotic pathogens. Ruminant Bacteroidales markers did not increase within the restricted cattle access reach of the stream, whereas the ruminant Bacteroidales marker increased significantly in the unrestricted cattle access reach. Human Bacteroidales markers significantly increased downstream of homes where septic issues were documented. Wildlife Bacteroidales markers were detected downstream of the cattle exclusion practice where stream and riparian habitat was protected, but detections decreased after the unrestricted pasture, where the stream and riparian zone was unprotected from livestock. Detection of a large number of human viruses was shown to increase downstream of homes, and similar trends were observed for the human Bacteroidales marker. There was considerable interplay among biomarkers with stream flow, season, and the cattle exclusion practices. There were no to very weak associations with Bacteroidales markers and bacterial, viral, and parasitic pathogens. Overall, discrete sample-by-sample coherence among the different microbial source tracking markers that expressed a similar microbial source was minimal, but spatial trends were physically meaningful in terms of land use (e.g., beneficial management practice) effects on sources of fecal pollution. PMID:23913430

  15. Total and infectious Cryptosporidium oocyst and total Giardia cyst concentrations from distinct agricultural and urban contamination sources in Eastern Canada.

    PubMed

    Lalancette, Cindy; Généreux, Mylène; Mailly, Jacinthe; Servais, Pierre; Côté, Caroline; Michaud, Aubert; Di Giovanni, George D; Prévost, Michèle

    2012-03-01

    Cryptosporidium and Giardia (oo)cyst concentrations are frequently used for assessing drinking water safety. The widely used USEPA Method 1623 provides total counts of (oo)cysts, but may not be accurate for human health risk characterization, since it does not provide infectivity information. The total counts and infectious fraction of Cryptosporidium oocysts and the total counts of Giardia cysts were assessed in major fecal pollution sources. Fresh calf and cow feces, their manure, and the discharge point were sampled in a small rural sub-watershed (n = 20, 21, 10, 10). Median concentrations for total (oo)cysts were higher in calves (333 oocysts g(-1); 111 cysts g(-1)) than in cows (52 oocysts g(-1); 7 cysts g(-1)). Infectious oocysts were found in 17 (7%) of the samples and none were found in manure or at the discharge point. Urban sources were sampled in the influent and effluent (n = 19, 18) of two wastewater treatment plants. Peak concentrations were 533 oocysts L(-1) and 9,010 cysts L(-1) for influents and 89 oocysts L(-1) and 472 cysts L(-1) for effluents. Infectious oocyst fractions varied from below the detection limit to 7-22% in the effluent and influent respectively. These infectious fractions are significantly lower than those currently used for quantitative microbial risk assessment estimates. PMID:22361710

  16. Immobilization of non-point phosphorus using stabilized magnetite nanoparticles with enhanced transportability and reactivity in soils.

    PubMed

    Pan, Gang; Li, Lei; Zhao, Dongye; Chen, Hao

    2010-01-01

    Laboratory batch and column experiments were conducted to investigate the immobilization of phosphorus (P) in soils using synthetic magnetite nanoparticles stabilized with sodium carboxymethyl cellulose (CMC-NP). Although CMC-stabilized magnetite particles were at the nanoscale, phosphorus removal by the nanoparticles was less than that of microparticles (MP) without the stabilizer due to the reduced P reactivity caused by the coating. The P reactivity of CMC-NP was effectively recovered when cellulase was added to degrade the coating. For subsurface non-point P pollution control for a water pond, it is possible to inject CMC-NP to form an enclosed protection wall in the surrounding soils. Non-stabilized "nanomagnetite" could not pass through the soil column under gravity because it quickly agglomerated into microparticles. The immobilized P was 30% in the control soil column, 33% when treated by non-stabilized MP, 45% when treated by CMC-NP, and 73% when treated by both CMC-NP and cellulase.

  17. COMBUSTION AREA SOURCES: DATA SOURCES

    EPA Science Inventory

    The report identifies, documents, and evaluates data sources for stationary area source emissions, including solid waste and agricultural burning. Area source emissions of particulate matter, sulfur dioxide, oxides of nitrogen, reactive volatile organic compounds, and carbon mon...

  18. Response of Polish rivers (Vistula, Oder) to reduced pressure from point sources and agriculture during the transition period (1988-2008)

    NASA Astrophysics Data System (ADS)

    Pastuszak, Marianna; Stålnacke, Per; Pawlikowski, Krzysztof; Witek, Zbigniew

    2012-06-01

    The Vistula and Oder Rivers, two out of the seven largest rivers in the Baltic drainage basin, were responsible for 25% of total riverine nitrogen (TN) and 37% of total riverine phosphorus (TP) input to the Baltic Sea in 2000. The aim of this paper is to evaluate the response of these two rivers to changes that took place in Polish economy during the transition period (1988-2008). The economic changes encompassed: construction of nearly 900 waste water treatment plants in 1999-2008, modernization or closure of obsolete factories, economizing in water consumption, closure or change of ownership of State-owned farms, a drop in fertilizer application, and a decline in livestock stocking. More intensive agriculture and higher point source emissions in the Oder than in the Vistula basin resulted in higher concentrations of TN, nitrate (NO3-N), and TP in the Oder waters in the entire period of our studies. In both rivers, nutrient concentrations and loads showed significant declining trends in the period 1988-2008. TN loads decreased by ca. 20% and 25% in the Vistula and Oder; TP loads dropped by ca. 15% and 65% in the Vistula and Oder. The reduction in phosphorus loads was particularly pronounced in the Oder basin, which was characterized by efficient management systems aiming at mitigation of nutrient emission from the point sources and greater extent of structural changes in agricultural sector during the transition period. The trends in riverine loads are discussed in the paper in relation to socio-economical changes during the transition period, and with respect to physiographic features.

  19. Integrating GRACE and multi-source data sets to quantify the seasonal groundwater depletion in mega agricultural regions

    NASA Astrophysics Data System (ADS)

    Tang, Y.; Wang, D.; Zhu, T.; Ringler, C.; Sun, A. Y.

    2015-12-01

    It is challenging to quantify the groundwater depletion in the mega basins owing to the huge spatial scale and the intensive anthrophonic activities (e.g. dams and reservoirs). Recently, the satellite Gravity Recovery and Climate Experiment (GRACE) data provides an opportunity to monitor large-scale groundwater depletion. However, the data is only available after 2002, limiting the understanding of inter-annual variability of seasonal groundwater depletion. In this study, a simple model with two parameters is developed, based on the seasonal Budyko framework for quantifying the seasonal groundwater depletion. The model is applied to the Indus and Ganges River basin in South Asia and the High Plain/Ogallala aquifer in United States. The parameters of the model are estimated by integrating GRACE and other multi-source data sets. Total water storage changes before 2003 are reconstructed based on the developed model with available data of evaporation, precipitation, and potential evaporation.

  20. Composition, sources, and potential toxicology of polycyclic aromatic hydrocarbons (PAHs) in agricultural soils in Liaoning, People's Republic of China.

    PubMed

    Cao, Xiu Feng; Liu, Miao; Song, Yu Fang; Ackland, M Leigh

    2013-03-01

    Surface soil (0-20 cm) samples (n = 143) were collected from vegetable, maize, and paddy farmland used for commercial crops in Liaoning, China. Sixteen priority polycyclic aromatic hydrocarbons (PAHs) listed in US Environmental Protection Agency were analyzed by high-performance liquid chromatography using a fluorescence detector. The soil concentrations of the 16 PAH ranged from 50 to 3,309 ng/g with a mean of 388 ng/g. The highest concentration of total PAHs found in soil of the vegetable farmland was 448 ng/g in average, followed by maize and paddy with total PAHs of 391 and 331 ng/g, respectively. Generally, the low molecular weight PAHs were more predominant than the high molecular weight PAHs in most of the soils. The evaluation of soil PAH contamination based on the Canadian criterion indicated that only naphthalene, phenanthrene, and pyrene were over the target values in several sampling sites. Isomer pair ratios and principal component analysis indicated that biomass and coal combustion were the main sources of PAHs in this area. And the average value of total B[a]Peq concentration in vegetable soils was higher than paddy and maize soils. We suggest that biomass burning should be abolished and commercial farming should be carried out far from the highways to ensure the safety of food products derived from commercial farming.

  1. Sources of atmospheric acidity in an agricultural-industrial region of São Paulo State, Brazil

    NASA Astrophysics Data System (ADS)

    Da Rocha, G. O.; Franco, A.; Allen, A. G.; Cardoso, A. A.

    2003-04-01

    Surface-based measurements of atmospheric formic acid (HCOOH), acetic acid (CH3COOH), sulfur dioxide (SO2), hydrogen chloride (HCl), and nitric acid (HNO3) were made in central São Paulo State, Brazil, between April 1999 and March 2000. Mean concentrations were 9.0 ppb (HCOOH), 1.3 ppb (CH3COOH), 4.9 ppb (SO2), 0.3 ppb (HCl), and 0.5 ppb (HNO3). Concentrations in sugar cane burning plumes were 1160-4230 ppb (HCOOH), 360-1750 ppb (CH3COOH), 10-630 ppb (SO2), 4-210 ppb (HCl), and 14-90 ppb (HNO3). Higher ambient concentrations of SO2, HCl and HNO3 were measured during the burning season (May-November). Concentrations of SO2 and HCl increased during the evening, and of HCOOH and CH3COOH were lowest in the morning, with peak levels in the afternoon. Ratios obtained between different species showed either nighttime maxima (SO2/HCOOH, SO2/CH3COOH, SO2/HNO3, CH3COOH/HNO3, SO2/HCl and HCOOH/HNO3), daytime maxima (HCOOH/HCl, CH3COOH/HCl and HNO3/HCl), or no clear trends (HCOOH/CH3COOH). Correlation analysis showed that SO2 and HCl were primary emissions from biomass burning and road transport; HCOOH, HNO3 and CH3COOH were products of photochemistry; HCOOH and CH3COOH were emitted directly during combustion as well as from biogenic sources. Biomass burning affected atmospheric acidity on a regional scale, while vehicular emissions had greater impact in urban and adjacent areas. Atmospheric ammonia levels were insufficient to neutralize atmospheric acidity, which was mainly removed by deposition to the surface.

  2. Development of a risk-based index for source water protection planning, which supports the reduction of pathogens from agricultural activity entering water resources.

    PubMed

    Goss, Michael; Richards, Charlene

    2008-06-01

    Source water protection planning (SWPP) is an approach to prevent contamination of ground and surface water in watersheds where these resources may be abstracted for drinking or used for recreation. For SWPP the hazards within a watershed that could contribute to water contamination are identified together with the pathways that link them to the water resource. In rural areas, farms are significant potential sources of pathogens. A risk-based index can be used to support the assessment of the potential for contamination following guidelines on safety and operational efficacy of processes and practices developed as beneficial approaches to agricultural land management. Evaluation of the health risk for a target population requires knowledge of the strength of the hazard with respect to the pathogen load (massxconcentration). Manure handling and on-site wastewater treatment systems form the most important hazards, and both can comprise confined and unconfined source elements. There is also a need to understand the modification of pathogen numbers (attenuation) together with characteristics of the established pathways (surface or subsurface), which allow the movement of the contaminant species from a source to a receptor (water source). Many practices for manure management have not been fully evaluated for their impact on pathogen survival and transport in the environment. A key component is the identification of potential pathways of contaminant transport. This requires the development of a suitable digital elevation model of the watershed for surface movement and information on local groundwater aquifer systems for subsurface flows. Both require detailed soils and geological information. The pathways to surface and groundwater resources can then be identified. Details of land management, farm management practices (including animal and manure management) and agronomic practices have to be obtained, possibly from questionnaires completed by each producer within the

  3. Using U-series Isotopes To Determine Sources Of Pedogenic Carbonates: Comparison Of Natural And Agricultural Soils In The Semi-arid Southern New Mexico And Western Texas

    NASA Astrophysics Data System (ADS)

    Nyachoti, S. K.; Ma, L.; Borrok, D. M.; Jin, L.; Tweedie, C. E.

    2012-12-01

    Pedogenic carbonates commonly precipitate from infiltrating soil water in arid and semi-arid lands and are observed in soils of southern New Mexico and western Texas. These carbonates could form an impermeable layer in the soil horizons impairing water infiltration, thus affecting crop growth and yield. It is important to determine the source of C and Ca in these carbonates and to understand conditions favoring their formation, kinetics and precipitation rates. In this study, major elements and U-series isotopes in bulk calcic soils, and weak acid leachates and residues were measured from one irrigated alfalfa site in the Hueco basin near El Paso, TX and one natural shrubland site on the USDA Jornada experimental range in southern NM. The combined geochemical and isotopic results allow us to determine the formation ages of the carbonates; investigate the mobility of U, Th, and major elements in these soils; and infer for the effects of irrigation on carbonate formation in agricultural soils. Our results show distinctive U and Th isotope systems in the two soil profiles analyzed. For example, (234U/238U) ratios in the Jornada bulk soils decrease from ~1.01 to 0.96 towards the surface, consistent with a preferential loss of 234U over 238U during chemical weathering. At the Jornada site, (238U/232Th) ratios decrease while (230Th/238U) increase towards the surface, consistent with a general depletion of U and the immobility of Th in the natural soils. By contrast at the Alfalfa site, (234U/238U) ratios of bulk soils increase from ~ 0.97 to 1.02 towards the surface, suggesting an additional source of external uranium, most likely the irrigation water from Rio Grande which has a (234U/238U) ratio of ~ 1.5 near El Paso. The (238U/232Th) and (230Th/238U) ratios also imply leaching of U from shallower soils but precipitation in greater depths at Alfalfa site; suggests that partial dissolution and re-precipitation of younger carbonates occur. Calculated carbonate ages from U

  4. Land-use controls on sources and fate of nitrate in shallow groundwater of an agricultural area revealed by multiple environmental tracers

    NASA Astrophysics Data System (ADS)

    Koh, Dong-Chan; Mayer, Bernhard; Lee, Kwang-Sik; Ko, Kyung-Seok,

    2010-10-01

    Sources and transformation processes of nitrate in groundwater from shallow aquifers were investigated in an agricultural area in the mid-western part of South Korea using a multi-tracer approach including δ 2H and δ 18O values of water, δ 15N and δ 18O values of nitrate, Cl/Br ratios and chlorofluorocarbons (CFCs). The study area was comprised of four land-use types with natural areas at higher altitudes, upland areas with fruit orchards, paddy fields and residential areas at lower elevations. The isotopic composition of water was suitable for distinguishing groundwater that had infiltrated in the higher elevation natural areas with lower δ 2H and δ 18O values from groundwater underneath paddy fields that was characterized by elevated δ 2H and δ 18O values due to evaporation. δ 18O-H 2O values and Cl - concentrations indicated that groundwater and contaminant sources were derived from three land-use types: natural areas, residential areas and paddy fields. Groundwater age determination based on CFCs showed that nitrate contamination of groundwater is primarily controlled by historic nitrogen loadings at least in areas with higher nitrate contamination. Nitrate sources were identified using the stable isotope composition of nitrate and Cl/Br ratios. Higher δ 15N-NO 3- values and Cl/Br ratios of 300 to 800 in residential areas indicated that waste water and septic effluents were major nitrate sources whereas lower δ 15N-NO 3- values and Cl/Br ratios of 100 to 700 in upland areas suggested that synthetic fertilizers constituted a major source of nitrate contamination of aquifers. With only few exceptions in the natural area, contributions of atmospheric nitrate were insignificant due to the resetting of δ 18O-NO 3- values via immobilization and re-mineralization of nitrate in the soil zone. In groundwater underneath paddy fields, 30% of samples had δ 18O-NO 3- values at least 2‰ higher than expected for nitrate formed by chemolithoautotrophic

  5. Land-use controls on sources and fate of nitrate in shallow groundwater of an agricultural area revealed by multiple environmental tracers.

    PubMed

    Koh, Dong-Chan; Mayer, Bernhard; Lee, Kwang-Sik; Ko, Kyung-Seok

    2010-10-21

    Sources and transformation processes of nitrate in groundwater from shallow aquifers were investigated in an agricultural area in the mid-western part of South Korea using a multi-tracer approach including δ²H and δ¹⁸O values of water, δ¹⁵N and δ¹⁸O values of nitrate, Cl/Br ratios and chlorofluorocarbons (CFCs). The study area was comprised of four land-use types with natural areas at higher altitudes, upland areas with fruit orchards, paddy fields and residential areas at lower elevations. The isotopic composition of water was suitable for distinguishing groundwater that had infiltrated in the higher elevation natural areas with lower δ²H and δ¹⁸O values from groundwater underneath paddy fields that was characterized by elevated δ²H and δ¹⁸O values due to evaporation. δ¹⁸O-H₂O values and Cl⁻ concentrations indicated that groundwater and contaminant sources were derived from three land-use types: natural areas, residential areas and paddy fields. Groundwater age determination based on CFCs showed that nitrate contamination of groundwater is primarily controlled by historic nitrogen loadings at least in areas with higher nitrate contamination. Nitrate sources were identified using the stable isotope composition of nitrate and Cl/Br ratios. Higher δ¹⁵N-NO₃⁻ values and Cl/Br ratios of 300 to 800 in residential areas indicated that waste water and septic effluents were major nitrate sources whereas lower δ¹⁵N-NO₃⁻ values and Cl/Br ratios of 100 to 700 in upland areas suggested that synthetic fertilizers constituted a major source of nitrate contamination of aquifers. With only few exceptions in the natural area, contributions of atmospheric nitrate were insignificant due to the resetting of δ¹⁸O-NO₃⁻ values via immobilization and re-mineralization of nitrate in the soil zone. In groundwater underneath paddy fields, 30% of samples had δ¹⁸O-NO₃⁻ values at least 2‰ higher than expected for nitrate formed

  6. Support vector machine-an alternative to artificial neuron network for water quality forecasting in an agricultural nonpoint source polluted river?

    PubMed

    Liu, Mei; Lu, Jun

    2014-09-01

    Water quality forecasting in agricultural drainage river basins is difficult because of the complicated nonpoint source (NPS) pollution transport processes and river self-purification processes involved in highly nonlinear problems. Artificial neural network (ANN) and support vector model (SVM) were developed to predict total nitrogen (TN) and total phosphorus (TP) concentrations for any location of the river polluted by agricultural NPS pollution in eastern China. River flow, water temperature, flow travel time, rainfall, dissolved oxygen, and upstream TN or TP concentrations were selected as initial inputs of the two models. Monthly, bimonthly, and trimonthly datasets were selected to train the two models, respectively, and the same monthly dataset which had not been used for training was chosen to test the models in order to compare their generalization performance. Trial and error analysis and genetic algorisms (GA) were employed to optimize the parameters of ANN and SVM models, respectively. The results indicated that the proposed SVM models performed better generalization ability due to avoiding the occurrence of overtraining and optimizing fewer parameters based on structural risk minimization (SRM) principle. Furthermore, both TN and TP SVM models trained by trimonthly datasets achieved greater forecasting accuracy than corresponding ANN models. Thus, SVM models will be a powerful alternative method because it is an efficient and economic tool to accurately predict water quality with low risk. The sensitivity analyses of two models indicated that decreasing upstream input concentrations during the dry season and NPS emission along the reach during average or flood season should be an effective way to improve Changle River water quality. If the necessary water quality and hydrology data and even trimonthly data are available, the SVM methodology developed here can easily be applied to other NPS-polluted rivers.

  7. Biogenic Volatile Organic Compound (BVOC) emissions from agricultural crop species: is guttation a possible source for methanol emissions following light/dark transition ?

    NASA Astrophysics Data System (ADS)

    Mozaffar, Ahsan; Amelynck, Crist; Bachy, Aurélie; Digrado, Anthony; Delaplace, Pierre; du Jardin, Patrick; Fauconnier, Marie-Laure; Schoon, Niels; Aubinet, Marc; Heinesch, Bernard

    2015-04-01

    In the framework of the CROSTVOC (CROp STress VOC) project, the exchange of biogenic volatile organic compounds (BVOCs) between two important agricultural crop species, maize and winter wheat, and the atmosphere has recently been measured during an entire growing season by using the eddy covariance technique. Because of the co-variation of BVOC emission drivers in field conditions, laboratory studies were initiated in an environmental chamber in order to disentangle the responses of the emissions to variations of the individual environmental parameters (such as PPFD and temperature) and to diverse abiotic stress factors. Young plants were enclosed in transparent all-Teflon dynamic enclosures (cuvettes) through which BVOC-free and RH-controlled air was sent. BVOC enriched air was subsequently sampled from the plant cuvettes and an empty cuvette (background) and analyzed for BVOCs in a high sensitivity Proton Transfer Reaction Mass Spectrometer (hs-PTR-MS) and for CO2 in a LI-7000 non-dispersive IR gas analyzer. Emissions were monitored at constant temperature (25 °C) and at a stepwise varying PPFD pattern (0-650 µmol m-2 s-1). For maize plants, sudden light/dark transitions at the end of the photoperiod were accompanied by prompt and considerable increases in methanol (m/z 33) and water vapor (m/z 39) emissions. Moreover, guttation droplets appeared on the sides and the tips of the leaves within a few minutes after light/dark transition. Therefore the assumption has been raised that methanol is also coming out with guttation fluid from the leaves. Consequently, guttation fluid was collected from young maize and wheat plants, injected in an empty enclosure and sampled by PTR-MS. Methanol and a large number of other compounds were observed from guttation fluid. Recent studies have shown that guttation from agricultural crops frequently occurs in field conditions. Further research is required to find out the source strength of methanol emissions by this guttation

  8. [Transformation Mechanism and Sources of Secondary Inorganic Components in PM2.5 at an Agriculture Site (Quzhou) in the North China Plain in Summer].

    PubMed

    Chen, Shi-yi; Zeng, Li-min; Dong, Hua-bin; Zhu, Tong

    2015-10-01

    Simultaneously on-line measurements of major water-soluble inorganic ions and gaseous pollutants were performed from June 9 to July 11, 2014 at Quzhou, an agriculture site in the North China Plain using a gas-aerosol collector (GAC) and ion chromatograph (IC), aiming to track the diurnal variation rule of secondary inorganic components and gas-phase precursors as well as their interactions. The transformation mechanism and sources of fine particles (PM2.5) were also discussed. The results showed that these water-soluble ions in PM2.5 and their gas-phase precursors varied regularly. As the dominant ionic components of PM2.5 (accounting for 76.23%), the average concentrations of SO4(2-), NH4(+), NO3(-) were 26.28 μg x m(-3), 18.08 μg x m(-3) and 16.36 μg m(-3) respectively. Among the precursor gases, the NH3, generated from the discharges of local agricultural activities, displayed a significantly higher concentration at an average value of 44.85 μg x m(-3). The average fine sulfate and nitrate oxidation ratios (SOR and NOR) were SOR = 0.60, NOR = 0.30, revealing the remarkable characteristics of secondary pollution. As could be found from the relevant analysis, the NH4(+) of Quzhou showed well relations with NO3(-) and SO4(2-), and the environment here was rich of ammonia. The NH4(+) existed in the form of (NH4)2SO4 and the generation of NO3(-) was limited by the HNO3. From the analysis for the equilibrium of NH4NO3, we observed that the atmospheric environment of Quzhou was adverse to the generation and maintenance of NH4NO3 during the daytime,in contrast with the night. Integrated with the study, the results displayed that the secondary transformation was the main source of fine particles in Quzhou, and the NH3 from field and compost was the significant factor leading to the high value of S-N-A. PMID:26841585

  9. Use of a multi-isotope and multi-tracer approach including organic matter isotopes for quantifying nutrient contributions from agricultural vs wastewater sources

    NASA Astrophysics Data System (ADS)

    Kendall, C.; Silva, S. R.; Young, M. B.

    2013-12-01

    While nutrient isotopes are a well-established tool for quantifying nutrients inputs from agricultural vs wastewater treatment plant (WWTP) sources, we have found that combining nutrient isotopes with the C, N, and S isotopic compositions of dissolved and particulate organic matter, as part of a comprehensive multi-isotope and multi-tracer approach, is a much more diagnostic approach. The main reasons why organic matter C-N-S isotopes are a useful adjunct to studies of nutrient sources and biogeochemical processes are that the dissolved and particulate organic matter associated with (1) different kinds of animals (e.g., humans vs cows) often have distinctive isotopic compositions reflecting the different diets of the animals, and (2) the different processes associated with the different land uses (e.g., in the WWTP or associated with different crop types) often result in significant differences in the isotopic compositions of the organics. The analysis of the δ34S of particulate organic matter (POM) and dissolved organic matter (DOM) has been found to be especially useful for distinguishing and quantifying water, nutrient, and organic contributions from different land uses in aquatic systems where much of the organic matter is aquatic in origin. In such environments, the bacteria and algae incorporate S from sulfate and sulfide that is isotopically labeled by the different processes associated with different land uses. We have found that there is ~35 permil range in δ34S of POM along the river-estuary continuum in the San Joaquin/Sacramento River basin, with low values associated with sulfate reduction in the upstream wetlands and high values associated with tidal inputs of marine water into the estuary. Furthermore, rice agriculture results in relatively low δ34S values whereas WWTP effluent in the Sacramento River produces distinctly higher values than upstream of the WWTP, presumably because SO2 is used to treat chlorinated effluent. The fish living

  10. [Transformation Mechanism and Sources of Secondary Inorganic Components in PM2.5 at an Agriculture Site (Quzhou) in the North China Plain in Summer].

    PubMed

    Chen, Shi-yi; Zeng, Li-min; Dong, Hua-bin; Zhu, Tong

    2015-10-01

    Simultaneously on-line measurements of major water-soluble inorganic ions and gaseous pollutants were performed from June 9 to July 11, 2014 at Quzhou, an agriculture site in the North China Plain using a gas-aerosol collector (GAC) and ion chromatograph (IC), aiming to track the diurnal variation rule of secondary inorganic components and gas-phase precursors as well as their interactions. The transformation mechanism and sources of fine particles (PM2.5) were also discussed. The results showed that these water-soluble ions in PM2.5 and their gas-phase precursors varied regularly. As the dominant ionic components of PM2.5 (accounting for 76.23%), the average concentrations of SO4(2-), NH4(+), NO3(-) were 26.28 μg x m(-3), 18.08 μg x m(-3) and 16.36 μg m(-3) respectively. Among the precursor gases, the NH3, generated from the discharges of local agricultural activities, displayed a significantly higher concentration at an average value of 44.85 μg x m(-3). The average fine sulfate and nitrate oxidation ratios (SOR and NOR) were SOR = 0.60, NOR = 0.30, revealing the remarkable characteristics of secondary pollution. As could be found from the relevant analysis, the NH4(+) of Quzhou showed well relations with NO3(-) and SO4(2-), and the environment here was rich of ammonia. The NH4(+) existed in the form of (NH4)2SO4 and the generation of NO3(-) was limited by the HNO3. From the analysis for the equilibrium of NH4NO3, we observed that the atmospheric environment of Quzhou was adverse to the generation and maintenance of NH4NO3 during the daytime,in contrast with the night. Integrated with the study, the results displayed that the secondary transformation was the main source of fine particles in Quzhou, and the NH3 from field and compost was the significant factor leading to the high value of S-N-A.

  11. Optimization of integrated water quality management for agricultural efficiency and environmental conservation.

    PubMed

    Fleifle, Amr; Saavedra, Oliver; Yoshimura, Chihiro; Elzeir, Mohamed; Tawfik, Ahmed

    2014-01-01

    The scarcity of water resources in Egypt has necessitated the use of various types of lower quality water. Agricultural drainage water is considered a strategic reserve for meeting increasing freshwater demands. In this study, a novel model series was applied to a drainage basin in the Nile Delta to optimize integrated water quality management for agriculture and the aquatic environment. The proposed model series includes a waste load allocation model, an export coefficient model, a stream water quality model, and a genetic algorithm. This model series offers an optimized solution for determining the required removal levels of total suspended solids (TSS), the chemical oxygen demand (COD) at point and non-point pollution sources, and the source flows that require treatment to meet a given water quality target. The model series was applied during the summer and winter to the El-Qalaa basin in the western delta of the Nile River. Increased pollutant removal and treated fractions at point and non-point sources reduced violations of the TSS standards from 732.6 to 238.9 mg/L in summer and from 543.1 to 380.9 mg/L in winter. Likewise, violations of the COD standards decreased from 112.4 mg/L to 0 (no violations) in summer and from 91.7 mg/L to no violations in winter. Thus, this model is recommended as a decision support tool for determining a desirable waste load allocation solution from a trade-off curve considering costs and the degree of compliance with water quality standards.

  12. Historical contributions of phosphorus from natural and agricultural sources and implications for stream water quality, Cheney Reservoir watershed, south-central Kansas

    USGS Publications Warehouse

    Pope, Larry M.; Milligan, Chad R.; Mau, David Phillip

    2002-01-01

    An examination of soil cores collected from 43 nonagricultural coring sites in the Cheney Reservoir watershed of south-central Kansas was conducted by the U.S. Geological Survey in September 1999. The cores were collected as part of an ongoing cooperative study with the city of Wichita, Kansas. The 43 sites (mostly cemeteries) were thought to have total phosphorus concentrations in the soil that are representative of natural conditions (unaffected by human activity). The purpose of this report is to present the analysis and evaluation of these soil cores, to quantify the phosphorus contributions to Cheney Reservoir from natural and agricultural sources, and to provide estimates of stream-water-quality response to natural concentrations of total phosphorus in the soil. Analysis of soil cores from the 43 sites produced natural concentrations of total phosphorus that ranged from 74 to 539 milligrams per kilogram with a median concentration of 245 milligrams per kilogram in 2-inch soil cores and from 50 to 409 milligrams per kilogram with a median concentration of 166 milligrams per kilogram in 8-inch soil cores. Natural concentrations of total phosphorus in soil were statistically larger in samples from coring sites in the eastern half of the watershed than in samples from coring sites in the western half of the watershed. This result partly explains a previously determined west-to-east increase in total phosphorus yields in streams of the Cheney Reservoir watershed. A comparison of total phosphorus concentrations in soil under natural conditions to the historical mean total phosphorus concentration in agriculturally enriched bottom sediment in Cheney Reservoir indicated that agricultural activities within the watershed have increased total phosphorus concentrations in watershed soil that is transported in streams to about 2.9 times natural concentrations. Retention efficiencies for phosphorus and sediment historically transported to Cheney Reservoir were calculated

  13. Nitrogen Isotope Tracing of Eutrophication Sources on a Watershed Scale: Nitrogen and Oxygen Isotopes of Nitrate

    NASA Astrophysics Data System (ADS)

    Showers, W. J.; Genna, B.; Karr, J.

    2001-05-01

    Nitrate contamination of shallow aquifers and surface waters associated with agricultural activities has become a major concern in river basins, like the Neuse, where significant agricultural land use is coupled with growing numbers of intensive animal operations (ILO's). The development of effective management practices to preserve water quality, or remediation strategies for basins already polluted requires source identification. The stable isotopes of nitrogen and oxygen in nitrate has been used as tracers to evaluate nitrogen sources on small scales, such as agricultural fields, or small watersheds with one dominate land use. This discrimination is possible because of the large fractionation associated with the volatilization of ammonia from animal wastes. Using stable isotopes on larger scales to evaluate nutrient sources is complicated by multiple sources, overlapping point and non-point sources, and co-existing biogeochemical processes that alter nitrate concentrations. To evaluate the potential of stable isotopes to determine the character of nutrient fluxes on larger scales, the isotopic/discharge relationship was examined for a watershed with little agricultural activity, an urban watershed, a watershed with mixed urban and agricultural land use, a watershed dominated by swine ILO's, and a watershed dominated by poultry ILO's. The watershed with little agricultural activity and the poultry watershed have similar isotope/discharge relationships with isotopic values at natural background levels and no change in concentration or isotopic composition in different discharge states. The urban watershed is dominated by point source isotopic values at all flow levels, the mixed urban and agricultural watershed is dominated by point source values during low flow conditions, and fertilizer non-point source values during high flow conditions. In this watershed nutrient concentrations also increase during low flow conditions. The swine watershed is dominated by

  14. Reducing pollution in agriculture land, agroforestry and Common Agrarian Policy

    NASA Astrophysics Data System (ADS)

    Rosa Mosquera Losada, Maria; Santiago-Freijanes, José Javier; Ferreiro-Domínguez, Nuria; Rois, Mercedes; Rigueiro-Rodríguez, Antonio

    2015-04-01

    Reducing non-point source pollution in Europe is a key activity for the European institutions and citizens. Ensuring high quality food supply while environment is sustainable managed is a highly relevant in the European agriculture. New CAP tries to promote sustainability with the greening measures in Pillar I (EU payments) and Pillar II (EU-Country cofinanced payments). The star component of the Pillar I is the greening. The greening includes three types of activities related to crop rotation, maintenance of permanent pasture and the promotion of Ecological Focus Areas (EFA). Greening practices are compulsory in arable lands when they are placed in regions with low proportion of forests and when the owner has large farms. Among the EFA, there are several options that include agroforestry practices like landscape features, buffer strips, agroforestry, strips of eligible hectares along forest edges, areas with short rotation coppice. These practices promote biodiversity and the inclusion of woody vegetation that is able to increase the uptake of the excess of nutrients like N or P. USA Agriculture Department has also recognize the importance of woody vegetation around the arable lands to reduce nutrient pollution and promote biodiversity.

  15. Nutrient sources in a Mediterranean catchment and their improvement for water quality management

    NASA Astrophysics Data System (ADS)

    Candela, Angela; Viviani, Gaspare

    2010-05-01

    . Regarding the inventory of point and non-point pollutants sources, the river receives a number of point source pollutants from small villages and some outskirts of Palermo, most of them untreated, and non point source pollutants from agricultural cropland and zoo-technical farms. In particular, the Oreto river receives untreated wastewater and stormwater from Altofonte (8200 inhabitants) and Pioppo (2500 inhabitants) . The model was first calibrated using meteorological, flow and water quality data collected at various stations through-out the catchment, in order to predict water and nutrient concentrations at the catchment outlet and then was used to evaluate the potential impact of various management strategies on surface water quality. The results demonstrates that point and non-point polluting sources have to be contiguously analysed because they concur to the definition of river water quality both during wet and dry periods.

  16. The seasonal dynamics of the stream sources and input flow paths of water and nitrogen of an Austrian headwater agricultural catchment.

    PubMed

    Exner-Kittridge, Michael; Strauss, Peter; Blöschl, Günter; Eder, Alexander; Saracevic, Ernis; Zessner, Matthias

    2016-01-15

    Our study examines the source aquifers and stream inputs of the seasonal water and nitrogen dynamics of a headwater agricultural catchment to determine the dominant driving forces for the seasonal dynamics in the surface water nitrogen loads and concentrations. We found that the alternating aquifer contributions throughout the year of the deep and shallow aquifers were the main cause for the seasonality of the nitrate concentration. The deep aquifer water typically contributed 75% of the total outlet discharge in the summer and 50% in the winter when the shallow aquifer recharges due to low crop evapotranspiration. The shallow aquifer supplied the vast majority of the nitrogen load to the stream due to the significantly higher total nitrogen concentration (11 mg-N/l) compared to the deep aquifer (0.50 mg-N/l). The main stream input pathway for the shallow aquifer nitrogen load was from the perennial tile drainages providing 60% of the total load to the stream outlet, while only providing 26% of the total flow volume. The diffuse groundwater input to the stream was the largest input to the stream (39%), but only supplied 27% to the total nitrogen load as the diffuse water was mostly composed of deep aquifer water. PMID:26562340

  17. Managing Artificially Drained Low-Gradient Agricultural Headwaters for Enhanced Ecosystem Functions

    PubMed Central

    Pierce, Samuel C.; Kröger, Robert; Pezeshki, Reza

    2012-01-01

    Large tracts of lowlands have been drained to expand extensive agriculture into areas that were historically categorized as wasteland. This expansion in agriculture necessarily coincided with changes in ecosystem structure, biodiversity, and nutrient cycling. These changes have impacted not only the landscapes in which they occurred, but also larger water bodies receiving runoff from drained land. New approaches must append current efforts toward land conservation and restoration, as the continuing impacts to receiving waters is an issue of major environmental concern. One of these approaches is agricultural drainage management. This article reviews how this approach differs from traditional conservation efforts, the specific practices of drainage management and the current state of knowledge on the ecology of drainage ditches. A bottom-up approach is utilized, examining the effects of stochastic hydrology and anthropogenic disturbance on primary production and diversity of primary producers, with special regard given to how management can affect establishment of macrophytes and how macrophytes in agricultural landscapes alter their environment in ways that can serve to mitigate non-point source pollution and promote biodiversity in receiving waters. PMID:24832519

  18. Application of nitrogen and phosphorus criteria for streams in agricultural landscapes.

    PubMed

    Chambers, P A; Benoy, G A; Brua, R B; Culp, J M

    2011-01-01

    Efforts to control eutrophication of water resources in agriculturally dominated ecosystems have focused on managing on-farm activities to reduce nutrient loss; however, another management measure for improving water quality is adoption of environmental performance criteria (or 'outcome-based standards'). Here, we review approaches for setting environmental quality criteria for nutrients, summarize approaches developed in Canada for setting 'ideal' and 'achievable' nutrient criteria for streams in agricultural watersheds, and consider how such criteria could be applied. As part of a 'National Agri-Environmental Standards Initiative', the Government of Canada committed to the development of non-regulatory environmental performance standards that establish total P (TP) and total N (TN) concentrations to protect ecological condition of agricultural streams. Application of four approaches for defining ideal standards using only chemistry data resulted in values for TP and TN spanning a relatively narrow range of concentrations within a given ecoregion. Cross-calibration of these chemically derived standards with information on biological condition resulted in recommendations for TP and TN that would likely protect aquatic life from adverse effects of eutrophication. Non-point source water quality modelling was then conducted in a specific watershed to estimate achievable standards, i.e. chemical conditions that could be attained using currently available and recommended management practices. Our research showed that, taken together, short-term achievable standards and ultimate ideal standards could be used to set policy targets that should, if realized, lower N and P concentrations in Canadian agricultural streams and improve biotic condition.

  19. Grassland agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agriculture in grassland environments is facing multiple stresses from: shifting demographics, declining and fragmented agricultural landscapes, declining environmental quality, variable and changing climate, volatile and increasing energy costs, marginal economic returns, and globalization. Degrad...

  20. Agricultural Production.

    ERIC Educational Resources Information Center

    Lehigh County Area Vocational-Technical School, Schnecksville, PA.

    This brochure describes the philosophy and scope of a secondary-level course in agricultural production. Addressed in the individual units of the course are the following topics: careers in agriculture and agribusiness, animal science and livestock production, agronomy, agricultural mechanics, supervised occupational experience programs, and the…

  1. Identifying the sources of nitrate contamination of groundwater in an agricultural area (Haean basin, Korea) using isotope and microbial community analyses.

    PubMed

    Kim, Heejung; Kaown, Dugin; Mayer, Bernhard; Lee, Jin-Yong; Hyun, Yunjung; Lee, Kang-Kun

    2015-11-15

    An integrated study based on hydrogeochemical, microbiological and dual isotopic approaches for nitrate and sulfate was conducted to elucidate sources and biogeochemical reactions governing groundwater contaminants in different seasons and under different land use in a basin of Korea. The land use in the study area is comprised of forests (58.0%), vegetable fields (27.6%), rice paddy fields (11.4%) and others (3.0%). The concentrations of NO3-N and SO4(2-) in groundwater in vegetable fields were highest with 4.2-15.2 mg L(-1) and 1.6-19.7 mg L(-1) respectively, whereas under paddy fields NO3-N concentrations ranged from 0 to 10.7 mg L(-1) and sulfate concentrations were ~15 mg L(-1). Groundwater with high NO3-N concentrations of >10mgL(-1) had δ(15)N-NO3(-) values ranging from 5.2 to 5.9‰ and δ(18)O values of nitrate between 2.7 and 4.6‰ suggesting that the nitrate was mineralized from soil organic matter that was amended by fertilizer additions. Elevated concentrations of SO4(2-) with δ(34)S-SO4(2-) values between 1 and 6‰ in aquifers in vegetable fields indicated that a mixture of sulfate from atmospheric deposition, mineralization of soil organic matter and from synthetic fertilizers is the source of groundwater sulfate. Elevated δ(18)O-NO3(-) and δ(18)O-SO4(2-) values in samples collected from the paddy fields indicated that denitrification and bacterial sulfate reduction are actively occurring removing sulfate and nitrate from the groundwater. This was supported by high occurrences of denitrifying and sulfate reducing bacteria in groundwater of the paddy fields as evidenced by 16S rRNA pyrosequencing analysis. This study shows that dual isotope techniques combined with microbial data can be a powerful tool for identification of sources and microbial processes affecting NO3(-) and SO4(2-) in groundwater in areas with intensive agricultural land use. PMID:26204420

  2. Identifying the sources of nitrate contamination of groundwater in an agricultural area (Haean basin, Korea) using isotope and microbial community analyses.

    PubMed

    Kim, Heejung; Kaown, Dugin; Mayer, Bernhard; Lee, Jin-Yong; Hyun, Yunjung; Lee, Kang-Kun

    2015-11-15

    An integrated study based on hydrogeochemical, microbiological and dual isotopic approaches for nitrate and sulfate was conducted to elucidate sources and biogeochemical reactions governing groundwater contaminants in different seasons and under different land use in a basin of Korea. The land use in the study area is comprised of forests (58.0%), vegetable fields (27.6%), rice paddy fields (11.4%) and others (3.0%). The concentrations of NO3-N and SO4(2-) in groundwater in vegetable fields were highest with 4.2-15.2 mg L(-1) and 1.6-19.7 mg L(-1) respectively, whereas under paddy fields NO3-N concentrations ranged from 0 to 10.7 mg L(-1) and sulfate concentrations were ~15 mg L(-1). Groundwater with high NO3-N concentrations of >10mgL(-1) had δ(15)N-NO3(-) values ranging from 5.2 to 5.9‰ and δ(18)O values of nitrate between 2.7 and 4.6‰ suggesting that the nitrate was mineralized from soil organic matter that was amended by fertilizer additions. Elevated concentrations of SO4(2-) with δ(34)S-SO4(2-) values between 1 and 6‰ in aquifers in vegetable fields indicated that a mixture of sulfate from atmospheric deposition, mineralization of soil organic matter and from synthetic fertilizers is the source of groundwater sulfate. Elevated δ(18)O-NO3(-) and δ(18)O-SO4(2-) values in samples collected from the paddy fields indicated that denitrification and bacterial sulfate reduction are actively occurring removing sulfate and nitrate from the groundwater. This was supported by high occurrences of denitrifying and sulfate reducing bacteria in groundwater of the paddy fields as evidenced by 16S rRNA pyrosequencing analysis. This study shows that dual isotope techniques combined with microbial data can be a powerful tool for identification of sources and microbial processes affecting NO3(-) and SO4(2-) in groundwater in areas with intensive agricultural land use.

  3. Agricultural Waste.

    PubMed

    Xue, Ling; Zhang, Panpan; Shu, Huajie; Chang, Chein-Chi; Wang, Renqing; Zhang, Shuping

    2016-10-01

    In recent years, the quantity of agricultural waste has been rising rapidly all over the world. As a result, the environmental problems and negative impacts of agricultural waste are drawn more and more attention. Therefore, there is a need to adopt proper approaches to reduce and reuse agricultural waste. This review presented about 200 literatures published in 2015 relating to the topic of agricultural waste. The review examined research on agricultural waste in 2015 from the following four aspects: the characterization, reuse, treatment, and management. Researchers highlighted the importance to reuse agricultural waste and investigated the potential to utilize it as biofertilizers, cultivation material, soil amendments, adsorbent, material, energy recycling, enzyme and catalyst etc. The treatment of agricultural waste included carbonization, biodegradation, composting hydrolysis and pyrolysis. Moreover, this review analyzed the differences of the research progress in 2015 from 2014. It may help to reveal the new findings and new trends in this field in 2015 comparing to 2014. PMID:27620093

  4. Agricultural Waste.

    PubMed

    Xue, Ling; Zhang, Panpan; Shu, Huajie; Chang, Chein-Chi; Wang, Renqing; Zhang, Shuping

    2016-10-01

    In recent years, the quantity of agricultural waste has been rising rapidly all over the world. As a result, the environmental problems and negative impacts of agricultural waste are drawn more and more attention. Therefore, there is a need to adopt proper approaches to reduce and reuse agricultural waste. This review presented about 200 literatures published in 2015 relating to the topic of agricultural waste. The review examined research on agricultural waste in 2015 from the following four aspects: the characterization, reuse, treatment, and management. Researchers highlighted the importance to reuse agricultural waste and investigated the potential to utilize it as biofertilizers, cultivation material, soil amendments, adsorbent, material, energy recycling, enzyme and catalyst etc. The treatment of agricultural waste included carbonization, biodegradation, composting hydrolysis and pyrolysis. Moreover, this review analyzed the differences of the research progress in 2015 from 2014. It may help to reveal the new findings and new trends in this field in 2015 comparing to 2014.

  5. Nitrate in groundwater and water sources used by riparian trees in an agricultural watershed: A chemical and isotopic investigation in southern Minnesota

    USGS Publications Warehouse

    Komor, S.C.; Magner, J.A.

    1996-01-01

    This study evaluates processes that affect nitrate concentrations in groundwater beneath riparian zones in an agricultural watershed. Nitrate pathways in the upper 2 m of groundwater were investigated beneath wooded and grass-shrub riparian zones next to cultivated fields. Because trees can be important components of the overall nitrate pathway in wooded riparian zones, water sources used by riparian trees and possible effects of trees on nitrate concentrations in groundwater were also investigated. Average nitrate concentrations in shallow groundwater beneath the cultivated fields were 5.5 mg/L upgradient of the wooded riparian zone and 3.5 mg/L upgradient of the grass-shrub zone. Shallow groundwater beneath the fields passed through the riparian zones and discharged into streams that had average nitrate concentrations of 8.5 mg/L (as N). Lateral variations of ??D values in groundwater showed that mixing among different water sources occurred beneath the riparian zones. In the wooded riparian zone, nitrate concentrations in shallow groundwater were diluted by upwelling, nitrate- poor, deep groundwater. Upwelling deep groundwater contained ammonium with a ??15N of 5??? that upon nitrification and mixing with nitrate in shallow groundwater caused nitrate ??15N values in shallow groundwater to decrease by as much as 19.5???. Stream water penetrated laterally beneath the wooded riparian zone as far as 19 m from the stream's edge and beneath the grass- shrub zone as far as 27 m from the stream's edge. Nitrate concentrations in shallow groundwater immediately upgradient of where it mixed with stream water averaged 0.4 mg/L in the wooded riparian zone and 0.8 mg/L near the grass-shrub riparian zone. Nitrate concentrations increased toward the streams because of mixing with nitrate-rich stream water. Because nitrate concentrations were larger in stream water than shallow groundwater, concentrated nitrate in the streams cannot have come from shallow groundwater at these

  6. Nitrate in ground water and water sources used by riparian trees in an agricultural watershed: A chemical and isotopic investigation in southern Minnesota

    USGS Publications Warehouse

    Komor, Stephen C.; Magner, J.

    1996-01-01

    This study evaluates processes that affect nitrate concentrations in groundwater beneath riparian zones in an agricultural watershed. Nitrate pathways in the upper 2 m of groundwater were investigated beneath wooded and grass-shrub riparian zones next to cultivated fields. Because trees can be important components of the overall nitrate pathway in wooded riparian zones, water sources used by riparian trees and possible effects of trees on nitrate concentrations in groundwater were also investigated. Average nitrate concentrations in shallow groundwater beneath the cultivated fields were 5.5 mg/L upgradient of the wooded riparian zone and 3.5 mg/L upgradient of the grass-shrub zone. Shallow groundwater beneath the fields passed through the riparian zones and discharged into streams that had average nitrate concentrations of 8.5 mg/L (as N). Lateral variations of δD values in groundwater showed that mixing among different water sources occurred beneath the riparian zones. In the wooded riparian zone, nitrate concentrations in shallow groundwater were diluted by upwelling, nitrate-poor, deep groundwater. Upwelling deep groundwater contained ammonium with a δ15N of 5‰ that upon nitrification and mixing with nitrate in shallow groundwater caused nitrate δ15N values in shallow groundwater to decrease by as much as 19.5‰. Stream water penetrated laterally beneath the wooded riparian zone as far as 19 m from the stream's edge and beneath the grass-shrub zone as far as 27 m from the stream's edge. Nitrate concentrations in shallow groundwater immediately upgradient of where it mixed with stream water averaged 0.4 mg/L in the wooded riparian zone and 0.8 mg/L near the grass-shrub riparian zone. Nitrate concentrations increased toward the streams because of mixing with nitrate-rich stream water. Because nitrate concentrations were larger in stream water than shallow groundwater, concentrated nitrate in the streams cannot have come from shallow groundwater at these

  7. The potential of vegetable oila s an alternate source of liquid fuel for agriculture in the Pacific Northwest - V: Final report, 1986--1987

    SciTech Connect

    Auld, D.L.; Davis, J.B.; Feldman, M.E.; Hall, M.C.; Hawley, K.N.; Korus, R.A.; Magenis, B.R.; Mahler, K.A.; Melville, D.E.; Mosgrove, D.L.

    1987-06-01

    This research was conducted to develop the technology necessary to produce, process, and utilize vegetable oil as a diesel fuel substitute for agricultural production in the Pacific Northwest. Additional studies were conducted to determine the economic threshold, to derive energy budgets for various crop production regions and to insure that expeller extracted meals would make acceptable animal feeds. This research was conducted by an integrated team of scientists from the University of Idaho which initiated efforts in this field in December of 1979. Experiments were conducted by agronomists, agricultural engineers, animal nutritionists, chemical engineers, and agricultural economists. This report summarizes data accumulated from April 1986 to May 1987 as part of USDA/ARS Research Agreement No. 58-7B30-2-402. Copies for this report can be obtained from the Director of the Idaho Agricultural Experiment Station, College of Agriculture, University of Idaho, Moscow, ID 83843.

  8. The potential of vegetable oil as an alternate source of liquid fuel for agriculture in the Pacific Northwest - IV: Final report, 1984-1986

    SciTech Connect

    Auld, D.L.; Hall, M.C.; Hawley, K.N.; Korus, R.A.; Madsen, J.P.; Mahler, K.A.; Mora, P.G.; Peterson, C.L.; Roelofsen, M.; Stibal, W.T.; Whitcraft, J.C.

    1986-01-01

    This research was conducted to develop the technology necessary to produce, process, and utilize vegtable oil as a diesel fuel substitute for agricultural production in the Pacific Northwest. Additional studies were conducted to determine the economic threshold, to derive energy budgets for various crop production regions, and to insure that expeller extracted meals would make acceptable animal feeds. This research was conducted by an integrated team of scientists from the University of Idaho which initiated efforts in this field in December of 1979. Experiments were conducted by agronomists, agricultural engineers, animal nutritionists, chemical engineers, and agricultural economists. This report summarized data accumulated from October 1984 to March 1986 as part of USDA/ARS Research Agreement No. 58-7B30-2-402. Copies of this report can be obtained from the Director of the Idaho Agricultural Experiment Station, College of Agriculture, University of Idaho, Moscow, ID 83843.

  9. Long-Term Monitoring of Waterborne Pathogens and Microbial Source Tracking Markers in Paired Agricultural Watersheds under Controlled and Conventional Tile Drainage Management

    PubMed Central

    Wilkes, Graham; Brassard, Julie; Edge, Thomas A.; Gannon, Victor; Gottschall, Natalie; Jokinen, Cassandra C.; Jones, Tineke H.; Khan, Izhar U. H.; Marti, Romain; Sunohara, Mark D.; Topp, Edward

    2014-01-01

    Surface waters from paired agricultural watersheds under controlled tile drainage (CTD) and uncontrolled tile drainage (UCTD) were monitored over 7 years in order to determine if there was an effect of CTD (imposed during the growing season) on occurrences and loadings of bacterial and viral pathogens, coliphages, and microbial source tracking markers. There were significantly lower occurrences of human, ruminant, and livestock (ruminant plus pig) Bacteroidales markers in the CTD watershed in relation to the UCTD watershed. As for pathogens, there were significantly lower occurrences of Salmonella spp. and Arcobacter spp. in the CTD watershed. There were no instances where there were significantly higher quantitative loadings of any microbial target in the CTD watershed, except for F-specific DNA (F-DNA) and F-RNA coliphages, perhaps as a result of fecal inputs from a hobby farm independent of the drainage practice treatments. There was lower loading of the ruminant marker in the CTD watershed in relation to the UCTD system, and results were significant at the level P = 0.06. The odds of Salmonella spp. occurring increased when a ruminant marker was present relative to when the ruminant marker was absent, yet for Arcobacter spp., the odds of this pathogen occurring significantly decreased when a ruminant marker was present relative to when the ruminant marker was absent (but increased when a wildlife marker was present relative to when the wildlife marker was absent). Interestingly, the odds of norovirus GII (associated with human and swine) occurring in water increased significantly when a ruminant marker was present relative to when a ruminant marker was absent. Overall, this study suggests that fecal pollution from tile-drained fields to stream could be reduced by CTD utilization. PMID:24727274

  10. Agricultural biosecurity.

    PubMed

    Waage, J K; Mumford, J D

    2008-02-27

    The prevention and control of new pest and disease introductions is an agricultural challenge which is attracting growing public interest. This interest is in part driven by an impression that the threat is increasing, but there has been little analysis of the changing rates of biosecurity threat, and existing evidence is equivocal. Traditional biosecurity systems for animals and plants differ substantially but are beginning to converge. Bio-economic modelling of risk will be a valuable tool in guiding the allocation of limited resources for biosecurity. The future of prevention and management systems will be strongly influenced by new technology and the growing role of the private sector. Overall, today's biosecurity systems are challenged by changing national priorities regarding trade, by new concerns about environmental effects of biological invasions and by the question 'who pays?'. Tomorrow's systems may need to be quite different to be effective. We suggest three changes: an integration of plant and animal biosecurity around a common, proactive, risk-based approach; a greater focus on international cooperation to deal with threats at source; and a commitment to refocus biosecurity on building resilience to invasion into agroecosystems rather than building walls around them.

  11. CARIBEAN GRASS SHRIMP (PALAEMONETES PUGIO HOLTHIUS) AS AN INDICATOR OF SEDIMENT QUALITY IN FLORIDA COASTAL AREAS AFFECTED BY POINT AND NON-POINT SOURCE CONTAMINATION.

    EPA Science Inventory

    Grass shrimp are one of the more widely distributed estuarine benthic organisms along the Gulf of Mexico and Atlantic coasts, but they were used infrequently in contaminated sediment assessments. Early-life stages of caridean grass shrimp, Palaemonetes pugio (Holthuis), were used...

  12. CARIDEAN GRASS SHRIMP (PALAEMONETES PUGIO HOLTHIUS) AS AN INDICATOR OF SEDIMENT QUALITY IN FLORIDA COASTAL AREAS AFFECTED BY POINT AND NON-POINT SOURCE CONTAMINATION

    EPA Science Inventory

    Grass shrimp are one of the more widely distributed estuarine benthic organisms along the Gulf of Mexico and Atlantic coasts, but they have been used infrequently in contaminated sediment assessments. Early life stages of the caridean grass shrimp, Palaemonetes pugio (Holthuis), ...

  13. Modeling nitrate contamination of groundwater in agricultural watersheds

    NASA Astrophysics Data System (ADS)

    Almasri, Mohammad N.; Kaluarachchi, Jagath J.

    2007-09-01

    SummaryThis paper presents and implements a framework for modeling the impact of land use practices and protection alternatives on nitrate pollution of groundwater in agricultural watersheds. The framework utilizes the national land cover database (NLCD) of the United State Geological Survey (USGS) grid and a geographic information system (GIS) to account for the spatial distribution of on-ground nitrogen sources and corresponding loadings. The framework employs a soil nitrogen dynamic model to estimate nitrate leaching to groundwater. These estimates were used in developing a groundwater nitrate fate and transport model. The framework considers both point and non-point sources of nitrogen across different land use classes. The methodology was applied for the Sumas-Blaine aquifer of Washington State, US, where heavy dairy industry and berry plantations are concentrated. Simulations were carried out using the developed framework to evaluate the overall impacts of current land use practices and the efficiency of proposed protection alternatives on nitrate pollution in the aquifer.

  14. Removal of Nitrogen and Pathogens in Agricultural or Urban Channles using Engineered Streambeds

    NASA Astrophysics Data System (ADS)

    McCray, J. E.; Herzog, S.; Higgins, C. P.

    2015-12-01

    Treating non-point source pollution is one of our greatest challenges in environmental hydrology. Previous efforts in agricultural or urban settings have focused on removing sources or implementing distributed best management practices (BMPs) throughout a watershed. However, for stream pollution, the most efficient point of treatment would be within the stream itself, which integrates flows from the entire watershed. Engineered streambed modifications in urban or agricultural streams and constructed channels have the potential to mitigate nonpoint source pollution. Geomedia designed to treat water pollutants and achieve an optimal residence time via hydraulic conductivity modifications are termed biohydrochemical enhancement structures for stream water treatment (BEST). BEST modules can efficiently drive interchange, attenuating nutrients and pathogens (and can be designed to remove other pollutants such as phosphorus, metals or trace organics). Numerical models, combined with data from bench-top and 2D experiments, demonstrate effective contaminant removal potential for practical applications. Nitrogen and pathogens could be attenuated within a series of BEST on the order of 50 m of stream length, and at a favorable cost compared to traditional BMPs, suggesting that BEST could be an effective best management practice for constructed stormwater channels (particularly outlets of detention ponds) or channels carrying irrigation return flows. New results from a constructed stream demonstrate the real-world applicability of the BEST system.

  15. VOCATIONAL AGRICULTURE.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento. Research Coordinating Unit.

    TO ASSIST THOSE WHO MAKE DECISIONS RELATING TO EDUCATIONAL PROGRAMS IN AGRICULTURE, RECENT RESEARCH IN VOCATIONAL AGRICULTURE IS SUMMARIZED. A 1963 STUDY TREATS THE RELATIONSHIP BETWEEN WORK EXPERIENCE AND STUDENT CHARACTERISTICS, PLANS, AND ASPIRATIONS. STUDIES ON POST-SECONDARY EDUCATION CONCERN GUIDELINES FOR TECHNICIAN PROGRAMS, JUSTIFICATION…

  16. Cost-effectiveness and cost-benefit analysis of BMPs in controlling agricultural nonpoint source pollution in China based on the SWAT model.

    PubMed

    Liu, Ruimin; Zhang, Peipei; Wang, Xiujuan; Wang, Jiawei; Yu, Wenwen; Shen, Zhenyao

    2014-12-01

    Best management practices (BMPs) have been widely used in managing agricultural nonpoint source pollution (ANSP) at the watershed level. Most BMPs are related to land use, tillage management, and fertilizer levels. In total, seven BMP scenarios (Reforest1, Reforest2, No Tillage, Contour tillage, and fertilizer level 1-4) that are related to these three factors were estimated in this study. The objectives were to investigate the effectiveness and cost-benefit of these BMPs on ANSP reduction in a large tributary of the Three Gorges Reservoir (TGR) in China, which are based on the simulation results of the Soil and Water Assessment Tool (SWAT) model. The results indicated that reforestation was the most economically efficient of all BMPs, and its net benefits were up to CNY 4.36×10(7) years(-1) (about USD 7.08×10(6) years(-1)). Regarding tillage practices, no tillage practice was more environmentally friendly than other tillage practices, and contour tillage was more economically efficient. Reducing the local fertilizer level to 0.8-fold less than that of 2010 can yield a satisfactory environmental and economic efficiency. Reforestation and fertilizer management were more effective in reducing total phosphorus (TP), whereas tillage management was more effective in reducing total nitrogen (TN). When CNY 10,000 (about USD 162) was applied to reforestation, no tillage, contour tillage, and an 0.8-fold reduction in the fertilizer level, then annual TN load can be reduced by 0.08, 0.16, 0.11, and 0.04 t and annual TP load can be reduced by 0.04, 0.02, 0.01 and 0.03 t, respectively. The cost-benefit (CB) ratios of the BMPs were as follows: reforestation (207 %) > contour tillage (129 %) > no tillage (114 %) > fertilizer management (96 and 89 %). The most economical and effective BMPs can be designated as follows: BMP1 (returning arable land with slopes greater than 25° to forests and those lands with slopes of 15-25° to orchards), BMP2 (implementing no tillage

  17. [Interception Effect of Ecological Ditch on Nitrogen Transport in Agricultural Runoff in Subtropical China].

    PubMed

    Wang, Di; Li, Hong-fang; Liu, Feng; Wang, Yi; Zhong, Yuan-chun; He, Yang; Xiao, Run-fin; Wu, Jin-shui

    2016-05-15

    Interception effects of an ecological ditch, used to control agricultural non-point source pollution in subtropical China, on nitrogen transport in surface runoff were studied by monthly measuring the runoff volume and concentrations of ammonium nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃⁻-N) and total nitrogen (TN) at the ditch inlet and outlet from 2013 to 2014. In addition, differences of NH₄⁺-N, NO₃⁻-N and TN removal were compared between 2013 and 2014. The results showed that the study ecological ditch worked effectively in N removal with average NH₄⁺-N, NO₃⁻-N and TN removal rates of 77.8%, 58.3%, and 48.7%; and their interception rates were 38.4, 59.6, and 171.1 kg · a⁻¹, respectively. The average proportion of NH₄⁺-N and NO₃⁻-N in TN was 47.5% at inlet, and 33.6% at outlet, which was significantly lower than that at inlet (P < 0.01). All hydrophytes in the ecological ditch were replaced by Myriophyllum aquaticum in 2014, which led to the increased average NO₃⁻-N and TN removal rates of 30.5% and 18.2%, respectively, Compared to in 2013. The vegetation of Myriophyllum aquaticum was beneficial to the improvement of N interception in ecological ditch. These findings clearly demonstrated that ecological ditch can substantially reduce N loss from surface runoff and be used as an important technique to prevent agricultural non-point N pollution. PMID:27506024

  18. [Interception Effect of Ecological Ditch on Nitrogen Transport in Agricultural Runoff in Subtropical China].

    PubMed

    Wang, Di; Li, Hong-fang; Liu, Feng; Wang, Yi; Zhong, Yuan-chun; He, Yang; Xiao, Run-fin; Wu, Jin-shui

    2016-05-15

    Interception effects of an ecological ditch, used to control agricultural non-point source pollution in subtropical China, on nitrogen transport in surface runoff were studied by monthly measuring the runoff volume and concentrations of ammonium nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃⁻-N) and total nitrogen (TN) at the ditch inlet and outlet from 2013 to 2014. In addition, differences of NH₄⁺-N, NO₃⁻-N and TN removal were compared between 2013 and 2014. The results showed that the study ecological ditch worked effectively in N removal with average NH₄⁺-N, NO₃⁻-N and TN removal rates of 77.8%, 58.3%, and 48.7%; and their interception rates were 38.4, 59.6, and 171.1 kg · a⁻¹, respectively. The average proportion of NH₄⁺-N and NO₃⁻-N in TN was 47.5% at inlet, and 33.6% at outlet, which was significantly lower than that at inlet (P < 0.01). All hydrophytes in the ecological ditch were replaced by Myriophyllum aquaticum in 2014, which led to the increased average NO₃⁻-N and TN removal rates of 30.5% and 18.2%, respectively, Compared to in 2013. The vegetation of Myriophyllum aquaticum was beneficial to the improvement of N interception in ecological ditch. These findings clearly demonstrated that ecological ditch can substantially reduce N loss from surface runoff and be used as an important technique to prevent agricultural non-point N pollution.

  19. Characterization and source apportionment of water pollution in Jinjiang River, China.

    PubMed

    Chen, Haiyang; Teng, Yanguo; Yue, Weifeng; Song, Liuting

    2013-11-01

    Characterizing water quality and identifying potential pollution sources could greatly improve our knowledge about human impacts on the river ecosystem. In this study, fuzzy comprehensive assessment (FCA), pollution index (PI), principal component analysis (PCA), and absolute principal component score-multiple linear regression (APCS-MLR) were combined to obtain a deeper understanding of temporal-spatial characterization and sources of water pollution with a case study of the Jinjiang River, China. Measurement data were obtained with 17 water quality variables from 20 sampling sites in the December 2010 (withered water period) and June 2011 (high flow period). FCA and PI were used to comprehensively estimate the water quality variables and compare temporal-spatial variations, respectively. Rotated PCA and receptor model (APCS-MLR) revealed potential pollution sources and their corresponding contributions. Application results showed that comprehensive application of various multivariate methods were effective for water quality assessment and management. In the withered water period, most sampling sites were assessed as low or moderate pollution with characteristics pollutants of permanganate index and total nitrogen (TN), whereas 90% sites were classified as high pollution in the high flow period with higher TN and total phosphorus. Agricultural non-point sources, industrial wastewater discharge, and domestic sewage were identified as major pollution sources. Apportionment results revealed that most variables were complicatedly influenced by industrial wastewater discharge and agricultural activities in withered water period and primarily dominated by agricultural runoff in high flow period.

  20. Agriculture Education. Agricultural Metal Working.

    ERIC Educational Resources Information Center

    Stuttgart Public Schools, AR.

    This curriculum guide is designed for group instruction of secondary agricultural education students enrolled in one or two semester-long courses in agricultural metal working. The guide presents units of study in the following areas: (1) oxyacetylene welding, (2) arc welding, (3) sheet metal, (4) blueprint reading for welders and (5) job…

  1. Variation in Quantity, Source and Bioreactivity of Dissolved Organic Matter in Streams Draining Watersheds along a Gradient of Agricultural Land Use

    NASA Astrophysics Data System (ADS)

    Shang, P.; Lu, Y.; Jaffe, R.; Du, Y.; Findlay, R.

    2015-12-01

    In order to address the effects of agricultural land use on stream water dissolved organic matter (DOM), we sampled a regional group of second to third order streams draining watersheds along a gradient of percentage agricultural lands in northwestern Alabama, USA. Samples were collected under baseflow conditions, five different times over the year 2014. We analyzed dissolved organic carbon (DOC) concentrations, DOM optical properties (i.e. ultraviolet-visible and fluorescence spectrophotometry), and DOM bioreactivity over the course of 22 d incubation. We found that air temperature and antecedent precipitation intensity (API) were two major factors positively controlling DOC concentrations. High DOC concentrations were associated with high fluorescence index values, low percent contributions from terrestrially derived humic-like DOM fluorescence component (C1), and high percent contributions from microbially derived humic-like DOM fluorescence component (C3). We suggest that elevated microbial DOM production under high temperature and API was the primary reason for DOC enrichment in stream water. Percentage agricultural land was the secondary predictor of DOM characteristics. The percentages of forest land use within watersheds positively correlated with percent protein-like DOM fluorescence component (C4). DOC concentrations and relative abundance of humic-like DOM fluorescence components (C1, C2 and C3) were higher in agricultural streams than in forested streams, which could be attributed to flow path differences between agricultural and forested watersheds. Larger amount and percentage of bioreactive DOC was observed in agricultural streams, which might decrease oxygen level and impact fluvial ecosystem in downstream regions during degradation.

  2. Urban conservation agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetables are important sources of vitamins and nutrients for human nutrition. United States Department of Agriculture recommends filling half of the food plates with vegetables in every meal. While it is important in promoting good health, access to fresh vegetables is limited especially in urban ...

  3. Agricultural Microbiology.

    ERIC Educational Resources Information Center

    Brill, Winston J.

    1981-01-01

    Elucidates strategies for applying microbiological techniques to traditional agricultural practices. Discusses the manipulation of microorganisms that live with plants and also the problems involved in the introduction of new genes into crop plants by recombinant DNA methods. (CS)

  4. Agricultural Geophysics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The four geophysical methods predominantly used for agricultural purposes are resistivity, electromagnetic induction, ground penetrating radar (GPR), and time domain reflectometry (TDR). Resistivity and electromagnetic induction methods are typically employed to map lateral variations of apparent so...

  5. Recycling biosolids and lake-dredged materials to pasture-based animal agriculture: Alternative nutrient sources for forage productivity and sustainability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestic sewage sludge or biosolids and lake-dredged materials are examples of materials that can be used to cut fertilizer costs in pasture-based animal agriculture. Sustainable biosolids and lake-dredged materials management is based upon controlling and influencing the quantity, quality and chara...

  6. Total Nitrogen Sources of the Three Gorges Reservoir — A Spatio-Temporal Approach

    PubMed Central

    Ren, Chunping; Wang, Lijing; Zheng, Binghui; Holbach, Andreas

    2015-01-01

    Understanding the spatial and temporal variation of nutrient concentrations, loads, and their distribution from upstream tributaries is important for the management of large lakes and reservoirs. The Three Gorges Dam was built on the Yangtze River in China, the world’s third longest river, and impounded the famous Three Gorges Reservoir (TGR). In this study, we analyzed total nitrogen (TN) concentrations and inflow data from 2003 till 2010 for the main upstream tributaries of the TGR that contribute about 82% of the TGR’s total inflow. We used time series analysis for seasonal decomposition of TN concentrations and used non-parametric statistical tests (Kruskal-Walli H, Mann-Whitney U) as well as base flow segmentation to analyze significant spatial and temporal patterns of TN pollution input into the TGR. Our results show that TN concentrations had significant spatial heterogeneity across the study area (Tuo River> Yangtze River> Wu River> Min River> Jialing River>Jinsha River). Furthermore, we derived apparent seasonal changes in three out of five upstream tributaries of the TGR rivers (Kruskal-Walli H ρ = 0.009, 0.030 and 0.029 for Tuo River, Jinsha River and Min River in sequence). TN pollution from non-point sources in the upstream tributaries accounted for 68.9% of the total TN input into the TGR. Non-point source pollution of TN revealed increasing trends for 4 out of five upstream tributaries of the TGR. Land use/cover and soil type were identified as the dominant driving factors for the spatial distribution of TN. Intensifying agriculture and increasing urbanization in the upstream catchments of the TGR were the main driving factors for non-point source pollution of TN increase from 2003 till 2010. Land use and land cover management as well as chemical fertilizer use restriction were needed to overcome the threats of increasing TN pollution. PMID:26510158

  7. Total Nitrogen Sources of the Three Gorges Reservoir--A Spatio-Temporal Approach.

    PubMed

    Ren, Chunping; Wang, Lijing; Zheng, Binghui; Holbach, Andreas

    2015-01-01

    Understanding the spatial and temporal variation of nutrient concentrations, loads, and their distribution from upstream tributaries is important for the management of large lakes and reservoirs. The Three Gorges Dam was built on the Yangtze River in China, the world's third longest river, and impounded the famous Three Gorges Reservoir (TGR). In this study, we analyzed total nitrogen (TN) concentrations and inflow data from 2003 till 2010 for the main upstream tributaries of the TGR that contribute about 82% of the TGR's total inflow. We used time series analysis for seasonal decomposition of TN concentrations and used non-parametric statistical tests (Kruskal-Walli H, Mann-Whitney U) as well as base flow segmentation to analyze significant spatial and temporal patterns of TN pollution input into the TGR. Our results show that TN concentrations had significant spatial heterogeneity across the study area (Tuo River> Yangtze River> Wu River> Min River> Jialing River>Jinsha River). Furthermore, we derived apparent seasonal changes in three out of five upstream tributaries of the TGR rivers (Kruskal-Walli H ρ = 0.009, 0.030 and 0.029 for Tuo River, Jinsha River and Min River in sequence). TN pollution from non-point sources in the upstream tributaries accounted for 68.9% of the total TN input into the TGR. Non-point source pollution of TN revealed increasing trends for 4 out of five upstream tributaries of the TGR. Land use/cover and soil type were identified as the dominant driving factors for the spatial distribution of TN. Intensifying agriculture and increasing urbanization in the upstream catchments of the TGR were the main driving factors for non-point source pollution of TN increase from 2003 till 2010. Land use and land cover management as well as chemical fertilizer use restriction were needed to overcome the threats of increasing TN pollution. PMID:26510158

  8. Total Nitrogen Sources of the Three Gorges Reservoir--A Spatio-Temporal Approach.

    PubMed

    Ren, Chunping; Wang, Lijing; Zheng, Binghui; Holbach, Andreas

    2015-01-01

    Understanding the spatial and temporal variation of nutrient concentrations, loads, and their distribution from upstream tributaries is important for the management of large lakes and reservoirs. The Three Gorges Dam was built on the Yangtze River in China, the world's third longest river, and impounded the famous Three Gorges Reservoir (TGR). In this study, we analyzed total nitrogen (TN) concentrations and inflow data from 2003 till 2010 for the main upstream tributaries of the TGR that contribute about 82% of the TGR's total inflow. We used time series analysis for seasonal decomposition of TN concentrations and used non-parametric statistical tests (Kruskal-Walli H, Mann-Whitney U) as well as base flow segmentation to analyze significant spatial and temporal patterns of TN pollution input into the TGR. Our results show that TN concentrations had significant spatial heterogeneity across the study area (Tuo River> Yangtze River> Wu River> Min River> Jialing River>Jinsha River). Furthermore, we derived apparent seasonal changes in three out of five upstream tributaries of the TGR rivers (Kruskal-Walli H ρ = 0.009, 0.030 and 0.029 for Tuo River, Jinsha River and Min River in sequence). TN pollution from non-point sources in the upstream tributaries accounted for 68.9% of the total TN input into the TGR. Non-point source pollution of TN revealed increasing trends for 4 out of five upstream tributaries of the TGR. Land use/cover and soil type were identified as the dominant driving factors for the spatial distribution of TN. Intensifying agriculture and increasing urbanization in the upstream catchments of the TGR were the main driving factors for non-point source pollution of TN increase from 2003 till 2010. Land use and land cover management as well as chemical fertilizer use restriction were needed to overcome the threats of increasing TN pollution.

  9. Screening of postharvest agricultural wastes as alternative sources of peroxidases: characterization and kinetics of a novel peroxidase from lentil ( Lens culinaris L.) stubble.

    PubMed

    Hidalgo-Cuadrado, Nazaret; Pérez-Galende, Patricia; Manzano, Teresa; De Maria, Cándido Garcia; Shnyrov, Valery L; Roig, Manuel G

    2012-05-16

    Aqueous crude extracts of a series of plant wastes (agricultural, wild plants, residues from sports activities (grass), ornamental residues (gardens)) from 17 different plant species representative of the typical biodiversity of the Iberian peninsula were investigated as new sources of peroxidases (EC 1.11.1.7). Of these, lentil (Lens culinaris L.) stubble crude extract was seen to provide one of the highest specific peroxidase activities, catalyzing the oxidation of guaiacol in the presence of hydrogen peroxide to tetraguaiacol, and was used for further studies. For the optimum extraction conditions found, the peroxidase activity in this crude extract (110 U mL(-1)) did not vary for at least 15 months when stored at 4 °C (k(inact) = 0.146 year(-1), t(1/2 inact) = 4.75 year), whereas, for comparative purposes, the peroxidase activity (60 U mL(-1)) of horseradish (Armoracia rusticana L.) root crude extract, obtained and stored under the same conditions, showed much faster inactivation kinetics (k(inact) = 2.2 × 10(-3) day(-1), t(1/2 inact) = 315 days). Using guaiacol as an H donor and a universal buffer (see above), all crude extract samples exhibited the highest peroxidase activity in the pH range between 4 and 7. Once semipurified by passing the crude extract through hydrophobic chromatography on phenyl-Sepharose CL-4B, the novel peroxidase (LSP) was characterized as having a purity number (RZ) of 2.5 and three SDS-PAGE electrophoretic bands corresponding to molecular masses of 52, 35, and 18 kDa. The steady-state kinetic study carried out on the H(2)O(2)-mediated oxidation of guaiacol by the catalytic action of this partially purified peroxidase pointed to apparent Michaelian kinetic behavior (K(m)(appH(2)O(2)) = 1.87 mM; V(max)(appH(2)O(2)) = 6.4 mM min(-1); K(m)(app guaicol) = 32 mM; V(max)(app guaicol) = 9.1 mM min(-1)), compatible with the two-substrate ping-pong mechanism generally accepted for peroxidases. Finally, after the effectiveness of the crude

  10. Agriculture and land use issues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Large-scale biofuels development as a source of renewable energy will shift current dynamics in the agricultural sector that deliver food, feed, and fiber. This chapter examines the potential for modern agriculture to support a biofuels industry without comprimising its critical role for delivering ...

  11. Constructed wetlands to reduce diffuse pollution from agriculture

    NASA Astrophysics Data System (ADS)

    Deasy, C.; Quinton, J. N.

    2009-04-01

    Across Europe, many rivers and lakes are polluted. Sediment can disturb aquatic ecosystems, and is associated with the transport of pesticides, pathogens, toxic metals and nutrients, including phosphorus (P). P is growth-limiting in freshwaters, and rivers and lakes may become eutrophic where concentrations are high, leading to algal blooms and loss of biodiversity. For example, in the UK, the Biodiversity Action Plan estimates that over 70% of lakes are eutrophic. Concern about water quality has resulted in EU policy drivers to protect rivers and lakes. Under the requirements of the Water Framework Directive (WFD), surface waters must achieve ‘good ecological and chemical condition' by 2015. Studies in the UK indicate that P concentrations need to be an order of magnitude lower in fresh waters to comply with the requirements of the WFD, and methods of controlling sediment and P inputs into surface waters are urgently required. Pollution sources such as sewage treatment works can be regulated, but non point (diffuse) sources are difficult to control. As agricultural activities have been estimated to account for 30% of P inputs to surface waters, controlling the transfer of diffuse pollutants in runoff from agricultural land is a priority for catchment managers. The use of in-field mitigation options such as reduced tillage has been found to be effective in the UK, but pollutants can still be lost from hillslopes unchecked via subsurface runoff pathways, some of which (e.g. field drains) may contribute very high loads of sediment and P to streams. Mitigation approaches, such as wetlands, which operate at the edge-of-field, where hillslope pathways have already discharged their pollutant loads into the receiving stream, are therefore essential. Over the next two years we will establish ten wetland sites in the UK and use these to: 1) reduce levels of sediment and nutrients leaving agricultural fields; 2) determine the effectiveness of different wetland designs for

  12. IDENTIFICATION AND CHARACTERIZATION OF FIVE NON- TRADITIONAL SOURCE CATEGORIES: CATASTROPHIC/ACCIDENTAL RELEASES, VEHICLE REPAIR FACILITIES, RECYCLING, PESTICIDE APPLICATION, AND AGRICULTURAL OPERATIONS

    EPA Science Inventory

    The report gives results of work that is part of EPA's program to identify and characterize emissions sources not currently accounted for by either the existing Aerometric Information Retrieval System (AIRS) or State Implementation Plan (SIP) area source methodologies and to deve...

  13. Agricultural Biodiversity.

    ERIC Educational Resources Information Center

    Postance, Jim

    1998-01-01

    The extinction of farm animals and crops is rarely brought up during discussions of endangered species and biodiversity; however, the loss of diversity in crops and livestock threatens the sustainability of agriculture. Presents three activities: (1) "The Colors of Diversity"; (2) "Biodiversity among Animals"; and (3) "Heirloom Plants." Discusses…

  14. AGRICULTURAL EDUCATION.

    ERIC Educational Resources Information Center

    STEVENS, GLENN Z.

    FEDERAL LEGISLATION HAS PROVIDED FOR PUBLIC PROGRAMS OF OCCUPATIONAL AGRICULTURE EDUCATION IN LAND GRANT COLLEGES AND UNIVERSITIES, LOCAL SCHOOL DISTRICTS, AND MANPOWER DEVELOPMENT PROGRAMS. PROGRAM OBJECTIVES SHOULD BE TO DEVELOP KNOWLEDGE AND SKILLS, PROVIDE OCCUPATIONAL GUIDANCE AND PLACEMENT, AND DEVELOP ABILITIES IN HUMAN RELATIONS AND…

  15. AGRICULTURAL EXTENSION.

    ERIC Educational Resources Information Center

    FARQUHAR, R.N.

    AUSTRALIAN AGRICULTURAL EXTENSION HAS LONG EMPHASIZED TECHNICAL ADVISORY SERVICE AT THE EXPENSE OF THE SOCIOECONOMIC ASPECTS OF FARM PRODUCTION AND FARM LIFE. ONLY IN TASMANIA HAS FARM MANAGEMENT BEEN STRESSED. DEMANDS FOR THE WHOLE-FARM APPROACH HAVE PRODUCED A TREND TOWARD GENERALISM FOR DISTRICT OFFICERS IN MOST STATES. THE FEDERAL GOVERNMENT,…

  16. Distribution and mobility of heavy elements in floodplain agricultural soils along the Ibar River (Southern Serbia and Northern Kosovo). Chemometric investigation of pollutant sources and ecological risk assessment.

    PubMed

    Barać, Nemanja; Škrivanj, Sandra; Bukumirić, Zoran; Živojinović, Dragana; Manojlović, Dragan; Barać, Milan; Petrović, Rada; Ćorac, Aleksandar

    2016-05-01

    This work investigates the influence of a high-magnitude flood event on heavy elements (HEs) pollution and mobility in the agricultural soils along Ibar River in Southern Serbia and Northern Kosovo. The study area was one of the most important Pb/Zn industrial regions in Europe. Soil samples (n = 50) collected before and after the floods in May 2014 were subjected to the sequential extraction procedure proposed by the Community Bureau of Reference (BCR). The results indicated that the floods significantly increased not only the pseudo total concentrations of HEs in the soil but also their mobile and potentially bioavailable amounts. Moreover, higher concentrations (both pseudo total and potentially bioavailable) were found in the agricultural soils closer to the industrial hotspots. Principal component analysis and hierarchical cluster analysis successfully grouped the analyzed elements according to their anthropogenic or natural origin. The floods significantly increased the potential ecological risk of HEs associated with Pb/Zn industrial activities in the study area. The potential ecological risk of Cd after the floods was highest and should be of special concern. PMID:26822217

  17. Managing multiple non-point pressures on water quality and ecological habitat: Spatially targeting effective mitigation actions at the landscape scale.

    NASA Astrophysics Data System (ADS)

    Reaney, S. M.

    2014-12-01

    Catchment systems deliver many benefits to society and ecology but also produce a range of undesirable externalities including flooding, diffuse pollution from agriculture, forestry and urban areas and the export of FIOs. These diffuse pressures are coupled with increasing stream temperature pressures on river from projected climate change. These pressures can be reduced through actions at the landscape scale but are often tackled individually. Any intervention may have benefits for other pressures and hence the challenge is to consider all of the different pressures simultaneously to find solutions with high levels of cross-pressure benefits. The general approach taken within this research has been to use simple but spatially distributed models to predict the pattern of each of the pressures at the landscape scale. These models follow a minimum information requirement approach along the lines of the SCIMAP modelling approach (www.scimap.org.uk). This approach aims to capture the key features of the processes in relative rather than an absolute sense and hence is good at determining key locations to act within a landscape for maximum benefit. The core of the approach is to define the critical sources areas for each pressure based on the analysis of the pattern of the pressure in the landscape and the connectivity from the sources areas to the rivers and lakes. To identify the optimal locations with the landscape for mitigation actions, the benefit of a mitigation action at each location in the landscape needs to be considered. However, as one action has been made, it may change the suitability of other locations in the landscape. For example, as tree cover reduces the temperature in one river reach, the impacts of this cooling are transported downstream with the flow. Therefore, actions need to be considered in sets across multiple sites and objectives to identify the optimal actions set. These modelling results are integrated into a decision support tool which

  18. Using Nitrate N and O Isotope Ratios to Identify Nitrate Sources and Dominant Nitrogen Cycling Processes in a 12ha Tile Drained Dryland Agricultural Field in the Palouse Basin of Eastern Washington State

    NASA Astrophysics Data System (ADS)

    Kelley, C. J.; Keller, C. K.; Evans, R. D.; Orr, C. H.; Smith, J. L.

    2010-12-01

    Agricultural systems are a leading source of reactive nitrogen to aquatic and atmospheric ecosystem. Understanding how anthropogenic nitrogen sources are cycled during transport from agricultural systems to aquatic and atmospheric systems is essential to identify the sink(s) of missing nitrogen and improve nitrogen management. Here we use natural nitrate 15N and 18O isotope abundances to determine the timing of nitrogen cycling process and to identify the source of nitrate discharged from a tile drained section of the WSU Cook Agronomy Farm. Previous research at the Cook Farm has shown that 5% to 20% of fertilizer nitrogen leaves the system as nitrate through the tile-drain. Identifying the timing of nitrogen cycling events and identifying the source(s) of tile drain nitrate is the first step to reduce nitrogen loss to aquatic systems bordering agricultural land. Throughout the 5 year study period δ18Onitrate averaged -1.26±1.48‰, indicating that nitrate-oxygen isotopes were not being enriched. Tile drain nitrate δ15N varied seasonally from -0.48‰ in the winter to +9.24‰ during the summer with an average of +3.19±2.62‰. The lack of nitrate-oxygen enrichment during the study period indicates that nitrification is the dominant nitrogen cycling process in the tile drained soil. The expected δ18Onitrate from nitrification based on the nitrification equation is -2.0‰, also supporting the claim that nitrification is the dominant nitrogen cycling process in the soil drained by the tile drain system. The large range of nitrate δ15N overlaps the expected isotope values for nitrate from nitrified synthetic nitrogen fertilizers and soil organic nitrogen. Nitrate-nitrogen and nitrate-oxygen isotope abundances have shown that nitrate in high nitrate concentration TD discharge originates from nitrification of reduced nitrogen fertilizers and nitrate in low nitrate concentration TD discharge originates from nitrification of; 1) soil organic nitrogen, 2) biotically

  19. Groundwater vulnerability assessment in agricultural areas using a modified DRASTIC model.

    PubMed

    Sadat-Noori, Mahmood; Ebrahimi, Kumars

    2016-01-01

    Groundwater contamination is a major concern for groundwater resource managers worldwide. We evaluated groundwater pollution potential by producing a vulnerability map of an aquifer using a modified Depth to water, Net recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, and Hydraulic conductivity (DRASTIC) model within a Geographic Information System (GIS) environment. The proposed modification which incorporated the use of statistical techniques optimizes the rating function of the DRASTIC model parameters, to obtain a more accurate vulnerability map. The new rates were computed using the relationships between the parameters and point data chloride concentrations in groundwater. The model was applied on Saveh-Nobaran plain in central Iran, and results showed that the coefficient of determination (R (2)) between the point data and the relevant vulnerability map increased significantly from 0.52 to 0.78 after modification. As compared to the original DRASTIC model, the modified version produced better vulnerability zonation. Additionally, single-parameter and parameter removal sensitivity analyses were performed to evaluate the relative importance of each DRASTIC parameter. The results from both analyses revealed that the vadose zone is the most sensitive parameter influencing the variability of the aquifers' vulnerability index. Based on the results, for non-point source pollution in agricultural areas, using the modified DRASTIC model is efficient compared to the original model. The proposed method can be effective for future groundwater assessment and plain-land management where agricultural activities are dominant. PMID:26650205

  20. Groundwater vulnerability assessment in agricultural areas using a modified DRASTIC model.

    PubMed

    Sadat-Noori, Mahmood; Ebrahimi, Kumars

    2016-01-01

    Groundwater contamination is a major concern for groundwater resource managers worldwide. We evaluated groundwater pollution potential by producing a vulnerability map of an aquifer using a modified Depth to water, Net recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, and Hydraulic conductivity (DRASTIC) model within a Geographic Information System (GIS) environment. The proposed modification which incorporated the use of statistical techniques optimizes the rating function of the DRASTIC model parameters, to obtain a more accurate vulnerability map. The new rates were computed using the relationships between the parameters and point data chloride concentrations in groundwater. The model was applied on Saveh-Nobaran plain in central Iran, and results showed that the coefficient of determination (R (2)) between the point data and the relevant vulnerability map increased significantly from 0.52 to 0.78 after modification. As compared to the original DRASTIC model, the modified version produced better vulnerability zonation. Additionally, single-parameter and parameter removal sensitivity analyses were performed to evaluate the relative importance of each DRASTIC parameter. The results from both analyses revealed that the vadose zone is the most sensitive parameter influencing the variability of the aquifers' vulnerability index. Based on the results, for non-point source pollution in agricultural areas, using the modified DRASTIC model is efficient compared to the original model. The proposed method can be effective for future groundwater assessment and plain-land management where agricultural activities are dominant.

  1. Transport through a Heterogeneous Alluvial Aquifer beneath an Agricultural Riparian Buffer

    NASA Astrophysics Data System (ADS)

    Johnson, R.; Mather, A. L.; Smith, E. A.; Green, C. T.

    2012-12-01

    Riparian buffer zones between agricultural fields and streams are intended to attenuate the groundwater transport of non-point-source pollutants. However, if the spatial variability in the alluvial aquifer structure provides pathways for rapid transit across the buffer, the effectiveness for mitigating transport of pollutants to the stream may be limited. The main objective of this work was to examine the effects of alluvial aquifer heterogeneity on groundwater transport beneath an agricultural riparian buffer. This was assessed first by performing a natural-gradient tracer experiment and characterizing the site heterogeneity through hydraulic conductivity profiling. Second, the field hydraulic conductivity data were used with a meandering geostatistical model to represent aquifer heterogeneity and a numerical groundwater model was constructed to simulate the tracer experiment. The tracer experiment showed that a portion of the injected plume (~10% of the total mass) moved at high velocity, while a significant fraction of the mass moved slowly and remained near the injection location. Both the tracer test and the numerical modeling indicate that transport velocities of a meter per day are likely to be present in localized regions throughout the riparian buffer. This highlights the dependence of solute residence time in the riparian zone, and therefore the concentrations arriving in rivers, on the local geological structure.

  2. Agricultural and urban pollution

    NASA Technical Reports Server (NTRS)

    Brehmer, M. L.

    1972-01-01

    The degradation produced by the introduction of agricultural and urban wastes into estuarine systems, with emphasis on the Chesapeake Bay area, is discussed. The subjects presented are: (1) effects of sediment loading and (2) organic and nutrient loading problems. The impact of high turbidity on the biological life of the bay is analyzed. The sources of nutrients which produce over-enrichment of the waters and the subsequent production of phytoplankton are examined.

  3. Utility of a Two-source Energy Balance Approach for Daily Mapping of Landsat-scale Fluxes Over Irrigated Agriculture in a Desert Environment

    NASA Astrophysics Data System (ADS)

    Houborg, R.; McCabe, M. F.; Rosas Aguilar, J.; Anderson, M. C.; Hain, C.

    2014-12-01

    The Middle East and North Africa (MENA) region is an area characterized by limited fresh water resources, an often inefficient use of these, and relatively poor in-situ monitoring as a result of sparse meteorological observations. Enhanced satellite-based monitoring systems are needed for aiding local water resource and agricultural management activities in these data poor arid environments. A multi-sensor and multi-scale land-surface flux monitoring capacity is being implemented over parts of MENA in order to provide meaningful decision support at relevant spatiotemporal scales. The integrated modeling system uses the Atmosphere-Land Exchange Inverse (ALEXI) model and associated flux disaggregation scheme (DisALEXI), and the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) in conjunction with model reanalysis data and remotely sensed data from polar orbiting (Landsat and MODIS; MODerate resolution Imaging Spectroradiometer) and geostationary (MSG; Meteosat Second Generation) satellite platforms to facilitate daily estimates of land surface fluxes down to sub-field scale (i.e. 30 m). Within this modeling system, thermal infrared satellite data provide information about the sub-surface moisture status and plant stress, obviating the need for precipitation input and error-prone soil surface characterizations. In this study, the integrated ALEXI-DisALEXI-STARFM framework is applied over an irrigated agricultural region in Saudi Arabia, and the daily estimates of Landsat scale water, energy and carbon fluxes are evaluated against available flux tower observations and other independent in-situ and satellite-based records. The study addresses the challenges associated with time-continuous sub-field scale mapping of land-surface fluxes in a harsh desert environment, and looks into the optimization of model descriptions and parameterizations and meteorological forcing and vegetation inputs for application over these regions.

  4. Holistic Watershed-Scale Approach for Studying Agricultural Chemicals

    NASA Astrophysics Data System (ADS)

    Capel, P. D.; Domagalski, J. L.

    2006-05-01

    The USGS National Water-Quality Assessment (NAWQA) Program studied the water quality of 51 areas across the United States during its first decade (1991-2001). Analyses of results from that phase of the NAWQA Program indicated that detailed studies of the processes affecting water quality could aid in the interpretation of these data, help to determine the direction and scope of future monitoring studies, and add to the understanding of the sources, transport and fate of non-point source chemicals, such as from agriculture. Now in the second decade of investigations, the NAWQA Program has initiated new process-based detailed studies to increase our understanding at the scale of a small watershed (about 3-15 square kilometers), nested within the larger basins studied during the first decade. The holistic, mass-budget approach for small agricultural watersheds that was adopted includes processes, and measures water and chemicals in the atmosphere, surface water, tile drains, overland flow, and within various sub-surface environments including the vadose, saturated, and hyporheic zones. The primary chemicals of interest were nutrients (nitrogen and phosphorous), the triazine and acetanilide herbicides, and the organophosphorus insecticides. Extensive field observations were made, and numerical models were developed to simulate important environmental compartments and interfaces associated with the transport and fate of agricultural chemicals. It is well recognized that these field measurements and simulations cannot fully achieve a full mass budget at this scale, but the approach provides a useful means for comparisons of various processes in different environmental settings. The results gained using this approach will add to the general knowledge of environmental transport and fate processes, and have transfer value to unstudied areas and different scales of investigation. The five initial study areas started in 2002, included watersheds in California, Indiana

  5. Real-Time N2O Gas Detection System for Agricultural Production Using a 4.6-μm-Band Laser Source Based on a Periodically Poled LiNbO3 Ridge Waveguide

    PubMed Central

    Tokura, Akio; Asobe, Masaki; Enbutsu, Koji; Yoshihara, Toshihiro; Hashida, Shin-nosuke; Takenouchi, Hirokazu

    2013-01-01

    This article describes a gas monitoring system for detecting nitrous oxide (N2O) gas using a compact mid-infrared laser source based on difference-frequency generation in a quasi-phase-matched LiNbO3 waveguide. We obtained a stable output power of 0.62 mW from a 4.6-μm-band continuous-wave laser source operating at room temperature. This laser source enabled us to detect atmospheric N2O gas at a concentration as low as 35 parts per billion. Using this laser source, we constructed a new real-time in-situ monitoring system for detecting N2O gas emitted from potted plants. A few weeks of monitoring with the developed detection system revealed a strong relationship between nitrogen fertilization and N2O emission. This system is promising for the in-situ long-term monitoring of N2O in agricultural production, and it is also applicable to the detection of other greenhouse gases. PMID:23921829

  6. Agricultural lung diseases.

    PubMed Central

    Kirkhorn, S R; Garry, V F

    2000-01-01

    Agriculture is considered one of the most hazardous occupations. Organic dusts and toxic gases constitute some of the most common and potentially disabling occupational and environmental hazards. The changing patterns of agriculture have paradoxically contributed to both improved working conditions and increased exposure to respiratory hazards. Animal confinement operations with increasing animal density, particularly swine confinement, have contributed significantly to increased intensity and duration of exposure to indoor air toxins. Ongoing research has implicated bacterial endotoxins, fungal spores, and the inherent toxicity of grain dusts as causes of upper and lower airway inflammation and as immunologic agents in both grain and animal production. Animal confinement gases, particularly ammonia and hydrogen sulfide, have been implicated as additional sources of respiratory irritants. It has become evident that a significant percentage of agricultural workers have clinical symptoms associated with long-term exposure to organic dusts and animal confinement gases. Respiratory diseases and syndromes, including hypersensitivity pneumonitis, organic dust toxic syndrome, chronic bronchitis, mucous membrane inflammation syndrome, and asthmalike syndrome, result from ongoing acute and chronic exposures. In this review we focus upon the emerging respiratory health issues in a changing agricultural economic and technologic environment. Environmental and occupational hazards and exposures will be emphasized rather than clinical diagnosis and treatment. Methods of prevention, from both engineering controls and personal respiratory perspectives, are also addressed. PMID:10931789

  7. Analysis of breast milk to assess exposure to chlorinated contaminants in Kazakhstan: sources of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposures in an agricultural region of southern Kazakhstan.

    PubMed

    Hooper, K; Chuvakova, T; Kazbekova, G; Hayward, D; Tulenova, A; Petreas, M X; Wade, T J; Benedict, K; Cheng, Y Y; Grassman, J

    1999-06-01

    High levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; up to 208 pg/g fat) were measured in samples of breast milk collected in 1997 from 64 donors [41 first-time mothers (primiparae)] living on state farms in southern Kazakhstan. TCDD was the major contributor (70%) to the toxic equivalents, matching the congener patterns found in breast milk and serum samples collected in 1994 and 1996 from donors in nearby villages. The highest TCDD levels were found in state farms adjacent to a reservoir (zone A), which receives agricultural runoff from cotton fields. TCDD levels in zone A were significantly higher than levels in a region more distant (zone B; > 10 miles) from the reservoir (zone A: mean 53 pg/g, n = 17; zone B: mean 21 pg/g, n = 24; p = 0.0017). Levels of TCDD in breast milk and animal-derived foodstuffs were 10 times U.S. levels. Body burden and dietary data suggest that exposures to TCDD are chronic, environmental, and long term and may be related to the use of chemicals in cotton agriculture. The data suggest that the most likely source is the use of cotton defoliants contaminated with TCDD, and the most likely pathway for human exposure is via the consumption of contaminated foodstuffs.

  8. Analysis of breast milk to assess exposure to chlorinated contaminants in Kazakhstan: sources of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposures in an agricultural region of southern Kazakhstan.

    PubMed Central

    Hooper, K; Chuvakova, T; Kazbekova, G; Hayward, D; Tulenova, A; Petreas, M X; Wade, T J; Benedict, K; Cheng, Y Y; Grassman, J

    1999-01-01

    High levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; up to 208 pg/g fat) were measured in samples of breast milk collected in 1997 from 64 donors [41 first-time mothers (primiparae)] living on state farms in southern Kazakhstan. TCDD was the major contributor (70%) to the toxic equivalents, matching the congener patterns found in breast milk and serum samples collected in 1994 and 1996 from donors in nearby villages. The highest TCDD levels were found in state farms adjacent to a reservoir (zone A), which receives agricultural runoff from cotton fields. TCDD levels in zone A were significantly higher than levels in a region more distant (zone B; > 10 miles) from the reservoir (zone A: mean 53 pg/g, n = 17; zone B: mean 21 pg/g, n = 24; p = 0.0017). Levels of TCDD in breast milk and animal-derived foodstuffs were 10 times U.S. levels. Body burden and dietary data suggest that exposures to TCDD are chronic, environmental, and long term and may be related to the use of chemicals in cotton agriculture. The data suggest that the most likely source is the use of cotton defoliants contaminated with TCDD, and the most likely pathway for human exposure is via the consumption of contaminated foodstuffs. Images Figure 1 Figure 2 Figure 3 PMID:10515712

  9. U.S.-State Agricultural Data. Agriculture Information Bulletin Number 501.

    ERIC Educational Resources Information Center

    Womack, Letricia M.; And Others

    This report presents agricultural information for each of the 50 states and the United States. Data are provided on population, land use, agricultural production, farm income, value of assets on farms, and selected characteristics of farms, such as size, tenure, and farm organization. Primary data sources are the 1982 Census of Agriculture and the…

  10. U.S.-State Agricultural Data. Agriculture Information Bulletin Number 512.

    ERIC Educational Resources Information Center

    Womack, Letricia M.; Traub, Larry G.

    This report presents agricultural information for each state and the United States as a whole for the years 1981-1985. Included are data on population, land use, agricultural production, farm income, value of assets on farms, and selected characteristics of farms. The primary data sources are the "1982 Census of Agriculture," the "Economic…

  11. [Multivariate geostatistics and GIS-based approach to study the spatial distribution and sources of heavy metals in agricultural soil in the Pearl River Delta, China].

    PubMed

    Cai, Li-mei; Ma, Jin; Zhou, Yong-zhang; Huang, Lan-chun; Dou, Lei; Zhang, Cheng-bo; Fu, Shan-ming

    2008-12-01

    One hundred and eighteen surface soil samples were collected from the Dongguan City, and analyzed for concentration of Cu, Zn, Ni, Cr, Pb, Cd, As, Hg, pH and OM. The spatial distribution and sources of soil heavy metals were studied using multivariate geostatistical methods and GIS technique. The results indicated concentrations of Cu, Zn, Ni, Pb, Cd and Hg were beyond the soil background content in Guangdong province, and especially concentrations of Pb, Cd and Hg were greatly beyond the content. The results of factor analysis group Cu, Zn, Ni, Cr and As in Factor 1, Pb and Hg in Factor 2 and Cd in Factor 3. The spatial maps based on geostatistical analysis show definite association of Factor 1 with the soil parent material, Factor 2 was mainly affected by industries. The spatial distribution of Factor 3 was attributed to anthropogenic influence. PMID:19256391

  12. Using Soluble Reactive Phosphorus and Ammonia to Identify Point Source Discharge from Large Livestock Facilities

    NASA Astrophysics Data System (ADS)

    Borrello, M. C.; Scribner, M.; Chessin, K.

    2013-12-01

    A growing body of research draws attention to the negative environmental impacts on surface water from large livestock facilities. These impacts are mostly in the form of excessive nutrient loading resulting in significantly decreased oxygen levels. Over-application of animal waste on fields as well as direct discharge into surface water from facilities themselves has been identified as the main contributor to the development of hypoxic zones in Lake Erie, Chesapeake Bay and the Gulf of Mexico. Some regulators claim enforcement of water quality laws is problematic because of the nature and pervasiveness of non-point source impacts. Any direct discharge by a facility is a violation of permits governed by the Clean Water Act, unless the facility has special dispensation for discharge. Previous research by the principal author and others has shown runoff and underdrain transport are the main mechanisms by which nutrients enter surface water. This study utilized previous work to determine if the effects of non-point source discharge can be distinguished from direct (point-source) discharge using simple nutrient analysis and dissolved oxygen (DO) parameters. Nutrient and DO parameters were measured from three sites: 1. A stream adjacent to a field receiving manure, upstream of a large livestock facility with a history of direct discharge, 2. The same stream downstream of the facility and 3. A stream in an area relatively unimpacted by large-scale agriculture (control site). Results show that calculating a simple Pearson correlation coefficient (r) of soluble reactive phosphorus (SRP) and ammonia over time as well as temperature and DO, distinguishes non-point source from point source discharge into surface water. The r value for SRP and ammonia for the upstream site was 0.01 while the r value for the downstream site was 0.92. The control site had an r value of 0.20. Likewise, r values were calculated on temperature and DO for each site. High negative correlations

  13. Tension on the Farm Fields: The Death of Traditional Agriculture?

    ERIC Educational Resources Information Center

    Oguamanam, Chidi

    2007-01-01

    Taking into account the historic transitions and progressions in agricultural science, this article examines the emergence of the phenomenon of agricultural biotechnology. It identifies pivotal sites of tension between agricultural biotechnology and alternative approaches to agriculture. The article identifies two distinct sources of contemporary…

  14. Landscape effects of a non-native grass facilitate source populations of a native generalist bug, Stenotus rubrovittatus, in a heterogeneous agricultural landscape.

    PubMed

    Yoshioka, A; Takada, M B; Washitani, I

    2014-01-01

    Non-native plant species can provide native generalist insects, including pests, with novel food and habitats. It is hypothesized that local and landscape-level abundances of non-native plants can affect the population size of generalist insects, although generalists are assumed to be less sensitive to habitat connectivity than specialists. In a heterogeneous landscape in Japan, the relationship between the density of a native pest of rice (Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae)) and the abundance of Italian ryegrass (Lolium multiflorum Lam. (Poales: Poaceae)), a non-native meadow grass known to facilitate S. rubrovittatus, was analyzed. Statistical analyses of data on bug density, vegetation, and the spatial distribution of fallow fields and meadows dominated by Italian ryegrass, obtained by field surveys, demonstrated that local and landscape-level abundances of Italian ryegrass (the unmowed meadow areas within a few hundred meters of a sampling plot) positively affected bug density before its immigration into rice fields. Our findings suggest that a generalist herbivorous insect that prefers non-native plants responds to spatial availability and connectivity of plant species patches at the metapopulation level. Fragmentation by selective mowing that decreases the total area of source populations and increases the isolation among them would be an effective and environmentally-friendly pest management method.

  15. Landscape Effects of a Non-Native Grass Facilitate Source Populations of a Native Generalist Bug, Stenotus rubrovittatus, in a Heterogeneous Agricultural Landscape

    PubMed Central

    Yoshioka, A.; Takada, M. B.; Washitani, I.

    2014-01-01

    Non-native plant species can provide native generalist insects, including pests, with novel food and habitats. It is hypothesized that local and landscape-level abundances of non-native plants can affect the population size of generalist insects, although generalists are assumed to be less sensitive to habitat connectivity than specialists. In a heterogeneous landscape in Japan, the relationship between the density of a native pest of rice (Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae)) and the abundance of Italian ryegrass (Lolium multiflorum Lam. (Poales: Poaceae)), a non-native meadow grass known to facilitate S. rubrovittatus, was analyzed. Statistical analyses of data on bug density, vegetation, and the spatial distribution of fallow fields and meadows dominated by Italian ryegrass, obtained by field surveys, demonstrated that local and landscape-level abundances of Italian ryegrass (the unmowed meadow areas within a few hundred meters of a sampling plot) positively affected bug density before its immigration into rice fields. Our findings suggest that a generalist herbivorous insect that prefers non-native plants responds to spatial availability and connectivity of plant species patches at the metapopulation level. Fragmentation by selective mowing that decreases the total area of source populations and increases the isolation among them would be an effective and environmentally-friendly pest management method. PMID:25205015

  16. The oxygen isotopic composition of phosphate in Elkhorn Slough, California: A tracer for phosphate sources

    NASA Astrophysics Data System (ADS)

    McLaughlin, Karen; Cade-Menun, Barbara J.; Paytan, Adina

    2006-11-01

    Elkhorn Slough, a small seasonal estuary in central California, has been subjected to increased nutrient loading from agricultural and other non-point sources. However, because nutrients do not behave conservatively, tracing nutrient sources and cycling in ecosystems like Elkhorn Slough has been difficult to assess. This is particularly true of phosphorus (P), which has only one stable isotope and cannot be used as an isotopic tracer. However, isotopic fractionation of oxygen in phosphate at surface water temperatures only occurs as a result of enzyme-mediated, biochemical reactions. Thus, if phosphate demand is low relative to input and is not heavily cycled within the ecosystem, the δ18O of phosphate will reflect the isotopic composition of phosphate sources to the system. We utilized the δ18O of dissolved inorganic phosphate (DIP) within the main channel of the slough and nearby Moss Landing Harbor and the δ18O of reactive phosphate from sediment and soil samples collected within the watershed to understand phosphate sources and cycling within Elkhorn Slough. Trends in the δ18O of DIP were seasonally consistent with high values near the mouth reflecting oceanic phosphate (19.1‰-20.3‰), dropping to a minimum value near Hummingbird Island in the central slough (point source, 14.1‰-14.4‰), and increasing again near the head of the slough, reflecting fertilizer input (18.9‰-19.3‰). Reactive phosphate δ18O values extracted from sediments and soils in the watershed range from 10.6‰ in a drainage ditch to 22.3‰ in creek sediments near agriculture fields. The wide range in phosphate δ18O values reflects the variations in land use and application of different fertilizers in this agriculturally dominated landscape. These data suggest that phosphate δ18O can be an effective tool for identifying P sources and understanding phosphate dynamics in estuarine ecosystems.

  17. Entomophagy and space agriculture

    NASA Astrophysics Data System (ADS)

    Katayama, N.; Ishikawa, Y.; Takaoki, M.; Yamashita, M.; Nakayama, S.; Kiguchi, K.; Kok, R.; Wada, H.; Mitsuhashi, J.; Space Agriculture Task Force, J.

    Supplying food for human occupants remains one of the primary issues in engineering space habitation Evidently for long-term occupation on a distant planet it is necessary to start agriculture on site Historically humans have consumed a variety of animals and it is required to fill our nutritional need when they live in space Among many candidate group and species of animal to breed in space agriculture insects are of great interest since they have a number of advantages over mammals and other vertebrates or invertebrates About 70-75 of animal species is insects and they play an important role in materials recycle loop of terrestrial biosphere at their various niche For space agriculture we propose several insect species such as the silkworm Bombyx mori the drugstore beetle Stegobium paniceum and the termite Macrotermes subhyalinus Among many advantages these insects do not compete with human in terms of food resources but convert inedible biomass or waste into an edible food source for human The silkworm has been domesticated since 5 000 years ago in China Silk moth has lost capability of flying after its domestication history This feature is advantageous in control of their breeding Silkworm larvae eat specifically mulberry leaves and metamorphose in their cocoon Silk fiber obtained from cocoon can be used to manufacture textile Farming system of the drugstore beetle has been well established Both the drugstore beetle and the termite are capable to convert cellulose or other inedible biomass

  18. Nonpoint Source Pollution.

    PubMed

    Mccoy, Nicholas; Chao, Bing; Gang, Daniel Dianchen

    2015-10-01

    The article presents a comprehensive review of research advancing in 2014 on nonpoint source pollution (NPS). The topics presented relate to nonpoint source pollution (NPS) within agricultural and urban areas. NPS pollution from agricultural areas is the main focus in this review. Management of NPS in agricultural, urban and rural areas is presented. Modeling of NPS pollution in different watersheds with various modeling tools is reviewed.

  19. Agriculture and climate change

    SciTech Connect

    Abelson, P.H.

    1992-07-03

    How will increases in levels of CO{sub 2} and changes in temperature affect food production A recently issued report analyzes prospects for US agriculture 1990 to 2030. The report, prepared by a distinguished Task Force, first projects the evolution of agriculture assuming increased levels of CO{sub 2} but no climate change. Then it deals with effects of climate change, followed by a discussion of how greenhouse emissions might be diminished by agriculture. Economic and policy matters are also covered. How the climate would respond to more greenhouse gases is uncertain. If temperatures were higher, there would be more evaporation and more precipitation. Where would the rain fall That is a good question. Weather in a particular locality is not determined by global averages. The Dust Bowl of the 1930s could be repeated at its former site or located in another region such as the present Corn Belt. But depending on the realities at a given place, farmers have demonstrated great flexibility in choosing what they may grow. Their flexibility has been increased by the numerous varieties of seeds of major crops that are now available, each having different characteristics such as drought resistance and temperature tolerance. In past, agriculture has contributed about 5% of US greenhouse gases. Two large components have involved emissions of CO{sub 2} from farm machinery and from oxidation of organic matter in soil due to tillage. Use of diesel fuel and more efficient machinery has reduced emissions from that source by 40%. In some areas changed tillage practices are now responsible for returning carbon to the soil. The report identifies an important potential for diminishing net US emissions of CO{sub 2} by growth and utilization of biomass. Large areas are already available that could be devoted to energy crops.

  20. Stable isotope and groundwater flow dynamics of agricultural irrigation recharge into groundwater resources of the Central Valley, California

    SciTech Connect

    Davisson, M.L.; Criss, R.E.

    1995-01-01

    Intensive agricultural irrigation and overdraft of groundwater in the Central Valley of California profoundly affect the regional quality and availability of shallow groundwater resources. In the natural state, the {delta}{sup 18}O values of groundwater were relatively homogeneous (mostly -7.0 {+-} 0.5{per_thousand}), reflecting local meteoric recharge that slowly (1-3m/yr) flowed toward the valley axis. Today, on the west side of the valley, the isotope distribution is dominated by high {sup 18}O enclosures formed by recharge of evaporated irrigation waters, while the east side has bands of low {sup 18}O groundwater indicating induced recharge from rivers draining the Sierra Nevada mountains. Changes in {delta}{sup 18}O values caused by the agricultural recharge strongly correlate with elevated nitrate concentrations (5 to >100 mg/L) that form pervasive, non-point source pollutants. Small, west-side cities dependent solely on groundwater resources have experienced increases of >1.0 mg/L per year of nitrate for 10-30 years. The resultant high nitrates threaten the economical use of the groundwater for domestic purposes, and have forced some well shut-downs. Furthermore, since >80% of modern recharge is now derived from agricultural irrigation, and because modern recharge rates are {approximately}10 times those of the natural state, agricultural land retirement by urbanization will severely curtail the current safe-yields and promote overdraft pumping. Such overdrafting has occurred in the Sacramento metropolitan area for {approximately}40 years, creating cones of depression {approximately}25m deep. Today, groundwater withdrawal in Sacramento is approximately matched by infiltration of low {sup 18}O water (-11.0{per_thousand}) away from the Sacramento and American Rivers, which is estimated to occur at 100-300m/year from the sharp {sup 18}O gradients in our groundwater isotope map.

  1. Programs in Animal Agriculture.

    ERIC Educational Resources Information Center

    Herring, Don R.; And Others

    1980-01-01

    Five topics relating to programs in animal agriculture are addressed: (1) the future of animal agriculture; (2) preparing teachers in animal agriculture; (3) how animal programs help young people; (4) a nontraditional animal agriculture program; and (5) developing competencies in animal agriculture. (LRA)

  2. Analysis of time-series of total and plant water stress levels using a dual-source energy balance model over agricultural crops and medium to low resolution thermal infra red remote sensing data

    NASA Astrophysics Data System (ADS)

    Boulet, Gilles; Mougenot, Bernard; Bahir, Malik; Fanise, Pascal; Saadi, Sameh; Simonneaux, Vincent; Chebbi, Wafa; Kassouk, Zeineb; Oualid, Toufik; Olioso, Albert; Lagouarde, Jean-Pierre; Le Dantec, Valérie; Rivalland, Vincent; Zribi, Mehrez; Lili-Chabaane, Zohra

    2015-04-01

    Detecting, monitoring and mapping plant water stress with remote sensing data is a crucial component of modern agricultural water management, especially in areas with scarce water resources such as the south and the eastern parts of the Mediterranean region. Developing efficient operational methods dedicated to those three actions is thus necessary to design observing systems for areas with a mixture of irrigated, rainfed and deficit irrigation agriculture. Those systems can assist managers in tasks such as early warning of drought, real time irrigated area mapping etc. A way to quantify plant and total water stress levels is to exploit the available surface temperature data from remote sensing as a signature of the surface energy balance, including the latent heat flux. Remotely sensed energy balance models enable to estimate evapotranspiration and the water status of continental surfaces. Two-source models, such as TSEB (Norman et al., 1995) allow deriving a rough estimate of the water stress of the vegetation instead of that of a soil-vegetation composite. For the latter, a realistic underlying assumption enables to invert two unknowns (evaporation and transpiration) from a single piece of information. This assumption states that, in most cases, vegetation is unstressed, and that if vegetation is stressed, evaporation is negligible. In the latter case, if vegetation stress is not properly accounted for, the resulting evaporation will decrease to unrealistic levels (negative fluxes) in order to maintain the same total surface temperature. Actual and potential transpiration rates are combined to derive an index of plant water stress applicable to low resolution data. Here, we evaluate time series of plant water stress indices in the Kairouan area in Central Tunisia in the last few years by comparing them with 1- maps of the irrigation sectors as well as rainfall data and 2- turbulent heat flux measurements obtained at low resolution (scintillometer, eddy

  3. Identification of Major Risk Sources for Surface Water Pollution by Risk Indexes (RI) in the Multi-Provincial Boundary Region of the Taihu Basin, China.

    PubMed

    Yao, Hong; Li, Weixin; Qian, Xin

    2015-08-21

    Environmental safety in multi-district boundary regions has been one of the focuses in China and is mentioned many times in the Environmental Protection Act of 2014. Five types were categorized concerning the risk sources for surface water pollution in the multi-provincial boundary region of the Taihu basin: production enterprises, waste disposal sites, chemical storage sites, agricultural non-point sources and waterway transportations. Considering the hazard of risk sources, the purification property of environmental medium and the vulnerability of risk receptors, 52 specific attributes on the risk levels of each type of risk source were screened out. Continuous piecewise linear function model, expert consultation method and fuzzy integral model were used to calculate the integrated risk indexes (RI) to characterize the risk levels of pollution sources. In the studied area, 2716 pollution sources were characterized by RI values. There were 56 high-risk sources screened out as major risk sources, accounting for about 2% of the total. The numbers of sources with high-moderate, moderate, moderate-low and low pollution risk were 376, 1059, 101 and 1124, respectively, accounting for 14%, 38%, 5% and 41% of the total. The procedure proposed could be included in the integrated risk management systems of the multi-district boundary region of the Taihu basin. It could help decision makers to identify major risk sources in the risk prevention and reduction of surface water pollution.

  4. Identification of Major Risk Sources for Surface Water Pollution by Risk Indexes (RI) in the Multi-Provincial Boundary Region of the Taihu Basin, China.

    PubMed

    Yao, Hong; Li, Weixin; Qian, Xin

    2015-08-01

    Environmental safety in multi-district boundary regions has been one of the focuses in China and is mentioned many times in the Environmental Protection Act of 2014. Five types were categorized concerning the risk sources for surface water pollution in the multi-provincial boundary region of the Taihu basin: production enterprises, waste disposal sites, chemical storage sites, agricultural non-point sources and waterway transportations. Considering the hazard of risk sources, the purification property of environmental medium and the vulnerability of risk receptors, 52 specific attributes on the risk levels of each type of risk source were screened out. Continuous piecewise linear function model, expert consultation method and fuzzy integral model were used to calculate the integrated risk indexes (RI) to characterize the risk levels of pollution sources. In the studied area, 2716 pollution sources were characterized by RI values. There were 56 high-risk sources screened out as major risk sources, accounting for about 2% of the total. The numbers of sources with high-moderate, moderate, moderate-low and low pollution risk were 376, 1059, 101 and 1124, respectively, accounting for 14%, 38%, 5% and 41% of the total. The procedure proposed could be included in the integrated risk management systems of the multi-district boundary region of the Taihu basin. It could help decision makers to identify major risk sources in the risk prevention and reduction of surface water pollution. PMID:26308032

  5. Identification of Major Risk Sources for Surface Water Pollution by Risk Indexes (RI) in the Multi-Provincial Boundary Region of the Taihu Basin, China

    PubMed Central

    Yao, Hong; Li, Weixin; Qian, Xin

    2015-01-01

    Environmental safety in multi-district boundary regions has been one of the focuses in China and is mentioned many times in the Environmental Protection Act of 2014. Five types were categorized concerning the risk sources for surface water pollution in the multi-provincial boundary region of the Taihu basin: production enterprises, waste disposal sites, chemical storage sites, agricultural non-point sources and waterway transportations. Considering the hazard of risk sources, the purification property of environmental medium and the vulnerability of risk receptors, 52 specific attributes on the risk levels of each type of risk source were screened out. Continuous piecewise linear function model, expert consultation method and fuzzy integral model were used to calculate the integrated risk indexes (RI) to characterize the risk levels of pollution sources. In the studied area, 2716 pollution sources were characterized by RI values. There were 56 high-risk sources screened out as major risk sources, accounting for about 2% of the total. The numbers of sources with high-moderate, moderate, moderate-low and low pollution risk were 376, 1059, 101 and 1124, respectively, accounting for 14%, 38%, 5% and 41% of the total. The procedure proposed could be included in the integrated risk management systems of the multi-district boundary region of the Taihu basin. It could help decision makers to identify major risk sources in the risk prevention and reduction of surface water pollution. PMID:26308032

  6. Agricultural Extension: Who Uses It?

    ERIC Educational Resources Information Center

    Nolan, Michael; Lasley, Paul

    1979-01-01

    A Missouri study conducted to determine agricultural extension usage patterns found that heavy users of extension publications tended to be younger farmers, those with a relatively large amount of land, and pork producers. Extension meetings were a less frequent source of information than either publications or county extension office visits. (LRA)

  7. Innovation and Teaching in Agriculture.

    ERIC Educational Resources Information Center

    Nieuwenhuis, Loek F. M.

    2002-01-01

    Two case studies were conducted: (1) linear innovation through technology diffusion in Dutch agriculture and (2) knowledge sources and learning processes of Dutch farmer- entrepreneurs. Learning and innovation were central to entrepreneurship. Innovative learning involved balancing the chaos of uncertainty and the status quo of experience.…

  8. Peruvian Arid Coast and Agriculture, South America

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The coast of Peru, between the Pacific Ocean and the Andes Mountains is very arid (16.5S, 72.5W). For several thousand years, water from numerous small streams has been used for traditional flood and canal irrigation agriculture. However, during the past decade innovative techniques have tapped new water sources for increased agricultural production. Ground water in the porous sedimentary rock formations has been tapped for well irrigation agriculture.

  9. Agricultural Education at Risk.

    ERIC Educational Resources Information Center

    Evans, Donald E.

    1988-01-01

    Discusses educational reform in the context of agricultural education. Covers a recent report on agricultural education reform by the National Academy of Sciences, state legislative initiatives, and several recommendations for the future of agricultural education. (CH)

  10. Perceived agricultural runoff impact on drinking water.

    PubMed

    Crampton, Andrea; Ragusa, Angela T

    2014-09-01

    Agricultural runoff into surface water is a problem in Australia, as it is in arguably all agriculturally active countries. While farm practices and resource management measures are employed to reduce downstream effects, they are often either technically insufficient or practically unsustainable. Therefore, consumers may still be exposed to agrichemicals whenever they turn on the tap. For rural residents surrounded by agriculture, the link between agriculture and water quality is easy to make and thus informed decisions about water consumption are possible. Urban residents, however, are removed from agricultural activity and indeed drinking water sources. Urban and rural residents were interviewed to identify perceptions of agriculture's impact on drinking water. Rural residents thought agriculture could impact their water quality and, in many cases, actively avoided it, often preferring tank to surface water sources. Urban residents generally did not perceive agriculture to pose health risks to their drinking water. Although there are more agricultural contaminants recognised in the latest Australian Drinking Water Guidelines than previously, we argue this is insufficient to enhance consumer protection. Health authorities may better serve the public by improving their proactivity and providing communities and water utilities with the capacity to effectively monitor and address agricultural runoff.

  11. The Land Grant Colleges of Agriculture.

    ERIC Educational Resources Information Center

    Campbell, Rex R.

    1991-01-01

    Discusses the following alternatives for the colleges of agriculture: (1) continue the status quo; (2) specialize to serve the needs of a group not currently served by traditional colleges of agriculture; or (3) reduce the dependence on traditional clientele groups through more funding with grants from industries or governmental sources. Provides…

  12. Area Source Emission Measurements Using EPA OTM 10

    EPA Science Inventory

    Measurement of air pollutant emissions from area and non-point sources is an emerging environmental concern. Due to the spatial extent and non-homogenous nature of these sources, assessment of fugitive emissions using point sampling techniques can be difficult. To help address th...

  13. BACTERIA SOURCE TRACKING AND HOST SPECIES SPECIFICITY ANALYSIS

    EPA Science Inventory

    Point and non-point pollution sources of fecal pollution on a watershed adversely impact the quality of drinking source waters and recreational waters. States are required to develop total maximum daily loads (TMDLs) and devise best management practices (BMPs) to reduce the pollu...

  14. DNA BASED MOLECULAR METHODS FOR BACTERIAL SOURCE TRACKING IN WATERSHEDS

    EPA Science Inventory

    Point and non-point pollution sources of fecal pollution on a watershed adversely impact the quality of drinking source waters and recreational waters. States are required to develop total maximum daily loads (TMDLs) and devise best management practices (BMPs) to reduce the po...

  15. Nitrate concentrations and fluxes in the River Thames, London UK 1868 to 2008: catchment-scale modelling of diffuse agricultural sources and groundwater response using the world's longest water quality time series

    NASA Astrophysics Data System (ADS)

    Howden, N. J.; Burt, T. P.; Worrall, F.; Mathias, S.; Whelan, M.

    2011-12-01

    This paper presents analyses of the world's longest water quality record: 140 years of monthly-average nitrate concentrations (1868 to 2008) and fluxes (1883 to 2008) for the River Thames north of London. We show how short- and long- term patterns in these time series are influenced by both climatic and anthropogenic pressures, in the case of the latter, particularly land use and land management practices. Climate change does not play a significant role in controlling annual average concentrations or fluxes, rather large-scale land conversions from permanent grassland to arable farming have created sustained diffuse sources of nitrate that have caused (almost four-fold) increases in concentrations and fluxes that persist for many decades after the initial changes. Our analyses of this unique time series highlight four areas of particular interest: (1) Despite several layers of regulation and source control, fluvial concentrations and fluxes remain in- tractably high - no decrease has been observed since the early 1970s; (2) Catchment response to changing nitrogen inputs from land use and land management is subject to considerable lag: present conditions in the river reflect land practices from some years ago; (3) Following (2), we suggest that current changes to land use and land management practices will not be reflected in river water quality for some time to come; (4) Overall, the long-term view afforded by this record questions the derivation of "baseline conditions" that are formulated from records that do not reflect the massive changes in land use and land management in the mid-20th century. Overall, a better understanding of the links, and time delays, between cause (i.e. changing land use / land management) and fluvial response (i.e. concentration increase/decrease) will improve our ability both to predict changes in the coming decades, and inform management decision making now, to ensure the appropriate balance between agricultural development and

  16. REMOTE SENSING, VISUALIZATION AND DECISION SUPPORT FOR WATERSHED MANAGEMENT AND SUSTAINABLE AGRICULTURE

    EPA Science Inventory

    The integration of satellite and airborne remote sensing, scientific visualization and decision support tools is discussed within the context of management techniques for minimizing the non-point source pollution load of inland waterways and the sustainability of food crop produc...

  17. Handbook of Agricultural Geophysics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Geophysical methods continue to show great promise for use in agriculture. The term “agricultural geophysics” denotes a subdiscipline of geophysics that is focused only on agricultural applications. The Handbook of Agricultural Geophysics was compiled to include a comprehensive overview of the geoph...

  18. Agricultural opportunities to mitigate greenhouse gas emissions.

    PubMed

    Johnson, Jane M-F; Franzluebbers, Alan J; Weyers, Sharon Lachnicht; Reicosky, Donald C

    2007-11-01

    Agriculture is a source for three primary greenhouse gases (GHGs): CO(2), CH(4), and N(2)O. It can also be a sink for CO(2) through C sequestration into biomass products and soil organic matter. We summarized the literature on GHG emissions and C sequestration, providing a perspective on how agriculture can reduce its GHG burden and how it can help to mitigate GHG emissions through conservation measures. Impacts of agricultural practices and systems on GHG emission are reviewed and potential trade-offs among potential mitigation options are discussed. Conservation practices that help prevent soil erosion, may also sequester soil C and enhance CH(4) consumption. Managing N to match crop needs can reduce N(2)O emission and avoid adverse impacts on water quality. Manipulating animal diet and manure management can reduce CH(4) and N(2)O emission from animal agriculture. All segments of agriculture have management options that can reduce agriculture's environmental footprint.

  19. Examining the departure in response of non-point detectors due to non-uniform illumination and displacement of effective center

    NASA Astrophysics Data System (ADS)

    Khabaz, Rahim

    2013-11-01

    A mathematical simulation approach based on the general purpose Monte Carlo N-particle transport code MCNP was developed to calculate the departure in reading of the neutron spectrometer instrument from that expected according to the inverse square law. The calculations were performed to evaluate the effects of beam divergence on the response of a 10 in. spherical device equipped with a long BF3 counter irradiated by 11 mono-energy neutron beams. The necessary geometry correction factor, because of non-uniform illumination, for the calibration of seven polyethylene spheres with several radionuclide neutron sources, i.e. Ra-Be, 241Am-Be, 241Am-B and Po-Be sources was also determined. In all calculations, the displacement of effective center from the geometric center of moderating spheres, when used as an instrument for neutron fluence measurement, was quantified.

  20. 1986 Agricultural Chartbook. Agriculture Handbook No. 663.

    ERIC Educational Resources Information Center

    Department of Agriculture, Washington, DC.

    This book contains 310 charts, tables, and graphs containing statistical information about agriculture-related commodities and services, primarily in the United States, in 1986. The book is organized in seven sections that cover the following topics: (1) the farm (farm income, farm population, farm workers, food and fiber system, agriculture and…

  1. Agricultural Aircraft for Site-Specific Agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural aircraft provide a convenient platform to aid in precision agriculture, in which pesticide, fertilizer or other field inputs are applied only where they are needed. This saves on chemical and farm resources, and reduces environmental loading. Remote sensing is used to spot areas of the ...

  2. Agricultural Chartbook 1988. Agriculture Handbook No. 673.

    ERIC Educational Resources Information Center

    Department of Agriculture, Washington, DC.

    These charts present an overview of the current economic health of American agriculture. The charts move from the national and international arenas to farm economic health measures and crop and livestock trends. A small amount of descriptive narrative accompanies most of the charts. Charts depicting the economic picture of U.S. agriculture include…

  3. A Glossary of Spanish-American Agricultural Terms.

    ERIC Educational Resources Information Center

    Mainous, Bruce H.; Rund, Maria T.

    The Spanish-English and English-Spanish glossary of agricultural and supporting terms is an expansion of an earlier glossary intended for North American agricultural specialists working in Latin America. It contains terminology from 50 articles in Spanish on Latin American agricultural topics. A list of those sources is included. (MSE)

  4. Understanding Canadian Agriculture. "Understanding Economics" Series No. 5.

    ERIC Educational Resources Information Center

    Loyns, R. M. A.

    This document for secondary school Canadian students analyzes the role of agriculture in the national economy and in Canadian trade, describes characteristics of Canadian farms, and discusses governmental inlfuences on Canadian agriculture. The document stresses that agriculture is a large source of national wealth; about 30% of Canadian farm…

  5. Resource Guide to Educational Materials about Agriculture. A Project of Agriculture in the Classroom. 1996 Edition.

    ERIC Educational Resources Information Center

    Department of Agriculture, Washington, DC. Office of the Secretary.

    This resource guide provides a list of materials available from public and private sources on agriculture and related issues. More than 300 organizations and publishers were asked what materials they were producing that could help regular K-12 classroom teachers incorporate more information about agriculture into their instruction. This guide is…

  6. Microbial Source Module (MSM): Documenting the Science and Software for Discovery, Evaluation, and Integration

    EPA Science Inventory

    The Microbial Source Module (MSM) estimates microbial loading rates to land surfaces from non-point sources, and to streams from point sources for each subwatershed within a watershed. A subwatershed, the smallest modeling unit, represents the common basis for information consume...

  7. Environmentally-friendly agricultural practices and their acceptance by smallholder farmers in China-A case study in Xinxiang County, Henan Province.

    PubMed

    Luo, Liangguo; Qin, Lihuan; Wang, Yan; Wang, Qian

    2016-11-15

    Intensive agriculture with high inputs has resulted in rapid development of crop production in China, accompanied by negative environmental effects such as serious non-point source agricultural pollution. Implementation of environmentally-friendly agricultural practices can effectively prevent such pollution. However, the acceptance and adoption of such practices are related not only to associated risks and potential benefits, but also to farmers' attitudes to and knowledge of scientifically validated practices. In the presented study we surveyed views of a stratified sample of 150 smallholder farmers and 10 extension service experts from Xinxiang, a high grain-producing county in Henan Province, China. Their opinions were explored in personal interviews using a questionnaire with three sections. The first section mainly sought information on surveyed farmers' demographic characteristics like gender, age and education. The second section concerned their awareness of the environmental problems and losses of yields associated with customary over-fertilization practices, and their main concerns about new practices. The third section addressed farmers' attitudes to, and the extension service experts' professional evaluations of, five selected practices in terms of the importance of seven factors (time demands, costs, risks, compatibility, complexity, trialability and observability). Acceptance indices were calculated from the responses to rank farmers' willingness to accept the five environmentally-friendly agricultural practices, and thus identify the most appropriate to promote in the study area. The results show that costs, followed by risks and observability, are the more important factors affecting farmers' decisions to adopt a practice. The results also indicate that no or minimum tillage and returning straw to the field are the most appropriate practices to promote initially at large scale in Xinxiang. The others could be popularized gradually after providing

  8. Environmentally-friendly agricultural practices and their acceptance by smallholder farmers in China-A case study in Xinxiang County, Henan Province.

    PubMed

    Luo, Liangguo; Qin, Lihuan; Wang, Yan; Wang, Qian

    2016-11-15

    Intensive agriculture with high inputs has resulted in rapid development of crop production in China, accompanied by negative environmental effects such as serious non-point source agricultural pollution. Implementation of environmentally-friendly agricultural practices can effectively prevent such pollution. However, the acceptance and adoption of such practices are related not only to associated risks and potential benefits, but also to farmers' attitudes to and knowledge of scientifically validated practices. In the presented study we surveyed views of a stratified sample of 150 smallholder farmers and 10 extension service experts from Xinxiang, a high grain-producing county in Henan Province, China. Their opinions were explored in personal interviews using a questionnaire with three sections. The first section mainly sought information on surveyed farmers' demographic characteristics like gender, age and education. The second section concerned their awareness of the environmental problems and losses of yields associated with customary over-fertilization practices, and their main concerns about new practices. The third section addressed farmers' attitudes to, and the extension service experts' professional evaluations of, five selected practices in terms of the importance of seven factors (time demands, costs, risks, compatibility, complexity, trialability and observability). Acceptance indices were calculated from the responses to rank farmers' willingness to accept the five environmentally-friendly agricultural practices, and thus identify the most appropriate to promote in the study area. The results show that costs, followed by risks and observability, are the more important factors affecting farmers' decisions to adopt a practice. The results also indicate that no or minimum tillage and returning straw to the field are the most appropriate practices to promote initially at large scale in Xinxiang. The others could be popularized gradually after providing

  9. Theme: Delivering Agricultural Literacy.

    ERIC Educational Resources Information Center

    Reed, Warren D.; And Others

    1990-01-01

    Eight articles in this theme issue deal with the nationwide implementation of agricultural literacy programs--discovering how to do it. Discussed are experiences in planning and conducting agricultural literacy programs at state and local levels. (JOW)

  10. Traditional Agriculture and Permaculture.

    ERIC Educational Resources Information Center

    Pierce, Dick

    1997-01-01

    Discusses benefits of combining traditional agricultural techniques with the concepts of "permaculture," a framework for revitalizing traditions, culture, and spirituality. Describes school, college, and community projects that have assisted American Indian communities in revitalizing sustainable agricultural practices that incorporate cultural…

  11. Vocational Agriculture in Ponape

    ERIC Educational Resources Information Center

    Dayrit, Ruben S.

    1975-01-01

    The general objectives of agriculture education in both the elementary and secondary schools in Ponape District are to develop interest in agriculture among students and to provide practical and technical skills in growing crops and raising domestic animals. (Author)

  12. Urban Agricultural Education.

    ERIC Educational Resources Information Center

    Corbellini, Margaret

    1991-01-01

    John Bourne High School in Queens, New York, offers an agricultural program enrolling more than 400 students. The curriculum includes agricultural career exploration, plant and animal science, summer land laboratories, and a special education component. (SK)

  13. Strategies for Agriculture.

    ERIC Educational Resources Information Center

    Crosson, Pierre R.; Rosenberg, Norman J.

    1989-01-01

    Discusses the change of agricultural methods with human population growth. Describes the trends of world food production, changes in farmland, use of fertilizer, and 13 agricultural research institutions. Lists 5 references for further reading. (YP)

  14. Biotechnology and Agriculture.

    ERIC Educational Resources Information Center

    Kenney, Martin

    Even at this early date in the application of biotechnology to agriculture, it is clear that agriculture may provide the largest market for new or less expensive biotechnologically manufactured products. The chemical and pharmaceutical industries that hold important positions in agricultural inputs are consolidating their positions by purchasing…

  15. Agriculture Business and Management.

    ERIC Educational Resources Information Center

    Seperich, George; And Others

    This curriculum guide is intended for vocational agriculture teachers who deliver agricultural business and management programs at the secondary or postsecondary level. It is based on the Arizona validated occupational competencies and tasks for management and supervisory positions in agricultural business. The competency/skill and task list…

  16. Agricultural Education: Value Adding.

    ERIC Educational Resources Information Center

    Riesenberg, Lou E.; And Others

    1989-01-01

    This issue develops the theme of "Agricultural Education--Value Adding." The concept value adding has been a staple in the world of agricultural business for describing adding value to a commodity that would profit the producer and the local community. Agricultural education should add value to individuals and society to justify agricultural…

  17. Chapter 3: Cropland Agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2013, cropland agriculture resulted in total emissions of approximately 209 MMT CO2 eq. of greenhouse gases (GHG). Cropland agriculture is responsible for almost half (46%) of all emissions from the agricultural sector. Nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) emissions from c...

  18. Dutch Agricultural Education.

    ERIC Educational Resources Information Center

    Netherlands Ministry of Agriculture and Fisheries, The Hauge.

    Agricultural Education in the