Science.gov

Sample records for agricultural field trials

  1. Evaluation of the leucine incorporation technique for detection of pollution-induced community tolerance to copper in a long-term agricultural field trial with urban waste fertilizers.

    PubMed

    Lekfeldt, Jonas Duus Stevens; Magid, Jakob; Holm, Peter E; Nybroe, Ole; Brandt, Kristian Koefoed

    2014-11-01

    Copper (Cu) is known to accumulate in agricultural soils receiving urban waste products as fertilizers. We here report the use of the leucine incorporation technique to determine pollution-induced community tolerance (Leu-PICT) to Cu in a long-term agricultural field trial. A significantly increased bacterial community tolerance to Cu was observed for soils amended with organic waste fertilizers and was positively correlated with total soil Cu. However, metal speciation and whole-cell bacterial biosensor analysis demonstrated that the observed PICT responses could be explained entirely by Cu speciation and bioavailability artifacts during Leu-PICT detection. Hence, the agricultural application of urban wastes (sewage sludge or composted municipal waste) simulating more than 100 years of use did not result in sufficient accumulation of Cu to select for Cu resistance. Our findings also have implications for previously published PICT field studies and demonstrate that stringent PICT detection criteria are needed for field identification of specific toxicants.

  2. Temporal variability of CO2 and N2O emissions in an agricultural long-term field trial regarding effects of different management practices and extreme weather effects

    NASA Astrophysics Data System (ADS)

    Koal, Philipp; Schilling, Rolf; Gerl, Georg; Pritsch, Karin; Munch, Jean Charles

    2016-04-01

    In order to achieve a reduction of greenhouse gas emissions, modern agronomic management practices need to be established. Therefore, to assess the effect of different farming practices on greenhouse gas emissions, reliable data are required. The experiment covers and compares main aspects of agricultural management for a better implementation of sustainable land use. The focus lies on the determination and interpretation of greenhouse gas emissions, where the effects of diverse tillage systems and fertilisation practices of an integrated farming system as well as the impacts of extreme weather conditions are observed. In addition, with analysis of the alterable biological, physical and chemical soil properties a link between the impact of different management systems on greenhouse gas emissions and the observed cycle of matter in the soil, especially the nitrogen and carbon cycle, is enabled. Measurements have been carried out on long-term field trials at the Research Farm Scheyern located in a Tertiary hilly landscape approximately 40 km north of Munich (South Germany). The long-term integrated farming system trial was started in 1992. Since then parcels of land (each around 0.2-0.4 ha) with a particular interior plot set-up have been conducted with the same crop rotation, tillage and fertilisation practice referring to integrated farming management. Thus, the management impacts on the soil of more than 20 years have been examined. Fluxes of CH4, N2O and CO2 have been monitored since 2007 for the integrated farming system trial using an automated system which consists of chambers (0.4 m2 area) with a motor-driven lid, an automated gas sampling unit, an on-line gas chromatographic analysis system, and a control and data logging unit. Precipitation and temperature data have been observed for the experimental field to include weather effects. The main outcomes are the analysis of temporal and spatial dynamics of greenhouse gas emissions influenced by management

  3. The Styx field trial

    PubMed Central

    Gemmell, M. A.

    1968-01-01

    An assessment was made of the effectiveness of the generally accepted methods recommended for controlling hydatid disease during the course of a field-trial, initiated in 1943 in an isolated region of New Zealand. The results obtained during the first 21 years are described. Basically, the trial was an attempt to compare the effectiveness of a general public health educational programme and an anthelmintic programme using arecoline hydrobromide for treatment of dogs with that of a specific educational programme using this compound as a diagnostic agent. Arecoline hydrobromide was found to be too uncertain in its action to be of practical value as an anthelmintic. The development of diagnostic techniques, described in this paper, made it possible to use the compound for diagnostic purposes and thus for educational purposes, since each dog could be examined for tapeworms in the presence of the owner. Using changes in the annual prevalence rate in sheep of the cysts of E. granulosus and those of T. hydatigena as the principal indicators, the conclusion has been reached that the specific diagnostic approach achieved more success than the general educational and treatment programme. The principal reason for this appears to be that the former approach induced a greater awareness in owners of the need for strict management to prevent dogs gaining access to infective raw offal than that stimulated in the community when the dogs were dosed but not examined. ImagesFIG. 2FIG. 4FIG. 5 PMID:5303843

  4. Agricultural fields, Khartoum, Sudan, Africa

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This herringbone pattern of irrigated agricultural fields near Khartoum, Sudan (14.5N, 33.5E) is very distinctive in both size and shape. The region contains thousands of these rectangular fields bounded by canals which carry water from both the White and Blue Nile Rivers. A crop rotation system is used so that some fields are in cotton, millit, sorghum or fallow to conserve moisture and control weeds and insects. See also STS049-96-003.

  5. Field spectroscopy of agricultural crops

    NASA Technical Reports Server (NTRS)

    Bauer, M. E.; Daughtry, C. S. T.; Biehl, L. L.; Kanemasu, E. T.; Hall, F. G.

    1986-01-01

    The development of the full potential of multispectral data acquired from satellites, requires quantitative knowledge, and physical models of the spectral properties of specific earth surface features. Knowledge of the relationships between spectral-radiometric characteristics and important biophysical parameters of agricultural crops and soils can best be obtained by carefully controlled studies of fields or plots. It is important to select plots where data describing the agronomic-biophysical properties of the crop canopies and soil background are attainable, taking into account also the feasibility of frequent timely calibrated spectral measurements. The term 'field spectroscopy' is employed for this research. The present paper is concerned with field research which was sponsored by NASA as part of the AgRISTARS Supporting Research Project. Attention is given to field research objectives, field research instrumentation, measurement procedures, spectral-temporal profile modeling, and the effects of cultural and environmental factors on crop reflectance.

  6. The Styx Field Trial

    PubMed Central

    Gemmell, M. A.

    1978-01-01

    A 13-year assessment has been made of the effectiveness of a monthly drug treatment programme for the control of tapeworms in dogs in order to prevent hydatidosis (Echinococcus granulosus) and cysticercosis (Taenia hydatigena and T. ovis) in sheep. The age-specific prevalence of T. hydatigena in lambs was used as the principal indicator. The trial was carried out in the Styx Valley of the Maniototo Plain in the South Island of New Zealand. Over an 8-year period dogs were treated monthly with bunamidine hydrochloride at about 25 mg/kg with little effect on the prevalence of T. hydatigena in lambs. The addition of niclosamide at 50 mg/kg for 1 year also had little effect. Eggs appeared to survive from one season to the next. Those shed prior to the lamb-rearing season gave rise to endemic-type patterns; whereas patent infections occurring during this period rapidly gave rise to an epidemic-type pattern or a ”cysticercosis storm”. In this 9-year period there were 16 ”cysticercosis storms” and all susceptible lambs were infected. These storms did not necessarily give rise to a similar prevalence on neighbouring farms, but may have contributed to the overall infective pattern. A similar situation occurred in the first year that nitroscanate at 100 mg/kg was introduced. During this 10-year period, arecoline surveillance of the dog population was undertaken in the remainder of the county and many dogs were found to harbour tapeworms. Both resident and introduced dogs may have contributed to the infective patterns in the Styx Valley. Treatment with nitroscanate was continued monthly in the Styx Valley and niclosamide was used in the remainder of the County for a further 3 years. There was a marked reduction in the age-specific prevalence and lambs on many farms were free from T. hydatigena at slaughter. However, one ”breakdown” occurred and this was almost certainly autochthonous. Comparisons with an earlier period when arecoline surveillance was used in the

  7. 50 CFR 27.91 - Field trials.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Field trials. 27.91 Section 27.91 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM PROHIBITED ACTS Other Disturbing Violations § 27.91 Field trials. The conducting or operation of field trials for dogs on national wildlife refuges is prohibited except as may...

  8. 50 CFR 27.91 - Field trials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Field trials. 27.91 Section 27.91 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM PROHIBITED ACTS Other Disturbing Violations § 27.91 Field trials. The conducting or operation of field trials for dogs on national wildlife refuges is prohibited except as may...

  9. Chemical and microbiological water quality of subsurface agricultural drains during a field trial of liquid dairy manure effluent application rate and varying tillage practices, Upper Tiffin Watershed, southeastern Michigan

    USGS Publications Warehouse

    Haack, Sheridan Kidd; Duris, Joseph W.

    2008-01-01

    A field trial was done in the Upper Tiffin River Watershed, in southeastern Michigan, to determine the influence of liquid dairy manure effluent (LDME) management practices on the quality of agricultural subsurface-drain water. Samples from subsurface drains were analyzed for nutrients, fecal-coliform and Escherichia coli (E. coli) bacteria, antibiotics, chemicals typically detected in wastewater, and the occurrence of genes indicating the presence of shiga-toxin-producing E. coli, or of bovine-specific Bacteroidetes bacteria. Samples were collected from November 2, 2006, to March 20, 2007, from eight subsurface drains under field plots that received no LDME and no tillage (controls) or received 4,000 or 8,000 gallons per acre (gal/acre) of LDME and either no tillage or two different types of tillage. The two types of tillage tested were (1) ground-driven, rotary, subsurface cultivation and (2) rolling-tine aeration. Samples were collected before LDME application and at 4 hours, and 1, 2, 6, 7, and 14 days post-application. Nutrient concentrations were high in subsurface-drain water throughout the field-trial period and could not be attributed to the field-trial LDME application. Of the 59 drain-water samples, including those collected before LDME application and control samples for each date, 56 had concentrations greater than the U.S. Environmental Protection Agency (USEPA), Ecoregion VI recommended surface-water criterion for total phosphorus, and all samples had concentrations greater than the recommended total nitrogen criterion. Nitrate + nitrite nitrogen concentration exceeded 20 milligrams per liter for every sample and contributed most to the total nitrogen concentrations. Substantial increases in drain-water concentrations of organic and ammonia nitrogen and total phosphorus were found for all treatments, including controls, at 14 days post-application after 0.84 inch of rainfall over 2 days. E. coli concentrations exceeded the USEPA recreational

  10. Chemical and Microbiological Water Quality of Subsurface Agricultural Drains during a Field Trial of Liquid Dairy Manure Effluent Application Rate and Varying Tillage Practices, Upper Tiffin Watershed, Southeastern Michigan

    USGS Publications Warehouse

    Haack, Sheridan Kidd; Duris, Joseph W.

    2008-01-01

    A field trial was done in the Upper Tiffin River Watershed, in southeastern Michigan, to determine the influence of liquid dairy manure effluent (LDME) management practices on the quality of agricultural subsurface-drain water. Samples from subsurface drains were analyzed for nutrients, fecal-coliform and Escherichia coli (E. coli) bacteria, antibiotics, chemicals typically detected in wastewater, and the occurrence of genes indicating the presence of shiga-toxin-producing E. coli, or of bovine-specific Bacteroidetes bacteria. Samples were collected from November 2, 2006, to March 20, 2007, from eight subsurface drains under field plots that received no LDME and no tillage (controls) or received 4,000 or 8,000 gallons per acre (gal/acre) of LDME and either no tillage or two different types of tillage. The two types of tillage tested were (1) ground-driven, rotary, subsurface cultivation and (2) rolling-tine aeration. Samples were collected before LDME application and at 4 hours, and 1, 2, 6, 7, and 14 days post-application. Nutrient concentrations were high in subsurface-drain water throughout the field-trial period and could not be attributed to the field-trial LDME application. Of the 59 drain-water samples, including those collected before LDME application and control samples for each date, 56 had concentrations greater than the U.S. Environmental Protection Agency (USEPA), Ecoregion VI recommended surface-water criterion for total phosphorus, and all samples had concentrations greater than the recommended total nitrogen criterion. Nitrate + nitrite nitrogen concentration exceeded 20 milligrams per liter for every sample and contributed most to the total nitrogen concentrations. Substantial increases in drain-water concentrations of organic and ammonia nitrogen and total phosphorus were found for all treatments, including controls, at 14 days post-application after 0.84 inch of rainfall over 2 days. E. coli concentrations exceeded the USEPA recreational

  11. 50 CFR 27.91 - Field trials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Field trials. 27.91 Section 27.91 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE... conducting or operation of field trials for dogs on national wildlife refuges is prohibited except as may...

  12. 7 CFR 3434.5 - Agriculture-related fields.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Agriculture-related fields. 3434.5 Section 3434.5 Agriculture Regulations of the Department of Agriculture (Continued) NATIONAL INSTITUTE OF FOOD AND AGRICULTURE HISPANIC-SERVING AGRICULTURAL COLLEGES AND UNIVERSITIES CERTIFICATION PROCESS § 3434.5...

  13. 7 CFR 3434.5 - Agriculture-related fields.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Agriculture-related fields. 3434.5 Section 3434.5 Agriculture Regulations of the Department of Agriculture (Continued) NATIONAL INSTITUTE OF FOOD AND AGRICULTURE HISPANIC-SERVING AGRICULTURAL COLLEGES AND UNIVERSITIES CERTIFICATION PROCESS § 3434.5...

  14. 7 CFR 1755.3 - Field trials.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... service degradation or hazards to life or property. (g) Field trials shall be conducted in accordance with...) Trunk carriers; (iii) Subscriber carrier; (iv) Point-to-point radio (Microwave); (v) Coaxial...

  15. 7 CFR 1755.3 - Field trials.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... service degradation or hazards to life or property. (g) Field trials shall be conducted in accordance with...) Trunk carriers; (iii) Subscriber carrier; (iv) Point-to-point radio (Microwave); (v) Coaxial...

  16. 7 CFR 1755.3 - Field trials.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... service degradation or hazards to life or property. (g) Field trials shall be conducted in accordance with...) Trunk carriers; (iii) Subscriber carrier; (iv) Point-to-point radio (Microwave); (v) Coaxial...

  17. Practical Issues when Planning for Field Trials

    NASA Astrophysics Data System (ADS)

    Andersson, Susanne; Andersson, Anna-Lena

    This chapter is written from a test site leader perspective and describes the role of planning and timing of field trials when testing technical solutions, which could enable people with dementia to live a more independent life. The chapter is based on experiences from setting up the first and second field trials in the three test sites of the COGKNOW project. The intention is to point out some key issues that are important in preparation and planning of a field trial. The chapter addresses issues in the preparatory, the actual and the post-test phase of the field trial in order to help achieve a high level of success both from a general perspective and with a special focus on people with dementia.

  18. Canadian MSAT field trial program user requirements

    NASA Technical Reports Server (NTRS)

    Pedersen, Allister

    1990-01-01

    A wide range of mobile satellite service offerings will be available in late 1993 with the launch of Canada's first satellite devoted almost exclusively to mobile and transportable services. During the last seven years, the Dept. of Communications has been meeting with potential MSAT users in government and the private sector as part of a $20M Communications Trials Program. User trials will be conducted using leased capacity as well as capacity on Canada's MSAT satellite. User requirements are discussed which were identified under the Communications Trials Program. Land, marine, aeronautical, and fixed applications are described from the perspective of the end users. Emphasis is placed on field trials being accomplished using leased capacity such as the marine data trial being implemented by Ultimateast Data Communications, trials using transportable briefcase terminals and additional field trials being considered for implementation with the TMI Mobile Data Service. The pre-MSAT trials that will be conducted using leased capacity are only a limited sample of the overall end user requirements that have been identified to date. Additional end user applications are discussed, along with a summary of user benefits.

  19. 7 CFR 1755.3 - Field trials.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.3 Field..., the borrower possesses: (1) Adequate financial resources so that no delay in the project will result... Telecommunications Equipment Field Trial (available from the Director, Administrative Services Division,...

  20. 7 CFR 1755.3 - Field trials.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., the borrower possesses: (1) Adequate financial resources so that no delay in the project will result from lack of funds. (2) The financial stability to overcome difficulties which may result from an... meets its financial obligations with respect to the field trial. (3) Qualified personnel to enable it...

  1. Field trials results of guided wave tomography

    SciTech Connect

    Volker, Arno Zon, Tim van; Leden, Edwin van der

    2015-03-31

    Corrosion is one of the industries major issues regarding the integrity of assets. Guided wave travel time tomography is a method capable of providing an absolute wall thickness map. This method is currently making the transition from the laboratory to the field. For this purpose a dedicated data acquisition system and special purpose EMAT sensor rings have been developed. The system can be deployed for permanent monitoring and inspections. Field trials have been conducted on various pipes with different diameters, containing either liquid or gas. The main focus has been on pipe supports. The results demonstrate the successful operation of the technology in the field. Expected corrosion damage was clearly visible on the produced results enabling asset owner to make calculated decisions on the pipelines safety, maintenance and operations.

  2. Field trials results of guided wave tomography

    NASA Astrophysics Data System (ADS)

    Volker, Arno; van Zon, Tim; van der Leden, Edwin

    2015-03-01

    Corrosion is one of the industries major issues regarding the integrity of assets. Guided wave travel time tomography is a method capable of providing an absolute wall thickness map. This method is currently making the transition from the laboratory to the field. For this purpose a dedicated data acquisition system and special purpose EMAT sensor rings have been developed. The system can be deployed for permanent monitoring and inspections. Field trials have been conducted on various pipes with different diameters, containing either liquid or gas. The main focus has been on pipe supports. The results demonstrate the successful operation of the technology in the field. Expected corrosion damage was clearly visible on the produced results enabling asset owner to make calculated decisions on the pipelines safety, maintenance and operations.

  3. Zoning of agricultural field using a fuzzy indicators model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zoning of agricultural fields is an important task for utilization of precision farming technology. One method for deciding how to subdivide a field into a few relatively homogenous zones is using applications of fuzzy sets theory. Data collected from a precision agriculture study in central Texas...

  4. Student Participation in Rover Field Trials

    NASA Astrophysics Data System (ADS)

    Bowman, C. D.; Arvidson, R. E.; Nelson, S. V.; Sherman, D. M.; Squyres, S. W.

    2001-12-01

    The LAPIS program was developed in 1999 as part of the Athena Science Payload education and public outreach, funded by the JPL Mars Program Office. For the past three years, the Athena Science Team has been preparing for 2003 Mars Exploration Rover Mission operations using the JPL prototype Field Integrated Design and Operations (FIDO) rover in extended rover field trials. Students and teachers participating in LAPIS work with them each year to develop a complementary mission plan and implement an actual portion of the annual tests using FIDO and its instruments. LAPIS is designed to mirror an end-to-end mission: Small, geographically distributed groups of students form an integrated mission team, working together with Athena Science Team members and FIDO engineers to plan, implement, and archive a two-day test mission, controlling FIDO remotely over the Internet using the Web Interface for Telescience (WITS) and communicating with each other by email, the web, and teleconferences. The overarching goal of LAPIS is to get students excited about science and related fields. The program provides students with the opportunity to apply knowledge learned in school, such as geometry and geology, to a "real world" situation and to explore careers in science and engineering through continuous one-on-one interactions with teachers, Athena Science Team mentors, and FIDO engineers. A secondary goal is to help students develop improved communication skills and appreciation of teamwork, enhanced problem-solving skills, and increased self-confidence. The LAPIS program will provide a model for outreach associated with future FIDO field trials and the 2003 Mars mission operations. The base of participation will be broadened beyond the original four sites by taking advantage of the wide geographic distribution of Athena team member locations. This will provide greater numbers of students with the opportunity to actively engage in rover testing and to explore the possibilities of

  5. Foliar fungicides on alfalfa: 2012 University extension field trial results from Minnesota and Wisconsin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To answer the increasing number of questions received regarding the use of foliar fungicide on alfalfa, a group of Extension and USDA Agricultural Research Station staff in southeastern Minnesota and Wisconsin worked together to conduct field research trials to examine the benefit of using a foliar ...

  6. Field potential soil variability index to identify precision agriculture opportunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precision agriculture (PA) technologies used for identifying and managing within-field variability are not widely used despite decades of advancement. Technological innovations in agronomic tools, such as canopy reflectance or electrical conductivity sensors, have created opportunities to achieve a ...

  7. Fungal biology and agriculture: revisiting the field

    USGS Publications Warehouse

    Yarden, O.; Ebbole, D.J.; Freeman, S.; Rodriguez, R.J.; Dickman, M. B.

    2003-01-01

    Plant pathology has made significant progress over the years, a process that involved overcoming a variety of conceptual and technological hurdles. Descriptive mycology and the advent of chemical plant-disease management have been followed by biochemical and physiological studies of fungi and their hosts. The later establishment of biochemical genetics along with the introduction of DNA-mediated transformation have set the stage for dissection of gene function and advances in our understanding of fungal cell biology and plant-fungus interactions. Currently, with the advent of high-throughput technologies, we have the capacity to acquire vast data sets that have direct relevance to the numerous subdisciplines within fungal biology and pathology. These data provide unique opportunities for basic research and for engineering solutions to important agricultural problems. However, we also are faced with the challenge of data organization and mining to analyze the relationships between fungal and plant genomes and to elucidate the physiological function of pertinent DNA sequences. We present our perspective of fungal biology and agriculture, including administrative and political challenges to plant protection research.

  8. Fungal biology and agriculture: revisiting the field.

    PubMed

    Yarden, O; Ebbole, D J; Freeman, S; Rodriguez, R J; Dickman, M B

    2003-10-01

    Plant pathology has made significant progress over the years, a process that involved overcoming a variety of conceptual and technological hurdles. Descriptive mycology and the advent of chemical plant-disease management have been followed by biochemical and physiological studies of fungi and their hosts. The later establishment of biochemical genetics along with the introduction of DNA-mediated transformation have set the stage for dissection of gene function and advances in our understanding of fungal cell biology and plant-fungus interactions. Currently, with the advent of high-throughput technologies, we have the capacity to acquire vast data sets that have direct relevance to the numerous subdisciplines within fungal biology and pathology. These data provide unique opportunities for basic research and for engineering solutions to important agricultural problems. However, we also are faced with the challenge of data organization and mining to analyze the relationships between fungal and plant genomes and to elucidate the physiological function of pertinent DNA sequences. We present our perspective of fungal biology and agriculture, including administrative and political challenges to plant protection research.

  9. Experimental Evaluation of Field Trips on Instruction in Vocational Agriculture.

    ERIC Educational Resources Information Center

    McCaslin, Norval L.

    To determine the effect of field trips on student achievement in each of four subject matter areas in vocational agriculture, 12 schools offering approved programs were randomly selected and divided into a treatment group and a control group. Uniform teaching outlines and reference materials were provided to each group. While no field trips were…

  10. A contemporary decennial global sample of changing agricultural field sizes

    NASA Astrophysics Data System (ADS)

    White, E.; Roy, D. P.

    2011-12-01

    In the last several hundred years agriculture has caused significant human induced Land Cover Land Use Change (LCLUC) with dramatic cropland expansion and a marked increase in agricultural productivity. The size of agricultural fields is a fundamental description of rural landscapes and provides an insight into the drivers of rural LCLUC. Increasing field sizes cause a subsequent decrease in the number of fields and therefore decreased landscape spatial complexity with impacts on biodiversity, habitat, soil erosion, plant-pollinator interactions, diffusion of disease pathogens and pests, and loss or degradation in buffers to nutrient, herbicide and pesticide flows. In this study, globally distributed locations with significant contemporary field size change were selected guided by a global map of agricultural yield and literature review and were selected to be representative of different driving forces of field size change (associated with technological innovation, socio-economic conditions, government policy, historic patterns of land cover land use, and environmental setting). Seasonal Landsat data acquired on a decadal basis (for 1980, 1990, 2000 and 2010) were used to extract field boundaries and the temporal changes in field size quantified and their causes discussed.

  11. Time course of soil carbon storage, 15N and radiocarbon signature in top- and subsoil of a 60-years agricultural field trial - indications for compensating effects of carbon input and turnover

    NASA Astrophysics Data System (ADS)

    Leifeld, Jens; Conen, Franz; Oberholzer, Hans Rudolf; Jochen, Mayer

    2014-05-01

    Soil carbon dynamics are controlled by the delicate balance between carbon inputs and outputs which both are co-regulated by land use and management (LUM) as important anthropogenic drivers. Upon land use change to cropland carbon stocks generally tend to decline but often the contribution of two opposing factors, namely changes in input and decomposition rates, to soil carbon stock changes is indistinguishable. Here we report on an ongoing cropland experiment in Zurich, Switzerland, named ZOFE (Zurich Organic Fertilization Experiment), established on former grassland in 1949. ZOFE encompasses a range of mineral and organic fertilization practices and a zero fertilizer treatment as control. The experiment has a block design with five replicates per treatment. We make use of productivity and fertilization gradients in selected treatments of the ZOFE trial to evaluate how low or high inputs (induced by differential yields and organic fertilization) may affect soil organic carbon storage and transformation. For the most recent sampling that also included subsoil down to 0.9 m, all properties were measured for every single replicate. Topsoil carbon storage declined after grassland conversion at rates of c. 0.2 t C ha-1 a-1, particularly in treatments with mineral fertilizer and high yields, and without fertilization and low yields. Organic matter amendments such as manure or compost could partially offset but not fully compensate some of the topsoil carbon loss. Over time the soil's delta 15N signature declined as well, probably due to increased atmospheric nitrogen deposition. It increased from the top- to the subsoil, indicating increasing microbial transformation, particularly with manure added. The soil's radiocarbon signature revealed distinct bomb peak patterns in all treatments but only in the topsoil. The 14C data confirmed that with higher productivity more recent organic matter was incorporated, both in top and subsoil. Because, in contrast to topsoil

  12. Illinois Occupational Skill Standards: Agricultural Laboratory and Field Technician Cluster.

    ERIC Educational Resources Information Center

    Illinois Occupational Skill Standards and Credentialing Council, Carbondale.

    These Illinois skill standards for the agricultural laboratory and field technician cluster are intended to serve as a guide to workforce preparation program providers as they define content for their programs and to employers as they establish the skills and standards necessary for job acquisition. They could also serve as a mechanism for…

  13. Lidar Based Particulate Flux Measurements of Agricultural Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A three-wavelength portable scanning lidar system was developed to derive information on particulate spatial aerosol distribution over remote distances. The lidar system and retrieval approach has been tested during several field campaigns measuring agricultural emissions from a swine feeding operat...

  14. Lost Hills Field Trial - incorporating new technology for resevoir management

    NASA Technical Reports Server (NTRS)

    Fielding, E. J.; Brink, J. L.; Patzek, T. W.; Silin, D. B.

    2002-01-01

    This paper will discuss how Chevron U.S.A. Production Company is implementing a field trial that will use Supervisory Control and Data Acquisition (SCADA)on injection wells, in conjunction with satellite images to measure ground elevation changes, to perform real-time resevoir management in the Lost Hills Field.

  15. Girdling defoliation of cotton; 2014 field trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton mechanical harvest requires field pre-treatment to remove leaves and moisture. Typical harvest preparation involves ground or aerial application of a combination of active ingredients. Some of these chemicals may come under regulatory pressure in future. Alternatives have been explored, su...

  16. Multi-optical mine detection: results from a field trial

    NASA Astrophysics Data System (ADS)

    Letalick, Dietmar; Tolt, Gustav; Sjökvist, Stefan K.; Nyberg, Sten; Grönwall, Christina; Andersson, Pierre; Linderhed, Anna; Forssell, Göran; Larsson, Håkan; Uppsäll, Magnus

    2006-05-01

    As a part of the Swedish mine detection project MOMS, an initial field trial was conducted at the Swedish EOD and Demining Centre (SWEDEC). The purpose was to collect data on surface-laid mines, UXO, submunitions, IED's, and background with a variety of optical sensors, for further use in the project. Three terrain types were covered: forest, gravel road, and an area which had recovered after total removal of all vegetation some years before. The sensors used in the field trial included UV, VIS, and NIR sensors as well as thermal, multi-spectral, and hyper-spectral sensors, 3-D laser radar and polarization sensors. Some of the sensors were mounted on an aerial work platform, while others were placed on tripods on the ground. This paper describes the field trial and the presents some initial results obtained from the subsequent analysis.

  17. Empirical trials of plant field guides.

    PubMed

    Hawthorne, W D; Cable, S; Marshall, C A M

    2014-06-01

    We designed 3 image-based field guides to tropical forest plant species in Ghana, Grenada, and Cameroon and tested them with 1095 local residents and 20 botanists in the United Kingdom. We compared users' identification accuracy with different image formats, including drawings, specimen photos, living plant photos, and paintings. We compared users' accuracy with the guides to their accuracy with only their prior knowledge of the flora. We asked respondents to score each format for usability, beauty, and how much they would pay for it. Prior knowledge of plant names was generally low (<22%). With a few exceptions, identification accuracy did not differ significantly among image formats. In Cameroon, users identifying sterile Cola species achieved 46-56% accuracy across formats; identification was most accurate with living plant photos. Botanists in the United Kingdom accurately identified 82-93% of the same Cameroonian species; identification was most accurate with specimens. In Grenada, users accurately identified 74-82% of plants; drawings yielded significantly less accurate identifications than paintings and photos of living plants. In Ghana, users accurately identified 85% of plants. Digital color photos of living plants ranked high for beauty, usability, and what users would pay. Black and white drawings ranked low. Our results show the potential and limitations of the use of field guides and nonspecialists to identify plants, for example, in conservation applications. We recommend authors of plant field guides use the cheapest or easiest illustration format because image type had limited bearing on accuracy; match the type of illustration to the most likely use of the guide for slight improvements in accuracy; avoid black and white formats unless the audience is experienced at interpreting illustrations or keeping costs low is imperative; discourage false-positive identifications, which were common; and encourage users to ask an expert or use a herbarium for

  18. Empirical trials of plant field guides.

    PubMed

    Hawthorne, W D; Cable, S; Marshall, C A M

    2014-06-01

    We designed 3 image-based field guides to tropical forest plant species in Ghana, Grenada, and Cameroon and tested them with 1095 local residents and 20 botanists in the United Kingdom. We compared users' identification accuracy with different image formats, including drawings, specimen photos, living plant photos, and paintings. We compared users' accuracy with the guides to their accuracy with only their prior knowledge of the flora. We asked respondents to score each format for usability, beauty, and how much they would pay for it. Prior knowledge of plant names was generally low (<22%). With a few exceptions, identification accuracy did not differ significantly among image formats. In Cameroon, users identifying sterile Cola species achieved 46-56% accuracy across formats; identification was most accurate with living plant photos. Botanists in the United Kingdom accurately identified 82-93% of the same Cameroonian species; identification was most accurate with specimens. In Grenada, users accurately identified 74-82% of plants; drawings yielded significantly less accurate identifications than paintings and photos of living plants. In Ghana, users accurately identified 85% of plants. Digital color photos of living plants ranked high for beauty, usability, and what users would pay. Black and white drawings ranked low. Our results show the potential and limitations of the use of field guides and nonspecialists to identify plants, for example, in conservation applications. We recommend authors of plant field guides use the cheapest or easiest illustration format because image type had limited bearing on accuracy; match the type of illustration to the most likely use of the guide for slight improvements in accuracy; avoid black and white formats unless the audience is experienced at interpreting illustrations or keeping costs low is imperative; discourage false-positive identifications, which were common; and encourage users to ask an expert or use a herbarium for

  19. Dengue surveillance in preparation for field vaccine trials.

    PubMed

    Letson, G William

    2009-10-01

    Preparations for dengue vaccine trials as well as vaccine introduction strategies require laboratory-based surveillance on an international and coordinated level. The Pediatric Dengue Vaccine Initiative (PDVI) has developed an international consortium of field sites in Latin America and Asia. These sites conduct community- based and enhanced passive laboratory-based surveillance of dengue fever. Through this consortium, PDVI is facilitating harmonized laboratory-based surveillance processes, so that disease incidence can be compared between different regions and countries. This process prepares sites for the rigorous case detection, diagnosis, recording and analysis to meet good clinical practice standards necessary for clinical dengue vaccine trials. In addition to several years of laboratory-based dengue surveillance data, dengue vaccine trial site criteria include low population migration of an endemic disease area, documentation of other local flavivirus epidemiology, good medical infrastructure, political stability, and country and target population commitment to vaccine trials and need for vaccine. Prevention of dengue fever is the most suitable primary end point for a proof-of-concept dengue vaccine trial. However, such trials may provide insufficient information for stratified analysis of outcomes according to varied risk factors and virus serotype. Consequently large community-based demonstration trials may be necessary.

  20. First generation leishmaniasis vaccines: a review of field efficacy trials.

    PubMed

    Noazin, Sassan; Modabber, Farrokh; Khamesipour, Ali; Smith, Peter G; Moulton, Lawrence H; Nasseri, Kiumarss; Sharifi, Iraj; Khalil, Eltahir A G; Bernal, Ivan Dario Velez; Antunes, Carlos M F; Kieny, Marie Paule; Tanner, Marcel

    2008-12-01

    First generation candidate vaccines against leishmaniasis, prepared using inactivated whole parasites as their main ingredient, were considered as promising because of their relative ease of production and low cost. These vaccines have been the subject of many investigations over several decades and are the only leishmaniasis vaccine candidates which have undergone phase 3 clinical trial evaluation. Although the studies demonstrated the safety of the vaccines and several studies showed reasonable immunogenicity and some indication of protection, an efficacious prophylactic vaccine is yet to be identified. Despite this overall failure, these trials contributed significantly to increasing knowledge on human leishmaniasis immunology. To provide a collective view, this review discusses the methods and findings of field efficacy trials of first generation leishmaniasis vaccine clinical trials conducted in the Old and New Worlds.

  1. Parkinson's Disease Prevalence and Proximity to Agricultural Cultivated Fields.

    PubMed

    Yitshak Sade, Maayan; Zlotnik, Yair; Kloog, Itai; Novack, Victor; Peretz, Chava; Ifergane, Gal

    2015-01-01

    The risk for developing Parkinson's disease (PD) is a combination of multiple environmental and genetic factors. The Negev (Southern Israel) contains approximately 252.5 km(2) of agricultural cultivated fields (ACF). We aimed to estimate the prevalence and incidence of PD and to examine possible geographical clustering and associations with agricultural exposures. We screened all "Clalit" Health Services members in the Negev (70% of the population) between the years 2000 and 2012. Individual demographic, clinical, and medication prescription data were available. We used a refined medication tracer algorithm to identify PD patients. We used mixed Poisson models to calculate the smoothed standardized incidence rates (SIRs) for each locality. We identified ACF and calculate the size and distance of the fields from each locality. We identified 3,792 cases of PD. SIRs were higher than expected in Jewish rural localities (median SIR [95% CI]: 1.41 [1.28; 1.53] in 2001-2004, 1.62 [1.48; 1.76] in 2005-2008, and 1.57 [1.44; 1.80] in 2009-2012). Highest SIR was observed in localities located in proximity to large ACF (SIR 1.54, 95% CI 1.32; 1.79). In conclusion, in this population based study we found that PD SIRs were higher than expected in rural localities. Furthermore, it appears that proximity to ACF and the field size contribute to PD risk.

  2. Methane uptake in agricultural and old-field ecosystems

    SciTech Connect

    Reed, W.L.; Halstead, S.J.; Robertson, G.P. Michigan State Univ., East Lansing )

    1993-06-01

    Atmospheric methane (CH[sub 4]) concentrations are rising approximately 1% per year, with important consequences for the earth's radiation balance and tropospheric chemistry. Sources of this increase are not well known; recent evidence suggests that land conversion to agriculture may play some role in this increase if CH[sub 4] consumption in upland soils is suppressed by agronomic activities. We tested this hypothesis in a series of replicated agricultural and old-field communities at the KBS LTER site in southwest Michigan. We measured CH[sub 4] flux with static chambers in 6 different cropping systems (conventional till and no-till annual crops, ridge-till organic based crops, perennial crops) and in early successional and mid-succession (never tilled) old field communities. Chambers were sampled 17 times over the 1992 growing season and analyzed for CH[sub 4], N[sub 2]O, and CO[sub 2]. We found significant but highly variable CH[sub 4] uptake on some dates in all 8 ecosystem types, with most consistent consumption in the organic based crops and old-field communities.

  3. Biochar: from laboratory mechanisms through the greenhouse to field trials

    NASA Astrophysics Data System (ADS)

    Masiello, C. A.; Gao, X.; Dugan, B.; Silberg, J. J.; Zygourakis, K.; Alvarez, P. J. J.

    2014-12-01

    The biochar community is excellent at pointing to individual cases where biochar amendment has changed soil properties, with some studies showing significant improvements in crop yields, reduction in nutrient export, and remediation of pollutants. However, many studies exist which do not show improvements, and in some cases, studies clearly show detrimental outcomes. The next, crucial step in biochar science and engineering research will be to develop a process-based understanding of how biochar acts to improve soil properties. In particular, we need a better mechanistic understanding of how biochar sorbs and desorbs contaminants, how it interacts with soil water, and how it interacts with the soil microbial community. These mechanistic studies need to encompass processes that range from the nanometer to the kilometer scale. At the nanometer scale, we need a predictive model of how biochar will sorb and desorb hydrocarbons, nutrients, and toxic metals. At the micrometer scale we need models that explain biochar's effects on soil water, especially the plant-available fraction of soil water. The micrometer scale is also where mechanistic information is neeed about microbial processes. At the macroscale we need physical models to describe the landscape mobility of biochar, because biochar that washes away from fields can no longer provide crop benefits. To be most informative, biochar research should occur along a lab-greenhouse-field trial trajectory. Laboratory experiments should aim determine what mechanisms may act to control biochar-soil processes, and then greenhouse experiments can be used to test the significance of lab-derived mechanisms in short, highly replicated, controlled experiments. Once evidence of effect is determined from greenhouse experiments, field trials are merited. Field trials are the gold standard needed prior to full deployment, but results from field trials cannot be extrapolated to other field sites without the mechanistic backup provided

  4. A Multisite Cluster Randomized Field Trial of Open Court Reading

    ERIC Educational Resources Information Center

    Borman, Geoffrey D.; Dowling, N. Maritza; Schneck, Carrie

    2008-01-01

    In this article, the authors report achievement outcomes of a multisite cluster randomized field trial of Open Court Reading 2005 (OCR), a K-6 literacy curriculum published by SRA/McGraw-Hill. The participants are 49 first-grade through fifth-grade classrooms from predominantly minority and poor contexts across the nation. Blocking by grade level…

  5. Large-scale field trials of active immunizing agents

    PubMed Central

    Cockburn, W. Charles

    1955-01-01

    In this discussion of the methods to be used in large-scale field trials of active immunizing agents and of the results to be expected from such trials, special emphasis is laid on pertussis vaccine trials in Great Britain. After a review of the criteria for strictly controlled field studies and of the investigation of typhoid vaccines conducted in 1904-08 by the Antityphoid Committee of the British Army, the author describes the pertussis vaccine studies which have been and are now being carried by the Whooping-Cough Immunization Committee of the Medical Research Council of Great Britain. The original strictly controlled trials have been completed and the results published. Studies are now being made of vaccines prepared by different methods and evaluated both in the field and in the laboratory. Each vaccine is given to some 2000-3000 children of 4-6 months to 4 years of age. By the end of the studies 30 000-40 000 children will have been followed up for a period of two years. Since in the current studies all the children are vaccinated and none are left as unvaccinated controls, the relative and not the absolute protective value of the vaccines will be measured. PMID:13270079

  6. 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…

  7. Classification and soil moisture determination of agricultural fields

    NASA Technical Reports Server (NTRS)

    Vandenbroek, A. C.; Groot, J. S.

    1993-01-01

    During the Mac-Europe campaign of 1991 several SAR (Synthetic Aperature Radar) experiments were carried out in the Flevoland test area in the Netherlands. The test site consists of a forested and an agricultural area with more than 15 different crop types. The experiments took place in June and July (mid to late growing season). The area was monitored by the spaceborne C-band VV polarized ERS-1, the Dutch airborne PHARS with similar frequency and polarization and the three-frequency PP-, L-, and C-band) polarimetric AIRSAR system of NASA/JPL. The last system passed over on June 15, 3, 12, and 28. The last two dates coincided with the overpasses of the PHARS and the ERS-1. Comparison of the results showed that backscattering coefficients from the three systems agree quite well. In this paper we present the results of a study of crop type classification (section 2) and soil moisture determination in the agricultural area (section 3). For these studies we used field averaged Stokes matrices extracted from the AIRSAR data (processor version 3.55 or 3.56).

  8. About soil cover heterogeneity of agricultural research stations' experimental fields

    NASA Astrophysics Data System (ADS)

    Rannik, Kaire; Kõlli, Raimo; Kukk, Liia

    2013-04-01

    Depending on local pedo-ecological conditions (topography, (geo) diversity of soil parent material, meteorological conditions) the patterns of soil cover and plant cover determined by soils are very diverse. Formed in the course of soil-plant mutual relationship, the natural ecosystems are always influenced to certain extent by the other local soil forming conditions or they are site specific. The agricultural land use or the formation of agro-ecosystems depends foremost on the suitability of soils for the cultivation of feed and food crops. As a rule, the most fertile or the best soils of the area, which do not present any or present as little as possible constraints for agricultural land use, are selected for this purpose. Compared with conventional field soils, the requirements for the experimental fields' soil cover quality are much higher. Experimental area soils and soil cover composition should correspond to local pedo-ecological conditions and, in addition to that, represent the soil types dominating in the region, whereas the fields should be as homogeneous as possible. The soil cover heterogeneity of seven arable land blocks of three research stations (Jõgeva, Kuusiku and Olustvere) was studied 1) by examining the large scale (1:10 000) digital soil map (available via the internet), and 2) by field researches using the transect method. The stages of soils litho-genetic and moisture heterogeneities were estimated by using the Estonian normal soils matrix, however, the heterogeneity of top- and subsoil texture by using the soil texture matrix. The quality and variability of experimental fields' soils humus status, was studied more thoroughly from the aspect of humus concentration (g kg-1), humus cover thickness (cm) and humus stocks (Mg ha-1). The soil cover of Jõgeva experimental area, which presents an accumulative drumlin landscape (formed during the last glacial period), consist from loamy Luvisols and associated to this Cambisols. In Kuusiku area

  9. Seed deterioration in flooded agricultural fields during winter

    USGS Publications Warehouse

    Nelms, C.O.; Twedt, D.J.

    1996-01-01

    We determined rate of seed deterioration for 3 crops (corn, rice, and soybean) and 8 weeds commonly found in agricultural fields and moist-soil management units in the Mississippi Alluvial Valley (MAV). The weeds were broadleaf signalgrass (Brachiaria platyphylla), junglerice barnyardgrass (Echinochloa colonum), morningglory (Ipomoea sp.), panic grass (Panicum sp.), bull paspalum (Paspalum boscianum), red rice (Oryza sativa), hemp sesbania (Sesbania exaltata), and bristlegrass (Setaria sp.). Weed seeds, except morningglory, deteriorated slower than corn and soybean, whereas rice decomposed slower than all weed seeds except red rice and bull paspalum. For land managers desiring to provide plant food for wintering waterfowl, rice is clearly the most persistent small grain crop in the MAV. Persistence of weed seeds under flooded conditions throughout winter makes them a cost-effective alternative to traditional crops on land managed for waterfowl.

  10. Telemedicine and Cooperative Remote Healthcare Services: COPD Field Trial.

    PubMed

    Gerdes, Martin; Smaradottir, Berglind; Reichert, Frank; Fensli, Rune

    2015-01-01

    The introduction of sustainable telemedicine solutions throughout Europe requires the development of secure, flexible and expandable systems and the evaluation of their operation in real-world settings such as field trials. This paper describes a system for a remote monitoring and care support field trial with Chronic Obstructive Pulmonary Disease (COPD) patients. By following a user-centred-development and Privacy by Design approach, the needs of all involved user groups could be addressed, while fulfilling, at the same time, national requirements with emphasis in security and privacy protection. The solution covers specific applications and services for COPD patients and their remote care takers, but allows the generalization of its applicability to other patient groups.

  11. Design and Management of Field Trials of Transgenic Cereals

    NASA Astrophysics Data System (ADS)

    Bedő, Zoltán; Rakszegi, Mariann; Láng, László

    The development of gene transformation systems has allowed the introgression of alien genes into plant genomes, thus providing a mechanism for broadening the genetic resources available to plant breeders. The design and the management of field trials vary according to the purpose for which transgenic cereals are developed. Breeders study the phenotypic and genotypic stability of transgenic plants, monitor the increase in homozygosity of transgenic genotypes under field conditions, and develop backcross generations to transfer the introduced genes into secondary transgenic cereal genotypes. For practical purposes, they may also multiply seed of the transgenic lines to produce sufficient amounts of grain for the detailed analysis of trait(s) of interest, to determine the field performance of transgenic lines, and to compare them with the non-transformed parental genotypes. Prior to variety registration, the Distinctness, Uniformity and Stability (DUS) tests and Value for Cultivation and Use (VCU) experiments are carried out in field trials. Field testing includes specific requirements for transgenic cereals to assess potential environmental risks. The capacity of the pollen to survive, establish and disseminate in the field test environment, the potential for gene transfer, the effects of products expressed by the introduced sequences and phenotypic and genotypic instability that might cause deleterious effects must all be specifically monitored, as required by EU Directives 2003/701/EC (1) on the release of genetically modified higher plants in the environment.

  12. Optimization of agricultural field workability predictions for improved risk management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Risks introduced by weather variability are key considerations in agricultural production. The sensitivity of agriculture to weather variability is of special concern in the face of climate change. In particular, the availability of workable days is an important consideration in agricultural practic...

  13. Trial-by-Trial Adaptation of Movements during Mental Practice under Force Field

    PubMed Central

    Anwar, Muhammad Nabeel

    2013-01-01

    Human nervous system tries to minimize the effect of any external perturbing force by bringing modifications in the internal model. These modifications affect the subsequent motor commands generated by the nervous system. Adaptive compensation along with the appropriate modifications of internal model helps in reducing human movement errors. In the current study, we studied how motor imagery influences trial-to-trial learning in a robot-based adaptation task. Two groups of subjects performed reaching movements with or without motor imagery in a velocity-dependent force field. The results show that reaching movements performed with motor imagery have relatively a more focused generalization pattern and a higher learning rate in training direction. PMID:23737857

  14. Agricultural Education Early Field Experience through the Lens of the EFE Model

    ERIC Educational Resources Information Center

    Smalley, Scott W.; Retallick, Michael S.

    2012-01-01

    The purpose of this national study was to describe agricultural teacher education early field experience (EFE) practices using the EFE model. The population for this study was all agricultural education teacher preparation programs (N = 83) listed in the AAAE Directory of University Faculty in Agricultural Education. Data were collected via an…

  15. Engineering and agronomy aspects of a long-term precision agriculture field experiment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much research has been conducted on specific precision agriculture tools and implementation strategies, but little has been reported on long-term evaluation of integrated precision agriculture field experiments. In 2004 our research team developed and initiated a multi-faceted “precision agriculture...

  16. Preliminary field trials of acrolein in the Sudan*

    PubMed Central

    Ferguson, Frederick F.; Dawood, Ismail K.; Blondeau, René

    1965-01-01

    Field trials of acrolein for the simultaneous control of aquatic weeds and snails were conducted in the Sudan. Phytotoxicity studies at 25 and 50 ppm showed minor or no damage to furrow-irrigated crops, but flood irrigation of vegetable seedlings at 15 ppm was toxic. Effective downstream carriage of acrolein was demonstrated for a distance of 1.6 km at a concentration of 25 ppm. Planorbid snails (Bulinus and Biomphalaria) were almost completely eliminated (98-99% kills). All submersed aquatic weeds were destroyed. PMID:14310912

  17. Conducting field trials for frost tolerance breeding in cereals.

    PubMed

    Cattivelli, Luigi

    2014-01-01

    Cereal species can be damaged by frost either during winter or at flowering stage. Frost tolerance per se is only a part of the mechanisms that allow the plants to survive during winter; winterhardiness also considers other biotic or physical stresses that challenge the plants during the winter season limiting their survival rate. While frost tolerance can also be tested in controlled environments, winterhardiness can be determined only with field evaluations. Post-heading frost damage occurs from radiation frost events in spring during the reproductive stages. A reliable evaluation of winterhardiness or of post-heading frost damage should be carried out with field trials replicated across years and locations to overcome the irregular occurrence of natural conditions which satisfactorily differentiate genotypes. The evaluation of post-heading frost damage requires a specific attention to plant phenology. The extent of frost damage is usually determined with a visual score at the end of the winter.

  18. Field trial of a Doppler sonar system for fisheries applications

    NASA Astrophysics Data System (ADS)

    Tollefsen, Cristina D. S.; Zedel, Len

    2003-10-01

    Various deployments of commercial Doppler current profiling systems have demonstrated that these instruments can detect fish and measure their swimming speeds. However, research into the possible application of Doppler sonar to fisheries problems is limited and has not taken advantage of coherent signal processing schemes. A field trial was undertaken in August 2002 to explore the capabilities of a coherent Doppler sonar when applied to detecting discrete targets. The passage of migrating salmon on the Fraser River in British Columbia provided an ideal test opportunity with fish of well-defined swimming behavior and allowed for comparisons with conventional fisheries acoustics techniques. The instrument tested was a 250-kHz sonar which provided for phase coding of transmit pulses and coherent sampling of successive acoustic returns. The field trial resulted in 11 consecutive days of Doppler sonar data acquired during the peak of the sockeye salmon (Oncorhynchus nerka) migration. A total of 7425 individual fish were identified and their swimming speed was measured with an accuracy of between 10 cms-1 and 20 cms-1, which depended on pulse length, pulse spacing, and target range. By comparison, water velocity measurements made with the same instrument can only achieve a theoretical accuracy of 60 cms-1.

  19. Composting in cold climates: Results from two field trials

    SciTech Connect

    McMillen, S.J.; Kerr, J.M.; Davis, P.S.; Bruney, J.M.

    1996-12-31

    Two composting field trials have been successfully completed at Exxon Company USA`s Big Stick Madison Unit (BSMU) in Billings, North Dakota and Imperial Oil`s (Exxon`s Canadian affiliate) Willesden Green producing field in the Province of Alberta, Canada. Composting is a bioremediation method in which bulking agents such as manure, wood chips, and straw are added to oily soil/sludge to improve the soil texture, tilth, air permeability, water holding capacity, and organic matter content. The compost mixture is placed in windrows or static piles where heat is generated by microbial breakdown of hydrocarbons and organic matter. Because composting conserves heat generated by biodegradation, it is well suited for bioremediating wastes in cold climates. In addition, the temperature in the piles increases the rate of the biochemical processes responsible for oil degradation and can significantly reduce the time required to achieve a remediation target. Elevated temperatures were observed in both field trials, and in Canada the compost piles remained warm throughout the winter months thereby expanding the normal bioremediation season. Hydrocarbon loss data indicate that clean-up criteria for both sites was met within a few months. Extensive hydrocarbon characterization confirmed that the total petroleum hydrocarbon losses were due to biodegradation. At the BSMU site 71 cubic yards (54 m{sup 3}) of oily soil were composted in five windrows that were aerated by periodic tilling, and at Willesden Green 1700 cubic yards (1300 m{sup 3}) of oily soil were composted in three static, passively aerated piles.

  20. Passive drainage and biofiltration of landfill gas: Australian field trial

    SciTech Connect

    Dever, S.A. . E-mail: stuart_dever@ghd.com.au; Swarbrick, G.E. . E-mail: g.swarbrick@unsw.edu.au; Stuetz, R.M. . E-mail: r.stuetz@unsw.edu.au

    2007-07-01

    In Australia a significant number of landfill waste disposal sites do not incorporate measures for the collection and treatment of landfill gas. This includes many old/former landfill sites, rural landfill sites, non-putrescible solid waste and inert waste landfill sites, where landfill gas generation is low and it is not commercially viable to extract and beneficially utilize the landfill gas. Previous research has demonstrated that biofiltration has the potential to degrade methane in landfill gas, however, the microbial processes can be affected by many local conditions and factors including moisture content, temperature, nutrient supply, including the availability of oxygen and methane, and the movement of gas (oxygen and methane) to/from the micro-organisms. A field scale trial is being undertaken at a landfill site in Sydney, Australia, to investigate passive drainage and biofiltration of landfill gas as a means of managing landfill gas emissions at low to moderate gas generation landfill sites. The design and construction of the trial is described and the experimental results will provide in-depth knowledge on the application of passive gas drainage and landfill gas biofiltration under Sydney (Australian) conditions, including the performance of recycled materials for the management of landfill gas emissions.

  1. Field trials in Egypt with acrolein herbicide-molluscicide*

    PubMed Central

    Unrau, G. O.; Farooq, M.; Dawood, Ismail K.; Miguel, Luis C.; Dazo, B. C.

    1965-01-01

    Acrolein is a dual-purpose chemical effective against both submersed weeds and snails, and it may therefore be of significance in bilharziasis control. During trials in the Egypt-49-project area in 1962, it was effective in clearing heavy mats of the major submersed aquatic weed Potamogeton crispus from irrigation canals. The resurgence of snails to pretreatment levels was delayed by 8-12 months, and submersed weeds did not reappear until 8 months after treatment. In phytotoxicity tests on local crops, it was found that the concentration of acrolein required for destroying submersed weeds (20-25 ppm) had no adverse effect on the crops. The field tests showed that it is important to have complete control of the water during the period of application. PMID:14310913

  2. Thermal Infrared Imagery for Better Water Conservation in Agricultural Fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water conservation is an issue that involves all citizens in Georgia. Within the agricultural row crop community, water is a very important part of producing a harvestable and profitable product. Although irrigation is used only as a supplement to natural rainfall, it can greatly affect crop yield...

  3. Agricultural "killing fields": the poisoning of Costa Rican banana workers.

    PubMed

    Sass, R

    2000-01-01

    The poisoning of Costa Rican banana workers by multinational corporations' excessive use of pesticides is not a local issue; it is embedded in a dominant ideology expressed by the phenomenon of globalization. This ideology seeps into every aspect of our social institutions--economic, political, and legal. The practice of this ideological perspective is evident in the industrialization of global agriculture and the shift from "developmentalism"--liberal welfarism, industrialization, and urbanization--to a dominant, undemocratic, global financial elite with "economism" and a neoliberal political agenda overriding the nation-state polis. A specific effect is to transform the agricultural workers of developing countries, such as Costa Rican banana workers, into politically superfluous flesh-and-blood human beings.

  4. Assessing and modelling ecohydrologic processes at the agricultural field scale

    NASA Astrophysics Data System (ADS)

    Basso, Bruno

    2015-04-01

    One of the primary goals of agricultural management is to increase the amount of crop produced per unit of fertilizer and water used. World record corn yields demonstrated that water use efficiency can increase fourfold with improved agronomic management and cultivars able to tolerate high densities. Planting crops with higher plant density can lead to significant yield increases, and increase plant transpiration vs. soil water evaporation. Precision agriculture technologies have been adopted for the last twenty years but seldom have the data collected been converted to information that led farmers to different agronomic management. These methods are intuitively appealing, but yield maps and other spatial layers of data need to be properly analyzed and interpreted to truly become valuable. Current agro-mechanic and geospatial technologies allow us to implement a spatially variable plan for agronomic inputs including seeding rate, cultivars, pesticides, herbicides, fertilizers, and water. Crop models are valuable tools to evaluate the impact of management strategies (e.g., cover crops, tile drains, and genetically-improved cultivars) on yield, soil carbon sequestration, leaching and greenhouse gas emissions. They can help farmers identify adaptation strategies to current and future climate conditions. In this paper I illustrate the key role that precision agriculture technologies (yield mapping technologies, within season soil and crop sensing), crop modeling and weather can play in dealing with the impact of climate variability on soil ecohydrologic processes. Case studies are presented to illustrate this concept.

  5. A contemporary decennial global Landsat sample of changing agricultural field sizes

    NASA Astrophysics Data System (ADS)

    White, Emma; Roy, David

    2014-05-01

    Agriculture has caused significant human induced Land Cover Land Use (LCLU) change, with dramatic cropland expansion in the last century and significant increases in productivity over the past few decades. Satellite data have been used for agricultural applications including cropland distribution mapping, crop condition monitoring, crop production assessment and yield prediction. Satellite based agricultural applications are less reliable when the sensor spatial resolution is small relative to the field size. However, to date, studies of agricultural field size distributions and their change have been limited, even though this information is needed to inform the design of agricultural satellite monitoring systems. Moreover, the size of agricultural fields is a fundamental description of rural landscapes and provides an insight into the drivers of rural LCLU change. In many parts of the world field sizes may have increased. Increasing field sizes cause a subsequent decrease in the number of fields and therefore decreased landscape spatial complexity with impacts on biodiversity, habitat, soil erosion, plant-pollinator interactions, and impacts on the diffusion of herbicides, pesticides, disease pathogens, and pests. The Landsat series of satellites provide the longest record of global land observations, with 30m observations available since 1982. Landsat data are used to examine contemporary field size changes in a period (1980 to 2010) when significant global agricultural changes have occurred. A multi-scale sampling approach is used to locate global hotspots of field size change by examination of a recent global agricultural yield map and literature review. Nine hotspots are selected where significant field size change is apparent and where change has been driven by technological advancements (Argentina and U.S.), abrupt societal changes (Albania and Zimbabwe), government land use and agricultural policy changes (China, Malaysia, Brazil), and/or constrained by

  6. A contemporary decennial examination of changing agricultural field sizes using Landsat time series data

    PubMed Central

    White, Emma V.

    2015-01-01

    Field size distributions and their changes have not been studied over large areas as field size change datasets are not available. This study quantifies agricultural field size changes in a consistent manner using Landsat satellite data that also provide geographic context for the observed decadal scale changes. Growing season cloud‐free Landsat 30 m resolution images acquired from 9 to 25 years apart were used to extract field object classifications at seven sites located by examination of a global agricultural yield map, agricultural production statistics, literature review, and analysis of the imagery in the US Landsat archive. High spatial resolution data were used to illustrate issues identifying small fields that are not reliably discernible at 30 m Landsat resolution. The predominant driver of field size change was attributed by literature review. Significant field size changes were driven by different factors, including technological advancements (Argentina and USA), government land use and agricultural policies (Malaysia, Brazil, France), and political changes (Albania and Zimbabwe). While observed local field size changes were complex, the reported results suggest that median field sizes are increasing due to technological advancements and changes to government policy, but may decrease where abrupt political changes affect the agricultural sector and where pastures are converted to arable land uses. In the limited sample considered, median field sizes increased from 45% (France) to 159% (Argentina) and decreased from 47% (Brazil) to 86% (Albania). These changes imply significant impacts on landscape spatial configuration and land use diversity with ecological and biogeochemical consequences. PMID:27669424

  7. A contemporary decennial examination of changing agricultural field sizes using Landsat time series data

    PubMed Central

    White, Emma V.

    2015-01-01

    Field size distributions and their changes have not been studied over large areas as field size change datasets are not available. This study quantifies agricultural field size changes in a consistent manner using Landsat satellite data that also provide geographic context for the observed decadal scale changes. Growing season cloud‐free Landsat 30 m resolution images acquired from 9 to 25 years apart were used to extract field object classifications at seven sites located by examination of a global agricultural yield map, agricultural production statistics, literature review, and analysis of the imagery in the US Landsat archive. High spatial resolution data were used to illustrate issues identifying small fields that are not reliably discernible at 30 m Landsat resolution. The predominant driver of field size change was attributed by literature review. Significant field size changes were driven by different factors, including technological advancements (Argentina and USA), government land use and agricultural policies (Malaysia, Brazil, France), and political changes (Albania and Zimbabwe). While observed local field size changes were complex, the reported results suggest that median field sizes are increasing due to technological advancements and changes to government policy, but may decrease where abrupt political changes affect the agricultural sector and where pastures are converted to arable land uses. In the limited sample considered, median field sizes increased from 45% (France) to 159% (Argentina) and decreased from 47% (Brazil) to 86% (Albania). These changes imply significant impacts on landscape spatial configuration and land use diversity with ecological and biogeochemical consequences.

  8. Field trial of a pulsed limestone diversion well

    USGS Publications Warehouse

    Sibrell, Philip L.; Denholm, C.; Dunn, Margaret

    2013-01-01

    The use of limestone diversion wells to treat acid mine drainage (AMD) is well-known, but in many cases, acid neutralization is not as complete as would be desired. Reasons for this include channeling of the water through the limestone bed, and the slow reaction rate of the limestone gravel. A new approach to improve the performance of the diversion well was tested in the field at the Jennings Environmental Education Center, near Slippery Rock, PA. In this approach, a finer size distribution of limestone was used so as to allow fluidization of the limestone bed, thus eliminating channeling and increasing particle surface area for faster reaction rates. Also, water flow was regulated through the use of a dosing siphon, so that consistent fluidization of the limestone sand could be achieved. Testing began late in the summer of 2010, and continued through November of 2011. Initial system performance during the 2010 field season was good, with the production of net alkaline water, but hydraulic problems involving air release and limestone sand retention were observed. In the summer of 2011, a finer size of limestone sand was procured for use in the system. This material fluidized more readily, but acid neutralization tapered off after several days. Subsequent observations indicated that the hydraulics of the system was compromised by the formation of iron oxides in the pipe leading to the limestone bed, which affected water distribution and flow through the bed. Although results from the field trial were mixed, it is believed that without the formation of iron oxides and plugging of the pipe, better acid neutralization and treatment would have occurred. Further tests are being considered using a different hydraulic configuration for the limestone sand fluidized bed.

  9. Mapping Agricultural Fields in Sub-Saharan Africa with a Computer Vision Approach

    NASA Astrophysics Data System (ADS)

    Debats, S. R.; Luo, D.; Estes, L. D.; Fuchs, T.; Caylor, K. K.

    2014-12-01

    Sub-Saharan Africa is an important focus for food security research, because it is experiencing unprecedented population growth, agricultural activities are largely dominated by smallholder production, and the region is already home to 25% of the world's undernourished. One of the greatest challenges to monitoring and improving food security in this region is obtaining an accurate accounting of the spatial distribution of agriculture. Households are the primary units of agricultural production in smallholder communities and typically rely on small fields of less than 2 hectares. Field sizes are directly related to household crop productivity, management choices, and adoption of new technologies. As population and agriculture expand, it becomes increasingly important to understand both the distribution of field sizes as well as how agricultural communities are spatially embedded in the landscape. In addition, household surveys, a common tool for tracking agricultural productivity in Sub-Saharan Africa, would greatly benefit from spatially explicit accounting of fields. Current gridded land cover data sets do not provide information on individual agricultural fields or the distribution of field sizes. Therefore, we employ cutting edge approaches from the field of computer vision to map fields across Sub-Saharan Africa, including semantic segmentation, discriminative classifiers, and automatic feature selection. Our approach aims to not only improve the binary classification accuracy of cropland, but also to isolate distinct fields, thereby capturing crucial information on size and geometry. Our research focuses on the development of descriptive features across scales to increase the accuracy and geographic range of our computer vision algorithm. Relevant data sets include high-resolution remote sensing imagery and Landsat (30-m) multi-spectral imagery. Training data for field boundaries is derived from hand-digitized data sets as well as crowdsourcing.

  10. Premium performance heating oil - Part 2, Field trial results

    SciTech Connect

    Jetter, S.M.; Hoskin, D.; McClintock, W.R.

    1996-07-01

    Limited field trial results of a heating oil additive package developed to minimize unscheduled maintenance indicate that it achieves its goal of keeping heating oil systems cleaner. The multifunctional additive package was developed to provide improved fuel oxidation stability, improved corrosion protection, and dispersency. This combination of performance benefits was chosen because we believed it would retard the formation of sludge, as well as allow sludge already present to be carried through the system without fouling the fuel system components (dispersency should keep sludge particles small so they pass through the filtering system). Since many unscheduled maintenance calls are linked to fouling of the fuel filtering system, the overall goal of this technology is to reduce these maintenance calls. Photographic evidence shows that the additive package not only reduces the amount of sludge formed, but even removes existing sludge from filters and pump strainers. This {open_quotes}clean-up{close_quotes} performance is provided trouble free: we found no indication that nozzle/burner performance was impaired by dispersing sludge from filters and pump strainers. Qualitative assessments from specific accounts that used the premium heating oil also show marked reductions in unscheduled maintenance.

  11. Systematic Motorcycle Management and Health Care Delivery: A Field Trial

    PubMed Central

    Rerolle, Francois; Rammohan, Sonali V.; Albohm, Davis C.; Muwowo, George; Moseson, Heidi; Sept, Lesley; Lee, Hau L.; Bendavid, Eran

    2016-01-01

    Objectives. We investigated whether managed transportation improves outreach-based health service delivery to rural village populations. Methods. We examined systematic transportation management in a small-cluster interrupted time series field trial. In 8 districts in Southern Zambia, we followed health workers at 116 health facilities from September 2011 to March 2014. The primary outcome was the average number of outreach trips per health worker per week. Secondary outcomes were health worker productivity, motorcycle performance, and geographical coverage. Results. Systematic fleet management resulted in an increase of 0.9 (SD = 1.0) trips to rural villages per health worker per week (P < .001), village-level health worker productivity by 20.5 (SD = 5.9) patient visits, 10.2 (SD = 1.5) measles immunizations, and 5.2 (SD = 5.4) child growth assessments per health worker per week. Motorcycle uptime increased by 3.5 days per week (P < .001), use by 1.5 days per week (P < .001), and mean distance by 9.3 kilometers per trip (P < .001). Geographical coverage of health outreach increased in experimental (P < .001) but not control districts. Conclusions. Systematic motorcycle management improves basic health care delivery to rural villages in resource-poor environments through increased health worker productivity and greater geographical coverage. PMID:26562131

  12. Electro-chemical arsenic remediation: field trials in West Bengal.

    PubMed

    Amrose, Susan E; Bandaru, Siva R S; Delaire, Caroline; van Genuchten, Case M; Dutta, Amit; DebSarkar, Anupam; Orr, Christopher; Roy, Joyashree; Das, Abhijit; Gadgil, Ashok J

    2014-08-01

    Millions of people in rural South Asia are exposed to high levels of arsenic through groundwater used for drinking. Many deployed arsenic remediation technologies quickly fail because they are not maintained, repaired, accepted, or affordable. It is therefore imperative that arsenic remediation technologies be evaluated for their ability to perform within a sustainable and scalable business model that addresses these challenges. We present field trial results of a 600 L Electro-Chemical Arsenic Remediation (ECAR) reactor operating over 3.5 months in West Bengal. These results are evaluated through the lens of a community scale micro-utility business model as a potential sustainable and scalable safe water solution for rural communities in South Asia. We demonstrate ECAR's ability to consistently reduce arsenic concentrations of ~266 μg/L to <5 μg/L in real groundwater, simultaneously meeting the international standards for iron and aluminum in drinking water. ECAR operating costs (amortized capital plus consumables) are estimated as $0.83-$1.04/m(3) under realistic conditions. We discuss the implications of these results against the constraints of a sustainable and scalable business model to argue that ECAR is a promising technology to help provide a clean water solution in arsenic-affected areas of South Asia.

  13. Modeling of Movement of Field Gudgeon, Gnathopogon elongatus elongatus, in Agricultural Canals in Yatsu Paddy Fields

    NASA Astrophysics Data System (ADS)

    Takemura, Takeshi; Koizumi, Noriyuki; Mizutani, Masakazu; Mori, Atsushi; Watabe, Keiji

    It is important as quantitative information for making a decision of project sites for networking of water area, to predict reproductive process of fish population when consolidating fish-ways on points dividing fish habitat. To that end, it is necessary to predict the number of individuals migrating to new habitats. Hence, modeling of movement of individuals is necessary as a first step in population modeling. We constructed a mathematical model of movement of field gudgeon in agricultural canals, comparing with observed data obtained by our surveys. A unit time span of this model is 50 days. This model is able to consider existence of 2 types of movement, namely, individuals of sedentary type and individuals of ambulant type. Parameters of the model were decided based on observed data which correspond to 1 unit span. Next, moving distances of 6 individuals for 4 unit span were calculated using those parameters. A histogram of calculated values was similar to that of observed data which correspond to 4 unit span. The model is expected to provide an important immigration component to a population dynamics model which is currently under development. The population model is needed to predict population recovery processes where areas of paddy fields are joined in larger networks through construction of fish-ways.

  14. Topographic effects on denitrification in drained agricultural fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Denitrification is affected by soil moisture, while soil moisture can be affected by topography. Therefore, denitrification can be spatially correlated to topographic gradients. Three prior converted fields on the Delmarva Peninsula were sampled spatially for denitrification enzyme activity. The up...

  15. Successional trends in Sonoran Desert abandoned agricultural fields in northern Mexico

    USGS Publications Warehouse

    Castellanos, A.E.; Martinez, M.J.; Llano, J.M.; Halvorson, W.L.; Espiricueta, M.; Espejel, I.

    2005-01-01

    Excessive ground-water use and saline intrusion to the aquifer led, in less than three decades, to an increase in abandoned agricultural fields at La Costa de Hermosillo, within the Sonoran Desert. Using a chronosequence from years since abandonment, patterns of field succession were developed. Contrary to most desert literature, species replacement was found, both in fields with and without saline intrusion. Seasonal photosynthetic capacity as well as water and nitrogen use efficiencies were different in dominant early and late successional plant species. These ecological findings provided a framework for a general explanation of species dominance and replacement within abandoned agricultural fields in the Sonoran Desert. ?? 2004 Elsevier Ltd. All rights reserved.

  16. Pesticide Leaching from Agricultural Fields with Ridges and Furrows

    PubMed Central

    Boesten, Jos J. T. I.

    2010-01-01

    In the evaluation of the risk of pesticide leaching to groundwater, the soil surface is usually assumed to be level, although important crops like potato are grown on ridges. A fraction of the water from rainfall and sprinkler irrigation may flow along the soil surface from the ridges to the furrows, thus bringing about an extra load of water and pesticide on the furrow soil. A survey of the literature reveals that surface-runoff from ridges to furrows is a well-known phenomenon but that hardly any data are available on the quantities of water and pesticide involved. On the basis of a field experiment with additional sprinkler irrigation, computer simulations were carried out with the Pesticide Emission Assessment at Regional and Local scales model for separate ridge and furrow systems in a humic sandy potato field. Breakthrough curves of bromide ion (as a tracer for water flow) and carbofuran (as example pesticide) were calculated for 1-m depth in the field. Bromide ion leached comparatively fast from the furrow system, while leaching from the ridge system was slower showing a maximum concentration of about half of that for the furrow system. Carbofuran breakthrough from the furrow system began about a month after application and increased steadily to substantial concentrations. Because the transport time of carbofuran in the ridge soil was much longer, no breakthrough occurred in the growing season. The maximum concentration of carbofuran leaching from the ridge–furrow field was computed to be a factor of six times as high as that computed for the corresponding level field. The study shows that the risk of leaching of pesticides via the furrow soil can be substantially higher than that via the corresponding level field soil. PMID:21076668

  17. Pesticide Leaching from Agricultural Fields with Ridges and Furrows.

    PubMed

    Leistra, Minze; Boesten, Jos J T I

    2010-11-01

    In the evaluation of the risk of pesticide leaching to groundwater, the soil surface is usually assumed to be level, although important crops like potato are grown on ridges. A fraction of the water from rainfall and sprinkler irrigation may flow along the soil surface from the ridges to the furrows, thus bringing about an extra load of water and pesticide on the furrow soil. A survey of the literature reveals that surface-runoff from ridges to furrows is a well-known phenomenon but that hardly any data are available on the quantities of water and pesticide involved. On the basis of a field experiment with additional sprinkler irrigation, computer simulations were carried out with the Pesticide Emission Assessment at Regional and Local scales model for separate ridge and furrow systems in a humic sandy potato field. Breakthrough curves of bromide ion (as a tracer for water flow) and carbofuran (as example pesticide) were calculated for 1-m depth in the field. Bromide ion leached comparatively fast from the furrow system, while leaching from the ridge system was slower showing a maximum concentration of about half of that for the furrow system. Carbofuran breakthrough from the furrow system began about a month after application and increased steadily to substantial concentrations. Because the transport time of carbofuran in the ridge soil was much longer, no breakthrough occurred in the growing season. The maximum concentration of carbofuran leaching from the ridge-furrow field was computed to be a factor of six times as high as that computed for the corresponding level field. The study shows that the risk of leaching of pesticides via the furrow soil can be substantially higher than that via the corresponding level field soil. PMID:21076668

  18. Overview of the Full-scale Radiological Dispersal Device Field Trials.

    PubMed

    Green, Anna Rae; Erhardt, Lorne; Lebel, Luke; Duke, M John M; Jones, Trevor; White, Dan; Quayle, Debora

    2016-05-01

    In 2012, Defence Research and Development Canada, in partnership with a number of other Canadian and International organizations, led a series of three field trials designed to simulate a Radiological Dispersal Device (RDD). These trials, known as the Full-Scale RDD (FSRDD) Field Trials, involved the explosive dispersal of a short-lived radioactive tracer ((140)La, t1/2 = 40.293 h). The FSRDD Field Trials required a significant effort in their planning, preparation, and execution to ensure that they were carried out in a safe, efficient manner and that the scientific goals of the trials were met. The discussion presented here details the planning and execution of the trials, outlines the relevant radiation safety aspects, provides a summary of the source term and atmospheric conditions for the three dispersal events, and provides an overview of the measurements that were made to track the plumes and deposition patterns.

  19. Infrared-temperature variability in a large agricultural field

    NASA Technical Reports Server (NTRS)

    Millard, J. P.; Goettelman, R. C.; Leroy, M. J.

    1981-01-01

    Dunnigan Agro-Meteorological Experiment airborne thermal scanner images of a large varying-terrain barley field are acquired and analyzed. Temperature variability that may occur within instantaneous fields of view (IFOV) is defined (coefficient of variation: standard deviation/mean temperature in degrees C), and the percentage of the area within various IFOV's within + or - 1, 2, 3, and 5 degrees of the mean is determined. With the exception of very rugged terrain, over 80% of the area within 4, 16, 65 and 258 ha cells was at temperatures within + or - 3 C of the mean cell temperature. Remote measurements of field temperature appeared to be slightly influenced by pixel size in the range 4 ha to 259 ha, and the area percentage within any pixel which contributes within + or - 1, 2, 3, and 5 degrees C of the mean, is nominally the same. In conclusion, no great advantage is found in utilizing a small IFOV instead of a large one for remote sensing of crop temperature.

  20. Characterization of a new fertilizer during field trials by hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Serranti, Silvia; Trella, Agata; Garcia Izquierdo, Carlos

    2016-05-01

    This work was carried out in the framework of the LIFE RESAFE Project (LIFE12 ENV/IT/000356) "Innovative fertilizer from urban waste, bio-char and farm residues as substitute of chemical fertilizers". The aim of RESAFE project is the production of a new fertilizer from waste for agricultural practices. The new fertilizer was tested on 5 different crops during field trials carried out in Spain: barley, corn, tomato, potato and melon. For each crop six different treatments were applied and compared to verify the quality of RESAFE fertilizer. Soil samples were collected at the beginning and at the end of the experiment. The possibility to apply hyperspectral imaging (HSI) to perform soil evolution monitoring and characterization in respect to the fertilizer utilization and quality of the resulting crops was investigated. Soil samples were acquired by HSI in the near infrared field (1000-1700 nm) and on the same samples classical chemical analyses were carried out with reference to total nitrogen, total organic carbon, C/N ratio, total organic matter. Hyperspectral data were analyzed adopting a chemometric approach through application of Principal Component Analysis (PCA) for exploratory purposes and Partial Least Squares Analysis (PLS) for estimation of chemical parameters. The results showed as the proposed hardware and software integrated architecture allows to implement low cost and easy to use analytical procedures able to quantitatively assess soil chemical-physical attributes according to different fertilization strategies, in respect of different environmental conditions and selected crops.

  1. The Impact of Landscape Complexity on Invertebrate Diversity in Edges and Fields in an Agricultural Area.

    PubMed

    Evans, Tracy R; Mahoney, Meredith J; Cashatt, Everett D; Noordijk, Jinze; de Snoo, Geert; Musters, C J M

    2016-01-01

    Invertebrate diversity is important for a multitude of ecosystem services and as a component of the larger ecological food web. A better understanding of the factors influencing invertebrate taxonomic richness and diversity at both local and landscape scales is important for conserving biodiversity within the agricultural landscape. The aim of this study was to determine if invertebrate richness and diversity in agricultural field interiors and edges in central Illinois, USA, were related to the complexity of the surrounding landscape. Our results show taxonomic richness and diversity in field edges is positively related to large scale landscape complexity, but the relationship is negative for field interiors. These unexpected results need further study.

  2. The Impact of Landscape Complexity on Invertebrate Diversity in Edges and Fields in an Agricultural Area

    PubMed Central

    Evans, Tracy R.; Mahoney, Meredith J.; Cashatt, Everett D.; Noordijk, Jinze; de Snoo, Geert; Musters, C. J. M.

    2016-01-01

    Invertebrate diversity is important for a multitude of ecosystem services and as a component of the larger ecological food web. A better understanding of the factors influencing invertebrate taxonomic richness and diversity at both local and landscape scales is important for conserving biodiversity within the agricultural landscape. The aim of this study was to determine if invertebrate richness and diversity in agricultural field interiors and edges in central Illinois, USA, were related to the complexity of the surrounding landscape. Our results show taxonomic richness and diversity in field edges is positively related to large scale landscape complexity, but the relationship is negative for field interiors. These unexpected results need further study. PMID:26848691

  3. Aproaches for mitigation of greenhouse gas emission from agricultural fields

    NASA Astrophysics Data System (ADS)

    Sudo, S.; Itoh, M.

    2009-12-01

    Percentage of atmospheric methane emitted form rice paddy is estimated at 60Tg/yr (20 - 100Tg/yr) which is near 10% of total global methane emission of 535Tg/yr (410 - 660Tg) (IPCC(1995), and which is near 30% of anthropogenic CH4 emission. Thus, mitigation of CH4 emission is required to be speed up. CH4 in paddy soil is emanated by the activities of anaerobic bacteria which is called methane producer through reduction of CO2 or decomposition of acetic acid, and it is transported to atmosphere through soil or paddy water surface. It is effective to control methane emission from rice paddy that period is prolonged on intermittent irrigation drainage, composted rice straw is incorporated as fertilizer instead of flesh one, or other. However, empirical approach of these kinds of experiments had not been sufficient because such a kind of experiment required significant times and efforts. In this study, we conducted demonstrative experiments to verify the effects of water management method differences in order to reduce CH4 emission from rice paddy at 9 experimental sites in 8 prefectures. In this, we used new gas analyzer which can measure CH4, CO2 and N2O at once developed by National Institute for Agro-Environmental Sciences (NIAES), Japan. In this report, we show the preliminary results in first year of this study. Nakaboshi (mid-season-drainage) is one of cultivation methods in rice paddy that surface water in paddy field is once drained for about 10 days and the field is maintained like upland field to give adequate stress to rice plant for better harvest qualities and yields. Our targeted evaluation was dependencies of Nakaboshi periods lengths and Nakaboshi periods to CH4 emission reduction amounts for total cultivation periods within harvest yield maintained. The longer length of Nakaboshi period was prolonged, the lesser emission amounts of CH4 decreased even after when Nakaboshi period lasted, as a whole. In some soil types, for example in Kagoshima

  4. Analysis of a large dataset of mycorrhiza inoculation field trials on potato shows highly significant increases in yield.

    PubMed

    Hijri, Mohamed

    2016-04-01

    An increasing human population requires more food production in nutrient-efficient systems in order to simultaneously meet global food needs while reducing the environmental footprint of agriculture. Arbuscular mycorrhizal fungi (AMF) have the potential to enhance crop yield, but their efficiency has yet to be demonstrated in large-scale crop production systems. This study reports an analysis of a dataset consisting of 231 field trials in which the same AMF inoculant (Rhizophagus irregularis DAOM 197198) was applied to potato over a 4-year period in North America and Europe under authentic field conditions. The inoculation was performed using a liquid suspension of AMF spores that was sprayed onto potato seed pieces, yielding a calculated 71 spores per seed piece. Statistical analysis showed a highly significant increase in marketable potato yield (ANOVA, P < 0.0001) for inoculated fields (42.2 tons/ha) compared with non-inoculated controls (38.3 tons/ha), irrespective of trial year. The average yield increase was 3.9 tons/ha, representing 9.5 % of total crop yield. Inoculation was profitable with a 0.67-tons/ha increase in yield, a threshold reached in almost 79 % of all trials. This finding clearly demonstrates the benefits of mycorrhizal-based inoculation on crop yield, using potato as a case study. Further improvements of these beneficial inoculants will help compensate for crop production deficits, both now and in the future.

  5. A Machine Learning Approach to Mapping Agricultural Fields Across Sub-Saharan Africa

    NASA Astrophysics Data System (ADS)

    Debats, S. R.; Fuchs, T. J.; Thompson, D. R.; Estes, L. D.; Evans, T. P.; Caylor, K. K.

    2013-12-01

    Food production in sub-Saharan Africa is dominated by smallholder agriculture. Rainfed farming practices and the prevailing dryland conditions render crop yields vulnerable to increasing climatic variability. As a result, smallholder farmers are among the poorest and most food insecure groups among the region's population. Quantifying the distribution of smallholder agriculture across sub-Saharan Africa would greatly assist efforts to boost food security. Existing agricultural land cover data sets are limited to estimating the percentage of cropland within a coarse grid cell. The goal of this research is to develop a statistical machine learning algorithm to map individual agricultural fields, mirroring the accuracy of hand-digitization. For the algorithm, a random forest pixel-wise classifier learns by example from training data to distinguish between fields and non-fields. The algorithm then applies this training to classify previously unseen data. These classifications can then be smoothed into coherent regions corresponding to agricultural fields. Our training data set consists of hand-digitized boundaries of agricultural fields in South Africa, commissioned by its government in 2008. Working with 1 km x 1 km scenes across South Africa, the hand-digitized field boundaries are matched with satellite images extracted from Google Maps. To highlight different information contained within the images, several image processing filters are applied. The inclusion of Landsat images for additional training information is also explored. After training and testing the algorithm in South Africa, we aim to expand our mapping efforts across sub-Saharan Africa. Through Princeton's Mapping Africa project, crowdsourcing will produce additional training data sets of hand-digitized field boundaries in new areas of interest. This algorithm and the resulting data sets will provide previously unavailable information at an unprecedented level of detail on the largest and most

  6. Field trial evaluation of a reo-coronavirus calf diarrhea vaccine.

    PubMed Central

    Thurber, E T; Bass, E P; Beckenhauer, W H

    1977-01-01

    Field trials were conducted using an experimental, modified live virus, oral vaccine for prevention of reo- and coronavirus calf diarrhea. Prior to the trials, one or both of the specific causative agents were identified from affected calves in each participating herd. In 21 herds, sequential trials were conducted in which results of uninterrupted vaccination were compared with disease rates during a preceding or subsequent control period. In these herds there was a statistically significant reduction in the morbidity and mortality from disease in 1,598 vaccinates compared with the rates in 829 prevaccination control calves. Morbidity and mortality in 206 post-vaccination control calves rose marginally above the rates in the same vaccinates. In 26 other herds, where double blind trials were conducted, rates of morbidity and mortality from disease were virtually the same for 1,080 vaccinated calves and 355 placebo calves. Vaccinates in the sequential trials had the lowest morbidity and mortality rates of any test group in either field trial format. In a selected dairy herd, both field trial formats were implemented and the results compared. In the double blind trial, vaccinates and placebo calves had comparable rates of morbidity and mortality from disease. When a sequential trial was later implemented, a statistically significant reduction in morbidity and mortality occurred in vaccinates compared with rates in control calves. PMID:193622

  7. Field-based study of connectivity in an agricultural catchment

    NASA Astrophysics Data System (ADS)

    Lexartza-Artza, I.; Wainwright, J.

    2009-12-01

    Field-based studies of hydrological connectivity can provide context-specific knowledge that might both help understand dynamic complex systems and contribute to other synthetic or modelling approaches. The importance of such an understanding of catchment processes and also of the knowledge of catchment connections with water bodies and the changes of concentration with scale for Integrated Catchment Management has been increasingly emphasized. To provide a holistic understanding, approaches to the study of connectivity need to include both structural and functional aspects of the system and must consider the processes taking place within and across different temporal and spatial scales. A semi-quantitative nested approach has been used to investigate connectivity and study the interactions and feedbacks between the factors influencing transfer processes in the Ingbirchworth Catchment, in the uplands of the River Don, England. A series of reconnaissance techniques have been combined with monitoring of aspects such as rainfall, runoff, sediment transfer and soil-moisture distribution from plot to catchment scale and with consideration of linkages between land and water bodies. The temporal aspect has also been considered, with a special focus on the temporal distribution of events and the influence of longer term catchment changes such as those in land use and management practices. A variability of responses has been observed in relation to the characteristics of events, land use and scale of observation, with elements traditionally considered as limiting or enhancing connectivity responding differently under changing conditions. Sediment redistribution, reshaping of structure and consequent reinforcing loops can be observed across all land uses and landscape units, but the relevance it terms of effective connectivity of highly connected patches varies as the scale is increased. The knowledge acquired can contribute to recognise emerging processes significant for

  8. Transgenic Field Trials for FHB Resistance and Related Research in Wheat and Barley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic wheat and barley lines expressing genes with the potential to reduce FHB and DON have been tested in field trials in Minnesota since 1997 and in North Dakota since 2001 (barley only). Replicated trials are planted, grown, and harvested to meet containment regulations of the Animal and Pla...

  9. Bioenergy Ecosystem Land-Use Modelling and Field Flux Trial

    NASA Astrophysics Data System (ADS)

    McNamara, Niall; Bottoms, Emily; Donnison, Iain; Dondini, Marta; Farrar, Kerrie; Finch, Jon; Harris, Zoe; Ineson, Phil; Keane, Ben; Massey, Alice; McCalmont, Jon; Morison, James; Perks, Mike; Pogson, Mark; Rowe, Rebecca; Smith, Pete; Sohi, Saran; Tallis, Mat; Taylor, Gail; Yamulki, Sirwan

    2013-04-01

    Climate change impacts resulting from fossil fuel combustion and concerns about the diversity of energy supply are driving interest to find low-carbon energy alternatives. As a result bioenergy is receiving widespread scientific, political and media attention for its potential role in both supplying energy and mitigating greenhouse (GHG) emissions. It is estimated that the bioenergy contribution to EU 2020 renewable energy targets could require up to 17-21 million hectares of additional land in Europe (Don et al., 2012). There are increasing concerns that some transitions into bioenergy may not be as sustainable as first thought when GHG emissions from the crop growth and management cycle are factored into any GHG life cycle assessment (LCA). Bioenergy is complex and encapsulates a wide range of crops, varying from food crop based biofuels to dedicated second generation perennial energy crops and forestry products. The decision on the choice of crop for energy production significantly influences the GHG mitigation potential. It is recognised that GHG savings or losses are in part a function of the original land-use that has undergone change and the management intensity for the energy crop. There is therefore an urgent need to better quantify both crop and site-specific effects associated with the production of conventional and dedicated energy crops on the GHG balance. Currently, there is scarcity of GHG balance data with respect to second generation crops meaning that process based models and LCAs of GHG balances are weakly underpinned. Therefore, robust, models based on real data are urgently required. In the UK we have recently embarked on a detailed program of work to address this challenge by combining a large number of field studies with state-of-the-art process models. Through six detailed experiments, we are calculating the annual GHG balances of land use transitions into energy crops across the UK. Further, we are quantifying the total soil carbon gain or

  10. Field trials of 100G and beyond: an operator's point of view

    NASA Astrophysics Data System (ADS)

    Vorbeck, S.; Schneiders, M.; Weiershausen, W.; Mayer, H.; Schippel, A.; Wagner, P.; Ehrhardt, A.; Braun, R.; Breuer, D.; Drafz, U.; Fritzsche, D.

    2011-01-01

    In this article we present a summary of the latest 100 Gbps field trials in the network of Deutsche Telekom AG with industry partners. We cover a brown field approach as alien wavelength on existing systems, a green field high speed overlay network approach and a high speed interface router-router coupling.

  11. Bird use of agricultural fields under reduced and conventional tillage in the Texas Panhandle

    USGS Publications Warehouse

    Flickinger, Edward L.; Pendleton, G.W.

    1994-01-01

    We conducted bird surveys in reduced-tillage and conventional tillage fields in spring, summer, fall, and winter from 1987 to 1991 in the Texas Panhandle. Eastern meadowlarks, longspurs, and savannah sparrows were more common in reduced-tillage (sorghum and wheat stubble) fields than in conventionally tilled (plowed) fields in at least 1 season. Other species also had patterns suggestive of greater abundance in reduced-tillage fields. Hornedlarks, which prefer habitat with sparse vegetation, were more abundant in plowed fields in all seasons except summer. Bird diversity was greater in reduced-tillage fields than in conventionally tilled fields in summer. Cover density and height were greater in reduced tillage fields in all seasons except spring. Cover density and height rather than cover composition (e.g.,grain stubble or live plants) seemed to be the important factors affecting bird distribution. Patterns of bird abundance between sorghum and wheat stubble fields also were dependent on cover. Herbicide use was not greater in reduced-tillage fields than in conventionally tilled fields. Reduced-tillage agriculture for sorghum and wheat farming should be encouraged in the southern Great Plains as a means of improving the attractiveness of agricultural land to many bird species.

  12. Comparing erosion rates in burnt forests and agricultural fields for a mountain catchment in NW Iberia

    NASA Astrophysics Data System (ADS)

    Nunes, João Pedro; Marisa Santos, Juliana; Bernard-Jannin, Léonard; Keizer, Jan Jacob

    2013-04-01

    A large part of northwestern Iberia is nowadays covered by commercial forest plantations of eucalypts and maritime pines, which have partly replaced traditional agricultural land-uses. The humid Mediterranean climate, with mild wet winters and warm dry summers, creates favorable conditions for the occurrence of frequent and recurrent forest fires. Erosion rates in recently burnt areas have been the subject of numerous studies; however, there is still a lack of information on their relevance when compared with agricultural erosion rates, impairing a comprehensive assessment of the role of forests for soil protection. This study focuses on Macieira de Alcoba, head-water catchment in the Caramulo Mountain Range, north-central Portugal, with a mixture of agricultural fields (mostly a rotation between winter pastures and summer cereals) on the lower slopes and forest plantations (mostly eucalypts) on the upper slopes. Agricultural erosion in this catchment has been monitored since 2010; a forest fire in 2011 presented an opportunity to compare post-fire and agricultural erosion rates at nearby sites with comparable soil and climatic conditions. Erosion rates were monitored between 2010 and 2013 by repeated surveys of visible erosion features and, in particular, by mapping and measuring rills and gullies after important rainfall events. During the 2011/2012 hydrological year, erosion rates in the burnt forest were two orders of magnitude above those in agricultural fields, amounting to 17.6 and. 0.1 Mg ha-1, respectively. Rills were widespread in the burnt area, while in the agricultural area they were limited to a small number of fields with higher slope; these particular fields experienced an erosion rate of 2.3 Mg ha-1, still one order of magnitude lower than at the burnt forest site. The timing of the erosion features was also quite distinct for the burnt area and the agricultural fields. During the first nine months after the fire, rill formation was not observed in

  13. Simple, Low-Cost Data Collection Methods for Agricultural Field Studies.

    ERIC Educational Resources Information Center

    Koenig, Richard T.; Winger, Marlon; Kitchen, Boyd

    2000-01-01

    Summarizes relatively simple and inexpensive methods for collecting data from agricultural field studies. Describes methods involving on-farm testing, crop yield measurement, quality evaluations, weed control effectiveness, plant nutrient status, and other measures. Contains 29 references illustrating how these methods were used to conduct…

  14. Anthropogenic effects on soil quality in ancient terraced agricultural fields of Chihuahua, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural soil quality was investigated in ancient field systems near Casas Grandes (also known as Paquimé), one of the largest and most complex prehistoric settlements in the North American Southwest. This research was completed as part of an interdisciplinary study of the anthropogenic ecology...

  15. 140° view of two agricultural fields with traces of irrigation ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    140° view of two agricultural fields with traces of irrigation ditches south of the lower holding pond. This negative forms a 360° composite panoramic when joined with AZ-2-75 and AZ-2-76. See AZ-2-86 for color version. - Tassi Ranch, Tassi Springs, Littlefield, Mohave County, AZ

  16. Definition of zones with different levels of productivity within an agricultural field using fuzzy modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zoning of agricultural fields is an important task for utilization of precision farming technology. One method for the definition of zones with different levels of productivity is based on fuzzy indicator model. Fuzzy indicator model for identification of zones with different levels of productivit...

  17. Status of Job Motivation and Job Performance of Field Level Extension Agents in Ogun State: Implications for Agricultural Development

    ERIC Educational Resources Information Center

    Fabusoro, E.; Awotunde, J. A.; Sodiya, C. I.; Alarima, C. I.

    2008-01-01

    The field level extension agents (FLEAs) are the lifeline of the agricultural extension system in Nigeria. Their motivation and job performance are therefore important to achieving faster agricultural development in Nigeria. The study identified the factors motivating the FLEAs working with Ogun State Agricultural development programme (OGADEP)…

  18. Californian demonstration and validation of automated agricultural field extraction from multi-temporal Landsat data

    NASA Astrophysics Data System (ADS)

    Yan, L.; Roy, D. P.

    2013-12-01

    The spatial distribution of agricultural fields is a fundamental description of rural landscapes and the location and extent of fields is important to establish the area of land utilized for agricultural yield prediction, resource allocation, and for economic planning. To date, field objects have not been extracted from satellite data over large areas because of computational constraints and because consistently processed appropriate resolution data have not been available or affordable. We present a fully automated computational methodology to extract agricultural fields from 30m Web Enabled Landsat data (WELD) time series and results for approximately 250,000 square kilometers (eleven 150 x 150 km WELD tiles) encompassing all the major agricultural areas of California. The extracted fields, including rectangular, circular, and irregularly shaped fields, are evaluated by comparison with manually interpreted Landsat field objects. Validation results are presented in terms of standard confusion matrix accuracy measures and also the degree of field object over-segmentation, under-segmentation, fragmentation and shape distortion. The apparent success of the presented field extraction methodology is due to several factors. First, the use of multi-temporal Landsat data, as opposed to single Landsat acquisitions, that enables crop rotations and inter-annual variability in the state of the vegetation to be accommodated for and provides more opportunities for cloud-free, non-missing and atmospherically uncontaminated surface observations. Second, the adoption of an object based approach, namely the variational region-based geometric active contour method that enables robust segmentation with only a small number of parameters and that requires no training data collection. Third, the use of a watershed algorithm to decompose connected segments belonging to multiple fields into coherent isolated field segments and a geometry based algorithm to detect and associate parts of

  19. Automated Agricultural Field Extraction from Multi-temporal Web Enabled Landsat Data

    NASA Astrophysics Data System (ADS)

    Yan, L.; Roy, D. P.

    2012-12-01

    Agriculture has caused significant anthropogenic surface change. In many regions agricultural field sizes may be increasing to maximize yields and reduce costs resulting in decreased landscape spatial complexity and increased homogenization of land uses with potential for significant biogeochemical and ecological effects. To date, studies of the incidence, drivers and impacts of changing field sizes have not been undertaken over large areas because of computational constraints and because consistently processed appropriate resolution data have not been available or affordable. The Landsat series of satellites provides near-global coverage, long term, and appropriate spatial resolution (30m) satellite data to document changing field sizes. The recent free availability of all the Landsat data in the U.S. Landsat archive now provides the opportunity to study field size changes in a global and consistent way. Commercial software can be used to extract fields from Landsat data but are inappropriate for large area application because they require considerable human interaction. This paper presents research to develop and validate an automated computational Geographic Object Based Image Analysis methodology to extract agricultural fields and derive field sizes from Web Enabled Landsat Data (WELD) (http://weld.cr.usgs.gov/). WELD weekly products (30m reflectance and brightness temperature) are classified into Satellite Image Automatic Mapper™ (SIAM™) spectral categories and an edge intensity map and a map of the probability of each pixel being agricultural are derived from five years of 52 weeks of WELD and corresponding SIAM™ data. These data are fused to derive candidate agriculture field segments using a variational region-based geometric active contour model. Geometry-based algorithms are used to decompose connected segments belonging to multiple fields into coherent isolated field objects with a divide and conquer strategy to detect and merge partial circle

  20. Field Balancing of Magnetically Levitated Rotors without Trial Weights

    PubMed Central

    Fang, Jiancheng; Wang, Yingguang; Han, Bangcheng; Zheng, Shiqiang

    2013-01-01

    Unbalance in magnetically levitated rotor (MLR) can cause undesirable synchronous vibrations and lead to the saturation of the magnetic actuator. Dynamic balancing is an important way to solve these problems. However, the traditional balancing methods, using rotor displacement to estimate a rotor's unbalance, requiring several trial-runs, are neither precise nor efficient. This paper presents a new balancing method for an MLR without trial weights. In this method, the rotor is forced to rotate around its geometric axis. The coil currents of magnetic bearing, rather than rotor displacement, are employed to calculate the correction masses. This method provides two benefits when the MLR's rotation axis coincides with the geometric axis: one is that unbalanced centrifugal force/torque equals the synchronous magnetic force/torque, and the other is that the magnetic force is proportional to the control current. These make calculation of the correction masses by measuring coil current with only a single start-up precise. An unbalance compensation control (UCC) method, using a general band-pass filter (GPF) to make the MLR spin around its geometric axis is also discussed. Experimental results show that the novel balancing method can remove more than 92.7% of the rotor unbalance and a balancing accuracy of 0.024 g mm kg−1 is achieved.

  1. Optical modeling of agricultural fields and rough-textured rock and mineral surfaces

    NASA Technical Reports Server (NTRS)

    Suits, G. H.; Vincent, R. K.; Horwitz, H. M.; Erickson, J. D.

    1973-01-01

    Review was made of past models for describing the reflectance and/or emittance properties of agricultural/forestry and geological targets in an effort to select the best theoretical models. An extension of the six parameter Allen-Gayle-Richardson model was chosen as the agricultural plant canopy model. The model is used to predict the bidirectional reflectance of a field crop from known laboratory spectra of crop components and approximate plant geometry. The selected geological model is based on Mie theory and radiative transfer equations, and will assess the effect of textural variations of the spectral emittance of natural rock surfaces.

  2. Deriving a per-field land use and land cover map in an agricultural mosaic catchment

    NASA Astrophysics Data System (ADS)

    Seo, B.; Bogner, C.; Poppenborg, P.; Martin, E.; Hoffmeister, M.; Jun, M.; Koellner, T.; Reineking, B.; Shope, C. L.; Tenhunen, J.

    2014-09-01

    Detailed data on land use and land cover constitute important information for Earth system models, environmental monitoring and ecosystem services research. Global land cover products are evolving rapidly; however, there is still a lack of information particularly for heterogeneous agricultural landscapes. We censused land use and land cover field by field in the agricultural mosaic catchment Haean in South Korea. We recorded the land cover types with additional information on agricultural practice. In this paper we introduce the data, their collection and the post-processing protocol. Furthermore, because it is important to quantitatively evaluate available land use and land cover products, we compared our data with the MODIS Land Cover Type product (MCD12Q1). During the studied period, a large portion of dry fields was converted to perennial crops. Compared to our data, the forested area was underrepresented and the agricultural area overrepresented in MCD12Q1. In addition, linear landscape elements such as waterbodies were missing in the MODIS product due to its coarse spatial resolution. The data presented here can be useful for earth science and ecosystem services research. The data are available at the public repository Pangaea (doi:110.1594/PANGAEA.823677).

  3. A note on elevated total gaseous mercury concentrations downwind from an agriculture field during tilling.

    PubMed

    Bash, Jesse O; Miller, David R

    2007-12-15

    Elevated mercury concentrations were measured at the University of Connecticut's mercury forest flux tower during spring agricultural field operations on an adjacent corn field. Concentrations at the tower were elevated, a peak of 7.03 ng m(-3) over the background concentration of 1.74+/-0.26 ng m(-3), during times when the prevailing wind was from the direction of the corn field and during periods when the soil was disturbed by tilling. Strong deposition to the forest was recorded at the point of measurement when atmospheric mercury concentrations were elevated. The strongest deposition rate was a 1 hour maximum of -4011 ng m(-2) h(-1) following the initial peak in atmospheric concentrations, Analyses of the meteorological conditions and mercury content in agricultural soil, manure and the diesel consumed in the tilling operation indicate that the source of the mercury was from the agricultural tilling operations and it was advected over the tower enriching the atmospheric concentrations above the forest canopy leading to deposition. These results indicate that agriculture operations resulting in a disturbed soil surface may be a source of atmospheric mercury originating from the pool of mercury bound in the soil. This represents a previously undocumented source of mercury emissions resulting from anthropogenic activities.

  4. SUPERFUND TREATABILITY CLEARINGHOUSE: FULL SCALE ROTARY KILN INCINERATOR FIELD TRIAL: PHASE I, VERIFICATION TRIAL BURN ON DIOXIN/HERBICIDE ORANGE CONTAMINATED SOIL

    EPA Science Inventory

    This treatability study reports on the results of one of a series of field trials using various remedial action technologies that may be capable of restoring Herbicide Orange (HO)XDioxin contaminated sites. A full-scale field trial using a rotary kiln incinerator capable of pro...

  5. Methods for classification of agricultural fields in aerial sequences: a comparative study

    NASA Astrophysics Data System (ADS)

    Houkes, Zweitze; Chen, Haijun; Blacquiere, Jan-Friso

    1998-12-01

    A comparative study of a selection of classification methods for agricultural fields in sequences of aerial images is presented. The image sequences are acquired by an RGB-CCD video camera which is assumed to be on board of an airplane, moving linear over the scene. The objects in the scenes being considered are agricultural fields. The classes of agricultural fields to be distinguished are determined by the type of crop, e.g. potatoes, sugar beet, wheat, etc. In order to recognize and classify these fields obtained from the aerial sequences of images, a common approach is in the use of surface texture. Textural features are extracted from the images to effectively characterize the vegetation. Methods based on Circular Symmetric Auto-Regression, Co-Occurrence Matrix and Local Binary Patterns are selected for the comparative study. The experiments are carried out with image sequences taken from a scaled model of a landscape and a selection from the Brodatz set. A few training images are used to set up the model bases for the three methods. The methods are tested using the same regions from other images of the sequence, and other sequences of images of similar fields. Comparison fa the methods is based on the confusion matrix. Sensitivity to variations in flight direction, variations in altitude and luminance conditions are being considered.

  6. Field-measured drag area is a key correlate of level cycling time trial performance.

    PubMed

    Peterman, James E; Lim, Allen C; Ignatz, Ryan I; Edwards, Andrew G; Byrnes, William C

    2015-01-01

    Drag area (Ad ) is a primary factor determining aerodynamic resistance during level cycling and is therefore a key determinant of level time trial performance. However, Ad has traditionally been difficult to measure. Our purpose was to determine the value of adding field-measured Ad as a correlate of level cycling time trial performance. In the field, 19 male cyclists performed a level (22.1 km) time trial. Separately, field-determined Ad and rolling resistance were calculated for subjects along with projected frontal area assessed directly (AP ) and indirectly (Est AP ). Also, a graded exercise test was performed to determine [Formula: see text] peak, lactate threshold (LT), and economy. [Formula: see text] peak ([Formula: see text]) and power at LT were significantly correlated to power measured during the time trial (r = 0.83 and 0.69, respectively) but were not significantly correlated to performance time (r = - 0.42 and -0.45). The correlation with performance time improved significantly (p < 0.05) when these variables were normalized to Ad . Of note, Ad alone was better correlated to performance time (r = 0.85, p < 0.001) than any combination of non-normalized physiological measure. The best correlate with performance time was field-measured power output during the time trial normalized to Ad (r = - 0.92). AP only accounted for 54% of the variability in Ad . Accordingly, the correlation to performance time was significantly lower using power normalized to AP (r = - 0.75) or Est AP (r = - 0.71). In conclusion, unless normalized to Ad , level time trial performance in the field was not highly correlated to common laboratory measures. Furthermore, our field-measured Ad is easy to determine and was the single best predictor of level time trial performance.

  7. Long-term monitoring of nitrate transport to drainage from three agricultural clayey till fields

    NASA Astrophysics Data System (ADS)

    Ernstsen, V.; Olsen, P.; Rosenbom, A. E.

    2015-08-01

    The application of nitrogen (N) fertilisers to crops grown on tile-drained fields is required to sustain most modern crop production, but it poses a risk to the aquatic environment since tile drains facilitate rapid transport pathways with no significant reduction in nitrate. To maintain the water quality of the aquatic environment and the provision of food from highly efficient agriculture in line with the EU's Water Framework Directive and Nitrates Directive, field-scale knowledge is essential for introducing water management actions on-field or off-field and producing an optimal differentiated N-regulation in future. This study strives to provide such knowledge by evaluating on 11 years of nitrate-N concentration measurements in drainage from three subsurface-drained clayey till fields (1.3-2.3 ha) representing approximately 71 % of the surface sediments in Denmark dominated by clay. The fields differ in their inherent hydrogeological field settings (e.g. soil-type, geology, climate, drainage and groundwater table) and the agricultural management of the fields (e.g. crop type, type of N fertilisers and agricultural practices). The evaluation revealed three types of clayey till fields characterised by: (i) low net precipitation, high concentration of nitrate-N, and short-term low intensity drainage at air temperatures often below 5 °C; (ii) medium net precipitation, medium concentration of nitrate-N, and short-term medium-intensity drainage at air temperatures often above 5 °C; and (iii) high net precipitation, low concentration of nitrate-N and long-term high intensity drainage at air temperatures above 5 °C. For each type, on-field water management actions, such as the selection of crop types and introduction of catch crops, appeared relevant, whereas off-field actions only seemed relevant for the latter two field types given the temperature-dependent reduction potential of nitrate off-field. This initial well-documented field-scale knowledge from fields

  8. Deriving a per-field land use and land cover map in an agricultural mosaic catchment

    NASA Astrophysics Data System (ADS)

    Seo, B.; Bogner, C.; Poppenborg, P.; Martin, E.; Hoffmeister, M.; Jun, M.; Koellner, T.; Reineking, B.; Shope, C. L.; Tenhunen, J.

    2014-04-01

    Detailed data on land use and land cover constitutes important information for Earth system models, environmental monitoring and ecosystem services research. Global land cover products are evolving rapidly, however, there is still a lack of information particularly for heterogeneous agricultural landscapes. We censused land use and land cover field by field in an agricultural mosaic catchment Haean, South Korea. We recorded the land cover types with additional information on agricultural practice and make this data available at the public repository Pangaea (doi:10.1594/PANGAEA.823677). In this paper we introduce the data, its collection and the post-processing protocol. During the studied period, a large portion of dry fields was converted to perennial crops. A comparison between our dataset and MODIS Land Cover Type (MCD12Q1) suggested that the MODIS product was restricted in this area since it does not distinguish irrigated fields from general croplands. In addition, linear landscape elements such as water bodies were not detected in the MODIS product due to its coarse spatial resolution. The data presented here can be useful for earth science and ecosystem services research.

  9. A mobile app for delivering in-field soil data for precision agriculture

    NASA Astrophysics Data System (ADS)

    Isaacs, John P.; Stojanovic, Vladeta; Falconer, Ruth E.

    2015-04-01

    In the last decade precision agriculture has grown from a concept to an emerging technology, largely due to the maturing of GPS and mobile mapping. We investigated methods for reliable delivery and display of appropriate and context aware in-field farm data on mobile devices by developing a prototype android mobile app. The 3D app was developed using OpenGL ES 2.0 and written in Java, using the Android Development Tools (ADT) SDK. The app is able to obtain GPS coordinates and automatically synchronise the view and load relevant data based on the user's location. The intended audience of the mobile app is farmers and agronomists. Apps are becoming an essential tool in an agricultural professional's arsenal however most existing apps are limited to 2D display of data even though the modern chips in mobile devices can support the display of 3D graphics at interactive rates using technologies such as webGL. This project investigated the use of games techniques in the delivery and 3D display of field data, recognising that this may be a departure from the way the field data is currently delivered and displayed to farmers and agronomists. Different interactive 3D visualisation methods presenting spatial and temporal variation in yield values were developed and tested. It is expected that this app can be used by farmers and agronomists to support decision making in the field of precision agriculture and this is a growing market in UK and Europe.

  10. Profiling Nematode Communities in Unmanaged Flowerbed and Agricultural Field Soils in Japan by DNA Barcode Sequencing

    PubMed Central

    Morise, Hisashi; Miyazaki, Erika; Yoshimitsu, Shoko; Eki, Toshihiko

    2012-01-01

    Soil nematodes play crucial roles in the soil food web and are a suitable indicator for assessing soil environments and ecosystems. Previous nematode community analyses based on nematode morphology classification have been shown to be useful for assessing various soil environments. Here we have conducted DNA barcode analysis for soil nematode community analyses in Japanese soils. We isolated nematodes from two different environmental soils of an unmanaged flowerbed and an agricultural field using the improved flotation-sieving method. Small subunit (SSU) rDNA fragments were directly amplified from each of 68 (flowerbed samples) and 48 (field samples) isolated nematodes to determine the nucleotide sequence. Sixteen and thirteen operational taxonomic units (OTUs) were obtained by multiple sequence alignment from the flowerbed and agricultural field nematodes, respectively. All 29 SSU rDNA-derived OTUs (rOTUs) were further mapped onto a phylogenetic tree with 107 known nematode species. Interestingly, the two nematode communities examined were clearly distinct from each other in terms of trophic groups: Animal predators and plant feeders were markedly abundant in the flowerbed soils, in contrast, bacterial feeders were dominantly observed in the agricultural field soils. The data from the flowerbed nematodes suggests a possible food web among two different trophic nematode groups and plants (weeds) in the closed soil environment. Finally, DNA sequences derived from the mitochondrial cytochrome oxidase c subunit 1 (COI) gene were determined as a DNA barcode from 43 agricultural field soil nematodes. These nematodes were assigned to 13 rDNA-derived OTUs, but in the COI gene analysis were assigned to 23 COI gene-derived OTUs (cOTUs), indicating that COI gene-based barcoding may provide higher taxonomic resolution than conventional SSU rDNA-barcoding in soil nematode community analysis. PMID:23284767

  11. Profiling nematode communities in unmanaged flowerbed and agricultural field soils in Japan by DNA barcode sequencing.

    PubMed

    Morise, Hisashi; Miyazaki, Erika; Yoshimitsu, Shoko; Eki, Toshihiko

    2012-01-01

    Soil nematodes play crucial roles in the soil food web and are a suitable indicator for assessing soil environments and ecosystems. Previous nematode community analyses based on nematode morphology classification have been shown to be useful for assessing various soil environments. Here we have conducted DNA barcode analysis for soil nematode community analyses in Japanese soils. We isolated nematodes from two different environmental soils of an unmanaged flowerbed and an agricultural field using the improved flotation-sieving method. Small subunit (SSU) rDNA fragments were directly amplified from each of 68 (flowerbed samples) and 48 (field samples) isolated nematodes to determine the nucleotide sequence. Sixteen and thirteen operational taxonomic units (OTUs) were obtained by multiple sequence alignment from the flowerbed and agricultural field nematodes, respectively. All 29 SSU rDNA-derived OTUs (rOTUs) were further mapped onto a phylogenetic tree with 107 known nematode species. Interestingly, the two nematode communities examined were clearly distinct from each other in terms of trophic groups: Animal predators and plant feeders were markedly abundant in the flowerbed soils, in contrast, bacterial feeders were dominantly observed in the agricultural field soils. The data from the flowerbed nematodes suggests a possible food web among two different trophic nematode groups and plants (weeds) in the closed soil environment. Finally, DNA sequences derived from the mitochondrial cytochrome oxidase c subunit 1 (COI) gene were determined as a DNA barcode from 43 agricultural field soil nematodes. These nematodes were assigned to 13 rDNA-derived OTUs, but in the COI gene analysis were assigned to 23 COI gene-derived OTUs (cOTUs), indicating that COI gene-based barcoding may provide higher taxonomic resolution than conventional SSU rDNA-barcoding in soil nematode community analysis.

  12. Mechanisation of large-scale agricultural fields in developing countries - a review.

    PubMed

    Onwude, Daniel I; Abdulstter, Rafia; Gomes, Chandima; Hashim, Norhashila

    2016-09-01

    Mechanisation of large-scale agricultural fields often requires the application of modern technologies such as mechanical power, automation, control and robotics. These technologies are generally associated with relatively well developed economies. The application of these technologies in some developing countries in Africa and Asia is limited by factors such as technology compatibility with the environment, availability of resources to facilitate the technology adoption, cost of technology purchase, government policies, adequacy of technology and appropriateness in addressing the needs of the population. As a result, many of the available resources have been used inadequately by farmers, who continue to rely mostly on conventional means of agricultural production, using traditional tools and equipment in most cases. This has led to low productivity and high cost of production among others. Therefore this paper attempts to evaluate the application of present day technology and its limitations to the advancement of large-scale mechanisation in developing countries of Africa and Asia. Particular emphasis is given to a general understanding of the various levels of mechanisation, present day technology, its management and application to large-scale agricultural fields. This review also focuses on/gives emphasis to future outlook that will enable a gradual, evolutionary and sustainable technological change. The study concludes that large-scale-agricultural farm mechanisation for sustainable food production in Africa and Asia must be anchored on a coherent strategy based on the actual needs and priorities of the large-scale farmers. © 2016 Society of Chemical Industry.

  13. Mechanisation of large-scale agricultural fields in developing countries - a review.

    PubMed

    Onwude, Daniel I; Abdulstter, Rafia; Gomes, Chandima; Hashim, Norhashila

    2016-09-01

    Mechanisation of large-scale agricultural fields often requires the application of modern technologies such as mechanical power, automation, control and robotics. These technologies are generally associated with relatively well developed economies. The application of these technologies in some developing countries in Africa and Asia is limited by factors such as technology compatibility with the environment, availability of resources to facilitate the technology adoption, cost of technology purchase, government policies, adequacy of technology and appropriateness in addressing the needs of the population. As a result, many of the available resources have been used inadequately by farmers, who continue to rely mostly on conventional means of agricultural production, using traditional tools and equipment in most cases. This has led to low productivity and high cost of production among others. Therefore this paper attempts to evaluate the application of present day technology and its limitations to the advancement of large-scale mechanisation in developing countries of Africa and Asia. Particular emphasis is given to a general understanding of the various levels of mechanisation, present day technology, its management and application to large-scale agricultural fields. This review also focuses on/gives emphasis to future outlook that will enable a gradual, evolutionary and sustainable technological change. The study concludes that large-scale-agricultural farm mechanisation for sustainable food production in Africa and Asia must be anchored on a coherent strategy based on the actual needs and priorities of the large-scale farmers. © 2016 Society of Chemical Industry. PMID:26940194

  14. Safety and immunogenicity of Ontario Rabies Vaccine Bait (ONRAB) in the first us field trial in raccoons (Procyon lotor).

    PubMed

    Slate, Dennis; Chipman, Richard B; Algeo, Timothy P; Mills, Samuel A; Nelson, Kathleen M; Croson, Christopher K; Dubovi, Edward J; Vercauteren, Kurt; Renshaw, Randall W; Atwood, Todd; Johnson, Shylo; Rupprecht, Charles E

    2014-07-01

    In 2011, we conducted a field trial in rural West Virginia, USA to evaluate the safety and immunogenicity of a live, recombinant human adenovirus (AdRG1.3) rabies virus glycoprotein vaccine (Ontario Rabies Vaccine Bait; ONRAB) in wild raccoons (Procyon lotor) and striped skunks (Mephitis mephitis). We selected ONRAB for evaluation because of its effectiveness in raccoon rabies management in Ontario and Quebec, Canada, and significantly higher antibody prevalence rates in raccoons compared with a recombinant vaccinia-rabies glycoprotein (V-RG) vaccine, Raboral V-RG®, in US-Canada border studies. Raccoon rabies was enzootic and oral rabies vaccination (ORV) had never been used in the study area. We distributed 79,027 ONRAB baits at 75 baits/km(2) mostly by fixed-wing aircraft along parallel flight lines at 750-m intervals. Antibody prevalence was significantly higher at 49.2% (n=262) in raccoons after ONRAB was distributed than the 9.6% (n=395) before ORV. This was the highest antibody prevalence observed in raccoons by US Department of Agriculture Wildlife Services for areas with similar management histories evaluated before and after an initial ORV campaign at 75 baits/km(2) with Raboral V-RG. Tetracycline biomarker (TTCC) was significantly higher among antibody-positive raccoons after ONRAB baiting and was similar among raccoons before ORV had been conducted, an indication of vaccine-induced rabies virus-neutralizing antibody production following consumption of bait containing TTCC. Skunk sample size was inadequate to assess ONRAB effects. Safety and immunogenicity results supported replication of this field trial and led to a recommendation for expanded field trials in 2012 to evaluate safety and immunogenicity of ground-distributed ONRAB at 150 baits/km(2) in residential and commercial habitats in Ohio, USA and aerially distributed ONRAB at 75 baits/km(2) in rural habitats along US-Quebec border. PMID:24807178

  15. Safety and immunogenicity of Ontario Rabies Vaccine Bait (ONRAB) in the first us field trial in raccoons (Procyon lotor).

    PubMed

    Slate, Dennis; Chipman, Richard B; Algeo, Timothy P; Mills, Samuel A; Nelson, Kathleen M; Croson, Christopher K; Dubovi, Edward J; Vercauteren, Kurt; Renshaw, Randall W; Atwood, Todd; Johnson, Shylo; Rupprecht, Charles E

    2014-07-01

    In 2011, we conducted a field trial in rural West Virginia, USA to evaluate the safety and immunogenicity of a live, recombinant human adenovirus (AdRG1.3) rabies virus glycoprotein vaccine (Ontario Rabies Vaccine Bait; ONRAB) in wild raccoons (Procyon lotor) and striped skunks (Mephitis mephitis). We selected ONRAB for evaluation because of its effectiveness in raccoon rabies management in Ontario and Quebec, Canada, and significantly higher antibody prevalence rates in raccoons compared with a recombinant vaccinia-rabies glycoprotein (V-RG) vaccine, Raboral V-RG®, in US-Canada border studies. Raccoon rabies was enzootic and oral rabies vaccination (ORV) had never been used in the study area. We distributed 79,027 ONRAB baits at 75 baits/km(2) mostly by fixed-wing aircraft along parallel flight lines at 750-m intervals. Antibody prevalence was significantly higher at 49.2% (n=262) in raccoons after ONRAB was distributed than the 9.6% (n=395) before ORV. This was the highest antibody prevalence observed in raccoons by US Department of Agriculture Wildlife Services for areas with similar management histories evaluated before and after an initial ORV campaign at 75 baits/km(2) with Raboral V-RG. Tetracycline biomarker (TTCC) was significantly higher among antibody-positive raccoons after ONRAB baiting and was similar among raccoons before ORV had been conducted, an indication of vaccine-induced rabies virus-neutralizing antibody production following consumption of bait containing TTCC. Skunk sample size was inadequate to assess ONRAB effects. Safety and immunogenicity results supported replication of this field trial and led to a recommendation for expanded field trials in 2012 to evaluate safety and immunogenicity of ground-distributed ONRAB at 150 baits/km(2) in residential and commercial habitats in Ohio, USA and aerially distributed ONRAB at 75 baits/km(2) in rural habitats along US-Quebec border.

  16. Effects of agricultural practices of three crops on the soil communities under Mediterranean conditions: field evaluation.

    NASA Astrophysics Data System (ADS)

    Leitão, Sara; José Cerejeira, Maria; Abreu, Manuela; Sousa, José Paulo

    2014-05-01

    Sustainable agricultural production relies on soil communities as the main actors in key soil processes necessary to maintain sustainable soil functioning. Soil biodiversity influences soil physical and chemical characteristics and thus the sustainability of crop and agro-ecosystems functioning. Agricultural practices (e.g.: soil tillage, pesticides and fertilizer applications, irrigation) may affects negatively or positively soil biodiversity and abundances by modifying the relationships between organisms in the soil ecosystem. The present study aimed to study the influence of agricultural practices of three crops (potato, onion and maize) under Mediterranean climate conditions on soil macro- and mesofauna during their entire crop cycles. Effects on soil communities were assessed at a higher tier of environmental risk assessment comprising field testing of indigenous edaphic communities in a selected study-site located in a major agriculture region of Central Portugal, Ribatejo e Oeste, neighbouring protected wetlands. A reference site near the agricultural field site was selected as a Control site to compare the terrestrial communities' composition and variation along the crop cycle. The field soil and Control site soil are sandy loam soils. Crops irrigation was performed by center-pivot (automated sprinkler that rotates in a half a circle area) and by sprinklers. Soil macro- and mesofauna were collected at both sites (field and Control) using two methodologies through pitfall trapping and soil sampling. The community of soil macro- and mesofauna of the three crops field varied versus control site along the crops cycles. Main differences were due to arachnids, coleopterans, ants and adult Diptera presence and abundance. The feeding activity of soil fauna between control site and crop areas varied only for potato and onion crops vs. control site but not among crops. Concentration of pesticides residues in soil did not cause apparent negative effects on the soil

  17. Assessing field vulnerability to phosphorus loss in Beijing agricultural area using Revised Field Phosphorus Ranking Scheme.

    PubMed

    Li, Qi; Chen, Li-ding; Qi, Xin; Zhang, Xin-yu; Ma, Yan; Fu, Bo-jie

    2007-01-01

    Guanting Reservoir, one of the drinking water supply sources of Beijing, suffers from water eutrophication. It is mainly supplied by Guishui River. Thus, to investigate the reasons of phosphorus (P) loss and improve the P management strategies in Guishui River watershed are important for the safety of drinking water in this region. In this study, a Revised Field P Ranking Scheme (PRS) was developed to reflect the field vulnerability of P loss at the field scale based on the Field PRS. In this new scheme, six factors are included, and each one was assigned a relative weight and a determination method. The affecting factors were classified into transport factors and source factors, and, the standards of environmental quality on surface water and soil erosion classification and degradation of the China were used in this scheme. By the new scheme, thirty-four fields in the Guishui River were categorized as "low", "medium" or "high" potential for P loss into the runoff. The results showed that the P loss risks of orchard and vegetable fields were higher than that of corn and soybean fields. The source factors were the main factors to affect P loss from the study area. In the study area, controlling P input and improving P usage efficiency are critical to decrease P loss. Based on the results, it was suggested that more attention should be paid on the fields of vegetable and orchard since they have extremely high usage rate of P and high soil test of P. Compared with P surplus by field measurements, the Revised Field PRS was more suitable for reflecting the characteristics of fields, and had higher potential capacity to identify critical source areas of P loss than PRS. PMID:17966855

  18. A GPS Backpack System for Mapping Soil and Crop Parameters in Agricultural Fields

    NASA Astrophysics Data System (ADS)

    Stafford, J. V.; Lebars, J. M.

    Farmers are having to gather increasing amounts of data on their soils and crops. Precision agriculture metre-by-metre is based on a knowledge of the spatial variation of soil and crop parameters across a field. The data has to be spatially located and GPS is an effective way of doing this. A backpack data logging system with GPS position tagging is described which has been designed to aid a fanner in the manual collection of data.

  19. Progress in the Understanding of Narrow Directional Scattering over Agricultural Fields

    NASA Astrophysics Data System (ADS)

    Wegmuller, U.; Santoro, M.; Mattia, F.; Balenzano, A.; Satalino, G.; Marzahn, P.; Fischer, G.; Ludwig, R.; Floury, N.

    2010-12-01

    Results achieved in a comprehensive study on directional microwave scattering over agricultural fields are presented. Major progress presented includes the much improved experimental evidence achieved and significant improvements in the understanding of the scatter phenomenon through the presented scatter model. Good progress is also made in the detection of directional scattering. It is concluded that directional scattering is relevant for applications and cannot just be ignored.

  20. Agricultural fields, Khartoum, Sudan, Africa Description: This herringbone pattern of irrigated

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This herringbone pattern of irrigated agricultural fields near Khartoum, Sudan (14.5N, 33.5E) was imaged with infrared film as part an experiment to compare the merits of color film versus color infrared film. Color film presents the image as it appears to the eye whereas color infrared film has an excellent haze penetration and vegetation definition capability. See color film image STS049-77-072 for a detailed scene description.

  1. Vegetation Water Content Mapping in a Diverse Agricultural Landscape: National Airborne Field Experiment 2006

    NASA Technical Reports Server (NTRS)

    Cosh, Michael H.; Jing Tao; Jackson, Thomas J.; McKee, Lynn; O'Neill, Peggy

    2011-01-01

    Mapping land cover and vegetation characteristics on a regional scale is critical to soil moisture retrieval using microwave remote sensing. In aircraft-based experiments such as the National Airborne Field Experiment 2006 (NAFE 06), it is challenging to provide accurate high resolution vegetation information, especially on a daily basis. A technique proposed in previous studies was adapted here to the heterogenous conditions encountered in NAFE 06, which included a hydrologically complex landscape consisting of both irrigated and dryland agriculture. Using field vegetation sampling and ground-based reflectance measurements, the knowledge base for relating the Normalized Difference Water Index (NDWI) and the vegetation water content was extended to a greater diversity of agricultural crops, which included dryland and irrigated wheat, alfalfa, and canola. Critical to the generation of vegetation water content maps, the land cover for this region was determined from satellite visible/infrared imagery and ground surveys with an accuracy of 95.5% and a kappa coefficient of 0.95. The vegetation water content was estimated with a root mean square error of 0.33 kg/sq m. The results of this investigation contribute to a more robust database of global vegetation water content observations and demonstrate that the approach can be applied with high accuracy. Keywords: Vegetation, field experimentation, thematic mapper, NDWI, agriculture.

  2. Field trials of line transect methods applied to estimation of desert tortoise abundance

    USGS Publications Warehouse

    Anderson, David R.; Burnham, Kenneth P.; Lubow, Bruce C.; Thomas, L. E. N.; Corn, Paul Stephen; Medica, Philip A.; Marlow, R.W.

    2001-01-01

    We examine the degree to which field observers can meet the assumptions underlying line transect sampling to monitor populations of desert tortoises (Gopherus agassizii). We present the results of 2 field trials using artificial tortoise models in 3 size classes. The trials were conducted on 2 occasions on an area south of Las Vegas, Nevada, where the density of the test population was known. In the first trials, conducted largely by experienced biologists who had been involved in tortoise surveys for many years, the density of adult tortoise models was well estimated (-3.9% bias), while the bias was higher (-20%) for subadult tortoise models. The bias for combined data was -12.0%. The bias was largely attributed to the failure to detect all tortoise models on or near the transect centerline. The second trials were conducted with a group of largely inexperienced student volunteers and used somewhat different searching methods, and the results were similar to the first trials. Estimated combined density of subadult and adult tortoise models had a negative bias (-7.3%), again attributable to failure to detect some models on or near the centerline. Experience in desert tortoise biology, either comparing the first and second trials or in the second trial with 2 experienced biologists versus 16 novices, did not have an apparent effect on the quality of the data or the accuracy of the estimates. Observer training, specific to line transect sampling, and field testing are important components of a reliable survey. Line transect sampling represents a viable method for large-scale monitoring of populations of desert tortoise; however, field protocol must be improved to assure the key assumptions are met.

  3. Mississippi exploration field trials using microbial, radiometrics, free soil gas, and other techniques

    SciTech Connect

    Moody, J.S.; Brown, L.R.; Thieling, S.C.

    1995-12-31

    The Mississippi Office of Geology has conducted field trials using the surface exploration techniques of geomicrobial, radiometrics, and free soil gas. The objective of these trials is to determine if Mississippi oil and gas fields have surface hydrocarbon expression resulting from vertical microseepage migration. Six fields have been surveyed ranging in depth from 3,330 ft to 18,500 ft. The fields differ in trapping styles and hydrocarbon type. The results so far indicate that these fields do have a surface expression and that geomicrobial analysis as well as radiometrics and free soil gas can detect hydrocarbon microseepage from pressurized reservoirs. All three exploration techniques located the reservoirs independent of depth, hydrocarbon type, or trapping style.

  4. Identifying Landscape Areas Prone to Generating Storm Runoff in Central New York Agricultural Fields

    NASA Astrophysics Data System (ADS)

    Hofmeister, K.; Walter, M. T.

    2015-12-01

    Nonpoint source (NPS) pollution continues to be a leading cause of surface water degradation, especially in agricultural areas. In humid regions where variable source area (VSA) hydrology dominates storm runoff, NPS pollution is generated where VSAs coincide with polluting activities. Mapping storm runoff risks could allow for more precise and informed targeting of NPS pollution mitigation practices in agricultural landscapes. Topographic wetness indices (TWI) provide good approximations of relative soil moisture patterns and relative storm runoff risks. Simulation models are typically used in conjunction with TWIs to quantify VSA behavior. In this study we use empirically derived relationships between TWI values, volumetric water content (VWC) and rainfall frequencies to develop runoff probability maps. Rainfall and soil VWC were measured across regionally representative agricultural areas in central New York over three years (2012-2015) to determine the volume of runoff generated from agricultural fields in the area. We assumed the threshold for storm runoff occurs when the combination of antecedent soil water and rainfall are sufficient to saturate the soil. We determined that approximately 50% of the storm runoff volume is generated from 10% of the land area during spring, summer, and autumn seasons, while the risk of storm runoff generation is higher in the spring and autumn seasons than in the summer for the same area of land.

  5. Determination of the immunization schedule for field trials with the synthetic malaria vaccine SPf 66.

    PubMed

    Rocha, C L; Murillo, L A; Mora, A L; Rojas, M; Franco, L; Cote, J; Valero, M V; Moreno, A; Amador, R; Nuñez, F

    1992-01-01

    The synthetic malaria vaccine SPf 66 has been shown to be safe, immunogenic and effective in trials performed with controlled groups naturally and experimentally exposed to the disease. In order to continue the trials in open populations, it was necessary to standardize the vaccination characteristics. We have performed four field trials with soldier volunteers with the aim, among others, of defining the number of doses required, the intervals between applications, the protein concentration, and the adjuvant to be used. In these trials, the vaccinated individuals' immune responses were evaluated by assaying anti-SPf 66 antibody titres, in vitro growth inhibition of the P. falciparum parasite, and the vaccinees' capacity to recognize P. falciparum native proteins. From these results we conclude that the best vaccination schedule, for adults, is three doses administered subcutaneously on days 0, 30 and 180, each containing 2 mg of the synthetic polymerized petide SPf 66 adsorbed to alum hydroxide.

  6. Shamba Maisha: Randomized controlled trial of an agricultural and finance intervention to improve HIV health outcomes in Kenya

    PubMed Central

    WEISER, Sheri D.; BUKUSI, Elizabeth A.; STEINFELD, Rachel L.; FRONGILLO, Edward A.; WEKE, Elly; DWORKIN, Shari L.; PUSATERI, Kyle; SHIBOSKI, Stephen; SCOW, Kate; BUTLER, Lisa M.; COHEN, Craig R.

    2015-01-01

    Objectives Food insecurity and HIV/AIDS outcomes are inextricably linked in sub-Saharan Africa. We report on health and nutritional outcomes of a multisectoral agricultural intervention trial among HIV-infected adults in rural Kenya. Design Pilot cluster randomized controlled trial Methods The intervention included a human-powered water pump, a microfinance loan to purchase farm commodities, and education in sustainable farming practices and financial management. Two health facilities in Nyanza Region, Kenya were randomly assigned as intervention or control. HIV-infected adults 18 to 49 years old who were on antiretroviral therapy and had access to surface water and land were enrolled beginning in April 2012 and followed quarterly for one year. Data were collected on nutritional parameters, CD4 T lymphocyte counts, and HIV RNA. Difference in difference fixed-effects regression models were used to test whether patterns in health outcomes differed over time from baseline between the intervention and control arms. Results We enrolled 72 and 68 participants in the intervention and control groups, respectively. At 12 months follow-up, we found a statistically significant increase in CD4 cell counts (165 cells/mm3, p<0.001) and proportion virologically suppressed in the intervention arm compared to the control arm (comparative improvement in proportion of 0.33 suppressed, OR 7.6, 95% CI: 2.2–26.8). Intervention participants experienced significant improvements in food security (3.6 scale points higher, p<0.001) and frequency of food consumption (9.4 times per week greater frequency, p=0.013) compared to controls. Conclusion Livelihood interventions may be a promising approach to tackle the intersecting problems of food insecurity, poverty and HIV/AIDS morbidity. PMID:26214684

  7. Methods for testing theory and evaluating impact in randomized field trials

    PubMed Central

    Brown, C. Hendricks; Wang, Wei; Kellam, Sheppard G.; Muthén, Bengt O.; Petras, Hanno; Toyinbo, Peter; Poduska, Jeanne; Ialongo, Nicholas; Wyman, Peter A.; Chamberlain, Patricia; Sloboda, Zili; MacKinnon, David P.; Windham, Amy

    2008-01-01

    Randomized field trials provide unique opportunities to examine the effectiveness of an intervention in real world settings and to test and extend both theory of etiology and theory of intervention. These trials are designed not only to test for overall intervention impact but also to examine how impact varies as a function of individual level characteristics, context, and across time. Examination of such variation in impact requires analytical methods that take into account the trial’s multiple nested structure and the evolving changes in outcomes over time. The models that we describe here merge multilevel modeling with growth modeling, allowing for variation in impact to be represented through discrete mixtures—growth mixture models—and nonparametric smooth functions—generalized additive mixed models. These methods are part of an emerging class of multilevel growth mixture models, and we illustrate these with models that examine overall impact and variation in impact. In this paper, we define intent-to-treat analyses in group-randomized multilevel field trials and discuss appropriate ways to identify, examine, and test for variation in impact without inflating the Type I error rate. We describe how to make causal inferences more robust to misspecification of covariates in such analyses and how to summarize and present these interactive intervention effects clearly. Practical strategies for reducing model complexity, checking model fit, and handling missing data are discussed using six randomized field trials to show how these methods may be used across trials randomized at different levels. PMID:18215473

  8. FIELD TRIALS OF NEWLY DEVELOPED POSITIVE DISPLACEMENT SUBMERSIBLE PUMP

    SciTech Connect

    Rob Beard

    2003-10-01

    The purpose of this grant was to evaluate under real world conditions the performance of a new type of downhole pump, the hydraulically driven submersible diaphragm pump. This pump is supplied by Pumping Solutions Incorporated, Albuquerque NM. The original scope of the project was to install 10 submersible pumps, and compare that to 10 similar installations of rod pumps. As an operator, the system as tested was not ready for prime time, but has shown the ability to reduce costs, and increase production, if run times can be improved. The PSI group did improve the product and offered excellent service. The latest design appears to be much better, but more test data is needed to show short run life is not a problem. PSI and Beard Oil intend to continue testing the pump with non-government funding. The testing to date did not uncover any fundamental problems that would preclude the widespread use of this pump, and as an operator, I believe that with further improvement and testing, the pump can have a significant impact on stripper well costs. On the positive side, the pump was easy to run, was more power efficient then a rod pump, and is the only submersible that could handle the large quantities of solids typical of the production environment found at the Weber field and in CMB production. The product shows much promise for the future, and with continued design and testing, this type of submersible pump has the potential to become the standard of the industry.

  9. Dissipation of PAHs in saturated, dredged sediments: a field trial.

    PubMed

    Smith, K E; Schwab, A P; Banks, M K

    2008-08-01

    Sediments dredged from navigable rivers often contain elevated concentrations of recalcitrant, potentially toxic organic compounds such as polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). The presence of these compounds often requires that the sediments be stored in fully contained disposal facilities. A 3-year field study was conducted at the Jones Island disposal facility in Milwaukee, Wisconsin, to compare bioremediation of PAHs in contaminated dredged sediments in the absence of plants to phytoremediation with Salix nigra (black willow) (SX61), Spartina pectinata (prairie cord grass), Carex aquatalis (lake sedge), Lolium multiflorum (annual rye), and Scirpus fluviatilis (bulrush). Nine PAHs were detected initially in the sediments. Over the 3-year experiment, acenaphthene dissipation ranged from 94% to 100%, whereas anthracene, benzo[a]pyrene and indo[1,2,3-cd]pyrene generally had modest decreases in concentration (0-30% decrease). The remaining five PAHs ranged in degree of disappearance from 23% to 82%. Planted treatments did not enhance PAH dissipation relative to those without plants, but treatments with high biomass yield and high transpiration plant species had significantly less removal of PAHs than unplanted controls. Significant, negative correlations between nitrogen removal and decreases in PAH concentration suggest that competition for nutrients between plants and microorganisms may have impeded the microbial degradation of PAHs in the rhizosphere of the more rapidly growing plant species.

  10. Field calibration of surface: a model of agricultural chemicals in surface waters.

    PubMed

    Gustafson, D I

    1990-10-01

    Agricultural chemicals sporadically occur at detectable levels in the surface waters of intensively farmed watersheds. HSPF, a previously released model of agricultural chemicals in surface water, had been used to predict concentrations which were much higher (10 X) than those actually observed during monitoring studies. A new model, SURFACE, is described here which is much simpler than HSPF and gives better predictions of surface water concentrations. SURFACE uses PRZM, an EPA model, to calculate edge-of-field runoff losses and simple hydraulic routing algorithms to determine concentrations at the bottom of large river basins. In water systems sampled during 1985 and 1986, SURFACE predictions of annualized mean concentrations for alachlor, atrazine, cyanazine and metolachlor were within 0.09 ppb half of the time.

  11. Multiple routes of pesticide exposure for honey bees living near agricultural fields.

    PubMed

    Krupke, Christian H; Hunt, Greg J; Eitzer, Brian D; Andino, Gladys; Given, Krispn

    2012-01-01

    Populations of honey bees and other pollinators have declined worldwide in recent years. A variety of stressors have been implicated as potential causes, including agricultural pesticides. Neonicotinoid insecticides, which are widely used and highly toxic to honey bees, have been found in previous analyses of honey bee pollen and comb material. However, the routes of exposure have remained largely undefined. We used LC/MS-MS to analyze samples of honey bees, pollen stored in the hive and several potential exposure routes associated with plantings of neonicotinoid treated maize. Our results demonstrate that bees are exposed to these compounds and several other agricultural pesticides in several ways throughout the foraging period. During spring, extremely high levels of clothianidin and thiamethoxam were found in planter exhaust material produced during the planting of treated maize seed. We also found neonicotinoids in the soil of each field we sampled, including unplanted fields. Plants visited by foraging bees (dandelions) growing near these fields were found to contain neonicotinoids as well. This indicates deposition of neonicotinoids on the flowers, uptake by the root system, or both. Dead bees collected near hive entrances during the spring sampling period were found to contain clothianidin as well, although whether exposure was oral (consuming pollen) or by contact (soil/planter dust) is unclear. We also detected the insecticide clothianidin in pollen collected by bees and stored in the hive. When maize plants in our field reached anthesis, maize pollen from treated seed was found to contain clothianidin and other pesticides; and honey bees in our study readily collected maize pollen. These findings clarify some of the mechanisms by which honey bees may be exposed to agricultural pesticides throughout the growing season. These results have implications for a wide range of large-scale annual cropping systems that utilize neonicotinoid seed treatments.

  12. Multiple Routes of Pesticide Exposure for Honey Bees Living Near Agricultural Fields

    PubMed Central

    Krupke, Christian H.; Hunt, Greg J.; Eitzer, Brian D.; Andino, Gladys; Given, Krispn

    2012-01-01

    Populations of honey bees and other pollinators have declined worldwide in recent years. A variety of stressors have been implicated as potential causes, including agricultural pesticides. Neonicotinoid insecticides, which are widely used and highly toxic to honey bees, have been found in previous analyses of honey bee pollen and comb material. However, the routes of exposure have remained largely undefined. We used LC/MS-MS to analyze samples of honey bees, pollen stored in the hive and several potential exposure routes associated with plantings of neonicotinoid treated maize. Our results demonstrate that bees are exposed to these compounds and several other agricultural pesticides in several ways throughout the foraging period. During spring, extremely high levels of clothianidin and thiamethoxam were found in planter exhaust material produced during the planting of treated maize seed. We also found neonicotinoids in the soil of each field we sampled, including unplanted fields. Plants visited by foraging bees (dandelions) growing near these fields were found to contain neonicotinoids as well. This indicates deposition of neonicotinoids on the flowers, uptake by the root system, or both. Dead bees collected near hive entrances during the spring sampling period were found to contain clothianidin as well, although whether exposure was oral (consuming pollen) or by contact (soil/planter dust) is unclear. We also detected the insecticide clothianidin in pollen collected by bees and stored in the hive. When maize plants in our field reached anthesis, maize pollen from treated seed was found to contain clothianidin and other pesticides; and honey bees in our study readily collected maize pollen. These findings clarify some of the mechanisms by which honey bees may be exposed to agricultural pesticides throughout the growing season. These results have implications for a wide range of large-scale annual cropping systems that utilize neonicotinoid seed treatments. PMID

  13. ETHICAL ISSUES IN FIELD TRIALS OF GENETICALLY MODIFIED DISEASE-RESISTANT MOSQUITOES

    PubMed Central

    RESNIK, DAVID B.

    2012-01-01

    Mosquito-borne diseases take a tremendous toll on human populations, especially in developing nations. In the last decade, scientists have developed mosquitoes that have been genetically modified to prevent transmission of mosquito-borne diseases, and field trials have been conducted. Some mosquitoes have been rendered infertile, some have been equipped with a vaccine they transmit to humans, and some have been designed to resist diseases. This article focuses on ethical issues raised by field trials of disease-resistant, genetically modified mosquitoes. Some of these issues include: protecting the public and the environment from harm, balancing benefits and risks, collaborating with the local community, avoiding exploitation, and safeguarding the rights and welfare of research subjects. One of the most difficult problems involves protecting the welfare of community members who will be impacted by the release of mosquitoes but who are not enrolled in the study as research subjects. To address this concern, field trials should take place only when the targeted disease is a significant public health problem in an isolated area, the benefits of the trial for the community are likely to outweigh the risks, community leaders approve of the trial, and there are measures in place to protect the welfare of un-enrolled community members, such as informing the community about the study and offering free treatment to people who contract mosquito-borne diseases. Since the justification of any field trial depends on a careful examination of the scientific and ethical issues, proposed studies should be evaluated on a case-by-case basis. PMID:23279283

  14. Effects of Academic Vocabulary Instruction for Linguistically Diverse Adolescents: Evidence from a Randomized Field Trial

    ERIC Educational Resources Information Center

    Lesaux, Nonie K.; Kieffer, Michael J.; Kelley, Joan G.; Harris, Julie Russ

    2014-01-01

    We conducted a randomized field trial to test an academic vocabulary intervention designed to bolster the language and literacy skills of linguistically diverse sixth-grade students (N = 2,082; n = 1,469 from a home where English is not the primary language), many demonstrating low achievement, enrolled in 14 urban middle schools. The 20-week…

  15. The Role of Treatment Fidelity on Outcomes during a Randomized Field Trial of an Autism Intervention

    ERIC Educational Resources Information Center

    Mandell, David S; Stahmer, Aubyn C; Shin, Sujie; Xie, Ming; Reisinger, Erica; Marcus, Steven C

    2013-01-01

    This randomized field trial comparing Strategies for Teaching based on Autism Research and Structured Teaching enrolled educators in 33 kindergarten-through-second-grade autism support classrooms and 119 students, aged 5-8 years in the School District of Philadelphia. Students were assessed at the beginning and end of the academic year using the…

  16. Effects of a Voluntary Summer Reading Intervention on Reading Achievement: Results from a Randomized Field Trial

    ERIC Educational Resources Information Center

    Kim, James S.

    2006-01-01

    The effects of a voluntary summer reading intervention were assessed in a randomized field trial involving 552 students in 10 schools. In this study, fourth-grade children received eight books to read during their summer vacation and were encouraged by their teachers to practice oral reading at home with a family member and to use comprehension…

  17. Edge-of-field research to quantify the impacts of agricultural practices on water quality in Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drainage is needed to sustain agricultural production to meet the demands of a growing global population, but it also transports nutrients from fields to surface water bodies. The State of Ohio is facing the tremendous challenge of maintaining agricultural production while protecting the environment...

  18. Dispersion characteristics and sinks for methyl bromide vapors downwind of treated agricultural fields

    SciTech Connect

    Seiber, J.N.; Woodrow, J.E.; Dowling, K.

    1995-12-31

    A study of methyl bromide volatilization and fate from a treated agricultural field was conducted in Monterey County, California, in 1994. Air concentrations were measured above and downwind from the field with the objective of comparing vertical and horizontal flux terms. Another objective was to compare observed downwind concentrations with those predicted by the Industrial Source Complex model, to begin the process of identifying potential sinks which might scavenge methyl bromide from the atmosphere. The final objective was to determine the limit of detection of our analytical method for airborne methyl bromide using field samples representing a wide range of concentrations. A description of the methods and results of the study will be presented, along with a discussion of data quality and interpretation.

  19. Occurrence of an herbicide-resistant plant trait in agricultural field margins.

    PubMed

    Gage, Karla L; Gibson, David J; Young, Bryan G; Young, Julie M; Matthews, Joseph L; Weller, Stephen C; Wilson, Robert G

    2015-09-01

    Agricultural environments allow study of evolutionary change in plants. An example of evolution within agroecological systems is the selection for resistance to the herbicide glyphosate within the weed, Conyza canadensis. Changes in survivorship and reproduction associated with the development of glyphosate resistance (GR) may impact fitness and influence the frequency of occurrence of the GR trait. We hypothesized that site characteristics and history would affect the occurrence of GR C. canadensis in field margins. We surveyed GR occurrence in field margins and asked whether there were correlations between GR occurrence and location, crop rotation, GR crop trait rotation, crop type, use of tillage, and the diversity of herbicides used. In a field experiment, we hypothesized that there would be no difference in fitness between GR and glyphosate-susceptible (GS) plants. We asked whether there were differences in survivorship, phenology, reproduction, and herbivory between 2 GR and 2 GS populations of C. canadensis in agrestal and ruderal habitats. We found that geographic location was an important factor in the occurrence of GR C. canadensis in field margins. Although not consistently associated with either glyphosate resistance or glyphosate susceptibility, there were differences in phenology, survivorship, and herbivory among biotypes of C. canadensis. We found equal or greater fitness in GR biotypes, compared to GS biotypes, and GR plants were present in field margins. Field margins or ruderal habitats may provide refugia for GR C. canadensis, allowing reproduction and further selection to occur as seeds recolonize the agrestal habitat. Agricultural practices may select for ecological changes that feed back into the evolution of plants in ruderal habitats. PMID:26445665

  20. Occurrence of an herbicide-resistant plant trait in agricultural field margins.

    PubMed

    Gage, Karla L; Gibson, David J; Young, Bryan G; Young, Julie M; Matthews, Joseph L; Weller, Stephen C; Wilson, Robert G

    2015-09-01

    Agricultural environments allow study of evolutionary change in plants. An example of evolution within agroecological systems is the selection for resistance to the herbicide glyphosate within the weed, Conyza canadensis. Changes in survivorship and reproduction associated with the development of glyphosate resistance (GR) may impact fitness and influence the frequency of occurrence of the GR trait. We hypothesized that site characteristics and history would affect the occurrence of GR C. canadensis in field margins. We surveyed GR occurrence in field margins and asked whether there were correlations between GR occurrence and location, crop rotation, GR crop trait rotation, crop type, use of tillage, and the diversity of herbicides used. In a field experiment, we hypothesized that there would be no difference in fitness between GR and glyphosate-susceptible (GS) plants. We asked whether there were differences in survivorship, phenology, reproduction, and herbivory between 2 GR and 2 GS populations of C. canadensis in agrestal and ruderal habitats. We found that geographic location was an important factor in the occurrence of GR C. canadensis in field margins. Although not consistently associated with either glyphosate resistance or glyphosate susceptibility, there were differences in phenology, survivorship, and herbivory among biotypes of C. canadensis. We found equal or greater fitness in GR biotypes, compared to GS biotypes, and GR plants were present in field margins. Field margins or ruderal habitats may provide refugia for GR C. canadensis, allowing reproduction and further selection to occur as seeds recolonize the agrestal habitat. Agricultural practices may select for ecological changes that feed back into the evolution of plants in ruderal habitats.

  1. Phosphorus adsorption and desorption potential of stream sediments and field soils in agricultural watersheds.

    PubMed

    Agudelo, Sandra C; Nelson, Nathan O; Barnes, Philip L; Keane, Timothy D; Pierzynski, Gary M

    2011-01-01

    Phosphorus release from stream sediments into water could increase P loads leaving agricultural watersheds and contribute to lag-time between implementation of best management practices and improvement in water quality. Improved understanding of P release from stream sediments can assist in setting water quality goals and designing stream monitoring programs. The objective of this study was to estimate the relative potential of sediments and soils to release P to stream water in two agricultural watersheds. Stream sediments were collected from banks, pools, riffles, and depositional features. Soils were sampled from wheat, row crop, pasture, and manure-amended fields. Sediments and soils were analyzed for equilibrium P concentration at zero net P sorption (EPC0), maximum P adsorption capacity (P(max)), anion exchange extractable P (P(lab)), and degree of P saturation. Dissolved reactive P (DRP) of stream water was monitored. Stream sediment EPC0 was similar to or less than EPC0 from field soils; however, P(lab) of stream sediments was three times less than field soils. Sediments were sandy and had low P(max) due to low oxalate-extractable Fe and Al, which could be explained by stream geomorphology. Manure-amended fields had the highest EPC0 and P(lab) due to continued inputs of manure-based P; however, conventionally fertilized fields also represented an important P source due to their vast extent. Stream water DRP was similar to EPC0 of sediments during base flow and similar to EPC0 of field soils during storm flow. These results indicate that sediments in these streams are a relatively minor P source. PMID:21488503

  2. Preparing students for higher education and careers in agriculture and related fields: An ethnography of an urban charter school

    NASA Astrophysics Data System (ADS)

    Henry, Kesha Atasha

    This study explored the preparation of students for higher education and careers in agriculturally-related fields at an urban charter high school. The data were collected through interviews, observations, and field notes. The data were analyzed by qualitative methodology with phenomenology as the theoretical framework. Findings indicated that administrators thought it was important to incorporate agricultural science courses into urban school curricula. They stated that agricultural science courses gave urban students a different way of looking at science and helped to enhance the science and technology focus of the school. Further, agricultural science courses helped to break urban students' stereotypes about agriculture and helped to bring in more state funding for educational programs. However they thought that it was more challenging to teach agricultural science in urban versus rural schools and they focused more on Science, Technology, Engineering, and Mathematics (STEM) related careers. The students had mixed views about higher education and careers in agriculture. This was based on their limited knowledge and stereotypes about agricultural majors and career options. The students highlighted several key reasons why they chose to enroll in agricultural science courses. This included the benefits of dual science credits and the ability to earn an associate degree upon successful completion of their program. Students also loved science and appreciated the science intensive nature of the agricultural courses. Additionally, they thought that the agricultural science courses were better than the other optional courses. The results also showed that electronic media such as radio and TV had a negative impact on students' perceptions about higher education and careers in agriculturally-related fields. Conclusions and recommendations are presented.

  3. Integrated analysis of root microbiomes of soybean and wheat from agricultural fields

    PubMed Central

    Rascovan, Nicolás; Carbonetto, Belén; Perrig, Diego; Díaz, Marisa; Canciani, Wilter; Abalo, Matías; Alloati, Julieta; González-Anta, Gustavo; Vazquez, Martín P.

    2016-01-01

    Root associated bacteria are critical for plant growth and health. Understanding the composition and role of root microbiota is crucial toward agricultural practices that are less dependent on chemical fertilization, which has known negative effects on the environment and human health. Here we analyzed the root-associated microbiomes of soybean and wheat under agricultural field conditions. We took samples from 11 different production fields across a large geographic area. We used 16S rRNA pyrosequencing to explore root microbial communities and also obtained 2,007 bacterial isolates from rhizospheres, which were tested for the presence of plant growth promoting (PGP) traits in-vitro. We observed that pH and nitrate content correlated with beta diversity variability of rhizospheric bacterial communities despite the variable field conditions. We described the dominant bacterial groups associated to roots from both crops at a large geographic scale and we found that a high proportion of them (60–70%) showed more than 97% similarity to bacteria from the isolated collection. Moreover, we observed that 55% of the screened isolates presented PGP activities in vitro. These results are a significant step forward in understanding crop-associated microbiomes and suggest that new directions can be taken to promote crop growth and health by modulating root microbiomes. PMID:27312589

  4. The Role Of Management Of The Field-Forest Boundary In Poland's Process Of Agricultural Restructuring

    NASA Astrophysics Data System (ADS)

    Woch, Franciszek; Borek, Robert

    2015-01-01

    The aim of the work described here has been to point to the relationships between the field-forest boundary and crop productivity as regards the present agrarian land-use structure in Poland, and to provide new opportunities for arranging the agrarian process and the spatial planning of the rural landscape in the context of the sustainable shaping of the field-forest boundary. Impacts of forests and woodlands on crop productivity have been assessed using available data from relevant Polish literature. An assessment of the plot-distribution pattern characterising farms in Poland was made on the basis of reference data from the Agency for the Restructuring and Modernisation of Agriculture. Finally, the possibility of afforestation of agricultural land has been evaluated within the existing legal framework, and on the basis of available data, with attention paid to the need to include organization of the field-forest boundary within the comprehensive management and planning of rural areas, and to preserve woody elements in patchy landscapes. This all creates an opportunity to test innovative approaches to integrated land use which combines the creation of public goods and local products based on participatory learning processes that bring in local stakeholders and decision-makers.

  5. Observation of soil moisture variability in agricultural and grassland field soils using a wireless sensor network

    NASA Astrophysics Data System (ADS)

    Priesack, Eckart; Schuh, Max

    2014-05-01

    Soil moisture dynamics is a key factor of energy and matter exchange between land surface and atmosphere. Therefore long-term observation of temporal and spatial soil moisture variability is important in studying impacts of climate change on terrestrial ecosystems and their possible feedbacks to the atmosphere. Within the framework of the network of terrestrial environmental observatories TERENO we installed at the research farm Scheyern in soils of two fields (of ca. 5 ha size each) the SoilNet wireless sensor network (Biogena et al. 2010). The SoilNet in Scheyern consists of 94 sensor units, 45 for the agricultural field site and 49 for the grassland site. Each sensor unit comprises 6 SPADE sensors, two sensors placed at the depths 10, 30 and 50 cm. The SPADE sensor (sceme.de GmbH, Horn-Bad Meinberg Germany) consists of a TDT sensor to estimate volumetric soil water content from soil electrical permittivity by sending an electromagnetic signal and measuring its propagation time, which depends on the soil dielectric properties and hence on soil water content. Additionally the SPADE sensor contains a temperature sensor (DS18B20). First results obtained from the SoilNet measurements at both fields sites will be presented and discussed. The observed high temporal and spatial variability will be analysed and related to agricultural management and basic soil properties (bulk density, soil texture, organic matter content and soil hydraulic characteristics).

  6. Field-measured drag area is a key correlate of level cycling time trial performance

    PubMed Central

    Peterman, James E.; Lim, Allen C.; Ignatz, Ryan I.; Edwards, Andrew G.

    2015-01-01

    Drag area (Ad) is a primary factor determining aerodynamic resistance during level cycling and is therefore a key determinant of level time trial performance. However, Ad has traditionally been difficult to measure. Our purpose was to determine the value of adding field-measured Ad as a correlate of level cycling time trial performance. In the field, 19 male cyclists performed a level (22.1 km) time trial. Separately, field-determined Ad and rolling resistance were calculated for subjects along with projected frontal area assessed directly (AP) and indirectly (Est AP). Also, a graded exercise test was performed to determine \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\dot {V}{O}_{2}$\\end{document}V˙O2 peak, lactate threshold (LT), and economy. \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\dot {V}{O}_{2}$\\end{document}V˙O2 peak (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$\\mathrm{l}~\\min ^{-1}$\\end{document}lmin−1) and power at LT were significantly correlated to power measured during the time trial (r = 0.83 and 0.69, respectively) but were not significantly correlated to performance time (r = − 0.42 and −0.45). The correlation with performance time improved significantly (p < 0.05) when these variables were normalized to Ad. Of note, Ad alone was better correlated to performance time (r = 0.85, p < 0.001) than any combination of non-normalized physiological

  7. Modelling field scale water partitioning using on-site observations in sub-Saharan rainfed agriculture

    NASA Astrophysics Data System (ADS)

    Makurira, H.; Savenije, H. H. G.; Uhlenbrook, S.

    2009-08-01

    Smallholder rainfed farming systems generally realise sub-optimal crop yields which are largely attributed to dry spell occurrences during crop growth stages. However, with improved farming practices, it seems possible to significantly increase yield levels even with little and highly variable rainfall. The presented results follow research conducted in the Makanya catchment in northern Tanzania where gross rainfall amounts to less than 400 mm/season which is insufficient to support staple food crops (e.g. maize). Alternative cultivation techniques such as runoff harvesting and in-field micro-storage structures are compared. These techniques aim to reduce soil and nutrient loss from the field but, more importantly, promote in-field infiltration and water retention. Water balance components have been observed in order to study water partitioning processes under different cultivation techniques. Based on rainfall, soil evaporation, transpiration, runoff and soil moisture measurements, a water balance model has been developed to simulate soil moisture variations over the growing season. It appears that about 50% of the diverted water leaves the root zone through deep percolation. Modelling shows that during the field trials the average productive transpiration flow ranged between 1.1-1.4 mm d-1 in the trial plots compared to 0.7-1.0 mm d-1 under traditional tillage practice. Productive transpiration processes accounted for 23-29% while losses to deep percolation accounted for 33-48% of the available water. Conclusions from the research are that the innovations tested are effective in enhancing soil moisture retention at field scale and that diversions allow crop growth moisture conditions to be attained with early rains. It is also concluded that there is more scope for efficient utilisation of the diverted runoff water if storage structures could be installed to regulate water flow to the root zone when required.

  8. Field experiments to evaluate nitrate-leaching from drained agriculturally used areas

    NASA Astrophysics Data System (ADS)

    Bednorz, Denise; Tauchnitz, Nadine; Christen, Olaf; Rupp, Holger; Meissner, Ralph

    2016-04-01

    Agricultural land use is one of the main sources for diffuse nitrogen (N) inputs into surface- and groundwater. To fulfill the objectives of the European water protection policy it is mandatory to optimize agricultural management and to adopt it to site specific conditions. N present in soil is dominated by organic N, and after mineralization inorganic plant available N, obtaining the components ammonia and nitrate (NO3-N). In the environment, NO3-N occurs as the negatively charged ion NO3- which is generally solved. Thus, NO3-N is the major N-species in waters, whereas its transport is directly influenced by the flow regime. In dependence of soil type and meteorological conditions, subsurface drainage was often installed to prevent water logged zones as a requirement for agricultural use. But drainage systems were often discussed as one of the main sources for NO3-N inputs into surface water due to temporary high discharge rates and short residence time of soil water resulting in limited conditions for NO3-N degradation via denitrification. In the study presented herein, two adjacent tile-drained agriculturally used areas with adjusted agronomic conditions but different soil properties were investigated regarding their flow regime and their N-kinetic from 11/1/2013 until 10/31/2015. Both fields obtained the same size and drainage network (drain depth 0.8 m, gab distance 10 m). Field I was influenced by confined groundwater conditions due to an alternating strata of sandy and loamy layers. Field II was impermeable from a depth of one meter, showing a backwater influenced flow regime. The temporal course of soil moisture (35, 60 and 85 cm depth), drain rate as well as ground- and backwater head was registered continuously at both sites. Furthermore NH4-N- and NO3-N-concentrations (cNO3-N) in each compartment were measured. The experimental results showed that field I revealed significantly lower discharged drain rates and NO3-N-loads (17.1 mm and 2.5 kg N

  9. Distribution of selenium in soils of agricultural fields, western San Joaquin Valley, California

    USGS Publications Warehouse

    Fujii, Roger; Deverel, S.J.; Hatfield, D.B.

    1988-01-01

    Soils from three agricultural fields in the Panoche Creek alluvial fan area in the western San Joaquin Valley, California, were analyzed for soluble, adsorbed, and total concentrations of selenium (Se) to assess the distribution and forms of Se in relation to the leaching of Se from soils. This assessment is needed to evaluate the importance of soil Se in affecting ground water concentrations. Soil samples were collected from three fields with drainage systems of different ages (6, 15, 1.5 yr) and different Se concentrations in drain water (58, 430, 3700 µg L−1, respectively). Concentrations of soluble Se and salinity were highest in soils from the field drained for 1.5 yr and lowest in the field drained for 6 yr. Of the total concentration of soil Se from all three fields, the proportion of adsorbed and soluble Se ranged from 1 to 11% and 2 > 0.68) in saturation extracts of soils sampled from below the water table. In contrast, most soluble salts and Se apparently have been leached from the unsaturated soils in the fields drained for 6 and 15 yr. For the leached soils, dissolution and precipitation of evaporite minerals containing Se may no longer control concentrations of soluble Se.

  10. Plot and Catchment Scale Hydrological Impacts of Agricultural Field Boundary Features

    NASA Astrophysics Data System (ADS)

    Coates, Victoria; Pattison, Ian

    2015-04-01

    Natural flood management aims to reduce downstream flow levels by delaying the movement of water through a catchment and increasing the amount of soil infiltration. Field boundary features such as hedgerows and dry stone walls are common features in the rural landscape. It is hypothesised that there presence could reduce runoff connectivity and change the soil moisture levels by altering the soil structure and porosity. The use of larger agricultural machinery has resulted in the removal of field boundaries and the subsequent increase in field sizes over the 20th Century. This change in the rural landscape is likely to have changed the partitioning of rainfall into runoff and the hydrological pathways throughout the catchment. However, the link between field boundaries and catchment scale flood risk has not yet been proven. We aim to address this need for evidence to support natural flood management by focussing on these widespread features in the rural landscape. Firstly, we quantify the change in the density of field boundaries over the past 120 years for the Skell catchment, Northern England using historical OS maps. The analysis has shown that field size has approximately doubled in the Skell catchment since 1892, due to the removal of field boundaries. Secondly, we assess the effect of field boundaries on local soil characteristics and hydrological processes through plot scale continuous monitoring of the hydrological processes along a 20m transect through the linear boundary features. For the summer period results show that soil moisture levels are lower immediately next to the hedgerow compared to distances greater than 1m from the hedgerow. Finally, we use this data to parameterise and validate a catchment scale hydrological model. The model is then applied to test the impact of a network of field boundaries on river flow extremes at the catchment scale.

  11. Distribution of selenium in soils of agricultural fields, western San Joaquin Valley, California

    USGS Publications Warehouse

    Fujii, Roger; Deverel, S.J.; Hatfield, D.B.

    1987-01-01

    Soils from three agricultural fields in the western San Joaquin Valley were analyzed for soluble, adsorbed, and total concentrations of selenium (Se) to assess the distribution and forms of Se, and the relation of the distribution and forms of Se to the leaching of Se from soils. Soil samples were collected in three fields with drainage systems of different ages (6, 15, 1.5 yr) and different Se concentrations in drain water (58, 430, 3700 micrograms/L respectively). Preliminary methods to determine total Se and estimate adsorbed Se were developed. Of the three fields, concentrations of soluble Se and salinity were highest in soils from the field drained for 1.5 yr and lowest in the field drained for 6 yr. The field drained for 1.5 yr also had the highest concentration of total Se in soil; a median of 1.2 microgram/gm. Of the total concentration of Se in soil from all three fields, the proportion of adsorbed Se and soluble Se ranged from 1 to 11% and < 1 to 63%, respectively. Most of the variance in soluble Se is explained by salinity ( r sq > 0.68) in saturation extracts of soils sampled from below the water table, reflecting evaporative concentration of Se and salinity. In contrast, most soluble salts and Se apparently have been leached from the unsaturated soils in the fields drained for 6 and 15 yr; therefore, the correlation was lower between Se and salinity in saturation extracts of those soils (r sq < 0.33). Among soils from all three fields, the ratio of Se to salinity in saturation extracts increased with increasing salinity. (Author 's abstract)

  12. Trichoderma Biodiversity of Agricultural Fields in East China Reveals a Gradient Distribution of Species

    PubMed Central

    Chen, Jing; Mao, Li-Juan; Feng, Xiao-Xiao; Zhang, Chu-Long; Lin, Fu-Cheng

    2016-01-01

    We surveyed the Trichoderma (Hypocreales, Ascomycota) biodiversity in agricultural fields in four major agricultural provinces of East China. Trichoderma strains were identified based on molecular approaches and morphological characteristics. In three sampled seasons (spring, summer and autumn), 2078 strains were isolated and identified to 17 known species: T. harzianum (429 isolates), T. asperellum (425), T. hamatum (397), T. virens (340), T. koningiopsis (248), T. brevicompactum (73), T. atroviride (73), T. fertile (26), T. longibrachiatum (22), T. pleuroticola (16), T. erinaceum (16), T. oblongisporum (2), T. polysporum (2), T. spirale (2), T. capillare (2), T. velutinum (2), and T. saturnisporum (1). T. harzianum, T. asperellum, T. hamatum, and T. virens were identified as the dominant species with dominance (Y) values of 0.057, 0.052, 0.048, and 0.039, respectively. The species amount, isolate numbers and the dominant species of Trichoderma varied between provinces. Zhejiang Province has shown the highest diversity, which was reflected in the highest species amount (14) and the highest Shannon–Wiener diversity index of Trichoderma haplotypes (1.46). We observed that relative frequencies of T. hamatum and T. koningiopsis under rice soil were higher than those under wheat and maize soil, indicating the preference of Trichoderma to different crops. Remarkable seasonal variation was shown, with summer exhibiting the highest biodiversity of the studied seasons. These results show that Trichoderma biodiversity in agricultural fields varies by region, crop, and season. Zhejiang Province (the southernmost province in the investigated area) had more T. hamatum than Shandong Province (the northernmost province), not only in isolate amounts but also in haplotype amounts. Furthermore, at haplotype level, only T. hamatum showed a gradient distribution from south to north in correspondence analysis among the four dominant species. The above results would contribute to the

  13. Trichoderma Biodiversity of Agricultural Fields in East China Reveals a Gradient Distribution of Species.

    PubMed

    Jiang, Yuan; Wang, Jin-Liang; Chen, Jing; Mao, Li-Juan; Feng, Xiao-Xiao; Zhang, Chu-Long; Lin, Fu-Cheng

    2016-01-01

    We surveyed the Trichoderma (Hypocreales, Ascomycota) biodiversity in agricultural fields in four major agricultural provinces of East China. Trichoderma strains were identified based on molecular approaches and morphological characteristics. In three sampled seasons (spring, summer and autumn), 2078 strains were isolated and identified to 17 known species: T. harzianum (429 isolates), T. asperellum (425), T. hamatum (397), T. virens (340), T. koningiopsis (248), T. brevicompactum (73), T. atroviride (73), T. fertile (26), T. longibrachiatum (22), T. pleuroticola (16), T. erinaceum (16), T. oblongisporum (2), T. polysporum (2), T. spirale (2), T. capillare (2), T. velutinum (2), and T. saturnisporum (1). T. harzianum, T. asperellum, T. hamatum, and T. virens were identified as the dominant species with dominance (Y) values of 0.057, 0.052, 0.048, and 0.039, respectively. The species amount, isolate numbers and the dominant species of Trichoderma varied between provinces. Zhejiang Province has shown the highest diversity, which was reflected in the highest species amount (14) and the highest Shannon-Wiener diversity index of Trichoderma haplotypes (1.46). We observed that relative frequencies of T. hamatum and T. koningiopsis under rice soil were higher than those under wheat and maize soil, indicating the preference of Trichoderma to different crops. Remarkable seasonal variation was shown, with summer exhibiting the highest biodiversity of the studied seasons. These results show that Trichoderma biodiversity in agricultural fields varies by region, crop, and season. Zhejiang Province (the southernmost province in the investigated area) had more T. hamatum than Shandong Province (the northernmost province), not only in isolate amounts but also in haplotype amounts. Furthermore, at haplotype level, only T. hamatum showed a gradient distribution from south to north in correspondence analysis among the four dominant species. The above results would contribute to the

  14. On-farm bioremediation of dimethazone and trifluralin residues in runoff water from an agricultural field.

    PubMed

    Antonious, George F

    2012-01-01

    Bioremediation is the use of living organisms, primarily microorganisms, to degrade environmental contaminants into less toxic forms. Nine biobeds (ground cavity filled with a mixture of composted organic matter, topsoil, and a surface grass) were established at Kentucky State University research farm (Franklin County, KY) to study the impact of this practice on reducing surface runoff water contamination by residues of dimethazone and trifluralin herbicides arising from an agricultural field. Biobed (biofilter) systems were installed at the bottom of the slope of specially designed runoff plots to examine herbicides retention and degradation before entering streams and rivers. In addition to biobed systems, three soil management practices: municipal sewage sludge (SS), SS mixed with yard waste compost (SS + YW), and no-mulch rototilled bare soil (NM used for comparison purposes) were used to monitor the impact of soil amendments on herbicide residues in soil following natural rainfall events. Organic amendments increased soil organic matter content and herbicide residues retained in soil following rainfall events. Biobeds installed in NM soil reduced dimethazone and trifluralin by 84 and 82%, respectively in runoff water that would have been transported down the land slope of agricultural fields and contaminated natural water resources. Biobeds installed in SS and SS+YW treatments reduced dimethazone by 65 and 46% and trifluralin by 52 and 79%, respectively. These findings indicated that biobeds are effective for treating dimethazone and trifluralin residues in runoff water.

  15. Gully evolution in field crops on vertic soils under conventional agriculture

    NASA Astrophysics Data System (ADS)

    Castillo, Carlos; Pérez, Rafael; Mora, Jose; Gómez, Jose A.

    2015-04-01

    Gully erosion is a major process contributing to soil degradation on cultivated areas. Its effects are especially intense in farms under conventional agriculture characterised by the use of heavy machinery for land levelling and herbicides leading to the depletion of natural vegetation in valley locations. When the soil (e.g. vertic soils) and parent material conditions (e.g. soft erodible marls) are favourable to incision, gully features may present large dimensions, producing the loss of significant proportions of productive land. This study evaluates the evolution of several gully networks located in Córdoba (Spain) within the Campiña area (a rolling landscape on Miocene marls) with conventional agriculture and gully filling operations as the predominant farm practices. The area of the catchments ranged from 10 to 100 ha, they were covered by field crops (mostly bean, sunflower and wheat) on vertic soils. Firstly, we carried out a historical analysis of the gully development during the last six decades by aerial image interpretation. Secondly, a number of field surveys were conducted to characterise the evolution of the gully morphology in a period of five years (2010-2014). For this purpose, a range of measurement techniques were used: pole and tape, differential GPS and 3D photo-reconstruction. Finally, the influence of topography (slope and drainage area) on gully dimensions along the longitudinal profile was assessed.

  16. Earthworm tolerance to residual agricultural pesticide contamination: field and experimental assessment of detoxification capabilities.

    PubMed

    Givaudan, Nicolas; Binet, Françoise; Le Bot, Barbara; Wiegand, Claudia

    2014-09-01

    This study investigates if acclimatization to residual pesticide contamination in agricultural soils is reflected in detoxification, antioxidant enzyme activities and energy budget of earthworms. Five fields within a joint agricultural area exhibited different chemical and farming histories from conventional cultivation to organic pasture. Soil multiresidual pesticide analysis revealed up to 9 molecules including atrazine up to 2.4 ng g(-1) dry soil. Exposure history of endogeic Aporrectodea caliginosa and Allolobophora chlorotica modified their responses to pesticides. In the field, activities of soluble glutathione-S-transferases (sGST) and catalase increased with soil pesticide contamination in A. caliginosa. Pesticide stress was reflected in depletion of energy reserves in A. chlorotica. Acute exposure of pre-adapted and naïve A. caliginosa to pesticides (fungicide Opus(®), 0.1 μg active ingredient epoxiconazole g(-1) dry soil, RoundUp Flash(®), 2.5 μg active ingredient glyphosate g(-1) dry soil, and their mixture), revealed that environmental pre-exposure accelerated activation of the detoxification enzyme sGST towards epoxiconazole. PMID:24874794

  17. Natural succession impeded by smooth brome (Bromus inermis) and intermediate wheatgrass (Agropyron intermedium) in an abandoned agricultural field

    SciTech Connect

    Nelson, J.K.

    1997-11-01

    In 1975, an abandoned agricultural field at Rocky Flats Environmental Technology Site (Site) that had been cultivated for more than 38 years, was seeded with smooth brome (Bromus inermis) and intermediate wheatgrass (Agropyron intermedium). Although these species are commonly planted in reclamation and roadside seed mixtures, few studies have documented their impact on the re-establishment of native plant communities. In 1994, species richness, cover, and biomass were sampled in the agricultural field and compared to the surrounding mixed-grass prairie at the Site. The agricultural field contained only 61 plant species (62% native), compared to 143 species (81% native) in the surrounding mixed-grass prairie. Community similarity based on species presence/absence was 0.47 (Sorensen coefficient of similarity). Basal vegetative cover was 11.2% in the agricultural field and 29.1% in the mixed-grass prairie. Smooth brome and intermediate wheatgrass accounted for 93% of the relative foliar cover and 96% of the biomass in the agricultural field. The aggressive nature of these two planted species has impeded the natural succession of the agricultural field to a more native prairie community. Studies of natural succession on abandoned fields and roads in northeastern Colorado have indicated that if left alone, fields would return to their native climax state in approximately 50 years and would be approaching their native state after 20--25 years. Based on the results of this study, this agricultural field may take more than 100 years to return to a native mixed-grass prairie state and it may never achieve a native state without human intervention.

  18. Passive microwave response to vegetation and soil moisture on agricultural fields

    NASA Astrophysics Data System (ADS)

    Miller, B.; Bullock, Paul R.

    2014-10-01

    The SMAPVEX12 (Soil Moisture Active/Passive Validation Experiment) was carried out over the summer of 2012 in Manitoba, Canada. The goal of the project was to improve the accuracy of satellite based remote sensing of soil moisture. Data were gathered during a 42-day field campaign with surface measurements on 55 different agricultural fields in south-western Manitoba. The extended duration of the campaign, contrast in soil textures, and variety of crop types over the study region provided an excellent range of soil moisture and vegetation conditions. The study fields ranged from bare to fully vegetated, with volumetric soil moisture levels spanning almost 50%. Remotely sensed data were collected on 17 days by aircraft at 1.4 Ghz with a microwave radiometer at two different resolutions. Observed brightness temperatures from the radiometer showed a typical inverse relationship to the near simultaneous soil moisture measurements from the field. This study will focus on improving existing models for passive microwave retrieval of soil moisture using a more extensive data set of field-measured soil temperature, soil moisture and vegetation biomass from a wider range of crops than has been available in previous studies. The extensive ground data collected will allow for both a validation of the high-resolution passive soil moisture estimate, as well as an analysis on the effect of scaling to a lower resolution passive measurement.

  19. Meteorological and associated data collected over agricultural fields in Pinal County, Arizona, 1989 and 1990

    USGS Publications Warehouse

    Owen-Joyce, Sandra J.; Brown, Paul W.

    1995-01-01

    Data were collected at temporary meteorological stations installed in agricultural fields in Pinal County, Arizona, to evaluate the spatial and temporal variability of point data and to examine how station location affects ground-based meteorological data and the resulting values of evapotranspiration calculated using remotely sensed multispectral data from satellites. Time-specific data were collected to correspond with satellite overpasses from April to October 1989, and June 27-28, 1990. Meteorological data consisting of air temperature, relative humidity, wind speed, solar radiation, and net radiation were collected at each station during all periods of the project. Supplementary measurements of soil temperature, soil heat flux density, and surface or canopy temperature were obtained at some locations during certain periods of the project. Additional data include information on data-collection periods, station positions, instrumentation, sensor heights, and field dimensions. Other data, which correspond to the extensive field measurements made in con- junction with satellite overpasses in 1989 and 1990, include crop type, canopy cover, canopy height, irrigation, cultivation, and orientation of rows. Field boundaries and crop types were mapped in a 2- to 3-square-kilometer area surrounding each meteorological station. Field data are presented in tabular and graphic form. Meteorological and supplementary data are available, upon request, in digital form.

  20. Emergent insect production in post-harvest flooded agricultural fields used by waterbirds

    USGS Publications Warehouse

    Moss, Richard C.; Blumenshine, Steven C.; Yee, Julie; Fleskes, Joseph P.

    2009-01-01

    California’s Tulare Lake Basin (TLB) is one of the most important waterbird areas in North America even though most wetlands there have been converted to cropland. To guide management programs promoting waterbird beneficial agriculture, which includes flooding fields between growing periods, we measured emergence rates of insects, an important waterbird food, in three crop types (tomato, wheat, alfalfa) in the TLB relative to water depth and days flooded during August–October, 2003 and 2004. We used corrected Akaike’s Information Criterion values to compare a set of models that accounted for our repeated measured data. The best model included crop type and crop type interacting with days flooded and depth flooded. Emergence rates (mg m−2 day−1) were greater in tomato than wheat or alfalfa fields, increased with days flooded in alfalfa and tomato but not wheat fields, and increased with water depth in alfalfa and wheat but not tomato fields. To investigate the relationship between the range of diel water temperatures and insect emergence rates, we rearedChironomus dilutus larvae in environmental chambers under high (15–32°C) and low fluctuation (20–26°C) temperature regimes that were associated with shallow and deep (respectively) sampling sites in our fields. Larval survival (4×) and biomass (2×) were greater in the low thermal fluctuation treatment suggesting that deeply flooded areas would support greater insect production.

  1. Scaling preferential flow processes in agricultural soils affected by tillage and trafficking at the field scale

    NASA Astrophysics Data System (ADS)

    Filipović, Vilim; Coquet, Yves

    2016-04-01

    There is an accumulation of experimental evidences that agricultural soils, at least the top horizons affected by tillage practices, are not homogeneous and present a structure that is strongly dependent on farming practices like tillage and trafficking. Soil tillage and trafficking can create compacted zones in the soil with hydraulic properties and porosity which are different from those of the non-compacted zones. This spatial variability can strongly influence transport processes and initiate preferential flow. Two or three dimensional models can be used to account for spatial variability created by agricultural practices, but such models need a detailed assessment of spatial heterogeneity which can be rather impractical to provide. This logically raises the question whether and how one dimensional model may be designed and used to account for the within-field spatial variability in soil structure created by agricultural practices. Preferential flow (dual-permeability) modelling performed with HYDRUS-1D will be confronted to classical modelling based on the Richards and convection-dispersion equations using HYDRUS-2D taking into account the various soil heterogeneities created by agricultural practices. Our goal is to derive one set of equivalent 1D soil hydraulic parameters from 2D simulations which accounts for soil heterogeneities created by agricultural operations. A field experiment was carried out in two phases: infiltration and redistribution on a plot by uniform sprinkle irrigation with water or bromide solution. Prior to the field experiment the soil structure of the tilled layer was determined along the face of a large trench perpendicular to the tillage direction (0.7 m depth and 3.1 m wide). Thirty TDR probes and tensiometers were installed in different soil structural zones (Δ compacted soil and Γ macroporous soil) which ensured soil water monitoring throughout the experiment. A map of bromide was constructed from small core samples (4 cm diam

  2. Effect of different agronomic management practices on greenhouse gas emissions and nutrient cycling in a long-term field trial

    NASA Astrophysics Data System (ADS)

    Koal, Philipp; Schilling, Rolf; Gerl, Georg; Pritsch, Karin; Munch, Jean Charles

    2015-04-01

    In order to achieve a reduction of greenhouse gas emissions, modern agronomic management practices need to be established. Therefore, to assess the effect of different farming practices on greenhouse gas emissions, reliable data are required. The experiment covers and compares two main aspects of agricultural management for a better implementation of sustainable land use. The focus lies on the determination and interpretation of greenhouse gas emissions, however, regarding in each case a different agricultural management system, namely an organic farming system and an integrated farming system where the effect of diverse tillage systems and fertilisation practices are observed. In addition, with analysis of the alterable biological, physical and chemical soil properties a link between the impact of different management systems on greenhouse gas emissions and the observed cycle of matter in the soil, especially the nitrogen and carbon cycle, will be enabled. Measurements have been carried out on long-term field trials at the Research Farm Scheyern located in a Tertiary hilly landscape approximately 40 km north of Munich (South Germany). The long-term field trials of the organic and integrated farming system were started in 1992. Since then parcels of land (each around 0.2-0.4 ha) with a particular interior plot set-up have been conducted with the same crop rotation, tillage and fertilisation practice referring to organic and integrated farming management. Thus, the management impacts on the soil of more than 20 years are being examined. Fluxes of CH4, N2O and CO2 have been monitored since 2007 for the integrated farming system trial and since 2012 for the organic farming system trial using an automated system which consists of chambers (0.4 m2 area) with a motor-driven lid, an automated gas sampling unit, an on-line gas chromatographic analysis system, and a control and data logging unit. Precipitation and temperature data have been observed for each experimental

  3. Observational Assessment Of Field Trial Site For The Implementation Of A PACS Network

    NASA Astrophysics Data System (ADS)

    Coristine, Marjorie A.; Tombaugh, Jo W.; Dillon, Richard F.

    1989-05-01

    In building an integrated radiological information system (IRIS) and preparing for field trials at a large hospital, it was necessary to consider the working conventions and needs of radiologists and clinicians. It was also necessary to analyse the current practices involved in the requesting, reading, and reporting of x-rays. Because IRIS is designed to be a mechanism for effective consultations, an understanding of the conventions and nature of x-ray related consultations was also needed. In order to gain this understanding, two observational studies were conducted. The first addressed issues of x-ray related behavior in the emergency department, and the second assessed the task requirements of radiologists when reporting x-rays or consulting with other physicians about x-rays. These findings had major implications for the design of IRIS and for conducting the field trials.

  4. Safety and immunogenicity of the synthetic malaria vaccine SPf66 in a large field trial.

    PubMed

    Amador, R; Moreno, A; Murillo, L A; Sierra, O; Saavedra, D; Rojas, M; Mora, A L; Rocha, C L; Alvarado, F; Falla, J C

    1992-07-01

    In the first field trial with synthetic malaria vaccine SPf66 in a large population naturally exposed to malaria, 9957 persons greater than 1 year old and residing on the Colombian Pacific coast received three doses of the vaccine. To evaluate vaccine safety, clinical observations were made 30 min and 48 h after each immunization. There were no adverse reactions in 95.7% of cases. In the 4.3% of cases with adverse reactions, local induration and erythema were the most frequent. In a randomly selected group of vaccinees, anti-SPf66 antibody titers were measured after the third dose: 93% of the vaccinees raised antibodies to SPf66. Among these, 55% had titers greater than 1:1600. These results demonstrate the safety and immunogenicity of the SPf66 vaccine in a large field trial.

  5. Modelling field scale water partitioning using on-site observations in sub-Saharan rainfed agriculture

    NASA Astrophysics Data System (ADS)

    Makurira, H.; Savenije, H. H. G.; Uhlenbrook, S.

    2010-04-01

    Smallholder rainfed farming systems generally realise sub-optimal crop yields which are largely attributed to dry spell occurrences during crop growth stages. However, through the introduction of appropriate farming practices, it is possible to substantially increase yield levels even with little and highly variable rainfall. The presented results follow research conducted in the Makanya catchment in northern Tanzania where gross rainfall amounts to less than 400 mm/season which is insufficient to support staple food crops (e.g. maize). The yields from farming system innovations (SIs), which are basically alternative cultivation techniques, are compared against traditional farming practices. The SIs tested in this research are runoff harvesting used in combination with in-field trenches and soil bunds (fanya juus). These SIs aim to reduce soil and nutrient loss from the field and, more importantly, promote in-field infiltration and water retention. Water balance components have been observed in order to study water partitioning processes for the "with" and "without" SI scenarios. Based on rainfall, soil evaporation, transpiration, runoff and soil moisture measurements, a water balance model has been developed to simulate soil moisture variations over the growing season. Simulation results show that, during the field trials, the average productive transpiration flow ranged between 1.1-1.4 mm d-1 in the trial plots compared to 0.7-1.0 mm d-1 under traditional tillage practice. Productive transpiration processes accounted for 23-29% while losses to deep percolation accounted for 33-48% of the available water. The field system has been successfully modelled using the spreadsheet-based water balance 1-D model. Conclusions from the research are that the SIs that were tested are effective in enhancing soil moisture retention at field scale and that diversions allow crop growth moisture conditions to be attained with early rains. From the partitioning analysis, it is also

  6. Effects of topography and soil properties on recharge at two sites in an agricultural field

    USGS Publications Warehouse

    Delin, G.N.; Healy, R.W.; Landon, M.K.; Böhlke, J.K.

    2000-01-01

    Field experiments were conducted from 1992 to 1995 to estimate ground water recharge rates at two sites located within a 2.7-hectare agricultural field. The field lies in a sand plain setting in central Minnesota and is cropped continuously in field corn. The sites are located at a topographically high (upland) site and a topographically low (lowland) site in an effort to quantify the effects of depression focusing of recharge. Three site-specific methods were used to estimate recharge rates: well hydrograph analysis, chlorofluorocarbon age dating, and an unsaturated zone water balance. All three recharge methods indicated that recharge rates at the lowland site (annual average of all methods of 29 cm) exceeded those at the upland site (annual average of 18 cm). On an annual basis, estimates by the individual methods ranged from 12 to 44 percent of precipitation at the upland site and from 21 to 83 percent at the lowland site. The difference in recharge rates between the sites is primarily attributed to depression focusing of surface water runon at the lowland site. However, two other factors were also important: the presence of thin lamellae at the upland site, and coarser textured soils below a depth of 1.5 m at the lowland site.

  7. Results from field trial of a low-cost solar cooker with novel concentrator geometry

    NASA Astrophysics Data System (ADS)

    Berryman, Ian; Jelley, Nick; Stone, Richard; Dadd, Mike

    2016-05-01

    Solar cookers are generally of either box-type or make use of parabolic dishes, including approximations thereof. The former are cheap but operate at low solar concentrations and temperatures, whilst the latter often require complex mirror geometries and can be prohibitively expensive to manufacture. This paper will present the results from a field trial of a prototype solar cooker which use of a novel concentrator geometry to achieve high temperatures.

  8. Field trial of a Caryospora species vaccine for controlling clinical coccidiosis in falcons.

    PubMed

    Forbes, N A; Fox, M T

    2005-01-29

    A Caryospora species vaccine was prepared and used in an attempt to prevent infection and associated morbidity in falcons. A blind field trial was conducted, involving a vaccinated group of 20 birds and two control groups of seven and four birds, which were subsequently challenged with a live mixed-species vaccine. There was a statistically significant reduction in morbidity and shedding of oocysts in the vaccinated group compared with the control groups.

  9. Chemosterilants as control agents of Ceratitis capitata (Diptera: Tephritidae) in field trials.

    PubMed

    Navarro-Llopis, V; Sanchis, J; Primo-Millo, J; Primo-Yúfera, E

    2007-08-01

    Lufenuron is a chitin synthesis inhibitor, which is able to impede Mediterranean fruit fly, Ceratitis capitata (Wiedemann), reproduction. In laboratory trials, following ingestion of lufenuron, the eggs laid by female Ceratitis capitata were prevented from hatching. In field trials in Valencia, Spain, lufenuron showed its effectiveness by reducing C. capitata wild populations and its continuous application to several generations of fruit fly resulted in increased pest control. This field trial was conducted in an isolated valley some 80 ha in size, over a continuous four-year period. In order to maintain the sterilizing effect in the field throughout the whole year, a new lufenuron bait gel was developed. This bait gel was introduced in to delta traps suspended in trees at a density of 24 traps ha-1, and these traps were replaced once a year during the field trial. Monitoring of the adult C. capitata population was conducted to assess the effects of the chemosterilant treatment. In the first year of treatment with sterilizing traps, a reduction of the C. capitata population was observed, indicating that the traps reduce the population right from the first generation. In the second, third and fourth years, a continuous and progressive reduction of the adult Mediterranean fruit fly population was observed. Therefore, the successive application of chemosterilization treatment has a cumulative effect on reducing the fly population year after year. Aerial treatment using malathion does not produce this cumulative effect, and consequently every year it is necessary to start again with the same number of flies as the year before. The possibility of using the chemosterilant method alone or combined with the sterile insect technique is discussed. PMID:17645817

  10. Balancing ballistic protection against physiological strain: evidence from laboratory and field trials.

    PubMed

    Taylor, Nigel A S; Burdon, Catriona A; van den Heuvel, Anne M J; Fogarty, Alison L; Notley, Sean R; Hunt, Andrew P; Billing, Daniel C; Drain, Jace R; Silk, Aaron J; Patterson, Mark J; Peoples, Gregory E

    2016-02-01

    This project was based on the premise that decisions concerning the ballistic protection provided to defence personnel should derive from an evaluation of the balance between protection level and its impact on physiological function, mobility, and operational capability. Civilians and soldiers participated in laboratory- and field-based studies in which ensembles providing five levels of ballistic protection were evaluated, each with progressive increases in protection, mass (3.4-11.0 kg), and surface-area coverage (0.25-0.52 m(2)). Physiological trials were conducted on volunteers (N = 8) in a laboratory, under hot-dry conditions simulating an urban patrol: walking at 4 km·h(-1) (90 min) and 6 km·h(-1) (30 min or to fatigue). Field-based trials were used to evaluate tactical battlefield movements (mobility) of soldiers (N = 31) under tropical conditions, and across functional tests of power, speed, agility, endurance, and balance. Finally, trials were conducted at a jungle training centre, with soldiers (N = 32) patrolling under tropical conditions (averaging 5 h). In the laboratory, work tolerance was reduced as protection increased, with deep-body temperature climbing relentlessly. However, the protective ensembles could be grouped into two equally stressful categories, each providing a different level of ballistic protection. This outcome was supported during the mobility trials, with the greatest performance decrement evident during fire and movement simulations, as the ensemble mass was increased (-2.12%·kg(-1)). The jungle patrol trials similarly supported this outcome. Therefore, although ballistic protection does increase physiological strain, this research has provided a basis on which to determine how that strain can be balanced against the mission-specific level of required personal protection.

  11. Long-term comparison of energy flux calculation methods over an agricultural field

    NASA Astrophysics Data System (ADS)

    Kolle, O.

    1996-05-01

    Since March 1990 micrometeorological measurements were carried out over an agricultural field with varying land use (wheat, barley, sunflowers, mustard) using a profile mast and an energy balance mast with an eddy correlation system for the sensible heat flux. Soil temperature, soil heat flux, soil moisture and precipitation were measured as well. Long-term measurements allow statistical analysis of the energy fluxes and comparisons of different methods for their calculation (eddy correlation, flux profile, Bowen ratio and the residual method). For the sensible heat flux a good agreement was found using these different methods after applying all necessary corrections. The latent heat flux shows greater deviations in the daily cycle between the flux profile method and the residual method due to the shape of the humidity profiles which often and especially at night show a maximum at heights between 1 m and 4 m, even if the soil is free of vegetation. This could be a consequence of the patchiness of the agricultural area, the position of the station on top of a hillock or high water absorption of the soil, respectively. The residual method seems to give more reliable results for the actual evapotranspiration than the flux profile method or the Bowen ratio method if an eddy correlation system is used to determine the sensible heat flux. Differences in the soil heat flux measured with heat flux plates and determined using the profiles of soil temperature and soil moisture can be explained by the heat flux plates being a disturbance to the soil matrix.

  12. Monitoring soil moisture dynamics via ground-penetrating radar survey of agriculture fields after irrigation

    NASA Astrophysics Data System (ADS)

    Muro, G.

    2015-12-01

    It is possible to examine the quality of ground-penetrating radar (GPR) as a measure of soil moisture content in the shallow vadose zone, where roots are most abundant and water conservation best management practices are critical in active agricultural fields. By analyzing temporal samplings of 100 Mhz reflection profiles and common-midpoint (CMP) soundings over a full growing season, the variability of vertical soil moisture distribution directly after irrigation events are characterized throughout the lifecycle of a production crop. Reflection profiles produce high-resolution travel time data and summed results of CMP sounding data provide sampling depth estimates for the weak, but coherent reflections amid strong point scatterers. The high ratio of clay in the soil limits the resolution of downward propagation of infiltrating moisture after irrigation; synthetic data analysis compared against soil moisture lysimeter logs throughout the profile allow identification of the discrete soil moisture content variation in the measured GPR data. The nature of short duration irrigation events, evapotranspiration, and drainage behavior in relation to root depths observed in the GPR temporal data allow further examination and comparison with the variable saturation model HYDRUS-1D. After retrieving soil hydraulic properties derived from laboratory measured soil samples and simplified assumptions about boundary conditions, the project aims to achieve good agreement between simulated and measured soil moisture profiles without the need for excessive model calibration for GPR-derived soil moisture estimates in an agricultural setting.

  13. Mycotoxins in the environment: I. Production and emission from an agricultural test field.

    PubMed

    Schenzel, Judith; Forrer, Hans-Rudolf; Vogelgsang, Susanne; Hungerbühler, Konrad; Bucheli, Thomas D

    2012-12-18

    Mycotoxins are secondary metabolites that are naturally produced by fungi which infest and contaminate agricultural crops and commodities (e.g., small grain cereals, fruits, vegetables, and organic soil material). Although these compounds have extensively been studied in food and feed, only little is known about their environmental fate. Therefore, we investigated over nearly two years the occurrence of various mycotoxins in a field cropped with winter wheat of the variety Levis, which was artificially inoculated with Fusarium spp., as well as their emission via drainage water. Mycotoxins were regularly quantified in whole wheat plants (0.1-133 mg/kg(dry weight), for deoxynivalenol), and drainage water samples (0.8 ng/L to 1.14 μg/L, for deoxynivalenol). From the mycotoxins quantified in wheat (3-acetyl-deoxynivalenol, deoxynivalenol, fusarenone-X, nivalenol, HT-2 toxin, T-2 toxin, beauvericin, and zearalenone), only the more hydrophilic ones or those prevailing at high concentrations were detected in drainage water. Of the total amounts produced in wheat plants (min: 2.3; max: 292 g/ha/y), 0.5-354 mg/ha/y, i.e. 0.002-0.12%, were emitted via drainage water. Hence, these compounds add to the complex mixture of natural and anthropogenic micropollutants particularly in small rural water bodies, receiving mainly runoff from agricultural areas. PMID:23145781

  14. Mycotoxins in the environment: I. Production and emission from an agricultural test field.

    PubMed

    Schenzel, Judith; Forrer, Hans-Rudolf; Vogelgsang, Susanne; Hungerbühler, Konrad; Bucheli, Thomas D

    2012-12-18

    Mycotoxins are secondary metabolites that are naturally produced by fungi which infest and contaminate agricultural crops and commodities (e.g., small grain cereals, fruits, vegetables, and organic soil material). Although these compounds have extensively been studied in food and feed, only little is known about their environmental fate. Therefore, we investigated over nearly two years the occurrence of various mycotoxins in a field cropped with winter wheat of the variety Levis, which was artificially inoculated with Fusarium spp., as well as their emission via drainage water. Mycotoxins were regularly quantified in whole wheat plants (0.1-133 mg/kg(dry weight), for deoxynivalenol), and drainage water samples (0.8 ng/L to 1.14 μg/L, for deoxynivalenol). From the mycotoxins quantified in wheat (3-acetyl-deoxynivalenol, deoxynivalenol, fusarenone-X, nivalenol, HT-2 toxin, T-2 toxin, beauvericin, and zearalenone), only the more hydrophilic ones or those prevailing at high concentrations were detected in drainage water. Of the total amounts produced in wheat plants (min: 2.3; max: 292 g/ha/y), 0.5-354 mg/ha/y, i.e. 0.002-0.12%, were emitted via drainage water. Hence, these compounds add to the complex mixture of natural and anthropogenic micropollutants particularly in small rural water bodies, receiving mainly runoff from agricultural areas.

  15. On dealing with the pollution costs in agriculture: A case study of paddy fields.

    PubMed

    Yaqubi, Morteza; Shahraki, Javad; Sabouhi Sabouni, Mahmood

    2016-06-15

    The main purpose of this study is to evaluate marginal abatement cost of the main agricultural pollutants. In this sense, we construct three indices including Net Global Warming Potential (NGWP) and Nitrogen Surplus (NS), simulated by a biogeochemistry model, and also an Environmental Impact Quotient (EQI) for paddy fields. Then, using a Data Envelopment Analysis (DEA) model, we evaluate environmental inefficiencies and shadow values of these indices. The results show that there is still room for improvement at no extra cost just through a better input management. Besides, enormous potential for pollution reduction in the region is feasible. Moreover, in paddy cultivation, marginal abatement cost of pesticides and herbicides are much bigger than nitrogen surplus and greenhouse gasses. In addition, in the status quo, the mitigation costs are irrelevant to production decisions. Finally, to deal with the private pollution costs, market-based instruments are proved to be better than command-and-control regulation.

  16. On dealing with the pollution costs in agriculture: A case study of paddy fields.

    PubMed

    Yaqubi, Morteza; Shahraki, Javad; Sabouhi Sabouni, Mahmood

    2016-06-15

    The main purpose of this study is to evaluate marginal abatement cost of the main agricultural pollutants. In this sense, we construct three indices including Net Global Warming Potential (NGWP) and Nitrogen Surplus (NS), simulated by a biogeochemistry model, and also an Environmental Impact Quotient (EQI) for paddy fields. Then, using a Data Envelopment Analysis (DEA) model, we evaluate environmental inefficiencies and shadow values of these indices. The results show that there is still room for improvement at no extra cost just through a better input management. Besides, enormous potential for pollution reduction in the region is feasible. Moreover, in paddy cultivation, marginal abatement cost of pesticides and herbicides are much bigger than nitrogen surplus and greenhouse gasses. In addition, in the status quo, the mitigation costs are irrelevant to production decisions. Finally, to deal with the private pollution costs, market-based instruments are proved to be better than command-and-control regulation. PMID:26998602

  17. Field trial for reducing porcine Taenia solium cysticercosis in Mexico by systematic vaccination of pigs.

    PubMed

    Molinari, J L; Rodríguez, D; Tato, P; Soto, R; Arechavaleta, F; Solano, S

    1997-04-01

    It has previously been demonstrated that immunization of pigs with a crude extract of Taenia solium metacestodes can confer a high level of protection against an egg challenge. Furthermore, vaccination of infected animals also induces an immune response against the larvae, which are either destroyed or rendered non-infectious. To assess the efficacy of immunization as a strategy for reducing the prevalence of porcine cysticercosis, a field trial of this vaccine was performed in an endemic area in the northern region of the Guerrero State, Mexico, Random samples of pigs belonging to 17 villages were examined for metacestodes by inspection of their tongues. Each animal was immunized with a dose of 150 micrograms of protein (antigenic extract from Taenia solium metacestodes) by the intramuscular route. A prevalence of 2.4% of porcine cysticercosis on average was found in these villages at the beginning of the trial (62 cysticercotic pigs out of 2650 inspected). Six of these villages were selected for the periodic vaccination of new random samples of pigs. A statistically significant decline in the prevalence of porcine cysticercosis was observed at the end of the trial, decreasing from 2.4% at the beginning of vaccination to 0.45% at the end of the trial. A reduction of 82% was observed in spite of the poor living conditions in these villages. These results are consistent with previous data and suggest that it may be possible to turn a susceptible pig population into a protected one by systematic vaccination.

  18. Simulation of plume dispersion from single release in Fusion Field Trial-07 experiment

    NASA Astrophysics Data System (ADS)

    Singh, Sarvesh Kumar; Sharan, Maithili

    2013-12-01

    Accurate description of source-receptor relationship is required for an efficient source reconstruction. This is examined by simulating the dispersion of plumes resulted from the available ten trials of single releases conducted at Fusion Field Trials, Dugway Proving Ground, Utah. The simulation is addressed with an earlier developed IIT (Indian Institute of Technology) dispersion model using the dispersion parameters in terms of measurements of turbulent velocity fluctuations. Simulation is described separately in both stable and unstable conditions, characterizing the peak as well as overall observed concentration distribution. Simulated results are compared with those obtained using AERMOD. With IIT model, peak concentrations are predicted within a factor of two in all the trials. The higher concentrations (>5 × 10-4 g m-3) are well predicted in stable condition and under-predicted (within a factor of two) in unstable condition whereas relatively smaller concentrations (<5 × 10-4 g m-3) are severely under-predicted in stable conditions and over-predicted in unstable conditions. The AERMOD exhibits the similar prediction of concentrations as shown by IIT model in most of the trials. Overall, both the models predict 70-80% concentrations in stable conditions and 85-95% concentrations in unstable conditions within a factor of six. The statistical measures for both the models are found well in agreement with the observations.

  19. Laboratory and field trials of Coriolis mass flow metering for three-phase flow measurement

    NASA Astrophysics Data System (ADS)

    Zhou, Feibiao; Henry, Manus; Tombs, Michael

    2014-04-01

    A new three-phase flow metering technology is discussed in this paper, which combines Coriolis mass flow and water cut readings and without applying any phase separation [1]. The system has undergone formal laboratory trials at TUV NEL (National Engineering Laboratory), UK and at VNIIR (National Flow Laboratory), Kazan, Russia; a number of field trials have taken place in Russia. Laboratory trial results from the TUV NEL will be described in detail. For the 50mm (2") metering system, the total liquid flow rate ranged from 2.4 kg/s up to 11 kg/s, the water cut ranged from 0% to 100%, and the gas volume fraction (GVF) from 0 to 50%. In a formally observed trial, 75 test points were taken at a temperature of approximately 40 °C and with a skid inlet pressure of approximately 350 kPa. Over 95% of the test results fell within the desired specification, defined as follows: the total (oil + water) liquid mass flow error should fall within ± 2.5%, and the gas mass flow error within ± 5.0%. The oil mass flow error limit is ± 6.0% for water cuts less than 70%, while for water cuts between 70% and 95% the oil mass flow error limit is ± 15.0%. These results demonstrate the potential for using Coriolis mass flow metering combined with water cut metering for three-phase (oil/water/gas) measurement.

  20. Quantifying the Usefulness of Ensemble-Based Precipitation Forecasts with Respect to Water Use and Yield during a Field Trial

    NASA Astrophysics Data System (ADS)

    Christ, E.; Webster, P. J.; Collins, G.; Byrd, S.

    2014-12-01

    Recent droughts and the continuing water wars between the states of Georgia, Alabama and Florida have made agricultural producers more aware of the importance of managing their irrigation systems more efficiently. Many southeastern states are beginning to consider laws that will require monitoring and regulation of water used for irrigation. Recently, Georgia suspended issuing irrigation permits in some areas of the southwestern portion of the state to try and limit the amount of water being used in irrigation. However, even in southern Georgia, which receives on average between 23 and 33 inches of rain during the growing season, irrigation can significantly impact crop yields. In fact, studies have shown that when fields do not receive rainfall at the most critical stages in the life of cotton, yield for irrigated fields can be up to twice as much as fields for non-irrigated cotton. This leads to the motivation for this study, which is to produce a forecast tool that will enable producers to make more efficient irrigation management decisions. We will use the ECMWF (European Centre for Medium-Range Weather Forecasts) vars EPS (Ensemble Prediction System) model precipitation forecasts for the grid points included in the 1◦ x 1◦ lat/lon square surrounding the point of interest. We will then apply q-to-q bias corrections to the forecasts. Once we have applied the bias corrections, we will use the check-book method of irrigation scheduling to determine the probability of receiving the required amount of rainfall for each week of the growing season. These forecasts will be used during a field trial conducted at the CM Stripling Irrigation Research Park in Camilla, Georgia. This research will compare differences in yield and water use among the standard checkbook method of irrigation, which uses no precipitation forecast knowledge, the weather.com forecast, a dry land plot, and the ensemble-based forecasts mentioned above.

  1. Pretreatment of agriculture field water for improving membrane flux during pesticide removal

    NASA Astrophysics Data System (ADS)

    Mehta, Romil; Saha, N. K.; Bhattacharya, A.

    2016-09-01

    Pretreatment of feed water to improve membrane flux during filtration of agriculture field water containing substituted phenyl urea pesticide diuron has been reported. Laboratory-made reverse osmosis membrane was used for filtration. Preliminary experiments were conducted with model solution containing natural organic matter extracted from commercial humic acids, divalent ions Ca2+, Mg2+. Membrane fouling was characterized by pure water flux decline, change in membrane hydrophilicity and infrared spectroscopy. Natural organic matter present in field water causes severe membrane fouling. The presence of divalent cations further aggravated fouling. Use of ethylenediaminetetraacetic acid (EDTA) and polyacrylic acids (PAA) in feed resulted in the decrease in membrane fouling. Pretreatment of field water is a must if it is contaminated with micro-organism having membrane fouling potential. Feed water pretreatment and use of PAA restricted membrane fouling to 16 % after 60 h of filtration. Membrane permeate flux decline was maximum at the first 12 h and thereafter remained steady at around 45-46 lm-2h-1 till the end of 60 h. Diuron rejection remained consistently greater than 93 % throughout the experiment. Diuron rejection was found to be unaffected by membrane fouling.

  2. Agricultural and Management Practices and Bacterial Contamination in Greenhouse versus Open Field Lettuce Production

    PubMed Central

    Holvoet, Kevin; Sampers, Imca; Seynnaeve, Marleen; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2014-01-01

    The aim of this study was to gain insight into potential differences in risk factors for microbial contamination in greenhouse versus open field lettuce production. Information was collected on sources, testing, and monitoring and if applicable, treatment of irrigation and harvest rinsing water. These data were combined with results of analysis on the levels of Escherichia coli as a fecal indicator organism and the presence of enteric bacterial pathogens on both lettuce crops and environmental samples. Enterohemorragic Escherichia coli (EHEC) PCR signals (vt1 or vt2 positive and eae positive), Campylobacter spp., and Salmonella spp. isolates were more often obtained from irrigation water sampled from open field farms (21/45, 46.7%) versus from greenhouse production (9/75, 12.0%). The open field production was shown to be more prone to fecal contamination as the number of lettuce samples and irrigation water with elevated E. coli was significantly higher. Farmers comply with generic guidelines on good agricultural practices available at the national level, but monitoring of microbial quality, and if applicable appropriateness of water treatment, or water used for irrigation or at harvest is restricted. These results indicate the need for further elaboration of specific guidelines and control measures for leafy greens with regard to microbial hazards. PMID:25546272

  3. Use of airborne hyperspectral imagery to map soil parameters in tilled agricultural fields

    USGS Publications Warehouse

    Hively, W. Dean; McCarty, Gregory W.; Reeves, James B.; Lang, Megan W.; Oesterling, Robert A.; Delwiche, Stephen R.

    2011-01-01

    Soil hyperspectral reflectance imagery was obtained for six tilled (soil) agricultural fields using an airborne imaging spectrometer (400–2450 nm, ~10 nm resolution, 2.5 m spatial resolution). Surface soil samples (n = 315) were analyzed for carbon content, particle size distribution, and 15 agronomically important elements (Mehlich-III extraction). When partial least squares (PLS) regression of imagery-derived reflectance spectra was used to predict analyte concentrations, 13 of the 19 analytes were predicted with R2 > 0.50, including carbon (0.65), aluminum (0.76), iron (0.75), and silt content (0.79). Comparison of 15 spectral math preprocessing treatments showed that a simple first derivative worked well for nearly all analytes. The resulting PLS factors were exported as a vector of coefficients and used to calculate predicted maps of soil properties for each field. Image smoothing with a 3 × 3 low-pass filter prior to spectral data extraction improved prediction accuracy. The resulting raster maps showed variation associated with topographic factors, indicating the effect of soil redistribution and moisture regime on in-field spatial variability. High-resolution maps of soil analyte concentrations can be used to improve precision environmental management of farmlands.

  4. Agricultural and management practices and bacterial contamination in greenhouse versus open field lettuce production.

    PubMed

    Holvoet, Kevin; Sampers, Imca; Seynnaeve, Marleen; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2014-12-23

    The aim of this study was to gain insight into potential differences in risk factors for microbial contamination in greenhouse versus open field lettuce production. Information was collected on sources, testing, and monitoring and if applicable, treatment of irrigation and harvest rinsing water. These data were combined with results of analysis on the levels of Escherichia coli as a fecal indicator organism and the presence of enteric bacterial pathogens on both lettuce crops and environmental samples. Enterohemorragic Escherichia coli (EHEC) PCR signals (vt1 or vt2 positive and eae positive), Campylobacter spp., and Salmonella spp. isolates were more often obtained from irrigation water sampled from open field farms (21/45, 46.7%) versus from greenhouse production (9/75, 12.0%). The open field production was shown to be more prone to fecal contamination as the number of lettuce samples and irrigation water with elevated E. coli was significantly higher. Farmers comply with generic guidelines on good agricultural practices available at the national level, but monitoring of microbial quality, and if applicable appropriateness of water treatment, or water used for irrigation or at harvest is restricted. These results indicate the need for further elaboration of specific guidelines and control measures for leafy greens with regard to microbial hazards.

  5. Green house gas emissions from open field burning of agricultural residues in India.

    PubMed

    Murali, S; Shrivastava, Rajnish; Saxena, Mohini

    2010-10-01

    In India, about 435.98 MMT of agro-residues are produced every year, out of which 313.62 MMT are surplus. These residues are either partially utilized or un-utilised due to various constraints. To pave the way for subsequent season for agriculture activity, the excess crop residues are burnt openly in the fields, unmindful of their ill effects on the environment. The present study has been undertaken to evaluate the severity of air pollution through emission of green house gases (GHGs) due to open field burning of agro-residues in India. Open field burning of surplus agro-residues in India results in the emission of GHG. Emissions of CH4 and N2O in 1997-98 and 2006-07 have been 3.73 and 4.06 MMT CO2 equivalent, which is an increase of 8.88% over a decade. About three-fourths of GHG emissions from agro-residues burning were CH4 and the remaining one-fourth were N2O. Burning of wheat and paddy straws alone contributes to about 42% of GHGs. These GHG emissions can be avoided once the agro-residues are employed for sustainable, cost-effective and environment- friendly options like power generation.

  6. Export of radioactive cesium from agricultural fields under simulated rainfall in Fukushima.

    PubMed

    Thai, Phong K; Suka, Yuma; Sakai, Masaru; Nanko, Kazuki; Yen, Jui-Hung; Watanabe, Hirozumi

    2015-06-01

    In this study, we investigated the impact of rainfall on runoff, soil erosion and consequently on the discharge of radioactive cesium in agricultural fields in Fukushima prefecture using a rainfall simulator. Simulated heavy rainfalls (50 mm h(-1)) generated significant runoff and soil erosion. The average concentration of radioactive cesium (the sum of (134)Cs and (137)Cs) in the runoff sediments was ∼3500 Bq kg(-1) dry soil, more than double the concentrations measured in the field soils which should be considered in studies using the (137)Cs loss to estimate long-term soil erosion. However, the estimated mass of cesium discharged through one runoff event was less than 2% of the cesium inventory in the field. This suggested that cesium discharge via soil erosion is not a significant factor in reducing the radioactivity of contaminated soils in Fukushima prefecture. However, the eroded sediment carrying radioactive cesium will deposit into the river systems and potentially pose a radioactivity risk for aquatic living organisms.

  7. Agricultural and management practices and bacterial contamination in greenhouse versus open field lettuce production.

    PubMed

    Holvoet, Kevin; Sampers, Imca; Seynnaeve, Marleen; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2015-01-01

    The aim of this study was to gain insight into potential differences in risk factors for microbial contamination in greenhouse versus open field lettuce production. Information was collected on sources, testing, and monitoring and if applicable, treatment of irrigation and harvest rinsing water. These data were combined with results of analysis on the levels of Escherichia coli as a fecal indicator organism and the presence of enteric bacterial pathogens on both lettuce crops and environmental samples. Enterohemorragic Escherichia coli (EHEC) PCR signals (vt1 or vt2 positive and eae positive), Campylobacter spp., and Salmonella spp. isolates were more often obtained from irrigation water sampled from open field farms (21/45, 46.7%) versus from greenhouse production (9/75, 12.0%). The open field production was shown to be more prone to fecal contamination as the number of lettuce samples and irrigation water with elevated E. coli was significantly higher. Farmers comply with generic guidelines on good agricultural practices available at the national level, but monitoring of microbial quality, and if applicable appropriateness of water treatment, or water used for irrigation or at harvest is restricted. These results indicate the need for further elaboration of specific guidelines and control measures for leafy greens with regard to microbial hazards. PMID:25546272

  8. Field Evaluation of Preferential Flow in Agricultural Soil of the Mississippi Delta

    NASA Astrophysics Data System (ADS)

    Perkins, K. S.; Nimmo, J. R.; Rose, C. E.; Coupe, R.

    2009-12-01

    In the Bogue Phalia basin in the Delta region of northwestern Mississippi, as in many farmed areas, intensive use of agricultural chemicals raises water quality concerns. The soils are fine textured and often exhibit surface ponding and runoff after irrigation and rainfall. There is extensive surface cracking during extended dry periods. Fields are typically land-formed to promote surface flow into irrigation ditches and streams that feed into larger river ecosystems. Deep percolation below the root zone has been considered to be minimal in this area; however, unsaturated zone processes, including the effects of a declining water table, are not well understood, and there are few measured unsaturated zone data relevant to deep percolation. In this study we assessed solute transport mechanisms within and below the root zone of a fallow soybean field by performing a 2-m ring infiltration experiment. Ponding continued for 67 hours using bromide and rhodamine tracers and subsurface instruments for measuring soil-water content, matric pressure, and solution sampling. Water percolated rapidly below the pond reaching 1 m depth in as little as 30 minutes, indicating preferential flow through the root zone, possibly related to shrink/swell features. Extensive lateral flow of water at shallow depths was apparent as the surface wetted outward to several meters from the pond in all directions with some evidence of preferentiality along slope toward the drainage ditch. Deeper lateral flow was detected at solution samplers 3 m from the pond edge at 5 m depth within a few weeks. Tracer was not detected in the unsaturated zone below 5 m however; the tracer was detected at the water table 12 m below land surface within 10 weeks of the experiment with concentrations increasing over a period of 10 months. A tracer mass balance also suggests the possibility for deep preferential transport of agricultural chemicals within the Bogue Phalia basin.

  9. Evaluation of Three Models for Simulating Pesticide Runoff from Irrigated Agricultural Fields.

    PubMed

    Zhang, Xuyang; Goh, Kean S

    2015-11-01

    Three models were evaluated for their accuracy in simulating pesticide runoff at the edge of agricultural fields: Pesticide Root Zone Model (PRZM), Root Zone Water Quality Model (RZWQM), and OpusCZ. Modeling results on runoff volume, sediment erosion, and pesticide loss were compared with measurements taken from field studies. Models were also compared on their theoretical foundations and ease of use. For runoff events generated by sprinkler irrigation and rainfall, all models performed equally well with small errors in simulating water, sediment, and pesticide runoff. The mean absolute percentage errors (MAPEs) were between 3 and 161%. For flood irrigation, OpusCZ simulated runoff and pesticide mass with the highest accuracy, followed by RZWQM and PRZM, likely owning to its unique hydrological algorithm for runoff simulations during flood irrigation. Simulation results from cold model runs by OpusCZ and RZWQM using measured values for model inputs matched closely to the observed values. The MAPE ranged from 28 to 384 and 42 to 168% for OpusCZ and RZWQM, respectively. These satisfactory model outputs showed the models' abilities in mimicking reality. Theoretical evaluations indicated that OpusCZ and RZWQM use mechanistic approaches for hydrology simulation, output data on a subdaily time-step, and were able to simulate management practices and subsurface flow via tile drainage. In contrast, PRZM operates at daily time-step and simulates surface runoff using the USDA Soil Conservation Service's curve number method. Among the three models, OpusCZ and RZWQM were suitable for simulating pesticide runoff in semiarid areas where agriculture is heavily dependent on irrigation.

  10. Evaluation of Three Models for Simulating Pesticide Runoff from Irrigated Agricultural Fields.

    PubMed

    Zhang, Xuyang; Goh, Kean S

    2015-11-01

    Three models were evaluated for their accuracy in simulating pesticide runoff at the edge of agricultural fields: Pesticide Root Zone Model (PRZM), Root Zone Water Quality Model (RZWQM), and OpusCZ. Modeling results on runoff volume, sediment erosion, and pesticide loss were compared with measurements taken from field studies. Models were also compared on their theoretical foundations and ease of use. For runoff events generated by sprinkler irrigation and rainfall, all models performed equally well with small errors in simulating water, sediment, and pesticide runoff. The mean absolute percentage errors (MAPEs) were between 3 and 161%. For flood irrigation, OpusCZ simulated runoff and pesticide mass with the highest accuracy, followed by RZWQM and PRZM, likely owning to its unique hydrological algorithm for runoff simulations during flood irrigation. Simulation results from cold model runs by OpusCZ and RZWQM using measured values for model inputs matched closely to the observed values. The MAPE ranged from 28 to 384 and 42 to 168% for OpusCZ and RZWQM, respectively. These satisfactory model outputs showed the models' abilities in mimicking reality. Theoretical evaluations indicated that OpusCZ and RZWQM use mechanistic approaches for hydrology simulation, output data on a subdaily time-step, and were able to simulate management practices and subsurface flow via tile drainage. In contrast, PRZM operates at daily time-step and simulates surface runoff using the USDA Soil Conservation Service's curve number method. Among the three models, OpusCZ and RZWQM were suitable for simulating pesticide runoff in semiarid areas where agriculture is heavily dependent on irrigation. PMID:26641333

  11. 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

  12. Efficacy of lufenuron as chemosterilant against Ceratitis capitata in field trials.

    PubMed

    Navarro-Llopis, Vicente; Sanchis-Cabanes, Juan; Ayala, Ildefonso; Casaña-Giner, Victor; Primo-Yüfera, Eduardo

    2004-09-01

    Two field trials in citrus orchards in Turis (Valencia, Spain) and Denia (Alicante, Spain) were performed in order to test the sterilant effect of the insect growth regulator lufenuron against wild medfly Ceratitis capitata (Wiedemann) populations. Two application methods for lufenuron were tested: spraying, in spots, an emulsion of lufenuron in a protein bait, and hanging delta traps that contained a proteinaceous gel with lufenuron (solid bait). The sterilant effect was measured as medfly population reduction, reduction of fruit damage in treated fields, and the number of eggs hatching in punctured fruits. In order to assess the efficacy of lufenuron treatments, we recorded results obtained from two different zones in both trial fields: an outer zone, close to untreated fields, and an inner zone, in the centre of lufenuron treated fields. We observed a minimum sterilant effect in the outer zone and a maximum sterilant effect in the inner one. The maximum sterilant effect was in the inner zone, where a reduction of medfly population of 80.4% in the sprayed field and a reduction of 77.6% in the solid bait field was observed. In addition, the greater the distance from the untreated zones of the treated orchard (inwards), the lower the fruit damage and medfly population level. In this inner zone, fruit punctured by medfly developed significantly fewer larvae (38.8%) than punctured fruits from the outer zone (68.6%). In addition, we recorded the decline in the activity of the lufenuron treatments with time. Lufenuron activity persisted in field for at least 2 weeks with spray applications, and for 3 months with bait gels. PMID:15384180

  13. Increased spring flooding of agricultural fields will exhibit altered production of greenhouse gases

    NASA Astrophysics Data System (ADS)

    Paul, R. F.; Smith, C. M.; Smyth, E. M.; Kantola, I. B.; DeLucia, E. H.

    2013-12-01

    The U.S. Corn Belt currently is a net source of carbon dioxide and nitrous oxide to the atmosphere, but is also a sink of methane. Among the proposed effects of climate change in the North American Midwest region is an increase in the frequency and duration of spring flooding events. This would cause ponding in fields which may change the greenhouse gas balance of the region, especially by providing a suitable anoxic environment for the proliferation of methanogens, increasing methane emissions. To determine whether methanogenesis occurs in flooded agricultural soils of the Midwest and how other gas fluxes are affected, we installed collars into the ground of a research field located in central Illinois. The control group was maintained at the same conditions as the surrounding field. Two groups of collars were sustained with water flooding the headspaces via a drip irrigation system; one treatment was analyzed for gas fluxes of CH4, N2O, and CO2 evolving from the collars, and a separate treatment of flooded collars was used for soil sampling. Comparing flooded soils versus control we measured reduced N2O fluxes (-3.12 x 10-6 × 6.8 x 10-7 g N m-2 min-1), reduced CO2 fluxes (-6.13 x 10-3 × 9.3 x 10-4 g CO2 m-2 min-1), and increased methane fluxes (+2.72 x 10-6 × 5.8 x 10-7 g CH4 m-2 min-1). After only one week of treatment the flooded soils switched from being sinks to sources of methane, which continued across the duration of the experiment. These preliminary results indicate that methanogenesis occurs in flooded agricultural fields, and suggest including regional modeling into further study. Although the global warming potential of methane is 25 times greater than CO2, our measured rates of methane production were compensated by reductions in nitrous oxide and CO2 fluxes, reducing the total 100-year horizon global warming potential of the flooded soils we studied by 64.8%. This indicates that accounting for more frequent seasonal ponding would significantly

  14. Transportability of confined field trial data from cultivation to import countries for environmental risk assessment of genetically modified crops.

    PubMed

    Nakai, Shuichi; Hoshikawa, Kana; Shimono, Ayako; Ohsawa, Ryo

    2015-12-01

    Requirement of in-country confined field trials for genetically modified (GM) crops prior to unrestricted release is well-established among countries with domestic regulations for the cultivation approval of GM crops. However, the requirement of in-country confined field trials is not common in countries where the scope of the application does not include cultivation. Nonetheless, Japan and China request in-country confined field trials for GM crops which are intended only for use as food, feed and processing. This paper considers the transportability of confined field trial data from cultivation countries (e.g. United States, Canada, and South American countries) to import countries like Japan for the environmental risk assessment of GM crops by reviewing: (1) the purpose of confined field trial assessment, (2) weediness potential, defined as "an ability to establish and persist in an unmanaged area that is frequently disturbed by human activity", of host crops, and (3) reliability of the confined field trial data obtained from cultivation countries. To review the reliability of the confined field data obtained in the US, this paper describes actual examples of three confined field trials of approved GM corn events conducted both in the US and Japan. Based on the above considerations, this paper concludes that confined field data of GM corn and cotton is transportable from cultivation countries to importing countries (e.g. from the US to Japan), regardless of the characteristics of the inserted gene(s). In addition, this paper advocates harmonization of protocols for confined field trials to facilitate more efficient data transportability across different geographies. PMID:26138875

  15. Transportability of confined field trial data from cultivation to import countries for environmental risk assessment of genetically modified crops.

    PubMed

    Nakai, Shuichi; Hoshikawa, Kana; Shimono, Ayako; Ohsawa, Ryo

    2015-12-01

    Requirement of in-country confined field trials for genetically modified (GM) crops prior to unrestricted release is well-established among countries with domestic regulations for the cultivation approval of GM crops. However, the requirement of in-country confined field trials is not common in countries where the scope of the application does not include cultivation. Nonetheless, Japan and China request in-country confined field trials for GM crops which are intended only for use as food, feed and processing. This paper considers the transportability of confined field trial data from cultivation countries (e.g. United States, Canada, and South American countries) to import countries like Japan for the environmental risk assessment of GM crops by reviewing: (1) the purpose of confined field trial assessment, (2) weediness potential, defined as "an ability to establish and persist in an unmanaged area that is frequently disturbed by human activity", of host crops, and (3) reliability of the confined field trial data obtained from cultivation countries. To review the reliability of the confined field data obtained in the US, this paper describes actual examples of three confined field trials of approved GM corn events conducted both in the US and Japan. Based on the above considerations, this paper concludes that confined field data of GM corn and cotton is transportable from cultivation countries to importing countries (e.g. from the US to Japan), regardless of the characteristics of the inserted gene(s). In addition, this paper advocates harmonization of protocols for confined field trials to facilitate more efficient data transportability across different geographies.

  16. A comparison of susceptibility to Myxobolus cerebralis among strains of rainbow trout and steelhead in field and laboratory trials

    USGS Publications Warehouse

    Densmore, Christine L.; Blazer, V.S.; Cartwright, Deborah D.; Schill, W.B.; Schachte, J.H.; Petrie, C.J.; Batur, M.V.; Waldrop, T.B.; Mack, A.; Pooler, P.S.

    2001-01-01

    Three strains of rainbow trout and steelhead Oncorhynchus mykiss were evaluated for the presence of whirling disease in field and laboratory trials. In the field exposures, fingerling Salmon River steelhead and Cayuga Lake and Randolph strains of rainbow trout were placed in wire cages in an earthen, stream-fed pond in New York State that was known to harbor Myxobolus cerebralis. Control fish were held at another hatchery that was free of whirling disease. In the controlled trials at the National Fish Health Research Laboratory, fingerling steelhead and Cayuga Lake and Mount Lassen rainbow trout were exposed to triactinomyxons at low (200 triactinomyxons/fish) or high (2,000 triactinomyxons/fish) levels for 2 h. Controls of each group were sham-exposed. Following an incubation period of 154 d for laboratory trials and 180 d for field trials, cranial tissue samples were taken for spore enumeration (field and laboratory trials) and histological analyses (laboratory only). Clinical signs of disease, including whirling behavior, blacktail, and skeletal deformities, were recorded for each fish in the laboratory trial at the terminal sampling. No clinical evidence of disease was noted among fish in the field trials. Clinical signs were noted among all strains in the laboratory trials at both exposure levels, and these signs were consistently greatest for the Mount Lassen strain. Whirling and skeletal deformities were more evident in the steelhead than in the Cayuga Lake rainbow trout; blacktail was more common in the Cayuga Lake fish. In both field and laboratory trials, spore counts were significantly higher for Cayuga Lake rainbow trout than in steelhead. In laboratory trials, moderate to marked cranial tissue lesions predominated in all three strains.

  17. Giving bednets "fair" tests in field trials against malaria:a case from Sabah, East Malaysia.

    PubMed

    Leake, D W; Hii, J L

    1989-09-01

    Insecticide-impregnated bednets appear to be a potentially cost-effective intervention against endemic malaria in the tropics, but this has yet to be confirmed by field trials. There are two aspects to consider in assessing such trials: (1) the extent to which subjects use nets regularly and properly, and (2) the effectiveness of nets which are truly used regularly and properly in reducing malaria transmission. The second aspect is currently of primary concern, to determine if human-vector relationships for a particular at-risk population are such that bednets can be effective. But to give bednets a "fair" test in this regard requires regular and proper use in the first place. The study described here suggests they did not get a "fair" test in one field trial in Sabah, East Malaysia. The study also strongly suggests that direct observations, rather than post hoc questioning of subjects, may be essential to accurately gauge bednet usage rates. Accurate usage rates are required to determine what proportion of a population needs to use nets to reduce malaria transmission, and to evaluate the effectiveness of promotional programs over time. Direct observations can also yield valuable data on night-time activities that increase malaria risk, such as television viewing that keeps people awake and out of bednets.

  18. Dosing free nitrous acid for sulfide control in sewers: results of field trials in Australia.

    PubMed

    Jiang, Guangming; Keating, Anthony; Corrie, Shaun; O'halloran, Kelly; Nguyen, Lam; Yuan, Zhiguo

    2013-09-01

    Intermittent dosing of free nitrous acid (FNA), with or without the simultaneous dosing of hydrogen peroxide, is a new strategy developed recently for the control of sulfide production in sewers. Six-month field trials have been carried out in a rising main sewer in Australia (150 mm in diameter and 1080 m in length) to evaluate the performance of the strategy that was previously demonstrated in laboratory studies. In each trial, FNA was dosed at a pumping station for a period of 8 or 24 h, some with simultaneous hydrogen peroxide dosing. The sulfide control effectiveness was monitored by measuring, on-line, the dissolved sulfide concentration at a downstream location of the pipeline (828 m from the pumping station) and the gaseous H2S concentration at the discharge manhole. Effective sulfide control was achieved in all nine consecutive trials, with sulfide production reduced by more than 80% in 10 days following each dose. Later trials achieved better control efficiency than the first few trials possibly due to the disrupting effects of FNA on sewer biofilms. This suggests that an initial strong dose (more chemical consumption) followed by maintenance dosing (less chemical consumption) could be a very cost-effective way to achieve consistent control efficiency. It was also found that heavy rainfall slowed the recovery of sulfide production after dosing, likely due to the dilution effects and reduced retention time. Overall, intermittent dose of FNA or FNA in combination with H2O2 was successfully demonstrated to be a cost-effective method for sulfide control in rising main sewers.

  19. Pulsed electromagnetic fields in knee osteoarthritis: a double blind, placebo-controlled, randomized clinical trial

    PubMed Central

    Miceli, Giovanni; Marino, Natale; Sciortino, Davide; Bagnato, Gian Filippo

    2016-01-01

    Objectives. This trial aimed to test the effectiveness of a wearable pulsed electromagnetic fields (PEMF) device in the management of pain in knee OA patients. Methods. In this randomized [with equal randomization (1:1)], double-blind, placebo-controlled clinical trial, patients with radiographic evidence of knee OA and persistent pain higher than 40 mm on the visual analog scale (VAS) were recruited. The trial consisted of 12 h daily treatment for 1 month in 60 knee OA patients. The primary outcome measure was the reduction in pain intensity, assessed through VAS and WOMAC scores. Secondary outcomes included quality of life assessment through the 36-item Medical Outcomes Study Short-Form version 2 (SF-36 v2), pressure pain threshold (PPT) and changes in intake of NSAIDs/analgesics. Results. Sixty-six patients were included, and 60 completed the study. After 1 month, PEMF induced a significant reduction in VAS pain and WOMAC scores compared with placebo. Additionally, pain tolerance, as expressed by PPT changes, and physical health improved in PEMF-treated patients. A mean treatment effect of −0.73 (95% CI − 1.24 to − 0.19) was seen in VAS score, while the effect size was −0.34 (95% CI − 0.85 to 0.17) for WOMAC score. Twenty-six per cent of patients in the PEMF group stopped NSAID/analgesic therapy. No adverse events were detected. Conclusion. These results suggest that PEMF therapy is effective for pain management in knee OA patients and also affects pain threshold and physical functioning. Future larger studies, including head-to-head studies comparing PEMF therapy with standard pharmacological approaches in OA, are warranted. Trial registration: ClinicalTrials.gov, http://www.clinicaltrials.gov, NCT01877278 PMID:26705327

  20. Dosing free nitrous acid for sulfide control in sewers: results of field trials in Australia.

    PubMed

    Jiang, Guangming; Keating, Anthony; Corrie, Shaun; O'halloran, Kelly; Nguyen, Lam; Yuan, Zhiguo

    2013-09-01

    Intermittent dosing of free nitrous acid (FNA), with or without the simultaneous dosing of hydrogen peroxide, is a new strategy developed recently for the control of sulfide production in sewers. Six-month field trials have been carried out in a rising main sewer in Australia (150 mm in diameter and 1080 m in length) to evaluate the performance of the strategy that was previously demonstrated in laboratory studies. In each trial, FNA was dosed at a pumping station for a period of 8 or 24 h, some with simultaneous hydrogen peroxide dosing. The sulfide control effectiveness was monitored by measuring, on-line, the dissolved sulfide concentration at a downstream location of the pipeline (828 m from the pumping station) and the gaseous H2S concentration at the discharge manhole. Effective sulfide control was achieved in all nine consecutive trials, with sulfide production reduced by more than 80% in 10 days following each dose. Later trials achieved better control efficiency than the first few trials possibly due to the disrupting effects of FNA on sewer biofilms. This suggests that an initial strong dose (more chemical consumption) followed by maintenance dosing (less chemical consumption) could be a very cost-effective way to achieve consistent control efficiency. It was also found that heavy rainfall slowed the recovery of sulfide production after dosing, likely due to the dilution effects and reduced retention time. Overall, intermittent dose of FNA or FNA in combination with H2O2 was successfully demonstrated to be a cost-effective method for sulfide control in rising main sewers. PMID:23764584

  1. A field vaccine trial in Tanzania demonstrates partial protection against malignant catarrhal fever in cattle

    PubMed Central

    Lankester, F.; Russell, G.C.; Lugelo, A.; Ndabigaye, A.; Mnyambwa, N.; Keyyu, J.; Kazwala, R.; Grant, D.; Percival, A.; Deane, D.; Haig, D.M.; Cleaveland, S.

    2016-01-01

    Malignant catarrhal fever (MCF) is a fatal lymphoproliferative disease of cattle that, in East Africa, results from transmission of the causative virus, alcelaphine herpesvirus 1 (AlHV-1), from wildebeest. A vaccine field trial involving an attenuated AlHV-1 virus vaccine was performed over two wildebeest calving seasons on the Simanjiro Plain of northern Tanzania. Each of the two phases of the field trial consisted of groups of 50 vaccinated and unvaccinated cattle, which were subsequently exposed to AlHV-1 challenge by herding toward wildebeest. Vaccination resulted in the induction of virus-specific and virus-neutralizing antibodies. Some cattle in the unvaccinated groups also developed virus-specific antibody responses but only after the start of the challenge phase of the trial. PCR of DNA from blood samples detected AlHV-1 infection in both groups of cattle but the frequency of infection was significantly lower in the vaccinated groups. Some infected animals showed clinical signs suggestive of MCF but few animals went on to develop fatal MCF, with similar numbers in vaccinated and unvaccinated groups. This study demonstrated a baseline level of MCF-seropositivity among cattle in northern Tanzania of 1% and showed that AlHV-1 virus-neutralizing antibodies could be induced in Tanzanian zebu shorthorn cross cattle by our attenuated vaccine, a correlate of protection in previous experimental trials. The vaccine reduced infection rates by 56% in cattle exposed to wildebeest but protection from fatal MCF could not be determined due to the low number of fatal cases. PMID:26706270

  2. A field vaccine trial in Tanzania demonstrates partial protection against malignant catarrhal fever in cattle.

    PubMed

    Lankester, F; Russell, G C; Lugelo, A; Ndabigaye, A; Mnyambwa, N; Keyyu, J; Kazwala, R; Grant, D; Percival, A; Deane, D; Haig, D M; Cleaveland, S

    2016-02-01

    Malignant catarrhal fever (MCF) is a fatal lymphoproliferative disease of cattle that, in East Africa, results from transmission of the causative virus, alcelaphine herpesvirus 1 (AlHV-1), from wildebeest. A vaccine field trial involving an attenuated AlHV-1 virus vaccine was performed over two wildebeest calving seasons on the Simanjiro Plain of northern Tanzania. Each of the two phases of the field trial consisted of groups of 50 vaccinated and unvaccinated cattle, which were subsequently exposed to AlHV-1 challenge by herding toward wildebeest. Vaccination resulted in the induction of virus-specific and virus-neutralizing antibodies. Some cattle in the unvaccinated groups also developed virus-specific antibody responses but only after the start of the challenge phase of the trial. PCR of DNA from blood samples detected AlHV-1 infection in both groups of cattle but the frequency of infection was significantly lower in the vaccinated groups. Some infected animals showed clinical signs suggestive of MCF but few animals went on to develop fatal MCF, with similar numbers in vaccinated and unvaccinated groups. This study demonstrated a baseline level of MCF-seropositivity among cattle in northern Tanzania of 1% and showed that AlHV-1 virus-neutralizing antibodies could be induced in Tanzanian zebu shorthorn cross cattle by our attenuated vaccine, a correlate of protection in previous experimental trials. The vaccine reduced infection rates by 56% in cattle exposed to wildebeest but protection from fatal MCF could not be determined due to the low number of fatal cases.

  3. 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.

  4. Field Trial and Molecular Characterization of RNAi-Transgenic Tomato Plants That Exhibit Resistance to Tomato Yellow Leaf Curl Geminivirus.

    PubMed

    Fuentes, Alejandro; Carlos, Natacha; Ruiz, Yoslaine; Callard, Danay; Sánchez, Yadira; Ochagavía, María Elena; Seguin, Jonathan; Malpica-López, Nachelli; Hohn, Thomas; Lecca, Maria Rita; Pérez, Rosabel; Doreste, Vivian; Rehrauer, Hubert; Farinelli, Laurent; Pujol, Merardo; Pooggin, Mikhail M

    2016-03-01

    RNA interference (RNAi) is a widely used approach to generate virus-resistant transgenic crops. However, issues of agricultural importance like the long-term durability of RNAi-mediated resistance under field conditions and the potential side effects provoked in the plant by the stable RNAi expression remain poorly investigated. Here, we performed field trials and molecular characterization studies of two homozygous transgenic tomato lines, with different selection markers, expressing an intron-hairpin RNA cognate to the Tomato yellow leaf curl virus (TYLCV) C1 gene. The tested F6 and F4 progenies of the respective kanamycin- and basta-resistant plants exhibited unchanged field resistance to TYLCV and stably expressed the transgene-derived short interfering RNA (siRNAs) to represent 6 to 8% of the total plant small RNAs. This value outnumbered the average percentage of viral siRNAs in the nontransformed plants exposed to TYLCV-infested whiteflies. As a result of the RNAi transgene expression, a common set of up- and downregulated genes was revealed in the transcriptome profile of the plants selected from either of the two transgenic events. A previously unidentified geminivirus causing no symptoms of viral disease was detected in some of the transgenic plants. The novel virus acquired V1 and V2 genes from TYLCV and C1, C2, C3, and C4 genes from a distantly related geminivirus and, thereby, it could evade the repressive sequence-specific action of transgene-derived siRNAs. Our findings shed light on the mechanisms of siRNA-directed antiviral silencing in transgenic plants and highlight the applicability limitations of this technology as it may alter the transcriptional pattern of nontarget genes.

  5. Field Trial and Molecular Characterization of RNAi-Transgenic Tomato Plants That Exhibit Resistance to Tomato Yellow Leaf Curl Geminivirus.

    PubMed

    Fuentes, Alejandro; Carlos, Natacha; Ruiz, Yoslaine; Callard, Danay; Sánchez, Yadira; Ochagavía, María Elena; Seguin, Jonathan; Malpica-López, Nachelli; Hohn, Thomas; Lecca, Maria Rita; Pérez, Rosabel; Doreste, Vivian; Rehrauer, Hubert; Farinelli, Laurent; Pujol, Merardo; Pooggin, Mikhail M

    2016-03-01

    RNA interference (RNAi) is a widely used approach to generate virus-resistant transgenic crops. However, issues of agricultural importance like the long-term durability of RNAi-mediated resistance under field conditions and the potential side effects provoked in the plant by the stable RNAi expression remain poorly investigated. Here, we performed field trials and molecular characterization studies of two homozygous transgenic tomato lines, with different selection markers, expressing an intron-hairpin RNA cognate to the Tomato yellow leaf curl virus (TYLCV) C1 gene. The tested F6 and F4 progenies of the respective kanamycin- and basta-resistant plants exhibited unchanged field resistance to TYLCV and stably expressed the transgene-derived short interfering RNA (siRNAs) to represent 6 to 8% of the total plant small RNAs. This value outnumbered the average percentage of viral siRNAs in the nontransformed plants exposed to TYLCV-infested whiteflies. As a result of the RNAi transgene expression, a common set of up- and downregulated genes was revealed in the transcriptome profile of the plants selected from either of the two transgenic events. A previously unidentified geminivirus causing no symptoms of viral disease was detected in some of the transgenic plants. The novel virus acquired V1 and V2 genes from TYLCV and C1, C2, C3, and C4 genes from a distantly related geminivirus and, thereby, it could evade the repressive sequence-specific action of transgene-derived siRNAs. Our findings shed light on the mechanisms of siRNA-directed antiviral silencing in transgenic plants and highlight the applicability limitations of this technology as it may alter the transcriptional pattern of nontarget genes. PMID:26713353

  6. N-C isotopic investigation of a zeolite-amended agricultural field

    NASA Astrophysics Data System (ADS)

    Ferretti, Giacomo; Natali, Claudio; Faccini, Barbara; Di Giuseppe, Dario; Bianchini, Gianluca; Coltorti, Massimo

    2016-04-01

    In this study, a C and N isotopic investigation in the soil-plant system of the ZeoLIFE project experimental field have been carried out. Since many years, natural and NH4-enriched zeolites have been used as soil amendant in agricultural context in order to reduce N losses, increase NUE (Nitrogen Use Efficiency) and crop yield. Nevertheless up to now there are no studies that, using the stable isotopes approach, highlighted the interaction between zeolites and plants in agricultural systems. The main aims of this study is to verify if natural zeolites amendment can enhance chemical fertilization efficiency and if N transfer from NH4-enriched zeolites to plants really occurs. Plants grown following traditional cultivation methods (with no zeolite addition) and plants grown on soils amended with natural and NH4-enriched zeolites (the latter obtained after mixing with pig-slurry with a very high 15N) were compared for two cultivation cycles (maize and wheat). As widely known, plants grown under conventional farming systems (use of chemical fertilizers as urea) and plants grown under organic farming can be discriminated by the isotopic signatures of plant tissues. For both years the main results of the study reveals that plants grown on plots amended with natural zeolites generally have their nitrogen isotopic signature more similar to that of the chemical fertilizers employed during the cultivation with respect to the plants cultivated in the non-amended plot. This suggests an enhanced N uptake by the plant from this specific N source with respect to the non-amended plot. On the other hand, plants grown on NH4-enriched zeolites registered a higher 15N, approaching the pig-slurry isotopic signature, confirming that this material can constitute an N pool for plants at least for two cultivation cycles. The distinct agricultural practices seem to be reflected in the plant physiology as recorded by the carbon discrimination factor (13C) which generally increases

  7. Field and Wind Tunnel Comparison of Four Aerosol Samplers Using Agricultural Dusts

    PubMed Central

    Reynolds, Stephen J.; Nakatsu, Jason; Tillery, Marvin; Keefe, Thomas; Mehaffy, John; Thorne, Peter S.; Donham, Kelley; Nonnenmann, Matthew; Golla, Vijay; O'shaughnessy, Patrick

    2009-01-01

    Occupational lung disease is a significant problem among agricultural workers exposed to organic dusts. Measurements of exposure in agricultural environments in the USA have traditionally been conducted using 37-mm closed-face cassettes (CFCs) and respirable Cyclones. Inhalable aerosol samplers offer significant improvement for dose estimation studies to reduce respiratory disease. The goals of this study were to determine correction factors between the inhalable samplers (IOM and Button) and the CFC and Cyclone for dusts sampled in livestock buildings and to determine whether these factors vary among livestock types. Determination of these correction factors will allow comparison between inhalable measurements and historical measurements. Ten sets of samples were collected in swine, chicken, turkey, and dairy facilities in both Colorado and Iowa. Pairs of each sampling device were attached to the front and back of a rotating mannequin. Laboratory studies using a still-air chamber and a wind tunnel provided information regarding the effect of wind speed on sampler performance. Overall, the IOM had the lowest coefficient of variation (best precision) and was least affected by changes in wind speed. The performance of the Button was negatively impacted in poultry environments where larger (feather) particulates clogged the holes in the initial screen. The CFC/IOM ratios are important for comparisons between newer and older studies. Wind speed and dust type were both important factors affecting ratios. Based on the field studies (Table 6), a ratio of 0.56 is suggested as a conversion factor for the CFC/IOM (average for all environments because of no statistical difference). Suggested conversion factors for the Button/IOM are swine (0.57), chicken (0.80), turkey (0.53), and dairy (0.67). Any attempt to apply a conversion factor between the Cyclone and inhalable samplers is not recommended. PMID:19443852

  8. Field-Scale Soil Moisture Observations in Irrigated Agriculture Fields Using the Cosmic-ray Neutron Rover

    NASA Astrophysics Data System (ADS)

    Franz, T. E.; Avery, W. A.; Finkenbiner, C. E.; Wang, T.; Brocca, L.

    2014-12-01

    Approximately 40% of global food production comes from irrigated agriculture. With the increasing demand for food even greater pressures will be placed on water resources within these systems. In this work we aimed to characterize the spatial and temporal patterns of soil moisture at the field-scale (~500 m) using the newly developed cosmic-ray neutron rover near Waco, NE. Here we mapped soil moisture of 144 quarter section fields (a mix of maize, soybean, and natural areas) each week during the 2014 growing season (May to September). The 11 x11 km study domain also contained 3 stationary cosmic-ray neutron probes for independent validation of the rover surveys. Basic statistical analysis of the domain indicated a strong inverted parabolic relationship between the mean and variance of soil moisture. The relationship between the mean and higher order moments were not as strong. Geostatistical analysis indicated the range of the soil moisture semi-variogram was significantly shorter during periods of heavy irrigation as compared to non-irrigated periods. Scaling analysis indicated strong power law behavior between the variance of soil moisture and averaging area with minimal dependence of mean soil moisture on the slope of the power law function. Statistical relationships derived from the rover dataset offer a novel set of observations that will be useful in: 1) calibrating and validating land surface models, 2) calibrating and validating crop models, 3) soil moisture covariance estimates for statistical downscaling of remote sensing products such as SMOS and SMAP, and 4) provide center-pivot scale mean soil moisture data for optimal irrigation timing and volume amounts.

  9. Improving Agricultural Drought Monitoring in East Africa with Unbiased Rainfall Fields and Detailed Land Surface Physics

    NASA Astrophysics Data System (ADS)

    McNally, A.; Yatheendradas, S.; Peters-Lidard, C. D.; Michaelsen, J.

    2010-12-01

    Monitoring drought is particularly challenging within rainfed agricultural and pastoral systems, where it can serve the greatest need. Such locations often have sparse or non-existent ground based measurements of precipitation, evapotranspiration (ET), and soil moisture. For more effective drought monitoring with limited hydroclimate observations, we simulate land surface states using the Community Noah Land Surface Model forced with different merged rainfall products inside a Land Information System (LIS). Using model outputs we will answer the questions: How sensitive are soil moisture and ET fields to differences in rainfall forcing and model physics? What are acceptable drought-specific tradeoffs between near-real time availability and skill of rainfall data? Preliminary results with the African Rainfall Estimation Algorithm Version 2 (RFE2.0) outperformed global products, suggesting that sub-global rainfall estimates are the way forward for regional drought monitoring. Specifically, the Noah model forced with RFE2.0 better resolved the heterogeneous patterns in crop stress than the Famine Early Warning System Network (FEWS NET) operational Water Requirement Satisfaction Index (WRSI) model. To further investigate the improvement in drought monitoring while maintaining timeliness, we unbias (using Africa specific climatology) the precipitation products from CPC Merged Analysis of Precipitation (CMAP), Tropical Rainfall Measurement Mission (TRMM), and RFE2.0. The skill (relative accuracy) and reliability (average agreement) of the unbiased rainfall are calculated against an unbiased precipitation product augmented with station data from Ethiopia and Kenya. Soil moisture and ET fields from Noah are compared to the operational FEWS NET WRSI, soil water anomaly index, and the World Food Program’s Crop and Food Security Assessment Mission reports. We anticipate that the unbiased rainfall fields will improve the accuracy, spatio-temporal resolution, and

  10. Agricultural terraces montoring and modeling: a field survey in Chianti region, Firenze, Italy - First part

    NASA Astrophysics Data System (ADS)

    Preti, Federico; Caruso, Marco; Dani, Andrea; Errico, Alessandro; Guastini, Enrico; Trucchi, Paolo

    2015-04-01

    The two abstracts present the design and set-up of an experimental field plant whose aim is the study and modeling of water circulation in a terraced slope together with its influence on the stability of the retaining dry stone walls. The pilot plant is located at "Fattoria di Lamole" (Greve in Chianti, Firenze, Italy) where both ancient and recently restored or rebuilt dry stone retaining walls are present. The intense vineyards cultivation makes it very representative in terms of range of external stresses that affect both hillslopes and walls. The research is developed within a bigger framework of landscape preservation as a way to prevent hydrogeological instabilities and landslide risks. First Part A first/preliminary field survey was carried out in order to estimate the hydraulic and mechanical soil characteristics. Field saturated hydraulic conductivity measurements with the Simplified Falling Head (SFH) method on a terrace along an alignment were performed. Infiltrometer tests with a double ring device and soil texture determinations with both fine particle-size and skeleton fraction distributions were also performed. The Direct shear test on undisturbed and reconstituted soil samples will offer an estimation of the Mohr-Coulomb failure envelope parameters (friction angle and cohesion). A reference portion of a dry stone wall will be also monitored. Lateral earth pressure at backfill-retaining wall interface (compared to temperature and air pressure measured values), backfill volumetric water content (both in saturated and unsaturated states) and ground-water level are measured. Acknowledgements Italian Research Project of Relevant Interest (PRIN2010-2011), prot. 20104ALME4, National network for monitoring, modeling, and sustainable management of erosion processes in agricultural land and hilly-mountainous area

  11. Linking field observations, Landsat and MODIS data to estimate agricultural change in European Russia.

    NASA Astrophysics Data System (ADS)

    de Beurs, K. M.; Ioffe, G.

    2011-12-01

    Agricultural reform has been one of the most important anthropogenic change processes in European Russia that has been unfolding since the formal collapse of the Soviet Union at the end of 1991. Widespread land abandonment is perhaps the most vivid side effect of the reform, even visible in synoptic imagery. Currently, Russia is transitioning into a country with an internal "archipelago" of islands of productive agriculture around cities embedded in a matrix of unproductive, abandoned lands. This heterogeneous spatial pattern is mainly driven by depopulation of the least favorable parts of the countryside, where "least favorable" is a function of fertility, remoteness, and their interaction. In this work we provide a satellite, GIS and field based overview of the current agricultural developments in Russia and look beyond the unstable period immediately following the collapse of the Soviet Union. We apply Landsat images in one of Russia's oblasts to create a detailed land cover map. We then use a logistic model to link the Landsat land cover map with the inter-annual variability in key phenological parameters calculated from MODIS to derive the percent of cropland per 500m MODIS pixel. By evaluating the phenological characteristics of the MODIS curves for each year we determine whether a pixel was actually cropped or left fallow. A comparison of satellite-estimated cropped areas with regional statistics (by rayon) revealed that the satellite estimates are highly correlated with the regional statistics for both arable lands and successfully cropped areas. We use the crop maps to determine the number of times a particular area was cropped between 2002 and 2009 by summing all the years with crops per pixel. This variable provides a good indication about the intensification and de-intensification of the Russian croplands over the last decade. We have visited several rural areas in Russia and we link the satellite data with information acquired through field interviews

  12. Implementation of a segmentation method for agricultural fields in aerial sequences of images based on CSAR model

    NASA Astrophysics Data System (ADS)

    Chen, Haijun; Houkes, Zweitze

    1998-09-01

    In this paper, a segmentation method for agricultural fields in aerial sequences of images based on the Circular Symmetri Auto-Regressive (CSAR) model is presented. The image sequences assumed to be acquired by a video camera (RGB-CCD system) from an aeroplane, which moves linearly over the scene. The objects in the scenes being considered in this paper, are agricultural fields. The classes of agricultural fields to be distinguished are determined by the type of crop, e.g. potatoes sugar beet, wheat, etc. In order to recognize and classify these fields from aerial sequence of images, a reliable segmentatio is required. Here texture features are used for segmentation. The implementation of segmentation for agricultural fields in aerial sequences of images is based on CSAR model in texture analysis. By comparing the estimated parameters of CSAR model from different area in an image, the characteristics and the class of a texture may be determined. The paper describes the segmentation method and its evaluation through experiments. Based on segmentation results, classification for surface texture of vegetation from aerial sequences of images is realized.

  13. HEP (hydraulic, electronic, pneumatic) pumping unit: performance characteristics, potential applications, and field trial results

    SciTech Connect

    Jesperson, P.J.; Laidlaw, R.N.; Scott, R.J.

    1981-01-01

    THe HEP pumping unit constitutes an alternative to the familiar beam pumping unit as a means of transferring energy from the prime mover to the sucker rod string of a pumping well. This paper addresses some basic concepts which are part of the HEP system design and describes some of the resultant unit performance characteristics. The potential for enhancement of pumping well operations utilizing the high degree of control over rod string motion attainable with the HEP system, is discussed together with the results of a number of field trials and some plans for further unit evaluation and development. A lift capacity comparison with conventional beam pumping units is also included. 8 refs.

  14. Field trial of 1% niclosamide as a topical antipenetrant to Schistosoma mansoni cercariae.

    PubMed

    Abu-Elyazeed, R R; Podgore, J K; Mansour, N S; Kilpatrick, M E

    1993-10-01

    A randomized, double-blind, placebo-controlled field trial of a topical antipenetrant lotion, 1% niclosamide, applied daily to the upper and lower limbs of farmers occupationally exposed to Schistosoma mansoni cercarial-infested water, was conducted in the Nile Delta to assess its safety and efficacy in preventing reinfection. Farmers aged 18-40 years were treated to cure their S. mansoni infections three months prior to the onset of the trial. Subjects were randomly assigned to receive niclosamide or placebo lotion that was self-applied daily for five months. A total of 186 subjects met the inclusion criteria and completed the trial. The exposure to schistosomal-infested water occurred during routine irrigation activities from June to November 1991. Stool specimens were evaluated monthly during and for two months following the lotion application period. The subjects applying the niclosamide lotion were comparable to those applying placebo lotion in age (mean 30 years for both), total water contact (184.5 hr versus 173.8 hr), reported lotion application compliance (88% versus 92%), and reported water contact involving skin exposure other than upper and lower limbs (23% versus 27%). The schistosomal reinfection rate was lower in the niclosamide group (53.3%) compared with the placebo lotion group (71.3%), (P < 0.02). Increased protection might be obtained with total body application for shorter, less intense, water contact exposures.

  15. Field trial of five repellent formulations against mosquitoes in Ahero, Kenya.

    PubMed

    Sherwood, Van; Kioko, Elizabeth; Kasili, Sichangi; Ngumbi, Philip; Hollingdale, Michael R

    2009-01-01

    Twelve volunteers, using one leg for repellent application and the other leg as a control, field-tested 5 insect repellent formulations--Avon's (New York, NY) SS220 Spray, SS220 Lotion, and Bayrepel Lotion, and SC Johnson's (Racine, Wisconsin) Autan Bayrepel Lotion--against the standard N,N-diethyl-3-methyl-benzamide (deet) in a rice-growing district near Kisumu, western Kenya, in 2 trials in May and June 2004. In addition to a control leg for each volunteer, an additional control was introduced into the study by the use of a sixth repellent, a "null repellent," which was literally a treatment application of no repellent at all. The 5 active repellent formulations were uniformly applied at the maximum Environmental Protection Agency recommended dose of 1.5 g per 600 cm2 in the first trial and half that dose in the second trial, and none of them failed during the nightly 12-hour test period over 6 consecutive days, May 19 through May 24, 2004, and June 14 through June 19, 2004. However, the repellent control legs demonstrated a statistically significant increased landing rate compared to both the null repellent and the null repellent control leg. This suggests that, in this approach, active repellents increased the capture rate on an adjacent control leg compared to null controls. A single human volunteer can act as his/her own control provided null treatment controls are included.

  16. Maize production and land degradation: a Portuguese agriculture field case study

    NASA Astrophysics Data System (ADS)

    Ferreira, Carla S. S.; Pato, João V.; Moreira, Pedro M.; Valério, Luís M.; Guilherme, Rosa; Casau, Fernando J.; Santos, Daniela; Keizer, Jacob J.; Ferreira, António J. D.

    2016-04-01

    While food security is a main challenge faced by human kind, intensive agriculture often leads to soil degradation which then can threaten productivity. Maize is one of the most important crops across the world, with 869 million tons produced worldwide in 2012/2013 (IGC 2015), of which 929.5 thousand tons in Portugal (INE 2014). In Portugal, maize is sown in April/May and harvest occurs generally in October. Conventional maize production requires high inputs of water and fertilizers to achieve higher yields. As Portuguese farmers are typically rather old (on average, 63 years) and typically have a low education level (INE 2014), sustainability of their land management practises is often not a principal concern. This could explain why, in 2009, only 4% of the Portuguese temporary crops were under no-tillage, why only 8% of the farmers performed soil analyses in the previous three years, and why many soils have a low organic matter content (INE 2014). Nonetheless, sustainable land management practices are generally accepted to be the key to reducing agricultural soil degradation, preventing water pollution, and assuring long-term crop production objectives and food security. Sustainable land management should therefore not only be a concern for policy makers but also for farmers, since land degradation will have negative repercussions on the productivity, thus, on their economical income. This paper aims to assess the impact of maize production on soil properties. The study focusses on an 8 ha maize field located in central Portugal, with a Mediterranean climate on a gently sloping terrain (<3%) and with a soil classified as Eutric Fluvisol. On the field, several experiments were carried out with different maize varieties as well as with different fertilizers (solid, liquid and both). Centre pivot irrigation was largely used. Data is available from 2003, and concerns crop yield, fertilization and irrigation practices, as well as soil properties assessed through

  17. Nitrate leaching to shallow groundwater systems from agricultural fields with different management practices.

    PubMed

    Nila Rekha, P; Kanwar, R S; Nayak, A K; Hoang, C K; Pederson, C H

    2011-09-01

    Monitoring the concentration of NO(3)-N from agricultural fields to the subsurface and shallow ground water resources have received considerable interest worldwide, since agriculture has been identified as a major source of nitrate-nitrogen (NO(3)-N) pollution of groundwater systems in intensively farmed watersheds. A study was conducted to quantify the impact of two tillage practices viz. chisel plow (CP) and no till (NT) with liquid swine manure application on nitrate leaching to the shallow ground water system under corn-soybean production system. This study is part of the long-term field experiments conducted at Iowa State University using completely randomized block design. The NO(3)-N concentrations in the shallow ground water were monitored at three depths viz., a network of subsurface drains at a depth of 1.2 m and piezometers at depths of 1.8 m and 2.4 m. Results of this study showed that the average NO(3)-N concentration during the study period was 16.1 mg l(-1), 14.4 mg l(-1) and 11.8 mg l(-1) at 1.2 m, 1.8 m and 2.4 m depths, respectively implying significant amount of NO(3)-N leaching past the subsurface drain depth of 1.2 m into the shallow groundwater but the NO(3)-N concentration decreases with the depth. The NO(3)-N concentrations in shallow groundwater were significantly higher under the chisel plow system in comparison with the no till method of tillage. Fall application of liquid swine manure caused more leaching in comparison with the spring application. Higher NO(3)-N concentration was observed under corn in comparison with the soybean plots. An in-depth analysis of the data showed a definite relationship between the NO(3)-N concentration in subsurface drain water at a depth of 1.2 m and shallow groundwater at depths of 1.8 m and 2.4 m depths.

  18. Noncrop flowering plants restore top-down herbivore control in agricultural fields.

    PubMed

    Balmer, Oliver; Pfiffner, Lukas; Schied, Johannes; Willareth, Martin; Leimgruber, Andrea; Luka, Henryk; Traugott, Michael

    2013-08-01

    Herbivore populations are regulated by bottom-up control through food availability and quality and by top-down control through natural enemies. Intensive agricultural monocultures provide abundant food to specialized herbivores and at the same time negatively impact natural enemies because monocultures are depauperate in carbohydrate food sources required by many natural enemies. As a consequence, herbivores are released from both types of control. Diversifying intensive cropping systems with flowering plants that provide nutritional resources to natural enemies may enhance top-down control and contribute to natural herbivore regulation. We analyzed how noncrop flowering plants planted as "companion plants" inside cabbage (Brassica oleracea) fields and as margins along the fields affect the plant-herbivore-parasitoid-predator food web. We combined molecular analyses quantifying parasitism of herbivore eggs and larvae with molecular predator gut content analysis and a comprehensive predator community assessment. Planting cornflowers (Centaurea cynanus), which have been shown to attract and selectively benefit Microplitis mediator, a larval parasitoid of the cabbage moth Mamestra brassicae, between the cabbage heads shifted the balance between trophic levels. Companion plants significantly increased parasitism of herbivores by larval parasitoids and predation on herbivore eggs. They furthermore significantly affected predator species richness. These effects were present despite the different treatments being close relative to the parasitoids' mobility. These findings demonstrate that habitat manipulation can restore top-down herbivore control in intensive crops if the right resources are added. This is important because increased natural control reduces the need for pesticide input in intensive agricultural settings, with cascading positive effects on general biodiversity and the environment. Companion plants thus increase biodiversity both directly, by introducing

  19. Inorganic nitrogen inventory in a lowland heterogeneous agricultural field: implications for groundwater quality monitoring and assessment

    NASA Astrophysics Data System (ADS)

    Mastrocicco, M.; Colombani, N.; Faccini, B.; Di Giuseppe, D.; Coltorti, M.

    2012-04-01

    The inorganic nitrogen leaching from agriculture can have a severe and long-lasting effect on groundwater quality and it can also affect surface water quality since the contaminated groundwater can be discharged into drains in reclaimed lowland territories, like in the Po river delta. These lands lye below the actual sea level, thus they are continuously drained by pumping stations which collect the water from a capillary distributed network of channels and ditches. A complicating factor in understanding and quantify the effective leaching of nitrogen from agricultural fertilizers is the background ammonium presence in the sub-soils, due to peat layers, which provide a natural source of organic nitrogen slowly mineralized into ammonium. This implies that the geochemical inventory of ammonium-bearing sediments in peaty soils and sediments has an important control for the future development of groundwater quality in these areas. To estimate the mass of inorganic nitrogen present within the unsaturated zone below agricultural fields, a 6 ha wide site was characterized with high resolution core depth profiles. Cores were analyzed for inorganic nitrogen content (nitrate, nitrite and ammonium) and for bromide, used as nonreactive tracer. The soils and sediments within the site are highly heterogeneous, since many sedimentological environments overlapped during the last few centuries, creating vertical and lateral facies heteropies. These facies heteropies were reconstructed in a GIS environment via grain size analysis, soil organic matter content and detailed stratigraphic logs. The vertical distribution of inorganic nitrogen species is nitrate prevalent in the first meter of soil, where oxic condition prevailed (also induced by tillage and drains); ammonium is the major nitrogen species from 1 to 4 m below ground level. Where buried sandy sediments (paleochannels) are present beneath 1 m below ground level, nitrate can penetrate slightly deeper in the unsaturated zone

  20. Not a load of rubbish: simulated field trials in large-scale containers.

    PubMed

    Hohmann, M; Stahl, A; Rudloff, J; Wittkop, B; Snowdon, R J

    2016-09-01

    Assessment of yield performance under fluctuating environmental conditions is a major aim of crop breeders. Unfortunately, results from controlled-environment evaluations of complex agronomic traits rarely translate to field performance. A major cause is that crops grown over their complete lifecycle in a greenhouse or growth chamber are generally constricted in their root growth, which influences their response to important abiotic constraints like water or nutrient availability. To overcome this poor transferability, we established a plant growth system comprising large refuse containers (120 L 'wheelie bins') that allow detailed phenotyping of small field-crop populations under semi-controlled growth conditions. Diverse winter oilseed rape cultivars were grown at field densities throughout the crop lifecycle, in different experiments over 2 years, to compare seed yields from individual containers to plot yields from multi-environment field trials. We found that we were able to predict yields in the field with high accuracy from container-grown plants. The container system proved suitable for detailed studies of stress response physiology and performance in pre-breeding populations. Investment in automated large-container systems may help breeders improve field transferability of greenhouse experiments, enabling screening of pre-breeding materials for abiotic stress response traits with a positive influence on yield. PMID:27144906

  1. Nanotechnologies in agriculture and food - an overview of different fields of application, risk assessment and public perception.

    PubMed

    Grobe, Antje; Rissanen, Mikko E

    2012-12-01

    Nanomaterials in agriculture and food are key issues of public and regulatory interest. Over the past ten years, patents for nanotechnological applications in the field of food and agriculture have become abundant. Uncertainty prevails however regarding their current development status and presence in the consumer market. Thus, the discussion on nanotechnologies in the food sector with its specific public perception of benefits and risks and the patterns of communication are becoming similar to the debate on genetically modified organisms. The food industry's silence in communication increased mistrust of consumer organisations and policy makers. The article discusses the background of the current regulatory debates, starting with the EU recommendation for defining nanomaterials, provides an overview of possible fields of application in agriculture and food industries and discusses risk assessment and the public debate on benefits and risks. Communicative recommendations are directed at researchers, the food industry and regulators in order to increase trust both in stakeholders, risk management and regulatory processes.

  2. Spatial probability of soil water repellency in an abandoned agricultural field in Lithuania

    NASA Astrophysics Data System (ADS)

    Pereira, Paulo; Misiūnė, Ieva

    2015-04-01

    Water repellency is a natural soil property with implications on infiltration, erosion and plant growth. It depends on soil texture, type and amount of organic matter, fungi, microorganisms, and vegetation cover (Doerr et al., 2000). Human activities as agriculture can have implications on soil water repellency (SWR) due tillage and addition of organic compounds and fertilizers (Blanco-Canqui and Lal, 2009; Gonzalez-Penaloza et al., 2012). It is also assumed that SWR has a high small-scale variability (Doerr et al., 2000). The aim of this work is to study the spatial probability of SWR in an abandoned field testing several geostatistical methods, Organic Kriging (OK), Simple Kriging (SK), Indicator Kriging (IK), Probability Kriging (PK) and Disjunctive Kriging (DK). The study area it is located near Vilnius urban area at (54 49' N, 25 22', 104 masl) in Lithuania (Pereira and Oliva, 2013). It was designed a experimental plot with 21 m2 (07x03 m). Inside this area it was measured SWR was measured every 50 cm using the water drop penetration time (WDPT) (Wessel, 1998). A total of 105 points were measured. The probability of SWR was classified in 0 (No probability) to 1 (High probability). The methods accuracy was assessed with the cross validation method. The best interpolation method was the one with the lowest Root Mean Square Error (RMSE). The results showed that the most accurate probability method was SK (RMSE=0.436), followed by DK (RMSE=0.437), IK (RMSE=0.448), PK (RMSE=0.452) and OK (RMSE=0.537). Significant differences were identified among probability tests (Kruskal-Wallis test =199.7597 p<0.001). On average the probability of SWR was high with the OK (0.58±0.08) followed by PK (0.49±0.18), SK (0.32±0.16), DK (0.32±0.15) and IK (0.31±0.16). The most accurate probability methods predicted a lower probability of SWR in the studied plot. The spatial distribution of SWR was different according to the tested technique. Simple Kriging, DK, IK and PK methods

  3. Development of a field worthy sensor system to monitor gaseous nitrogen transfer from agricultural cropland

    SciTech Connect

    Not Available

    1992-11-01

    Nitrogen fertilizer accounts for 25 to 33% of the energy requirements in modern crop agriculture in the world today. Energy input for the manufacture of these N fertilizers is in the range of 460 [times] 10[sup 12] Btu per year. Unfortunately, for some N sources up to 70% of this energy in the form of NK can be lost through improper application techniques and poor N management strategies. Anhydrous NH[sub 3] may be lost to the atmosphere during and after placement due to soil conditions placement. Measurement of volatile N is difficult, especially under field conditions. A precise and convenient method of measuring gaseous NH[sub 3] near and above the soil surface is prerequisite to the development and evaluation of altemative fertilizer management strategies and application techniques which can reduce the potential for significant loss. Recent advances in integrated-optic (IO) based sensing offers the potential of measuring low levels of NH[sub 3] loss from a cropping system in the range of 100 ppB. The integrated design of an IO system allows for a more durable device that can be mass produced at low cost. Under Phase I of this project, two IO devices were designed and tested: an absorption device using an oxazine dye as a waveguide coating and an interferometric device using an anilinium salt as a waveguide coating.

  4. THE USE OF CHEMICALS IN THE FIELD OF FARM ANIMAL HEALTH (NUTRITION, ENTOMOLOGY, PATHOLOGY). AGRICULTURAL CHEMICALS TECHNOLOGY, NUMBER 7.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    DEVELOPED BY A NATIONAL TASK FORCE ON THE BASIS OF STATE STUDIES, THIS MODULE IS ONE OF A SERIES DESIGNED TO ASSIST TEACHERS IN PREPARING POST-SECONDARY STUDENTS FOR AGRICULTURAL CHEMICAL OCCUPATIONS. THE SPECIFIC OBJECTIVE OF THIS MODULE IS TO PREPARE TECHNICIANS IN THE FIELD OF THE USE OF CHEMICALS FOR ANIMAL HEALTH. SECTIONS INCLUDE -- (1)…

  5. Estimation of decay rates for fecal indicator bacteria and bacterial pathogens in agricultural field-applied manure

    EPA Science Inventory

    Field-applied manure is an important source of pathogenic exposure in surface water bodies for humans and ecological receptors. We analyzed the persistence and decay of fecal indicator bacteria and bacterial pathogens from three sources (cattle, poultry, swine) for agricultural f...

  6. Bringing Buprenorphine-Naloxone Detoxification to Community Treatment Providers: The NIDA Clinical Trials Network Field Experience

    PubMed Central

    Amass, Leslie; Ling, Walter; Freese, Thomas E.; Reiber, Chris; Annon, Jeffrey J.; Cohen, Allan J.; M.F.T.; McCarty, Dennis; Reid, Malcolm S.; Brown, Lawrence S.; Clark, Cynthia; Ziedonis, Douglas M.; Krejci, Jonathan; Stine, Susan; Winhusen, Theresa; Brigham, Greg; Babcock, Dean; L.C.S.W.; Muir, Joan A.; Buchan, Betty J.; Horton, Terry

    2005-01-01

    In October 2002, the U.S. Food and Drug Administration approved buprenorphine-naloxone (Suboxone®) sublingual tablets as an opioid dependence treatment available for use outside traditionally licensed opioid treatment programs. The NIDA Center for Clinical Trials Network (CTN) sponsored two clinical trials assessing buprenorphine-naloxone for short-term opioid detoxification. These trials provided an unprecedented field test of its use in twelve diverse community-based treatment programs. Opioid-dependent men and women were randomized to a thirteen-day buprenorphine-naloxone taper regimen for short-term opioid detoxification. The 234 buprenorphine-naloxone patients averaged 37 years old and used mostly intravenous heroin. Direct and rapid induction onto buprenorphine-naloxone was safe and well tolerated. Most patients (83%) received 8 mg buprenorphine-2 mg naloxone on the first day and 90% successfully completed induction and reached a target dose of 16mg buprenorphine-4 mg naloxone in three days. Medication compliance and treatment engagement was high. An average of 81% of available doses was ingested, and 68% of patients completed the detoxification. Most (80.3%) patients received some ancillary medications with an average of 2.3 withdrawal symptoms treated. The safety profile of buprenorphine-naloxone was excellent. Of eighteen serious adverse events reported, only one was possibly related to buprenorphine-naloxone. All providers successfully integrated buprenorphine-naloxone into their existing treatment milieus. Overall, data from the CTN field experience suggest that buprenorphine-naloxone is practical and safe for use in diverse community treatment settings, including those with minimal experience providing opioid-based pharmacotherapy and/or medical detoxification for opioid dependence. PMID:15204675

  7. Guest Molecule Exchange Kinetics for the 2012 Ignik Sikumi Gas Hydrate Field Trial

    SciTech Connect

    White, Mark D.; Lee, Won Suk

    2014-05-14

    A commercially viable technology for producing methane from natural gas hydrate reservoirs remains elusive. Short-term depressurization field tests have demonstrated the potential for producing natural gas via dissociation of the clathrate structure, but the long-term performance of the depressurization technology ultimately requires a heat source to sustain the dissociation. A decade of laboratory experiments and theoretical studies have demonstrated the exchange of pure CO2 and N2-CO2 mixtures with CH4 in sI gas hydrates, yielding critical information about molecular mechanisms, recoveries, and exchange kinetics. Findings indicated the potential for producing natural gas with little to no production of water and rapid exchange kinetics, generating sufficient interest in the guest-molecule exchange technology for a field test. In 2012 the U.S. DOE/NETL, ConocoPhillips Company, and Japan Oil, Gas and Metals National Corporation jointly sponsored the first field trial of injecting a mixture of N2-CO2 into a CH4-hydrate bearing formation beneath the permafrost on the Alaska North Slope. Known as the Ignik Sikumi #1 Gas Hydrate Field Trial, this experiment involved three stages: 1) the injection of a N2-CO2 mixture into a targeted hydrate-bearing layer, 2) a 4-day pressurized soaking period, and 3) a sustained depressurization and fluid production period. Data collected during the three stages of the field trial were made available after an extensive quality check. These data included continuous temperature and pressure logs, injected and recovered fluid compositions and volumes. The Ignik Sikumi #1 data set is extensive, but contains no direct evidence of the guest-molecule exchange process. This investigation is directed at using numerical simulation to provide an interpretation of the collected data. A numerical simulator, STOMP-HYDT-KE, was recently completed that solves conservation equations for energy, water, mobile fluid guest molecules, and hydrate guest

  8. Raman distributed temperature sensor for oil leakage detection in soil: a field trial and future trends

    NASA Astrophysics Data System (ADS)

    Signorini, Alessandro; Nannipieri, Tiziano; Gabella, Luca; Di Pasquale, Fabrizio; Latini, Gilberto; Ripari, Daniele

    2014-05-01

    In this paper we perform field validation of distributed Raman temperature sensing (RDTS) for oil leakage detection in soil. The capability of the distributed Raman sensor in detecting and locating, with high accuracy and spatial resolution, drop leakages in soil is demonstrated through a water leakage simulation in a field trial. The future trends and the high potential of the Raman DTS technology for oil and gas leakage detection in long pipelines is then outlined in this paper by reporting lab experiments demonstrating accurate meter scale temperature measurement over more than 50 km of standard single mode fiber. The proposed solution, based on distributed Simplex coding techniques, can be competitive in terms of cost and performance with respect to other distributed sensing technologies.

  9. Attentive scanning behavior drives one-trial potentiation of hippocampal place fields.

    PubMed

    Monaco, Joseph D; Rao, Geeta; Roth, Eric D; Knierim, James J

    2014-05-01

    The hippocampus is thought to have a critical role in episodic memory by incorporating the sensory input of an experience onto a spatial framework embodied by place cells. Although the formation and stability of place fields requires exploration, the interaction between discrete exploratory behaviors and the specific, immediate and persistent modifications of neural representations required by episodic memory has not been established. We recorded place cells in rats and found that increased neural activity during exploratory head-scanning behaviors predicted the formation and potentiation of place fields on the next pass through that location, regardless of environmental familiarity and across multiple testing days. These results strongly suggest that, during the attentive behaviors that punctuate exploration, place cell activity mediates the one-trial encoding of ongoing experiences necessary for episodic memory.

  10. On the "Optimal" Choice of Trial Functions for Modelling Potential Fields

    NASA Astrophysics Data System (ADS)

    Michel, Volker

    2015-04-01

    There are many trial functions (e.g. on the sphere) available which can be used for the modelling of a potential field. Among them are orthogonal polynomials such as spherical harmonics and radial basis functions such as spline or wavelet basis functions. Their pros and cons have been widely discussed in the last decades. We present an algorithm, the Regularized Functional Matching Pursuit (RFMP), which is able to choose trial functions of different kinds in order to combine them to a stable approximation of a potential field. One main advantage of the RFMP is that the constructed approximation inherits the advantages of the different basis systems. By including spherical harmonics, coarse global structures can be represented in a sparse way. However, the additional use of spline basis functions allows a stable handling of scattered data grids. Furthermore, the inclusion of wavelets and scaling functions yields a multiscale analysis of the potential. In addition, ill-posed inverse problems (like a downward continuation or the inverse gravimetric problem) can be regularized with the algorithm. We show some numerical examples to demonstrate the possibilities which the RFMP provides.

  11. Seeking mathematics success for college students: a randomized field trial of an adapted approach

    NASA Astrophysics Data System (ADS)

    Gula, Taras; Hoessler, Carolyn; Maciejewski, Wes

    2015-11-01

    Many students enter the Canadian college system with insufficient mathematical ability and leave the system with little improvement. Those students who enter with poor mathematics ability typically take a developmental mathematics course as their first and possibly only mathematics course. The educational experiences that comprise a developmental mathematics course vary widely and are, too often, ineffective at improving students' ability. This trend is concerning, since low mathematics ability is known to be related to lower rates of success in subsequent courses. To date, little attention has been paid to the selection of an instructional approach to consistently apply across developmental mathematics courses. Prior research suggests that an appropriate instructional method would involve explicit instruction and practising mathematical procedures linked to a mathematical concept. This study reports on a randomized field trial of a developmental mathematics approach at a college in Ontario, Canada. The new approach is an adaptation of the JUMP Math program, an explicit instruction method designed for primary and secondary school curriculae, to the college learning environment. In this study, a subset of courses was assigned to JUMP Math and the remainder was taught in the same style as in the previous years. We found consistent, modest improvement in the JUMP Math sections compared to the non-JUMP sections, after accounting for potential covariates. The findings from this randomized field trial, along with prior research on effective education for developmental mathematics students, suggest that JUMP Math is a promising way to improve college student outcomes.

  12. Pen and field trials of flupropadine against the house mouse (Mus musculus L.).

    PubMed

    Rowe, F P; Bradfield, A; Swinney, T

    1985-10-01

    Laboratory and field trials were conducted to determine the efficacy of the candidate rodenticide flupropadine against the house mouse (Mus musculus L.). In laboratory feeding tests, family groups of wild mice maintained in pens and conditioned to feeding on plain foods were offered flupropadine at either 0.10%, 0.15%, 0.18% or 0.20% in pinhead oatmeal bait. Overall mortalities in replicated 21-day treatments were 66/71 (93.0%), 71/79 (89.9%), 72/76 (94.7%) and 69/75 (92.0%) respectively. In 17 field trials carried out against mice infesting farm buildings, flupropadine was used at 0.10%, 0.15% and 0.18% in oatmeal bait. Mean treatment success, estimated from live-capture and mortality data, was 88.6%, 96.2% and 96.6% respectively. Flupropadine was found to be as near effective against mice as calciferol/warfarin and the second-generation anticoagulant rodenticides difenacoum, bromadiolone and brodifacoum. In further comparison with the anticoagulants, treatment with flupropadine bait achieved markedly quicker control. PMID:4067302

  13. Pen and field trials of flupropadine against the house mouse (Mus musculus L.).

    PubMed Central

    Rowe, F. P.; Bradfield, A.; Swinney, T.

    1985-01-01

    Laboratory and field trials were conducted to determine the efficacy of the candidate rodenticide flupropadine against the house mouse (Mus musculus L.). In laboratory feeding tests, family groups of wild mice maintained in pens and conditioned to feeding on plain foods were offered flupropadine at either 0.10%, 0.15%, 0.18% or 0.20% in pinhead oatmeal bait. Overall mortalities in replicated 21-day treatments were 66/71 (93.0%), 71/79 (89.9%), 72/76 (94.7%) and 69/75 (92.0%) respectively. In 17 field trials carried out against mice infesting farm buildings, flupropadine was used at 0.10%, 0.15% and 0.18% in oatmeal bait. Mean treatment success, estimated from live-capture and mortality data, was 88.6%, 96.2% and 96.6% respectively. Flupropadine was found to be as near effective against mice as calciferol/warfarin and the second-generation anticoagulant rodenticides difenacoum, bromadiolone and brodifacoum. In further comparison with the anticoagulants, treatment with flupropadine bait achieved markedly quicker control. PMID:4067302

  14. Simulation of nZVI Transport at a Push-Pull Field Trial

    NASA Astrophysics Data System (ADS)

    O'Carroll, D. M.; Oleniuk, A. J.; Kocur, C. M.; Sleep, B. E.; Xiong, Z.; Bennett, P.

    2010-12-01

    Nano-scale Zero Valent Iron (nZVI) is receiving significant attention due to its ability to rapidly reduce priority source zone contaminants (eg: chlorinated compounds) in controlled laboratory experiments. Although nZVI has shown significant promise in laboratory experiments the limited field studies completed to date have found that nZVI subsurface mobility is less than expected. For example, nZVI is stable in aqueous solutions for extended periods of time (eg: days) and stabilized nZVI is quite mobile in laboratory column experiments. However, field scale studies have found mobility decreases significantly in one day. To explore the causes for lower than expected mobility at the field scale a two-dimensional numerical model (Compsim) was developed to simulate the movement of nZVI observed at an actual field pilot study. Simulation results were in very good agreement with the three conservative tracer and nZVI push-pull field trials. Results suggest that subsurface heterogeneities and the viscous nature of the polymers used to stabilize nZVI decrease pore water velocity thereby limiting nZVI transport. Furthermore, nZVI aggregation in the injection vessel decreased the amount of nZVI delivered to the subsurface below what was expected. Results from this study will be used to optimize nZVI injection strategies.

  15. Seasonal OVOC fluxes from an agricultural field planted with sugar beet

    NASA Astrophysics Data System (ADS)

    Custer, T. G.; Schade, G. W.

    2005-12-01

    Although agricultural crops are generally not strong isoprenoid emitters, they do emit a variety of other atmospherically significant species collectively known as oxygenated VOCs (OVOCs), such as methanol, acetaldehyde, or various hexenal and hexenol compounds. Many OVOCs have longer atmospheric lifetimes than isoprenoid compounds and can affect the atmosphere's oxidative potential at higher elevations and far from sources. We performed selected OVOC flux measurements for select species above an agricultural field planted with sugar beets ( B. vulgaris) in northern Germany in 2004 to better understand the magnitude and controls over these OVOC emissions. Virtual disjunct eddy covariance was used to measure fluxes beginning immediately following seeding and continuing until past harvest. A commercial PTR-MS provided mixing ratios of methanol (m/z 33), acetaldehyde (m/z 45), acetone (m/z 59), and the sum of the isoprene oxidation products methacrolein and methyl vinyl ketone (m/z 71) while 3D wind velocities were measured using a Gill R3 sonic anemometer. Here, we compare the fluxes of methanol and acetone over the growth cycle of sugar beet to plant development as measured by the leaf area index. Methanol fluxes ranged from approximately -0.05 to 0.15 mg C m-2 h-1 (mixing ratios from ~1 to 15 ppbv) and showed a clear diurnal cycle after the sugar beets established a significant leaf area. Acetone fluxes ranged from approximately -0.2 to 0.2 mg C m-2 h-1 (mixing ratios from ~0.2 to 3 ppb). Higher specific emissions were found during earlier growth stages. Methanol flux correlated strongly with latent heat flux (or alternatively, with canopy conductance derived from the latent heat flux), while acetone flux did not. Acetone flux was small compared to methanol flux and sugar beet is likely not a significant acetone emitter. Weekly measurements of soil OVOC exchange using a flux chamber showed that the soil may have contributed significantly to the overall flux values

  16. Organic particulate emissions from field burning of garden and agriculture residues

    NASA Astrophysics Data System (ADS)

    Gonçalves, Cátia; Evtyugina, Margarita; Alves, Célia; Monteiro, Cristina; Pio, Casimiro; Tomé, Mário

    2011-08-01

    To assess the particulate matter (PM) composition, the smoke from three different agriculture and garden residues, commonly subjected to open field burning in Northern Portugal (potato haulm (A), arable weed vegetation (B) and collard greens stalks/pruned green leafy-twigs (C)) have been sampled into 3 different size fractions (PM 2.5, PM 2.5-10 and PM > 10 ). To replicate another frequent practise of reducing or dispose agriculture/garden debris, residue C was complementarily burned in a metal container with addition of used lubricant oil. The size-segregated aerosol samples were analysed for elemental (EC) and organic (OC) carbon by a thermal-optical transmission technique. The organosoluble OC was fractionated by vacuum flash chromatography and analysed by gas chromatography-mass spectrometry (GC-MS). Burning of residue C produced the highest PM emissions. OC was the dominant carbonaceous component in all aerosol samples, contributing to about 98% of total carbon (TC). The detailed chemical profiles of particulate emissions, including organic tracer compounds, have been assessed. The contribution of phenolics (0.2-39% OC, w/w) and organic acids (1.5-13% OC, w/w) to OC was always predominant over other organic compounds, whose distribution patterns were found to vary from one residue to another. The polyphenols, as the guaiacyl derivatives, were particularly abundant in PM from the residue C burning, but anthropogenic constituents completely superimposed the emission profiles after addition of used lubricant oil. It was shown that the prevailing ambient conditions (such as high humidity) likely contributed to atmospheric processes (e.g. coagulation and hygroscopic growth), which influenced the particle size characteristics of the smoke tracers, shifting their distribution to larger diameters. Since it was shown that the relative contribution of different carbon forms and organic compounds may strongly depend on the size of the particulate matter, the barely

  17. Long-term impact of precision agriculture on a farmer’s field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Targeting management practices and inputs with precision agriculture has high potential to meet some of the grand challenges of sustainability in the coming century. Although potential is high, few studies have documented long-term effects of precision agriculture on crop production and environmenta...

  18. Optimising and Evaluating the Characteristics of a Multiple Antigen ELISA for Detection of Mycobacterium bovis Infection in a Badger Vaccine Field Trial

    PubMed Central

    Aznar, Inma; Frankena, Klaas; More, Simon J.; Whelan, Clare; Martin, Wayne; Gormley, Eamonn; Corner, Leigh A. L.; Murphy, Denise; De Jong, Mart C. M.

    2014-01-01

    A long-term research programme has been underway in Ireland to evaluate the usefulness of badger vaccination as part of the national bTB (bovine tuberculosis) control strategy. This culminated in a field trial which commenced in county Kilkenny in 2009 to determine the effects of badger vaccination on Mycobacterium bovis transmission in badgers under field conditions. In the present study, we sought to optimise the characteristics of a multiplex chemiluminescent assay for detection of M. bovis infection in live badgers. Our goal was to maximise specificity, and therefore statistical power, during evaluation of the badger vaccine trial data. In addition, we also aimed to explore the effects of vaccination on test characteristics. For the test optimisation, we ran a stepwise logistic regression with analytical weights on the converted Relative Light Units (RLU) obtained from testing blood samples from 215 badgers captured as part of culling operations by the national Department of Agriculture, Food and the Marine (DAFM). The optimised test was applied to two other datasets obtained from two captive badger studies (Study 1 and Study 2), and the sensitivity and specificity of the test was attained separately for vaccinated and non-vaccinated badgers. During optimisation, test sensitivity was maximised (30.77%), while retaining specificity at 99.99%. When the optimised test was then applied to the captive badger studies data, we observed that test characteristics did not vary greatly between vaccinated and non-vaccinated badgers. However, a different time lag between infection and a positive test result was observed in vaccinated and non-vaccinated badgers. We propose that the optimized multiplex immunoassay be used to analyse the vaccine trial data. In relation to the difference in the time lag observed for vaccinated and non-vaccinated badgers, we also present a strategy to enable the test to be used during trial evaluation. PMID:24983473

  19. Estimation of spatially distributed surface energy fluxes using remotely-sensed data for agricultural fields

    NASA Astrophysics Data System (ADS)

    Melesse, Assefa M.; Nangia, Vijay

    2005-09-01

    ). The flux estimation procedure from the SEBAL-TSEB model was useful and applicable to agricultural fields.

  20. Visual Field Outcomes for the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT)

    PubMed Central

    Wall, Michael; Johnson, Chris A.; Cello, Kimberly E.; Zamba, K. D.; McDermott, Michael P.; Keltner, John L.

    2016-01-01

    Purpose The Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) showed that acetazolamide provided a modest, significant improvement in mean deviation (MD). Here, we further analyze visual field changes over the 6-month study period. Methods Of 165 subjects with mild visual loss in the IIHTT, 125 had perimetry at baseline and 6 months. We evaluated pointwise linear regression of visual sensitivity versus time to classify test locations in the worst MD (study) eye as improving or not; pointwise changes from baseline to month 6 in decibels; and clinical consensus of change from baseline to 6 months. Results The average study eye had 36 of 52 test locations with improving sensitivity over 6 months using pointwise linear regression, but differences between the acetazolamide and placebo groups were not significant. Pointwise results mostly improved in both treatment groups with the magnitude of the mean change within groups greatest and statistically significant around the blind spot and the nasal area, especially in the acetazolamide group. The consensus classification of visual field change from baseline to 6 months in the study eye yielded percentages (acetazolamide, placebo) of 7.2% and 17.5% worse, 35.1% and 31.7% with no change, and 56.1% and 50.8% improved; group differences were not statistically significant. Conclusions In the IIHTT, compared to the placebo group, the acetazolamide group had a significant pointwise improvement in visual field function, particularly in the nasal and pericecal areas; the latter is likely due to reduction in blind spot size related to improvement in papilledema. (ClinicalTrials.gov number, NCT01003639.) PMID:26934136

  1. Changes in water budgets and sediment yields from a hypothetical agricultural field as a function of landscape and management characteristics--A unit field modeling approach

    USGS Publications Warehouse

    Roth, Jason L.; Capel, Paul D.

    2012-01-01

    Crop agriculture occupies 13 percent of the conterminous United States. Agricultural management practices, such as crop and tillage types, affect the hydrologic flow paths through the landscape. Some agricultural practices, such as drainage and irrigation, create entirely new hydrologic flow paths upon the landscapes where they are implemented. These hydrologic changes can affect the magnitude and partitioning of water budgets and sediment erosion. Given the wide degree of variability amongst agricultural settings, changes in the magnitudes of hydrologic flow paths and sediment erosion induced by agricultural management practices commonly are difficult to characterize, quantify, and compare using only field observations. The Water Erosion Prediction Project (WEPP) model was used to simulate two landscape characteristics (slope and soil texture) and three agricultural management practices (land cover/crop type, tillage type, and selected agricultural land management practices) to evaluate their effects on the water budgets of and sediment yield from agricultural lands. An array of sixty-eight 60-year simulations were run, each representing a distinct natural or agricultural scenario with various slopes, soil textures, crop or land cover types, tillage types, and select agricultural management practices on an isolated 16.2-hectare field. Simulations were made to represent two common agricultural climate regimes: arid with sprinkler irrigation and humid. These climate regimes were constructed with actual climate and irrigation data. The results of these simulations demonstrate the magnitudes of potential changes in water budgets and sediment yields from lands as a result of landscape characteristics and agricultural practices adopted on them. These simulations showed that variations in landscape characteristics, such as slope and soil type, had appreciable effects on water budgets and sediment yields. As slopes increased, sediment yields increased in both the arid and

  2. Effects of microelements on soil nematode assemblages seven years after contaminating an agricultural field.

    PubMed

    Nagy, Péter; Bakonyi, Gábor; Bongers, Tom; Kádár, Imre; Fábián, Miklós; Kiss, István

    2004-03-29

    Long-term effects of Cd, Cr, Cu, Se and Zn were studied 7 years after artificially contaminating plots of an agricultural field on a calcareous chernozem soil. Effects of three to four different contamination levels (originally 10, 30, 90 and 270 mg kg(-1)) were studied. Nematode density was significantly reduced by 90 and 270 mg kg(-1) Se as well as by 270 mg kg(-1) Cr, while 90 and 270 mg kg(-1) Se also reduced nematode generic richness. Maturity Index values (calculated for c-p 2-5 nematodes) consistently decreased with increasing Cr and Se concentration and to a lesser extent in Zn plots as well. Structure Index showed decreasing trends in increasing Cr, Se and (to a lesser extent) in Zn treatments, while in Cd it shows a moderate increase. Distribution of c-p groups was negatively affected by the increasing Cr and Se concentration, while in Zn plots, this decrease was not significant. Response of feeding groups to pollutions was similar to other parameters: Cr and Se caused significant changes toward the loss of variability. The proportion of the most sensitive omnivorous and predatory nematodes decreased clearly as a consequence of Cr and Se treatments. Zn pollution also resulted in a slight decrease in this group, while Cd caused an increase. Nematode diversity profiles showed a significant decrease in the plots of increased Cr and Se concentrations, while increased concentrations of Cu and Zn resulted in ambiguous effects. Besides providing evidence on the harmful effects of Cr and Se on a soil nematode assemblage, our results suggest that simultaneous analysis of Maturity Index, Structure Index and diversity profiles provide a promising tool in nematological indication of soil pollution.

  3. Simulation of plume dispersion of multiple releases in Fusion Field Trial-07 experiment

    NASA Astrophysics Data System (ADS)

    Pandey, Gavendra; Sharan, Maithili

    2015-12-01

    For an efficient source term estimation, it is important to use an accurate dispersion model with appropriate dispersion parameters. This is examined by simulating the dispersion of plumes resulted from the available multiple releases conducted at Fusion Field Trials, Dugway Proving Ground, Utah. The simulation is carried out with an earlier developed IIT (Indian Institute of Technology) dispersion model using the dispersion parameters in terms of measurements of turbulent velocity fluctuations. Simulation is discussed separately in both stable and unstable conditions in light of (i) plume behavior of observed and predicted concentrations in the form of isopleths, (ii) peak/maximum concentrations and (iii) overall concentration distribution. Simulated results from IIT model are compared with those obtained using AERMOD. Both, IIT model and AERMOD, predicted peak concentrations within a factor of two in all the releases and tracer transport is mostly along the mean wind direction. With IIT model, the higher concentrations are predicted close to observations in all the trials of stable conditions and with in a factor of two in the trials of unstable conditions. However, the relatively smaller concentrations are under-predicted severely in stable conditions and over-predicted in unstable conditions. The AERMOD exhibits the similar prediction of concentrations as in IIT model except slightly over-prediction in stable conditions and under-prediction in unstable conditions. The statistical measures for both the models are found good in agreement with the observations and a quantitative analysis based on F-test shows that the performance from both the models are found to be similar at 5% significance level.

  4. Fields of dreams: Agriculture, economy and nature in Midwest United States biofuel production

    NASA Astrophysics Data System (ADS)

    Gillon, Sean Thomas

    This work explores the social and ecological dimensions of recent biofuel production increases in the United States (US), focusing on the case of Iowa. Biofuels are proposed to mitigate the greenhouse gas emissions that cause climate change, improve US energy security, and support rural economies. Little research has examined how increased US Midwestern biofuels production will change social and ecological outcomes at farm and regional levels or interact with broader governance processes at the nexus of agriculture, energy and environment. These broad questions guide my research: (1) How does biofuel production reconfigure agricultural practice and landscapes in Iowa? (2) What are the costs, benefits and risks of increased biofuels production as seen by farmers and rural residents, and how do these factors influence farmer decisions about agriculture and conservation practice? (3) How and with what effects are biofuels initiatives constituted as a form of environmental governance through scientific knowledge and practice and political economic dynamics? To address these questions, this research integrates both qualitative and quantitative methods, drawing on a political ecological approach complemented by agroecological analysis and theoretical insights from geographical analyses of nature-society relations. Quantitative analysis focuses on changing land use patterns in agriculture and conservation practice in Iowa. Qualitative methods include extensive interviews, participant observation, and policy and document analyses. Fieldwork focused on Northeastern Iowa to understand regional changes in agricultural and conservation practice, the renegotiated position of farmers in agriculture and biofuel production, and biofuel industry development. I find that biofuel production presents significant social and ecological challenges for rural places of production. Longstanding, unequal political economic relations in industrialized agriculture limit rural economic benefits

  5. Cable development for distributed geophysical sensing with a field trial in surface seismic

    NASA Astrophysics Data System (ADS)

    Lumens, Paul; Franzen, Andre; Hornman, Kees; Grandi Karam, Samantha; Hemink, Gijs; Kuvshinov, Boris; La Follett, Jon; Wyker, Brendan; Zwartjes, Paul

    2013-05-01

    Fibre-optic distributed sensing has the potential to revolutionize well and reservoir surveillance in the oil and gas industry. Benefits include the passive nature of optical fibre sensors, the potential for cost-effective installations, combined with the possibility of densely distributed measurements along the entire length of the fibre. Amongst a range of fibre-optic sensing technologies, Distributed Acoustic Sensing has the potential to provide a low cost alternative for conventional seismic technologies. To widen the geophysical application scope further, the fibre-optic sensing cable should be made more sensitive to incoming seismic waves that arrive at the cable perpendicular ("broadside") to its axial direction. We introduce the development of such cable concepts, and present results of a successful cable deployment in a surface seismic field trial. Efforts continue to realize cost-effective directionally-sensitive cables for geophysical use, for deployment down-hole and on surface.

  6. Field trials of the Baby Check score card: mothers scoring their babies at home.

    PubMed

    Thornton, A J; Morley, C J; Green, S J; Cole, T J; Walker, K A; Bonnett, J M

    1991-01-01

    The Baby Check score card has been developed to help parents and health professionals grade the severity of acute illness in babies. This paper reports the results of two field trials in which mothers used Baby Check at home, 104 mothers scoring their babies daily for a week and 56 using it for six months. They all found Baby Check easy to use, between 68% and 81% found it useful, and 96% would recommended it to others. Over 70% of those using it daily used it very competently. Those using it infrequently did less well, suggesting that familiarity with the assessment is important. The scores obtained show that Baby Check's use would not increase the number of mothers seeking medical advice. With introduction and practice most mothers should be able to use Baby Check effectively. It should help them assess their babies' illnesses and make appropriate decisions about seeking medical advice.

  7. [Phytoremediation of polychlorinated biphenyls contaminated soil by leguminosae-gramineae intercropping: a field trial].

    PubMed

    Tu, Chen; Teng, Ying; Luo, Yong-Ming; Pan, Cheng; Sun, Xiang-Hui; Li, Zhen-Gao

    2010-12-01

    Phytoremediation of polychlorinated biphenyls (PCBs) contaminated soil by leguminosae (alfalfa) and gramineae (ryegrass and tall fescue) was studied in a field trial. All planted treatments had significantly higher PCBs removal efficiency compared with those of unplanted control after 270 days of in-situ phytoremediation. Alfalfa monoculture received the highest removal efficiency of soil PCBs by 59.6%. Analysis of PCBs congeners composition showed that the percentage of di-chlorinated biphenyl decreased in all planted treatments. Alfalfa produced the maximum biomass among the 3 plants. Total PCBs concentration in alfalfa roots reached 355.1 microg/kg, which was significantly higher than those in ryegrass and tall fescue. The phytoextraction efficiency of different treatment was in order of alfalfa > alfalfa-ryegrass-tall fescue > alfalfa-ryegrass > ryegrass > alfalfa-tall fescue > tall fescue. The results suggest that alfalfa may be an ideal candidate for the phytoremediation of PCBs contaminated soil. PMID:21360900

  8. IAEA workshop and field trial at the Oak Ridge K-25 Site

    SciTech Connect

    Hembree, D.M. Jr.; Ross, H.H.; Carter, J.A.

    1995-03-01

    In March 1994, members of the International Safeguards Department in the National Security Program Office (NSPO) hosted an environmental monitoring field trial workshop for International Atomic Energy Agency (IAEA) inspectors. The workshop was held at the Oak Ridge K-25 Site and its primary purpose was to train the inspectors in the techniques needed for effective environmental sample collection and handling. The workshop emphasized both sampling theory and practice. First, detailed techniques for swipe, vegetation, soil, biota, and water-associated sampling were covered in the classroom. Subsequently, the inspectors were divided into three groups for actual sample collection in and around the K-25 locale. The collected samples were processed by the Department of Energy (DOE) Network of Analytical Laboratories using established analytical techniques. This activity is part of the IAEA ``Programme 93+2 in. assessment of measures to enhance IAEA safeguards.

  9. Analysis of airborne multi-spectral imagery of an oil spill field trial

    SciTech Connect

    Kalnins, V.J.; Freemantle, J.R.; Brown, C.E.

    1996-12-31

    A field trial was conducted at Canadian Forces Base Petawawa in May 1993 by the Emergencies Science Division of Environment Canada to test the effectiveness of remote sensing systems to detect oil spills. Shallow test pools covered with various thicknesses and types of oil were overflown by a number of sensors. Imagery from one of the sensors used, the Multi-element Electro-optical Imaging Scanner (MEIS), has recently been transcribed from high density digital tape and analyzed. The MEIS sensor was flown on a Falcon 20 jet and collected data at 7 different wavelengths from 518 nm to 873 nm. Preliminary results show that one of the slicks, Hydraulic Fluid, can be readily identified by its distinctive color in the visible region. The oil slicks, at least under these very controlled conditions, presented unique spectral signatures which could be identified using normal image processing classification techniques.

  10. Auxiliary-field based trial wave functions in quantum Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Chang, Chia-Chen; Rubenstein, Brenda; Morales, Miguel

    We propose a simple scheme for generating correlated multi-determinant trial wave functions for quantum Monte Carlo algorithms. The method is based on the Hubbard-Stratonovich transformation which decouples a two-body Jastrow-type correlator into one-body projectors coupled to auxiliary fields. We apply the technique to generate stochastic representations of the Gutzwiller wave function, and present benchmark resuts for the ground state energy of the Hubbard model in one dimension. Extensions of the proposed scheme to chemical systems will also be discussed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, 15-ERD-013.

  11. Children's mental health care following Hurricane Katrina: a field trial of trauma-focused psychotherapies.

    PubMed

    Jaycox, Lisa H; Cohen, Judith A; Mannarino, Anthony P; Walker, Douglas W; Langley, Audra K; Gegenheimer, Kate L; Scott, Molly; Schonlau, Matthias

    2010-04-01

    New Orleans school children participated in an assessment and field trial of two interventions 15 months after Hurricane Katrina. Children (N = 195) reported on hurricane exposure, lifetime trauma exposure, peer and parent support, posttraumatic stress disorder (PTSD), and depressive symptoms. Teachers reported on behavior. At baseline, 60.5% screened positive for PTSD symptoms and were offered a group intervention at school or individual treatment at a mental health clinic. Uptake of the mental health care was uneven across intervention groups, with 98% beginning the school intervention, compared to 37% beginning at the clinic. Both treatments led to significant symptom reduction of PTSD symptoms, but many still had elevated PTSD symptoms at posttreatment. Implications for future postdisaster mental health work are discussed.

  12. Evaluation of biological aerosol stand-off detection at a field trial

    NASA Astrophysics Data System (ADS)

    Jonsson, Per; Elmqvist, Magnus; Gustafsson, Ove; Kullander, Fredrik; Persson, Rolf; Olofsson, Göran; Tjärnhage, Torbjörn; Farsund, Øystein; Haavardsholm, Trym Vegard; Rustad, Gunnar

    2009-09-01

    We have performed a field trial to evaluate technologies for stand-off detection of biological aerosols, both in daytime and at night. Several lidar (light detection and ranging) systems were tested in parallel. We present the results from three different lidar systems; one system for detection and localization of aerosol clouds using elastic backscattering at 1.57 μm, and two systems for detection and classification of aerosol using spectral detection of ultraviolet laser-induced fluorescence (UV LIF) excited at 355 nm. The UV lidar systems were utilizing different technologies for the spectral detection, a photomultiplier tube (PMT) array and an intensified charge-coupled device (ICCD), respectively. During the first week of the field trial, the lidar systems were measuring towards a semi-closed chamber at a distance of 230 m. The chamber was built from two docked standard 20-feet containers with air curtains in the short sides to contain the aerosol inside the chamber. Aerosol was generated inside the semi-closed chamber and monitored by reference equipments, e.g. slit sampler and particle counters. Signatures from several biological warfare agent simulants and interferents were measured at different aerosol concentrations. During the second week the aerosol was released in the air and the reference equipments were located in the centre of the test site. The lidar systems were measuring towards the test site centre at distances of either 230 m or approximately 1 km. In this paper we are presenting results and some preliminary signal processing for discrimination between different types of simulants and interference aerosols.

  13. Are Birth-preparedness Programmes Effective? Results From a Field Trial in Siraha District, Nepal

    PubMed Central

    McPherson, Robert A.; Moore, Judith M.; Sharma, Meena

    2006-01-01

    The birth-preparedness package (BPP) promotes active preparation and decision-making for births, including pregnancy/postpartum periods, by pregnant women and their families. This paper describes a district-wide field trial of the BPP implemented through the government health system in Siraha, Nepal, during 2003–2004. The aim of the field trial was to determine the effectiveness of the BPP to positively influence planning for births, household-level behaviours that affect the health of pregnant and postpartum women and their newborns, and their use of selected health services for maternal and newborn care. Community health workers promoted desired behaviours through inter-personal counselling with individuals and groups. Content of messages included maternal and newborn-danger signs and encouraged the use of healthcare services and preparation for emergencies. Thirty-cluster baseline and endline household surveys of mothers of infants aged less than one year were used for estimating the change in key outcome indicators. Fifty-four percent of respondents (n=162) were directly exposed to BPP materials while pregnant. A composite index of seven indicators that measure knowledge of respondents, use of health services, and preparation for emergencies increased from 33% at baseline to 54% at endline (p=0.001). Five key newborn practices increased by 19 to 29 percentage points from baseline to endline (p values ranged from 0.000 to 0.06). Certain key maternal health indicators, such as skilled birth attendance and use of emergency obstetric care, did not change. The BPP can positively influence knowledge and intermediate health outcomes, such as household practices and use of some health services. The BPP can be implemented by government health services with minimal outside assistance but should be comprehensively integrated into the safe motherhood programme rather than implemented as a separate intervention. PMID:17591345

  14. Criteria for Identifying and Evaluating Candidate Sites for Open-Field Trials of Genetically Engineered Mosquitoes

    PubMed Central

    Brown, David M.; Alphey, Luke S.; McKemey, Andrew; Beech, Camilla

    2014-01-01

    Abstract Recent laboratory successes in the development of genetically engineered mosquitoes for controlling pathogen transmission have fostered the need for standardized procedures for advancing the technical achievements to practical tools. It is incumbent in many cases for the same scientists doing the in-laboratory discovery research to also take on the initial challenges of developing the pathway that will move the technologies to the field. One of these challenges is having a set of criteria for selecting collaborators and sites for efficacy and safety field trials that combine rigorous science with good ethical and legal practices. Specific site-selection criteria were developed in four categories—Scientific, Regulatory, Community Engagement, and Resources—in anticipation of open-field releases of a transgenic mosquito strain designed to suppress populations of the dengue vector mosquito, Aedes aegypti. The criteria are derived from previous published material, discussions, and personal experiences with the expectation of providing guidance to laboratory scientists for addressing the conceptual and operational considerations for identifying partner researchers and countries with whom to collaborate. These criteria are not intended to be prescriptive nor can they be applied to every circumstance where genetic approaches are proposed for deployment. However, we encourage those involved in the discovery phase of research to consider each criterion during project planning activities, and where appropriate, incorporate them into a “go/no-go” decision-making process for further development and testing of the technologies. PMID:24689963

  15. Iron coated sand/glauconite filters for phosphorus removal from artificially drained agricultural fields

    NASA Astrophysics Data System (ADS)

    Vandermoere, Stany; De Neve, Stefaan

    2016-04-01

    Flanders (Belgium) is confronted with reactive phosphorus concentrations in streams and lakes which are three to four times higher than the 0.1 ppm P limit set by the Water Framework Directive. Much of the excessive P input in surface waters is derived from agriculture. Direct P input from artificially drained fields (short-circuiting the buffering capacity of the subsoil) is suspected to be one of the major sources. We aim to develop simple and cheap filters that can be directly installed in the field to reduce P concentration from the drain water. Here we report on the performance of such filters tested at lab scale. As starting materials for the P filter, iron coated sand and acid pre-treated glauconite were used. These materials, both rich in Fe, were mixed in ratios of 75/25, 65/35, 50/50 and 0/100 (iron coated sand/glauconite ratio based on weight basis) and filled in plastic tubes. A screening experiment using the constant head method with a 0.01 M CaCl2 solution containing 1 ppm P showed that all four types of mixtures reduced the P concentration in the outflowing water to almost zero, and that the 75/25, 65/35 and 0/100 mixtures had a sufficiently large hydraulic conductivity of 0.9 to 6.0 cm/min, while the hydraulic conductivity of the 50/50 mixture was too low (< 0.4 cm/min). In a second experiment the iron coated sand and acid pre-treated glauconite were mixed in ratios of 75/25, 65/35 and 0/100 and filled in the same plastic tubes as in the first experiment. Subsequently a 0.01 M CaCl2 solution containing 1 ppm P was passed through the filters over several days, in amounts equivalent to half of the yearly water volume passing through the drains. This experiment firstly showed that in all cases the hydraulic conductivity fluctuated strongly: it decreased from 4.0-6.0 cm/min to 2.0-1.5 cm/min for the 75/25 filter, and to values < 0.4 cm/min for the 65/35 filter, whereas it increased from 0.8 to 1.4 cm/min for the 0/100 filter. Secondly, we observed a

  16. 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

  17. 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.

  18. Mitigation of dimethazone residues in soil and runoff water from agricultural field.

    PubMed

    Antonious, George F

    2011-01-01

    Dimethazone, also known as clomazone [2-[(2-chlorophenyl) methyl]- 4,4-dimethyl-3-isoxaolidinone] is a pre-emergent nonionic herbicide commonly used in agriculture. A field study was conducted on a silty-loam soil of 10 % slope to monitor off-site movement and persistence of dimethazone in soil under three management practices. Eighteen plots of 22 x 3.7 m each were separated using stainless steel metal borders and the soil in six plots was mixed with municipal sewage sludge (MSS) and yard waste (YW) compost (MSS+YW) at 15 t acre⁻¹ on dry weight basis, six plots were mixed with MSS at 15 t acre⁻¹, and six unamended plots (NM) were used for comparison purposes. The objectives of this investigation were to: (i) monitor the dissipation and half-life (T₁/₂) of dimethazone in soil under three management practices; (ii) determine the concentration of dimethazone residues in runoff and infiltration water following natural rainfall events; and (iii) assess the impact of soil amendments on the transport of NO₃, NH₄, and P into surface and subsurface water. Gas chromatography/mass spectrometery (GC/MS) analyses of soil extracts indicated the presence of ion fragments at m/z 125 and 204 that can be used for identification of dimethazone residues. Intitial deposits of dimethazone varied from 1.3 μg g⁻¹ dry native soil to 3.2 and 11.8 μg g⁻¹ dry soil in MSS and MSS+YW amended soil, respectively. Decline of dimethazone residues in the top 15 cm native soil and soil incorporated with amendments revealed half-life (T₁/₂) values of 18.8, 25.1, and 43.0 days in MSS+YW, MSS, and NM treatments, respectively. Addition of MSS+YW mix and MSS alone to native soil increased water infiltration, lowering surface runoff water volume and dimethazone residues in runoff following natural rainfall events.

  19. The fate and transport of the Cry1Ab protein in an agricultural field and laboratory aquatic microcosms.

    PubMed

    Strain, Katherine E; Lydy, Michael J

    2015-08-01

    Genetically engineered crops expressing insecticidal crystalline proteins derived from Bacillus thuringiensis (Bt), were commercialized almost two decades ago as a means to manage agricultural pests. The Bt proteins are highly specific and only lethal upon ingestion, limiting the scope of toxicity to target insects. However, concern of exposure to non-target organisms and negative public perceptions regarding Bt crops has caused controversy surrounding their use. The objective of this research was to monitor the fate and transport of a Bt protein, Cry1Ab, in a large-scale agricultural field containing maize expressing the Cry1Ab protein and a non-Bt near isoline, and in aquatic microcosms. The highest environmental concentrations of the Cry1Ab protein were found in runoff water and sediment, up to 130ngL(-1) and 143ngg(-1) dry weight, respectively, with the Cry1Ab protein detected in both Bt and non-Bt maize fields. As surface runoff and residual crop debris can transport Bt proteins to waterways adjacent to agricultural fields, a series of laboratory experiments were conducted to determine the potential fate of the Cry1Ab protein under different conditions. The results showed that sediment type and temperature can influence the degradation of the Cry1Ab protein in an aquatic system and that the Cry1Ab protein can persist for up to two months. Although Cry1Ab protein concentrations measured in the field soil indicate little exposure to terrestrial organisms, the consistent input of Bt-contaminated runoff and crop debris into agricultural waterways is relevant to understanding potential consequences to aquatic species. PMID:25828252

  20. Soil hydrological and soil property changes resulting from termite activity on agricultural fields in Burkina Faso

    NASA Astrophysics Data System (ADS)

    Mettrop, I.; Cammeraat, L. H.; Verbeeten, E.

    2009-04-01

    Termites are important ecosystem-engineers in subtropical and tropical regions. The effect of termite activity affecting soil infiltration is well documented in the Sahelian region. Most studies find increased infiltration rates on surfaces that are affected by termite activity in comparison to crusted areas showing non-termite presence. Crusted agricultural fields in the Sanmatenga region in Burkina Faso with clear termite activity were compared to control fields without visual ground dwelling termite activity. Fine scale rainfall simulations were carried out on crusted termite affected and control sites. Furthermore soil moisture change, bulk density, soil organic matter as well as general soil characteristics were studied. The top soils in the study area were strongly crusted (structural crust) after the summer rainfall and harvest of millet. They have a loamy sand texture underlain by a shallow sandy loam Bt horizon. The initial soil moisture conditions were significantly higher on the termite plots when compared to control sites. It was found that the amount of runoff produced on the termite plots was significantly higher, and also the volumetric soil moisture content after the experiments was significantly lower if compared to the control plots. Bulk density showed no difference whereas soil organic matter was significantly higher under termite affected areas, in comparison to the control plots. Lab tests showed no significant difference in hydrophobic behavior of the topsoil and crust material. Micro and macro-structural properties of the topsoil did not differ significantly between the termite sites and the control sites. The texture of the top 5 cm of the soil was also found to be not significantly different. The infiltration results are contradictory to the general literature, which reports increased infiltration rates after prolonged termite activity although mostly under different initial conditions. The number of nest entrances was clearly higher in

  1. Char BC amendments for soil and sediment amelioration: BC quantification and field pilot trials

    NASA Astrophysics Data System (ADS)

    Cornelissen, G.; Braendli, R. C.; Eek, E.; Henriksen, T.; Hartnik, T.; Breedveld, G. D.

    2008-12-01

    Background Activated char BC binds organic contaminants and possibly mercury so strongly that their bioaccumulation and transport to other environmental compartments are reduced. The advantages of black carbon amendment over many other remediation methods include i) it can be used as an in situ risk reduction method, ii) the price is low, and iii) it overcomes significant controversies associated with disposal of dredged and excavated materials. In this study BC amendment is used in pilot trials in the field for soil and sediment amelioration. Quantification of amended char BC Two methods for char BC quantification were tested: i) chemothermal oxidation (CTO) at a range of temperatures and ii) wet chemical oxidation with a potassium dichromate/sulfuric acid solution. The amount of BC amended to three soils was accurately determined by CTO at 375°C. For two sediments, much of the BC disappeared during combustion at 375°C, which could probably be explained by catalytic effects caused by sediment constituents such as metals, mineral oxides and salts. Attempts to avoid these effects through rinsing with acid before combustion did not result in higher char BC recoveries. CTO at lower temperatures (325-350°C) was a feasible alternative for one of the sediments. Wet oxidation with potassium dichromate/sulfuric acid proved to effectively function for BC quantification in sediments, since almost complete BC recovery (81-92 %) was observed for both sediments, while the amount of organic carbon remaining was low (5-16 %). Field pilots Earlier, we showed the effectiveness of BC amendment in the laboratory. In the laboratory it was shown that BC amendments (2 %) reduced freely dissolved porewater concentrations (factor of 10-50) and bioaccumulation (factor of 5). This presentation will describe 50 × 50 m pilot field trials in Norway (2007-2008): Trondheim Harbor (sediment) and Drammen (soil). The presentation will focus on physical monitoring (distribution of BC in the

  2. Does Encouragement Matter in Improving Gender Imbalances in Technical Fields? Evidence from a Randomized Controlled Trial.

    PubMed

    Unkovic, Cait; Sen, Maya; Quinn, Kevin M

    2016-01-01

    Does encouragement help address gender imbalances in technical fields? We present the results of one of the first and largest randomized controlled trials on the topic. Using an applied statistics conference in the social sciences as our context, we randomly assigned half of a pool of 3,945 graduate students to receive two personalized emails encouraging them to apply (n = 1,976) and the other half to receive nothing (n = 1,969). We find a robust, positive effect associated with this simple intervention and suggestive evidence that women responded more strongly than men. However, we find that women's conference acceptance rates are higher within the control group than in the treated group. This is not the case for men. The reason appears to be that female applicants in the treated group solicited supporting letters at lower rates. Our findings therefore suggest that "low dose" interventions may promote diversity in STEM fields but may also have the potential to expose underlying disparities when used alone or in a non-targeted way.

  3. Trial of Engineer Educating of Manufacturing Field in Kagoshima National College of Technology

    NASA Astrophysics Data System (ADS)

    Nakamura, Itaru; Hombu, Mitsuyuki; Kusuhara, Yoshito; Kashine, Kenji; Sakasegawa, Eiichi; Tashima, Daisuke; Fukidome, Hiromi

    In Kagoshima National College of Technology, based on investigation with “the job boost measure investigation work in a power supply area” undertaken in the 2005 fiscal year, we accepted the trust from Kyushu Bureau of Economy, Trade and Industry, and undertook “the small-and-medium-sized-enterprises personnel educating work which utilized the technical college etc.” for three years from the 2006 fiscal year to the 2008 fiscal year. As the trial of engineer educating according to the electrical engineering concept to the manufacturing field based on a conventional result, we act as a professor of the base technique for applying alternative energy (a fuel cell and a solar cell) in which social needs are powerful these days, and aim at aiming at cultivation of the problem-solving type engineer who can contribute to a low carbon society through manufacturing, we undertook this work according to the manufacturing bearer educating work (personnel educating and secured work of the manufacturing field) in the 2009 fiscal year of National Federation of Small Business Associations.

  4. Field trials of stereoscopic video with an underwater remotely operated vehicle

    NASA Astrophysics Data System (ADS)

    Woods, Andrew J.; Docherty, Tom; Koch, Rolf

    1994-04-01

    We have developed a flicker-free stereoscopic video system which uses commercial television components. This system has been installed on an underwater remotely operated vehicle (ROV) that is used for service and inspection tasks at a gas production platform 130 km off the North-West coast of Western Australia. We report the results of field and laboratory time trials of remote manipulation tasks and also the general experience gained in the field operation of the system. Stereoscopic video provides the operator with an intuitive sense of the depth relationships of the work site. Operators report that this reduces frustration and mental effort as well as giving them confidence in their actions. Some of the other advantages that we have observed include the increased ability to see through suspended matter (fine particles) in the water. The system is most useful in manipulative tasks but also useful for general `flying' of the ROV making navigation through the platform easier. Our results indicate that stereoscopic video will be a valuable tool in the operation of remotely operated vehicles in the underwater environment.

  5. Oil industry first field trial of inter-well reservoir nanoagent tracers

    NASA Astrophysics Data System (ADS)

    Kanj, Mazen Y.; Kosynkin, Dmitry V.

    2015-05-01

    This short manuscript highlights the industry's first proven reservoir nanoagents' design and demonstrates a successful multi-well field trial using these agents. Our fundamental nanoparticles tracer template, A-Dots or Arab-D Dots, is intentionally geared towards the harsh but prolific Arab-D carbonate reservoir environment of 100+°C temperature, 150,000+ppm salinity, and an abundant presence of divalent ions in the connate water. Preliminary analyses confirmed nanoparticles' breakthrough at a producer nearly 500m from the injector at the reservoir level; thus, proving the tracer nanoparticles' mobility and transport capability. This is considered industry-first and a breakthrough achievement complementing earlier accomplishments in regard to the nanoagents' reservoir stability with the first successful single well test and ease of scale up with the synthesis of one metric ton of this material. The importance of this accomplishment is not in how sophisticated is the sensing functionalities of this design but rather in its stability, mobility, scalability, and field application potentials. This renders the concept of having active, reactive, and even communicative, in-situ reservoir nanoagents for underground sensing and intervention a well anticipated near-future reality.

  6. Does Encouragement Matter in Improving Gender Imbalances in Technical Fields? Evidence from a Randomized Controlled Trial

    PubMed Central

    Unkovic, Cait; Sen, Maya; Quinn, Kevin M.

    2016-01-01

    Does encouragement help address gender imbalances in technical fields? We present the results of one of the first and largest randomized controlled trials on the topic. Using an applied statistics conference in the social sciences as our context, we randomly assigned half of a pool of 3,945 graduate students to receive two personalized emails encouraging them to apply (n = 1,976) and the other half to receive nothing (n = 1,969). We find a robust, positive effect associated with this simple intervention and suggestive evidence that women responded more strongly than men. However, we find that women’s conference acceptance rates are higher within the control group than in the treated group. This is not the case for men. The reason appears to be that female applicants in the treated group solicited supporting letters at lower rates. Our findings therefore suggest that “low dose” interventions may promote diversity in STEM fields but may also have the potential to expose underlying disparities when used alone or in a non-targeted way. PMID:27097315

  7. Does Encouragement Matter in Improving Gender Imbalances in Technical Fields? Evidence from a Randomized Controlled Trial.

    PubMed

    Unkovic, Cait; Sen, Maya; Quinn, Kevin M

    2016-01-01

    Does encouragement help address gender imbalances in technical fields? We present the results of one of the first and largest randomized controlled trials on the topic. Using an applied statistics conference in the social sciences as our context, we randomly assigned half of a pool of 3,945 graduate students to receive two personalized emails encouraging them to apply (n = 1,976) and the other half to receive nothing (n = 1,969). We find a robust, positive effect associated with this simple intervention and suggestive evidence that women responded more strongly than men. However, we find that women's conference acceptance rates are higher within the control group than in the treated group. This is not the case for men. The reason appears to be that female applicants in the treated group solicited supporting letters at lower rates. Our findings therefore suggest that "low dose" interventions may promote diversity in STEM fields but may also have the potential to expose underlying disparities when used alone or in a non-targeted way. PMID:27097315

  8. Reconstruction of an atmospheric tracer source in Fusion Field Trials: Analyzing resolution features

    NASA Astrophysics Data System (ADS)

    Singh, Sarvesh Kumar; Turbelin, Gregory; Issartel, Jean-Pierre; Kumar, Pramod; Feiz, Amir Ali

    2015-06-01

    Reconstruction of unknown atmospheric releases using measured concentrations is an ill-posed inverse problem. Due to insufficient measurements and dispersion model uncertainties, reliable interpretation of a retrieved source is limited by lack of resolution, nonuniqueness, and instability in the inverse solution. The study presents an optimality analysis, in terms of resolution, stability, and reliability, of an inverse solution given by a recently proposed inversion technique, called as renormalization. The inversion technique is based on an adjoint source-receptor framework and construction of a weight function which interprets a priori information about the unknown release apparent to the monitoring network. The properties of weight function provide a perfect data resolution, maximum model resolution, and minimum variance (or stability) for the retrieved source. The reliability of the retrieved source is interpreted in view of the information derived from the geometry of the monitoring network. The inversion technique and resolution features are evaluated for a point source reconstruction using measurements from a recent dispersion experiment (Fusion Field Trials 2007) conducted at Dugway Proving Ground, Utah. With the real measurements, the point release is reconstructed within an average distance of 23 m from the true release where the average distance of the nearest receptor from the true source was 32 m. In all the trials, the point release is retrieved within 3-60 m Euclidean distance from their true location. The source strength is retrieved within a factor of 1.5 to the true release mass. The posterior uncertainty in the release parameters is observed to be within 20% of their mean value. The source localization features are resolved to its maximum extent feasible with the design of the monitoring network. The sensitivity studies are conducted to highlight the importance of receptors reporting zero concentration measurements and variations in the

  9. Barriers to the Adoption of Sustainable Agriculture on Rented Land: An Examination of Contesting Social Fields

    ERIC Educational Resources Information Center

    Carolan, Michael S.

    2005-01-01

    While over half of the cropland in the United States is rented, interest in land tenancy within sociological circles has been sporadic at best. In light of the prevalence of rented land in agriculture--particularly in the Midwest--it is vital that further research be conducted to investigate the effect that the rental relationship has upon the…

  10. The Impact of Crop, Pest, and Agricultural Management Practices on Mycotoxin Contamination of Field Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mycotoxins are highly toxic secondary metabolites produced by several fungal genera which occur in a wide variety of agricultural commodities worldwide. Health issues and economic losses due to mycotoxin contamination occur at all stages of the food and feed production process. Mycotoxigenic fungi...

  11. 7 CFR Appendix A to Part 3434 - List of Agriculture-Related Fields

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., Environmental Studies 03.0104, Environmental Science 03.0199, Natural Resources Conservation and Research, Other... 01.0307, Horse Husbandry/Equine Science and Management 01.0308, Agroecology and Sustainable... Communication/Journalism 01.0899, Agricultural Public Services, Other 01.0901, Animal Sciences, General...

  12. 7 CFR Appendix A to Part 3434 - List of Agriculture-Related Fields

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., Environmental Studies 03.0104, Environmental Science 03.0199, Natural Resources Conservation and Research, Other... 01.0307, Horse Husbandry/Equine Science and Management 01.0308, Agroecology and Sustainable... Communication/Journalism 01.0899, Agricultural Public Services, Other 01.0901, Animal Sciences, General...

  13. 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...

  14. Validating a high-resolution digital soil map for precision agriculture across multiple fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Digital soil mapping (DSM) for precision agriculture (PA) management is aimed at developing models that predict soil properties or classes using legacy soil data, sensors, and environmental covariates. The utility of DSM for PA is based on its ability to provide useful spatial soil information for o...

  15. The role of a fertilizer trial in reconciling agricultural expectations and landscape ecology requirements on an opencast coal site in South Wales, United Kingdom

    SciTech Connect

    Humphries, C.E.L.; Humphries, R.N.; Wesemann, H.

    1999-07-01

    Since the 1940s the restoration of opencast coal sites in the UK has been predominantly to productive agriculture and forestry. With new UK government policies on sustainability and biodiversity such land uses may be no longer be acceptable or appropriate in the upland areas of South Wales. A scheme was prepared for the upland Nant Helen site with the objective of restoring the landscape ecology of the site; it included acid grassland to provide the landscape setting and for grazing. The scheme met with the approval of the planning authority. An initial forty hectares (about 13% of the site) was restored between 1993 and 1996. While the approved low intensity grazing and low fertilizer regime met the requirements of the planning authority and the statutory agencies, it was not meeting the expectations of the grazers who had grazing rights to the land. To help reconcile the apparent conflict a fertilizer trial was set up. The trial demonstrated that additional fertilizer and intensive grazing was required to meet the nutritional needs of sheep. It also showed typical upland stocking densities of sheep could be achieved with the acid grassland without the need for reseeding with lowland types. However this was not acceptable to the authority and agencies as such fertilizer and grazing regimes would be detrimental to the landscape and ecological objectives of the restoration scheme. A compromise was agreed whereby grazing intensity and additional fertilizer have been zoned. This has been implemented and is working to the satisfaction of all parties. Without the fertilizer trial it is unlikely that the different interests could have been reconciled.

  16. A field experiment with variable-suction multi-compartment samplers to measure the spatio-temporal distribution of solute leaching in an agricultural soil.

    PubMed

    Bloem, E; Hogervorst, F A N; de Rooij, G H

    2009-04-01

    Solutes spread out in time and space as they move downwards from the soil surface with infiltrating water. Solute monitoring in the field is often limited to observations of resident concentrations, while flux concentrations govern the movement of solutes in soils. A recently developed multi-compartment sampler is capable of measuring fluxes at a high spatial resolution with minimal disturbance of the local pressure head field. The objective of this paper is to use this sampler to quantify the spatial and temporal variation of solute leaching below the root zone in an agricultural field under natural rainfall in winter and spring. We placed two samplers at 31 and 25 cm depth in an agricultural field, leaving the soil above undisturbed. Each sampler contained 100 separate cells of 31x31 mm. Water fluxes were measured every 5 min for each cell. We monitored leaching of a chloride pulse under natural rainfall by frequently extracting the collected leachate while leaving the samplers buried in situ. This experiment was followed by a dye tracer experiment. This setting yielded information that widely surpassed the information that can be provided by separate anionic and dye tracer trials, and solute transport monitoring by coring or suction cups. The detailed information provided by the samplers showed that percolation at the sampling depth started much faster (approximately 3 h after the start of rainfall) in initially wet soil (pressure head above -65 cm) than in drier soil (more than 14 h at pressure heads below -80 cm). At any time, 25% of the drainage passed through 5-6% of the sampled area, reflecting the effect of heterogeneity on the flow paths. The amount of solute carried by individual cells varied over four orders of magnitude. The lateral concentration differences were limited though. This suggests a convective-dispersive regime despite the short vertical travel distance. On the other hand, the dilution index indicates a slight tendency towards stochastic

  17. Celtic field agriculture and Early Anthropogenic Environmental change in the Meuse-Demer-Scheldt region, NW Europe

    NASA Astrophysics Data System (ADS)

    Van der Sanden, Germaine; Kluiving, Sjoerd; Roymans, Nico

    2016-04-01

    The field of Archaeology remains focused on historical issues while underexploring its potential contribution on currently existing societal problems, e.g. climate change. The aim of this paper is to show the relevance of archeological studies for the research of the 'human species as a significant moving agent' in terms of the changing natural environment during a much earlier time frame. This research is based on the study area of the Meuse-Demer-Scheldt region in the Netherlands and Belgium and exhibits the period from the Late Bronze Age to the Early Roman period. This period is characterized by the widespread introduction and use of an agricultural system, often referred to as the Celtic Field system that served as one of the most modifying systems in terms of anthropogenic-environmental change during this period. Emphasis in this research is given to results generated by the use of the remote sensing technology, LiDAR. New information is reported considering a correlation between singular field size and the overall surface of the agricultural complexes and secondly, the presentation of newly identified Celtic field systems in the Meuse-Demer-Scheldt region are presented. The study of the dynamics of the Celtic Field agricultural system provides evidence for a significant anthropogenic footprint on the natural environment due to land cover dominance, soil degeneration, increased soil acidification and forest clearance. Soil exhaustion forced the inhabitants to re-establish their relationship with the landscape in terms of fundamental changes in the habitation pattern and the agrarian exploitations of the land.

  18. Forecasting the Feasibility of Implementing Isolation Perimeters Between GM and non-GM Maize Fields Under Agricultural Conditions

    NASA Astrophysics Data System (ADS)

    Devos, Yann; Cougnon, Mathias; Thas, Olivier; De Clercq, Eva M.; Cordemans, Karl; Reheul, Dirk

    2008-10-01

    Although spatially isolating genetically modified (GM) maize fields from non-GM maize fields is a robust on-farm strategy to keep the adventitious presence of GM material in the harvests of neighboring non-GM maize fields due to cross-fertilizations below established labeling thresholds (and thus to ensure the spatial co-existence between maize cropping systems), the practical implementation of isolation perimeters attracted little research efforts. In this study, the feasibility of implementing isolation perimeters around GM maize fields is investigated. Using Geographic Information System datasets and Monte Carlo simulations, various scenarios differing in shares and spatial distributions of GM maize were tested for various isolation perimeters in six agricultural areas in Flanders. Factors that affect the feasibility of implementing isolation perimeters are discussed.

  19. Selection of flooded agricultural fields and other landscapes by female northern pintails wintering in Tulare Basin, California

    USGS Publications Warehouse

    Fleskes, Joseph P.; Jarvis, Robert L.; Gilmer, David S.

    2003-01-01

    Habitat selection and use are measures of relative importance of habitats to wildlife and necessary information for effective wildlife conservation. To measure the relative impor- tance of flooded agricultural fields and other landscapes to northern pintails (Anas acuta) wintering in Tulare Basin (TB), California, we radiotagged female pintails during late August-early October, 1991-1993 in TB and other San Joaquin Valley areas and deter- mined use and selection of these TB landscapes through March each year. Availability of landscape and field types in TB changed within and among years. Pintail use and selec- tion (based upon use-to-availability log ratios) of landscape and field types differed among seasons, years, and diel periods. Fields flooded after harvest and before planting (i.e., pre-irrigated) were the most available, used, and selected landscape type before the hunting season (Prehunt). Safflower was the most available, used, and-except in 1993, when pre-irrigated fallow was available-selected pre-irrigated field type during Prehunt. Pre-irrigated barley-wheat received 19-22% of use before hunting season, but selection varied greatly among years and diel periods. During and after hunting season, managed marsh was the most available, used, and, along with floodwater areas, selected landscape type; pre-irrigated cotton and alfalfa were the least selected field types and accounted for <13% of pintail use. Agricultural drainwater evaporation ponds, sewage treatment ponds, and reservoirs accounted for 42-48% of flooded landscape available but were lit- tle used and least selected. Exodus of pintails from TB coincided with drying of pre-irri- gated fallow, safflower, and barley-wheat fields early in winter, indicating that preferred habitats were lacking in TB during late winter. Agriculture conservation programs could improve TB for pintails by increasing flooding of fallow and harvested safflower and grain fields. Conservation of remaining wetlands should

  20. Field Trial Results of an Improved Refractory Material for Slagging Gasifiers

    SciTech Connect

    Bennett, J.P.; Kwong, K.-S.; Powell, C.P.; Petty, A.V., Jr.; Thomas, H.; Prior, H.D.; Schnake, M.

    2006-09-01

    Gasifiers are used commercially to react a carbon feedstock with water and oxygen under reducing conditions; producing chemicals used as feedstock for other processes, fuel for power plants, and/or steam used in other processes. A gasifier acts as a high temperature, high pressure reaction chamber, typically operating between 1250-1575°C, and with pressures between 300-1000 psi. Ash that originates from mineral impurities in the carbon feedstock becomes a by-product of gasification. In a slagging gasifier it melts, forming a liquid which flows down the gasifier sidewall; penetrating and wearing away the refractory liner by corrosive dissolution, abrasive wear, or by other processes such as spalling. The refractory liner must withstand the severe service environment, protecting the steel shell against corrosive gases, temperature, and material wear. Users have identified refractory service life as the most important limitation to sustained on-line availability of gasifiers, limiting gasifier acceptance and use by industry. The National Energy Technology Laboratory in Albany, OR, has developed and patented (US Patent # 6,815,386) a phosphate containing high chrome oxide refractory for use in slagging gasifiers. In cooperation with ANH Refractories Company, this refractory material has been commercially produced and is undergoing field tests in commercial gasifiers. An analysis of data from these field tests indicates that the phosphate containing refractory results in an improved service life over other refractory materials currently used as gasifier liners. Results from the post-mortem analysis of the field trial in relation to the failure mechanisms in a slagging gasifier will be presented.

  1. Mindfulness Training and Reductions in Teacher Stress and Burnout: Results from Two Randomized, Waitlist-Control Field Trials

    ERIC Educational Resources Information Center

    Roeser, Robert W.; Schonert-Reichl, Kimberly A.; Jha, Amishi; Cullen, Margaret; Wallace, Linda; Wilensky, Rona; Oberle, Eva; Thomson, Kimberly; Taylor, Cynthia; Harrison, Jessica

    2013-01-01

    The effects of randomization to mindfulness training (MT) or to a waitlist-control condition on psychological and physiological indicators of teachers' occupational stress and burnout were examined in 2 field trials. The sample included 113 elementary and secondary school teachers (89% female) from Canada and the United States. Measures were…

  2. A Combined Motivation and Parent-Child Interaction Therapy Package Reduces Child Welfare Recidivism in a Randomized Dismantling Field Trial

    ERIC Educational Resources Information Center

    Chaffin, Mark; Funderburk, Beverly; Bard, David; Valle, Linda Anne; Gurwitch, Robin

    2011-01-01

    Objective: A package of parent-child interaction therapy (PCIT) combined with a self-motivational (SM) orientation previously was found in a laboratory trial to reduce child abuse recidivism compared with services as usual (SAU). Objectives of the present study were to test effectiveness in a field agency rather than in a laboratory setting and to…

  3. First Field Trial of Optical Label-Based Switching and Packet Drop on a 477km NTON/Sprint Link

    SciTech Connect

    Hernandez, V J; Pan, Z; Cao, J; Tsui, V K; Bansal, Y; Fong, S K H; Zhang, Y; Jeon, M Y; Yoo, S J B; Bodtker, B; Bond, S; Lennon, W J; Higashi, H; Lyles, B; McDonald, R

    2001-12-10

    We demonstrate the first field trial of optical label-based wavelength switching and packet drop on 476.8km of the National Transparent Optical Network. Subcarrier multiplexed labels control a switch fabric that includes a tunable wavelength converter and arrayed waveguide grating router.

  4. Implementing Randomized Controlled Trial Studies in Afterschool Settings: The State of the Field. Afterschool Research Brief. Issue No. 1

    ERIC Educational Resources Information Center

    Vaden-Kiernan, Michael; Jones, Debra Hughes; Rudo, Zena

    2008-01-01

    SEDL is providing analytic and technical support to three large-scale randomized controlled trials assessing the efficacy of promising literacy curriculum in afterschool settings on student academic achievement. In the field of educational research, competition among research organizations and researchers can often impede collaborative efforts in…

  5. Assessment Data-Informed Guidance to Individualize Kindergarten Reading Instruction: Findings from a Cluster-Randomized Control Field Trial

    ERIC Educational Resources Information Center

    Al Otaiba, Stephanie; Connor, Carol M.; Folsom, Jessica S.; Greulich, Luana; Meadows, Jane; Li, Zhi

    2011-01-01

    The purpose of this cluster-randomized control field trial was to examine whether kindergarten teachers could learn to differentiate classroom reading instruction using Individualized Student Instruction for Kindergarten (ISI-K) and to test the efficacy of differentiation on reading outcomes. The study involved 14 schools, 23 ISI-K (n = 305…

  6. Productivity and water use efficiency of Agave americana in the first field trial as bioenergy feedstock on arid lands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agave species are known as high-yielding crassulacean acid metabolism (CAM) plants, some of which have been grown commercially in the past and are recognized as potential bioenergy species for dry regions of the world. This study is the first field trial of Agave species for bioenergy in the United ...

  7. Field Studies Show That In Situ Greenhouse Gas Emission Factors for East African Agriculture Are Less Than IPCC Values

    NASA Astrophysics Data System (ADS)

    Pelster, D.; Butterbach-Bahl, K.; Rufino, M.; Rosenstock, T. S.; Wanyama, G.

    2015-12-01

    Greenhouse gas (GHG) emissions from African agricultural systems are thought to comprise a large portion of total emissions from the continent, however these estimates have been calculated using emission factors (EF) from other regions due to the lack of field studies in Africa, which results in large uncertainties for these estimates. Field measurements from western Kenya calculating emissions over a year in 59 different sites found that GHG emissions from typical smallholder farms ranged from 2.8 to 15.0 Mg CO2-C ha-1, -6.0 to 2.4 kg CH4-C ha-1 and -0.1 to 1.8 kg N2O-N ha-1, and were not affected by management intensity. The lack of a response in N2O emissions to N fertilization suggests that the EF currently used in national inventories overestimates N2O emissions from typical smallholder agriculture. Another study measuring N2O and CH4 emissions from manure deposited by grazing cattle found that the N2O EF ranged from 0.1 to 0.2%, while the CH4 EF ranged from 0.04 to 0.14 Kg CH4-C per 173 kg animal. These suggest that the current IPCC EF overestimate agricultural soil and manure GHG emissions for Kenya, and likely for much of East Africa.

  8. Human pharmaceuticals, hormones, and personal care product ingredients in runoff from agricultural fields irrigated with treated wastewater.

    PubMed

    Pedersen, Joel A; Soliman, Mary; Suffet, I H Mel

    2005-03-01

    Irrigation of crops with treated wastewater has the potential to introduce effluent-derived organic microcontaminants into surface waters through agricultural runoff. To determine whether compounds indicative of the presence of treated effluent in irrigation water could be identified in agricultural runoff, surface runoff samples collected from effluent-irrigated and rain-fed cultivated fields were analyzed for a broad spectrum of organic compounds. A variety of compounds was identified that appeared to be associated with irrigation with treated wastewater. These compounds included human pharmaceuticals (e.g., carbamazepine, gemfibrozil, carisoprodol), personal care product ingredients (e.g., insect repellent, polycyclic musks), and alkyl phosphate flame retardant chemicals. Most of these compounds appear not to have been previously reported in agricultural runoff. These compounds were present at concentrations below the few published aquatic toxicology data available; however, their potential to elicit more subtle effects in aquatic organisms cannot be excluded. None of these compounds were detected by broad-spectrum analysis in samples from the same fields during runoff-producing rain events.

  9. Biological and Agricultural Studies on Application of Discharge Plasma and Electromagnetic Fields 5. Effects of High Electric Fields on Animals

    NASA Astrophysics Data System (ADS)

    Isaka, Katsuo

    The biological effects of extremely low frequency electric fields on animals are reviewed with emphasis on studies of the nervous system, behavior, endocrinology, and blood chemistry. First, this paper provides a histrical overview of studies on the electric field effects initiated in Russia and the United States mainly regarding electric utility workers in high voltage substations and transmission lines. Then, the possible mechanisms of electric field effects are explained using the functions of surface electric fields and induced currents in biological objects. The real mechanisms have not yet been identified. The thresholds of electric field perception levels for rats, baboons, and humans are introduced and compared. The experimental results concerning the depression of melatonin secretion in rats exposed to electric fields are described.

  10. Nematode 18S rRNA gene is a reliable tool for environmental biosafety assessment of transgenic banana in confined field trials.

    PubMed

    Nakacwa, R; Kiggundu, A; Talwana, H; Namaganda, J; Lilley, C; Tushemereirwe, W; Atkinson, H

    2013-10-01

    Information on relatedness in nematodes is commonly obtained by DNA sequencing of the ribosomal internal transcribed spacer region. However, the level of diversity at this locus is often insufficient for reliable species differentiation. Recent findings suggest that the sequences of a fragment of the small subunit nuclear ribosomal DNA (18S rRNA or SSU), identify genera of soil nematodes and can also distinguish between species in some cases. A database of soil nematode genera in a Ugandan soil was developed using 18S rRNA sequences of individual nematodes from a GM banana confined field trial site at the National Agricultural Research Laboratories, Kawanda in Uganda. The trial was planted to evaluate transgenic bananas for resistance to black Sigatoka disease. Search for relatedness of the sequences gained with entries in a public genomic database identified a range of 20 different genera and sometimes distinguished species. Molecular markers were designed from the sequence information to underpin nematode faunal analysis. This approach provides bio-indicators for disturbance of the soil environment and the condition of the soil food web. It is being developed to support environmental biosafety analysis by detecting any perturbance by transgenic banana or other GM crops on the soil environment.

  11. Product amount and quality monitoring in agricultural fields with remote sensing satellite and radio-control helicopter

    NASA Astrophysics Data System (ADS)

    Arai, Kohei

    Product amount and quality monitoring in agricultural fields with remote sensing satellite and radio-control helicopter is proposed. In particular, tealeaves and rice crop quality and amoujnt monitorings are peoposed as examples. Nitrogen rich tealeaves tasts good. Therefore, quality of tealeaves can be estimated with nitrogen content which is related with near infrared reflectance of the tealeves in concern. Also, rice crop quality depends on protein content in rice grain which is related to near infrared reflectance of rice leaves. Therefore, product quality can be estimated with observation of near infrared reflectance of the leaves in concern. Near infared reflectance is provided by near infrared radiometers onboard remote sensing satellites and by near infrared cameras onboard radio-control helicopter. This monitoring system is applicable to the other agricultural plant products. Through monitoring near ingfrared reflectance, it is possible to estimate quality as well as product amount.

  12. Combining auctions and performance-based payments in a forest enrichment field trial in Western Kenya.

    PubMed

    Khalumba, Mercelyne; Wünscher, Tobias; Wunder, Sven; Büdenbender, Mirjam; Holm-Müller, Karin

    2014-06-01

    Cost-effectiveness is an important aspect in the assessment of payments for environmental services (PES) initiatives. In participatory field trials with communities in Western Kenya, we combined procurement auctions for forest enrichment contracts with performance-based payments and compared the outcomes with a baseline scenario currently used by the Kenyan Forest Service. Procurement auctions were the most cost-effective. The competitive nature of the auction reduced contracting expenses (provision costs), and the result-oriented payments provided additional incentives to care for the planted seedlings, resulting in their improved survival rates (service quantity). These gains clearly exceeded increases in transaction costs associated with conducting an auction. The number of income-poor auction participants and winners was disproportionately high and local institutional buy-in was remarkably strong. Our participatory approach may, however, require adaptations when conducted at a larger scale. Although the number of contracts we monitored was limited and prohibited the use of statistical tests, our study is one of the first to reveal the benefits of using auctions for PES in developing countries.

  13. Technology Development and Field Trials of EGS Drilling Systems at Chocolate Mountain

    DOE Data Explorer

    Steven Knudsen

    2012-01-01

    Polycrystalline diamond compact (PDC) bits are routinely used in the oil and gas industry for drilling medium to hard rock but have not been adopted for geothermal drilling, largely due to past reliability issues and higher purchase costs. The Sandia Geothermal Research Department has recently completed a field demonstration of the applicability of advanced synthetic diamond drill bits for production geothermal drilling. Two commercially-available PDC bits were tested in a geothermal drilling program in the Chocolate Mountains in Southern California. These bits drilled the granitic formations with significantly better Rate of Penetration (ROP) and bit life than the roller cone bit they are compared with. Drilling records and bit performance data along with associated drilling cost savings are presented herein. The drilling trials have demonstrated PDC bit drilling technology has matured for applicability and improvements to geothermal drilling. This will be especially beneficial for development of Enhanced Geothermal Systems whereby resources can be accessed anywhere within the continental US by drilling to deep, hot resources in hard, basement rock formations.

  14. Combining auctions and performance-based payments in a forest enrichment field trial in Western Kenya.

    PubMed

    Khalumba, Mercelyne; Wünscher, Tobias; Wunder, Sven; Büdenbender, Mirjam; Holm-Müller, Karin

    2014-06-01

    Cost-effectiveness is an important aspect in the assessment of payments for environmental services (PES) initiatives. In participatory field trials with communities in Western Kenya, we combined procurement auctions for forest enrichment contracts with performance-based payments and compared the outcomes with a baseline scenario currently used by the Kenyan Forest Service. Procurement auctions were the most cost-effective. The competitive nature of the auction reduced contracting expenses (provision costs), and the result-oriented payments provided additional incentives to care for the planted seedlings, resulting in their improved survival rates (service quantity). These gains clearly exceeded increases in transaction costs associated with conducting an auction. The number of income-poor auction participants and winners was disproportionately high and local institutional buy-in was remarkably strong. Our participatory approach may, however, require adaptations when conducted at a larger scale. Although the number of contracts we monitored was limited and prohibited the use of statistical tests, our study is one of the first to reveal the benefits of using auctions for PES in developing countries. PMID:24665907

  15. A field trial for an ex-situ bioremediation of a drilling mud-polluted site.

    PubMed

    Rojas-Avelizapa, N G; Roldán-Carrillo, T; Zegarra-Martínez, H; Muñoz-Colunga, A M; Fernández-Linares, L C

    2007-01-01

    The remediation of drilling mud-polluted sites in the Southeast of Mexico is a top priority for Mexican oil industry. The objective of this work was to find a technology to remediate these sites. A field trial was performed by composting in biopiles, where four 1ton soil-biopiles were established, one treatment in triplicate and one unamended biopile. Amended biopiles were added with nutrients to get a C/N/P ratio of 100/3/0.5 plus a bulking agent (straw) at a soil/straw ratio of 97/3. Moisture content was maintained around 30-35%. Results showed that, after 180 d, total petroleum hydrocarbon (TPH) concentrations decreased from 99300+/-23000mgTPHkg(-1) soil to 5500+/-770mgTPHkg(-1) for amended biopiles and to 22900+/-7800mgTPHkg(-1) for unamended biopile. An undisturbed soil control showed no change in TPH concentrations. Gas chromatographic analysis showed residual alkyl dibenzothiophene type compounds. Highest bacterial counts were observed during the first 30 d which correlated with highest TPH removal, whereas fungal count increased at the end of the experimentation period. Results suggested an important role of the straw, nutrient addition and water content in stimulating aerobic microbial activity and thus hydrocarbon removal. This finding opens an opportunity to remediate old polluted sites with recalcitrant and high TPH concentration.

  16. Restoration of a Mediterranean forest after a fire: bioremediation and rhizoremediation field-scale trial.

    PubMed

    Pizarro-Tobías, Paloma; Fernández, Matilde; Niqui, José Luis; Solano, Jennifer; Duque, Estrella; Ramos, Juan-Luis; Roca, Amalia

    2015-01-01

    Forest fires pose a serious threat to countries in the Mediterranean basin, often razing large areas of land each year. After fires, soils are more likely to erode and resilience is inhibited in part by the toxic aromatic hydrocarbons produced during the combustion of cellulose and lignins. In this study, we explored the use of bioremediation and rhizoremediation techniques for soil restoration in a field-scale trial in a protected Mediterranean ecosystem after a controlled fire. Our bioremediation strategy combined the use of Pseudomonas putida strains, indigenous culturable microbes and annual grasses. After 8 months of monitoring soil quality parameters, including the removal of monoaromatic and polycyclic aromatic hydrocarbons as well as vegetation cover, we found that the site had returned to pre-fire status. Microbial population analysis revealed that fires induced changes in the indigenous microbiota and that rhizoremediation favours the recovery of soil microbiota in time. The results obtained in this study indicate that the rhizoremediation strategy could be presented as a viable and cost-effective alternative for the treatment of ecosystems affected by fires.

  17. Pulsed electromagnetic fields on postmenopausal osteoporosis in Southwest China: a randomized, active-controlled clinical trial.

    PubMed

    Liu, Hui-Fang; Yang, Lin; He, Hong-Chen; Zhou, Jun; Liu, Ying; Wang, Chun-Yan; Wu, Yuan-Chao; He, Cheng-Qi

    2013-05-01

    A randomized, active-controlled clinical trial was conducted to examine the effect of pulsed electromagnetic fields (PEMFs) on women with postmenopausal osteoporosis (PMO) in southwest China. Forty-four participants were randomly assigned to receive alendronate or one course of PEMFs treatment. The primary endpoint was the mean percentage change in bone mineral density of the lumbar spine (BMDL), and secondary endpoints were the mean percentage changes in left proximal femur bone mineral density (BMDF), serum 25OH vitamin D3 (25(OH)D) concentrations, total lower-extremity manual muscle test (LE MMT) score, and Berg Balance Scale (BBS) score. The BMDL, BMDF, total LE MMT score and BBS score were recorded at baseline, 5, 12, and 24 weeks. Serum concentrations of 25(OH)D were measured at baseline and 5 weeks. Using a mixed linear model, there was no significant treatment difference between the two groups in the BMDL, BMDF, total LE MMT score, and BBS score (P ≥ 0.05). For 25(OH)D concentrations, the effects were also comparable between the two groups (P ≥ 0.05) with the Mann-Whitney's U-test. These results suggested that a course of PEMFs treatment with specific parameters was as effective as alendronate in treating PMO within 24 weeks.

  18. Restoration of a Mediterranean forest after a fire: bioremediation and rhizoremediation field-scale trial

    PubMed Central

    Pizarro-Tobías, Paloma; Fernández, Matilde; Niqui, José Luis; Solano, Jennifer; Duque, Estrella; Ramos, Juan-Luis; Roca, Amalia

    2015-01-01

    Forest fires pose a serious threat to countries in the Mediterranean basin, often razing large areas of land each year. After fires, soils are more likely to erode and resilience is inhibited in part by the toxic aromatic hydrocarbons produced during the combustion of cellulose and lignins. In this study, we explored the use of bioremediation and rhizoremediation techniques for soil restoration in a field-scale trial in a protected Mediterranean ecosystem after a controlled fire. Our bioremediation strategy combined the use of Pseudomonas putida strains, indigenous culturable microbes and annual grasses. After 8 months of monitoring soil quality parameters, including the removal of monoaromatic and polycyclic aromatic hydrocarbons as well as vegetation cover, we found that the site had returned to pre-fire status. Microbial population analysis revealed that fires induced changes in the indigenous microbiota and that rhizoremediation favours the recovery of soil microbiota in time. The results obtained in this study indicate that the rhizoremediation strategy could be presented as a viable and cost-effective alternative for the treatment of ecosystems affected by fires. PMID:25079309

  19. Combined remediation technologies: results from field trials at chlorinated solvent impacted sites

    NASA Astrophysics Data System (ADS)

    O'Carroll, D. M.; Chowdhury, A. I.; Lomheim, L.; Boparai, H. K.; Weber, K.; Austrins, L. M.; Edwards, E.; Sleep, B.; de Boer, C. V.; Garcia, A. N.

    2015-12-01

    Non-aqueous phase liquids (NAPLs) are one class of waste liquids often generated from waste mixtures in industrial processes containing surfactants, chlorinated hydrocarbons and other compounds. Chlorinated solvents, a particularly persistent NAPL contaminant, frequently contaminate water sources for decades and are one of the more common contaminants at brownfield and industrialized sites. Although considerable advances in our understanding of the phenomena governing NAPL remediation have been made, and a number of innovative remediation technologies have been developed, existing technologies are rarely able to achieve clean up goals in contaminated aquifers at the completion of remedial activities. The development and pilot scale testing of new and innovative remediation technologies is, therefore, crucial to achieve clean up goals at contaminated sites. Our research group is currently investigating a number of innovative remediation technologies, either individually or as combined remedies. This includes the applicability of nanometals and ISCO (e.g., persulfate) for contaminated site remediation. These technologies can be combined with technologies to enhance amendment delivery (e.g., electrokinetics) or create conditions favorable for enhanced biotic contaminant degradation. This presentation will discuss outcomes from a number of field trials conducted at chlorinated solvent impacted sites by our group with a particular focus on combined remediation technologies.

  20. Predicting plant invasions under climate change: are species distribution models validated by field trials?

    PubMed

    Sheppard, Christine S; Burns, Bruce R; Stanley, Margaret C

    2014-09-01

    Climate change may facilitate alien species invasion into new areas, particularly for species from warm native ranges introduced into areas currently marginal for temperature. Although conclusions from modelling approaches and experimental studies are generally similar, combining the two approaches has rarely occurred. The aim of this study was to validate species distribution models by conducting field trials in sites of differing suitability as predicted by the models, thus increasing confidence in their ability to assess invasion risk. Three recently naturalized alien plants in New Zealand were used as study species (Archontophoenix cunninghamiana, Psidium guajava and Schefflera actinophylla): they originate from warm native ranges, are woody bird-dispersed species and of concern as potential weeds. Seedlings were grown in six sites across the country, differing both in climate and suitability (as predicted by the species distribution models). Seedling growth and survival were recorded over two summers and one or two winter seasons, and temperature and precipitation were monitored hourly at each site. Additionally, alien seedling performances were compared to those of closely related native species (Rhopalostylis sapida, Lophomyrtus bullata and Schefflera digitata). Furthermore, half of the seedlings were sprayed with pesticide, to investigate whether enemy release may influence performance. The results showed large differences in growth and survival of the alien species among the six sites. In the more suitable sites, performance was frequently higher compared to the native species. Leaf damage from invertebrate herbivory was low for both alien and native seedlings, with little evidence that the alien species should have an advantage over the native species because of enemy release. Correlations between performance in the field and predicted suitability of species distribution models were generally high. The projected increase in minimum temperature and reduced

  1. A Randomized, Controlled Field Trial for the Prevention of Jellyfish Stings With a Topical Sting Inhibitor

    PubMed Central

    Boulware, David R.

    2007-01-01

    Background Jellyfish stings are a common occurrence among ocean goers worldwide with an estimated 150 million envenomations annually. Fatalities and hospitalizations occur annually, particularly in the Indo-Pacific regions. A new topical jellyfish sting inhibitor based on the mucous coating of the clown fish prevents 85% of jellyfish stings in laboratory settings. The field effectiveness is unknown. The objective is to evaluate the field efficacy of the jellyfish sting inhibitor, Safe Sea™. Methods A double-blind, randomized, placebo-controlled trial occurred at the Dry Tortugas National Park, FL, USA and Sapodilla Cayes, Belize. Participants were healthy volunteers planning to snorkel for 30 to 45 minutes. Ten minutes prior to swimming, each participant was directly observed applying a blinded sample of Safe Sea (Nidaria Technology Ltd, Jordan Valley, Israel) to one side of their body and a blinded sample of Coppertone® (Schering-Plough, Kenilworth, NJ, USA) to the contralateral side as placebo control. Masked 26 g samples of both Safe Sea SPF15 and Coppertone® SPF15 were provided in identical containers to achieve 2 mg/cm2 coverage. Sides were randomly chosen by participants. The incidence of jellyfish stings was the main outcome measure. This was assessed by participant interview and examination as subjects exited the water. Results A total of 82 observed water exposures occurred. Thirteen jellyfish stings occurred during the study period for a 16% incidence. Eleven jellyfish stings occurred with placebo, two with the sting inhibitor, resulting in a relative risk reduction of 82% (95% confidence interval: 21%–96%; p = 0.02). No seabather’s eruption or side effects occurred. Conclusions Safe Sea is a topical barrier cream effective at preventing >80% jellyfish stings under real-world conditions. PMID:16706948

  2. Field trials assessing deltamethrin (Butox®) treatments of sheep against Culicoides species.

    PubMed

    Weiher, Wiebke; Bauer, Burkhard; Mehlitz, Dieter; Nijhof, Ard M; Clausen, Peter-Henning

    2014-07-01

    Culicoides (Diptera: Ceratopogonidae) biting midges may transmit various diseases of economic importance, including bluetongue virus (BTV) and Schmallenberg (SV) virus, which affect ruminants. During the outbreak of BTV in central and northern Europe in 2006, and in the absence of BTV vaccines, many national veterinary services recommended the treatment of susceptible livestock with pyrethroids as a first-line defense against biting midges, although these insecticides were officially not registered and authorized for use against Culicoides midges. The efficacy of Butox® pour on (7.5 mg deltamethrin/mL) against biting midges was therefore evaluated in a double-blinded GCP field trial performed in Brandenburg, Germany. Forty female Merino sheep with an average body weight of 38 kg (±7 kg) were used for the study. Twenty randomly selected sheep were treated with 10 mL Butox® pour on. The remaining 20 sheep were left untreated and served as a control group. Midge collections took place in two separate drop traps covering two crush pens with three confined treated/untreated sheep standing inside, on weekdays at 1, 7, 14, 21, 28, and 35 days post treatment. A total of 19,057 midges were collected during this period. Midges were identified as belonging to the subgenus Avaritia, Fox (84.6%) and subgenus Culicoides, Latreille (15.4%). A total of 12,031 midges were collected inside the drop trap containing untreated sheep, in comparison to 7,026 midges collected from the vicinity of the treated sheep. Significantly, more midges had fed on control compared to treated sheep with 757 and 103 engorged midges, respectively. The results indicate that treatment of sheep with Butox® pour on provided a significant decrease in Culicoides feeding rates under field conditions for at least 35 days.

  3. Randomised field trial to evaluate serological response after foot-and-mouth disease vaccination in Turkey.

    PubMed

    Knight-Jones, T J D; Bulut, A N; Gubbins, S; Stärk, K D C; Pfeiffer, D U; Sumption, K J; Paton, D J

    2015-02-01

    Despite years of biannual mass vaccination of cattle, foot-and-mouth disease (FMD) remains uncontrolled in Anatolian Turkey. To evaluate protection after mass vaccination we measured post-vaccination antibodies in a cohort of cattle (serotypes O, A and Asia-1). To obtain results reflecting typical field protection, participants were randomly sampled from across Central and Western Turkey after routine vaccination. Giving two-doses one month apart is recommended when cattle are first vaccinated against FMD. However, due to cost and logistics, this is not routinely performed in Turkey, and elsewhere. Nested within the cohort, we conducted a randomised trial comparing post-vaccination antibodies after a single-dose versus a two-dose primary vaccination course. Four to five months after vaccination, only a third of single-vaccinated cattle had antibody levels above a threshold associated with protection. A third never reached this threshold, even at peak response one month after vaccination. It was not until animals had received three vaccine doses in their lifetime, vaccinating every six months, that most (64% to 86% depending on serotype) maintained antibody levels above this threshold. By this time cattle would be >20 months old with almost half the population below this age. Consequently, many vaccinated animals will be unprotected for much of the year. Compared to a single-dose, a primary vaccination course of two-doses greatly improved the level and duration of immunity. We concluded that the FMD vaccination programme in Anatolian Turkey did not produce the high levels of immunity required. Higher potency vaccines are now used throughout Turkey, with a two-dose primary course in certain areas. Monitoring post-vaccination serology is an important component of evaluation for FMD vaccination programmes. However, consideration must be given to which antigens are present in the test, the vaccine and the field virus. Differences between these antigens affect the

  4. Predicting plant invasions under climate change: are species distribution models validated by field trials?

    PubMed

    Sheppard, Christine S; Burns, Bruce R; Stanley, Margaret C

    2014-09-01

    Climate change may facilitate alien species invasion into new areas, particularly for species from warm native ranges introduced into areas currently marginal for temperature. Although conclusions from modelling approaches and experimental studies are generally similar, combining the two approaches has rarely occurred. The aim of this study was to validate species distribution models by conducting field trials in sites of differing suitability as predicted by the models, thus increasing confidence in their ability to assess invasion risk. Three recently naturalized alien plants in New Zealand were used as study species (Archontophoenix cunninghamiana, Psidium guajava and Schefflera actinophylla): they originate from warm native ranges, are woody bird-dispersed species and of concern as potential weeds. Seedlings were grown in six sites across the country, differing both in climate and suitability (as predicted by the species distribution models). Seedling growth and survival were recorded over two summers and one or two winter seasons, and temperature and precipitation were monitored hourly at each site. Additionally, alien seedling performances were compared to those of closely related native species (Rhopalostylis sapida, Lophomyrtus bullata and Schefflera digitata). Furthermore, half of the seedlings were sprayed with pesticide, to investigate whether enemy release may influence performance. The results showed large differences in growth and survival of the alien species among the six sites. In the more suitable sites, performance was frequently higher compared to the native species. Leaf damage from invertebrate herbivory was low for both alien and native seedlings, with little evidence that the alien species should have an advantage over the native species because of enemy release. Correlations between performance in the field and predicted suitability of species distribution models were generally high. The projected increase in minimum temperature and reduced

  5. 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...

  6. Neonicotinoid-Coated Zea mays Seeds Indirectly Affect Honeybee Performance and Pathogen Susceptibility in Field Trials.

    PubMed

    Alburaki, Mohamed; Boutin, Sébastien; Mercier, Pierre-Luc; Loublier, Yves; Chagnon, Madeleine; Derome, Nicolas

    2015-01-01

    Thirty-two honeybee (Apis mellifera) colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp) on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were extensively monitored for their performance and health traits over a period of two years. Honeybee viruses (brood queen cell virus BQCV, deformed wing virus DWV, and Israeli acute paralysis virus IAPV) and the brain specific expression of a biomarker of host physiological stress, the Acetylcholinesterase gene AChE, were investigated using RT-qPCR. Liquid chromatography-mass spectrometry (LC-MS) was performed to detect pesticide residues in adult bees, honey, pollen, and corn flowers collected from the studied hives in each location. In addition, general hive conditions were assessed by monitoring colony weight and brood development. Neonicotinoids were only identified in corn flowers at low concentrations. However, honeybee colonies located in neonicotinoid treated cornfields expressed significantly higher pathogen infection than those located in untreated cornfields. AChE levels showed elevated levels among honeybees that collected corn pollen from treated fields. Positive correlations were recorded between pathogens and the treated locations. Our data suggests that neonicotinoids indirectly weaken honeybee health by inducing physiological stress and increasing pathogen loads. PMID:25993642

  7. Neonicotinoid-Coated Zea mays Seeds Indirectly Affect Honeybee Performance and Pathogen Susceptibility in Field Trials.

    PubMed

    Alburaki, Mohamed; Boutin, Sébastien; Mercier, Pierre-Luc; Loublier, Yves; Chagnon, Madeleine; Derome, Nicolas

    2015-01-01

    Thirty-two honeybee (Apis mellifera) colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp) on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were extensively monitored for their performance and health traits over a period of two years. Honeybee viruses (brood queen cell virus BQCV, deformed wing virus DWV, and Israeli acute paralysis virus IAPV) and the brain specific expression of a biomarker of host physiological stress, the Acetylcholinesterase gene AChE, were investigated using RT-qPCR. Liquid chromatography-mass spectrometry (LC-MS) was performed to detect pesticide residues in adult bees, honey, pollen, and corn flowers collected from the studied hives in each location. In addition, general hive conditions were assessed by monitoring colony weight and brood development. Neonicotinoids were only identified in corn flowers at low concentrations. However, honeybee colonies located in neonicotinoid treated cornfields expressed significantly higher pathogen infection than those located in untreated cornfields. AChE levels showed elevated levels among honeybees that collected corn pollen from treated fields. Positive correlations were recorded between pathogens and the treated locations. Our data suggests that neonicotinoids indirectly weaken honeybee health by inducing physiological stress and increasing pathogen loads.

  8. Neonicotinoid-Coated Zea mays Seeds Indirectly Affect Honeybee Performance and Pathogen Susceptibility in Field Trials

    PubMed Central

    Alburaki, Mohamed; Boutin, Sébastien; Mercier, Pierre-Luc; Loublier, Yves; Chagnon, Madeleine; Derome, Nicolas

    2015-01-01

    Thirty-two honeybee (Apis mellifera) colonies were studied in order to detect and measure potential in vivo effects of neonicotinoid pesticides used in cornfields (Zea mays spp) on honeybee health. Honeybee colonies were randomly split on four different agricultural cornfield areas located near Quebec City, Canada. Two locations contained cornfields treated with a seed-coated systemic neonicotinoid insecticide while the two others were organic cornfields used as control treatments. Hives were extensively monitored for their performance and health traits over a period of two years. Honeybee viruses (brood queen cell virus BQCV, deformed wing virus DWV, and Israeli acute paralysis virus IAPV) and the brain specific expression of a biomarker of host physiological stress, the Acetylcholinesterase gene AChE, were investigated using RT-qPCR. Liquid chromatography-mass spectrometry (LC-MS) was performed to detect pesticide residues in adult bees, honey, pollen, and corn flowers collected from the studied hives in each location. In addition, general hive conditions were assessed by monitoring colony weight and brood development. Neonicotinoids were only identified in corn flowers at low concentrations. However, honeybee colonies located in neonicotinoid treated cornfields expressed significantly higher pathogen infection than those located in untreated cornfields. AChE levels showed elevated levels among honeybees that collected corn pollen from treated fields. Positive correlations were recorded between pathogens and the treated locations. Our data suggests that neonicotinoids indirectly weaken honeybee health by inducing physiological stress and increasing pathogen loads. PMID:25993642

  9. Application of ERTS-1 imagery in the fields of geology, agriculture, forestry, and hydrology to selected test sites in Iran

    NASA Technical Reports Server (NTRS)

    Ebtehadj, K.

    1973-01-01

    The preliminary study of the ERTS-1 imagery coverage of Iran, commenced on October 26, 1972. All of the images were carefully examined, and a photomosaic covering approximately ninety-five per cent of the country was prepared. A number of images of selected areas were studied in detail. In the field of geology, a number of large scale faults were identified, which do not figure on geological maps. Furthermore, a preliminary study was carried out on the recent sediments, their possible sources, and origin. A limited number of geological work maps were prepared as well. In the fields of agriculture and forestry, studies based on color composite prints of certain areas were undertaken, with a purpose of identifying potential arable areas. Investigations in the field of water resources resulted in the discovery of a number of small lakes, and streams. Furthermore, fluctuations of the water level in some lakes were observed.

  10. Modelling Water Flow, Heat Transport, Soil Freezing and Thawing, and Snow Processes in a Clayey, Subsurface Drained Agricultural Field

    NASA Astrophysics Data System (ADS)

    Warsta, L.; Turunen, M.; Koivusalo, H. J.; Paasonen-Kivekäs, M.; Karvonen, T.; Taskinen, A.

    2012-12-01

    Simulation of hydrological processes for the purposes of agricultural water management and protection in boreal environment requires description of winter time processes, including heat transport, soil freezing and thawing, and snow accumulation and melt. Finland is located north of the latitude of 60 degrees and has one third to one fourth of the total agricultural land area (2.3 milj. ha) on clay soils (> 30% of clay). Most of the clayey fields are subsurface drained to provide efficient drainage and to enable heavy machines to operate on the fields as soon as possible after the spring snowmelt. Generation of drainflow and surface runoff in cultivated fields leads to nutrient and sediment load, which forms the major share of the total load reaching surface waters at the national level. Water, suspended sediment, and soluble nutrients on clayey field surface are conveyed through the soil profile to the subsurface drains via macropore pathways as the clayey soil matrix is almost impermeable. The objective of the study was to develop the missing winter related processes into the FLUSH model, including soil heat transport, snow pack simulation and the effects of soil freezing and thawing on the soil hydraulic conductivity. FLUSH is an open source (MIT license), distributed, process-based model designed to simulate surface runoff and drainflow in clayey, subsurface drained agricultural fields. 2-D overland flow is described with the diffuse wave approximation of the Saint Venant equations and 3-D subsurface flow with a dual-permeability model. Both macropores and soil matrix are simulated with the Richards equation. Soil heat transport is described with a modified 3-D convection-diffusion equation. Runoff and groundwater data was available from different periods from January 1994 to April 1999 measured in a clayey, subsurface drained field section (3.6 ha) in southern Finland. Soil temperature data was collected in two locations (to a depth of 0.8 m) next to the

  11. 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.

  12. Biodiversity in Organic Farmland - How Does Landscape Context Influence Species Diversity in Organic Vs. Conventional Agricultural Fields?

    NASA Astrophysics Data System (ADS)

    Seufert, V.; Wood, S.; Reid, A.; Gonzalez, A.; Rhemtulla, J.; Ramankutty, N.

    2014-12-01

    The most important current driver of biodiversity loss is the conversion of natural habitats for human land uses, mostly for the purpose of food production. However, by causing this biodiversity loss, food production is eroding the very same ecosystem services (e.g. pollination and soil fertility) that it depends on. We therefore need to adopt more wildlife-friendly agricultural practices that can contribute to preserving biodiversity. Organic farming has been shown to typically host higher biodiversity than conventional farming. But how is the biodiversity benefit of organic management dependent on the landscape context farms are situated in? To implement organic farming as an effective means for protecting biodiversity and enhancing ecosystem services we need to understand better under what conditions organic management is most beneficial for species. We conducted a meta-analysis of the literature to answer this question, compiling the most comprehensive database to date of studies that monitored biodiversity in organic vs. conventional fields. We also collected information about the landscape surrounding these fields from remote sensing products. Our database consists of 348 study sites across North America and Europe. Our analysis shows that organic management can improve biodiversity in agricultural fields substantially. It is especially effective at preserving biodiversity in homogeneous landscapes that are structurally simplified and dominated by either cropland or pasture. In heterogeneous landscapes conventional agriculture might instead already hold high biodiversity, and organic management does not appear to provide as much of a benefit for species richness as in simplified landscapes. Our results suggest that strategies to maintain biodiversity-dependent ecosystem services should include a combination of pristine natural habitats, wildlife-friendly farming systems like organic farming, and high-yielding conventional systems, interspersed in structurally

  13. Effects of agricultural fungicides on microorganisms associated with floral nectar: susceptibility assays and field experiments.

    PubMed

    Bartlewicz, Jacek; Pozo, María I; Honnay, Olivier; Lievens, Bart; Jacquemyn, Hans

    2016-10-01

    Pesticides have become an inseparable element of agricultural intensification. While the direct impact of pesticides on non-target organisms, such as pollinators, has recently received much attention, less consideration has been given to the microorganisms that are associated with them. Specialist yeasts and bacteria are known to commonly inhabit floral nectar and change its chemical characteristics in numerous ways, possibly influencing pollinator attraction. In this study, we investigated the in vitro susceptibility of nectar yeasts Metschnikowia gruessi, Metschnikowia reukaufii, and Candida bombi to six widely used agricultural fungicides (prothioconazole, tebuconazole, azoxystrobin, fenamidone, boscalid, and fluopyram). Next, a commercial antifungal mixture containing tebuconazole and trifloxystrobin was applied to natural populations of the plant Linaria vulgaris and the occurrence, abundance, and diversity of nectar-inhabiting yeasts and bacteria was compared between treated and untreated plants. The results showed that prothioconazole and tebuconazole were highly toxic to nectar yeasts, inhibiting their growth at concentrations varying between 0.06 and 0.5 mg/L. Azoxystrobin, fenamidone, boscalid, and fluopyram on the other hand exhibited considerably lower toxicity, inhibiting yeast growth at concentrations between 1 and 32 mg/L or in many cases not inhibiting microbial growth at all. The application of the antifungal mixture in natural plant populations resulted in a significant decrease in the occurrence and abundance of yeasts in individual flowers, but this did not translate into noticeable changes in bacterial incidence and abundance. Yeast and bacterial species richness and distribution did not also differ between treated and untreated plants. We conclude that the application of fungicides may have negative effects on the abundance of nectar yeasts in floral nectar. The consequences of these effects on plant pollination processes in agricultural

  14. Spatial variability of soil magnetic susceptibility in an agricultural field located in Eastern Ukraine

    NASA Astrophysics Data System (ADS)

    Menshov, Oleksandr; Pereira, Paulo; Kruglov, Oleksandr

    2015-04-01

    Magnetic susceptibility (MS) have been used to characterize soil properties. It gives an indirect information about heavy metals content and degree of human impacts on soil contamination derived from atmospheric pollution (Girault et al., 2011). This method is inexpensive in relation to chemical analysis and very useful to track soil pollution, since several toxic components deposited on soil surface are rich in particulates produced by oxidation processes (Boyko et al., 2004; Morton-Bernea et al., 2009). Thus, identify the spatial distribution of MS is of major importance, since can give an indirect information of high metals content (Dankoub et al., 2012). This allows also to distinguish the pedogenic and technogenic origin magnetic signal. For example Ukraine chernozems contain fine-grained oxidized magnetite and maghemite of pedogenic origin formed by weathering of the parent material (Jeleńska et al., 2004). However, to a correct understanding of variables distribution, the identification of the most accurate interpolation method is fundamental for a better interpretation of map information (Pereira et al., 2013). The objective of this work is to study the spatial variability of soil MS in an agricultural fields located in the Tcherkascy Tishki area (50.11°N, 36.43 °E, 162 m a.s.l), Ukraine. Soil MS was measured in 77 sampling points in a north facing slope. To estimate the best interpolation method, several interpolation methods were tested, as inverse distance to a weight (IDW) with the power of 1,2,3,4 and 5, Local Polynomial (LP) with the power of 1 and 2, Global Polynomial (GP), radial basis functions - spline with tension (SPT), completely regularized spline (CRS), multiquatratic (MTQ), inverse multiquatratic (IMTQ), and thin plate spline (TPS) - and some geostatistical methods as, ordinary kriging (OK), Simple Kriging (SK) and Universal Kriging (UK), used in previous works (Pereira et al., 2014). On average, the soil MS of the studied plot had 686

  15. Spatial variability of soil magnetic susceptibility in an agricultural field located in Eastern Ukraine

    NASA Astrophysics Data System (ADS)

    Menshov, Oleksandr; Pereira, Paulo; Kruglov, Oleksandr

    2015-04-01

    Magnetic susceptibility (MS) have been used to characterize soil properties. It gives an indirect information about heavy metals content and degree of human impacts on soil contamination derived from atmospheric pollution (Girault et al., 2011). This method is inexpensive in relation to chemical analysis and very useful to track soil pollution, since several toxic components deposited on soil surface are rich in particulates produced by oxidation processes (Boyko et al., 2004; Morton-Bernea et al., 2009). Thus, identify the spatial distribution of MS is of major importance, since can give an indirect information of high metals content (Dankoub et al., 2012). This allows also to distinguish the pedogenic and technogenic origin magnetic signal. For example Ukraine chernozems contain fine-grained oxidized magnetite and maghemite of pedogenic origin formed by weathering of the parent material (Jeleńska et al., 2004). However, to a correct understanding of variables distribution, the identification of the most accurate interpolation method is fundamental for a better interpretation of map information (Pereira et al., 2013). The objective of this work is to study the spatial variability of soil MS in an agricultural fields located in the Tcherkascy Tishki area (50.11°N, 36.43 °E, 162 m a.s.l), Ukraine. Soil MS was measured in 77 sampling points in a north facing slope. To estimate the best interpolation method, several interpolation methods were tested, as inverse distance to a weight (IDW) with the power of 1,2,3,4 and 5, Local Polynomial (LP) with the power of 1 and 2, Global Polynomial (GP), radial basis functions - spline with tension (SPT), completely regularized spline (CRS), multiquatratic (MTQ), inverse multiquatratic (IMTQ), and thin plate spline (TPS) - and some geostatistical methods as, ordinary kriging (OK), Simple Kriging (SK) and Universal Kriging (UK), used in previous works (Pereira et al., 2014). On average, the soil MS of the studied plot had 686

  16. European project AMUSE: advanced multimedia services for residential users--report on a first field trial in Munich

    NASA Astrophysics Data System (ADS)

    von der Straten, Gernot; Theimer, Thomas; Hessenmueller, Horst; Martin, Hermann

    1996-12-01

    In the framework of the European ACTS (Advanced Communication Technologies and Services) program, the large project AMUSE has been established involving 25 partners from 8 European countries and Israel. The project aims to develop, specify, implement and trial advanced multimedia services to test these new services under real conditions in field trials in several locations based on Hybrid Fiber Coax (HFC), Asymmetrical Digital Subscriber Line and Fiber to the Curb/Building technologies and finally to show the implementation of an end-to-end ATM infrastructure for various types of access networks. This paper describes the first of a series of the project's HFC trials which has been carried out in the city of Munich, Germany.

  17. Utility of thermal image sharpening for monitoring field-scale evapotranspiration over rainfed and irrigated agricultural regions

    NASA Astrophysics Data System (ADS)

    Agam, Nurit; Kustas, William P.; Anderson, Martha C.; Li, Fuqin; Colaizzi, Paul D.

    2008-01-01

    The utility of a thermal image sharpening algorithm (TsHARP) in providing fine resolution land surface temperature data to a Two-Source-Model for mapping evapotranspiration (ET) was examined over two agricultural regions in the U.S. One site is in a rainfed corn and soybean production region in central Iowa. The other lies within the Texas High Plains, an irrigated agricultural area. It is concluded that in the absence of fine (sub-field scale) resolution thermal data, TsHARP provides an important tool for monitoring ET over rainfed agricultural areas. In contrast, over irrigated regions, TsHARP applied to kilometer-resolution thermal imagery is unable to provide accurate fine resolution land surface temperature due to significant sub-pixel moisture variations that are not captured in the sharpening procedure. Consequently, reliable estimation of ET and crop stress requires thermal imagery acquired at high spatial resolution, resolving the dominant length-scales of moisture variability present within the landscape.

  18. Chemical and biological characterization of products of incomplete combustion from the simulated field burning of agricultural plastic

    SciTech Connect

    Ryan, J.V.; Perry, E.; Linak, W.P.; DeMarini, D.M.; Williams, R.W.

    1989-01-01

    Chemical and biological analyses were performed to characterize products of incomplete combustion emitted during the simulated open-field burning of agricultural plastic. A small utility shed equipped with an air delivery system was used to simulate pile burning and forced-air-curtain incineration of a nonhalogenated agricultural plastic that reportedly consisted of polyethylene and carbon black. Emissions were analyzed for combustion gases; volatile, semi-volatile, and particulate organics; and toxic and mutagenic properties. Emission samples, as well as samples of the used (possibly pesticide-contaminated) plastic, were analyzed for the presence of several pesticides to which the plastic may have been exposed. When mutagenicity was evaluated by exposing Salmonella bacteria (Ames assay) to whole vapor and vapor/particulate emissions, no toxic or mutagenic effects were observed. However, organic extracts of the particulate samples were moderately mutagenic. The study highlights the benefits of a combined chemical/biological approach to the characterization of complex, multi-component combustion emissions. These results may not reflect those of other types of plastic that may be used for agricultural purposes, especially those containing halogens.

  19. Field evaluation of willow under short rotation coppice for phytomanagement of metal-polluted agricultural soils.

    PubMed

    Van Slycken, Stijn; Witters, Nele; Meiresonne, Linda; Meers, Erik; Ruttens, Ann; Van Peteghem, Pierre; Weyens, Nele; Tack, Filip M G; Vangronsveld, Jaco

    2013-01-01

    Short rotation coppice (SRC) of willow and poplar might be a promising phytoremediation option since it uses fast growing, high biomass producing tree species with often a sufficient metal uptake. This study evaluates growth, metal uptake and extraction potentials of eight willow clones (Belders, Belgisch Rood, Christina, Inger, Jorr, Loden, Tora and Zwarte Driebast) on a metal-contaminated agricultural soil, with total cadmium (Cd) and zinc (Zn) concentrations of 6.5 +/- 0.8 and 377 +/- 69 mg kg(-1) soil, respectively. Although, during the first cycle, on average generally low productivity levels (3.7 ton DM (dry matter) ha(-1) y(-1)) were obtained on this sandy soil, certain clones exhibited quite acceptable productivity levels (e.g. Zwarte Driebast 12.5 ton DM ha(-1) y(-1)). Even at low biomass productivity levels, SRC of willow showed promising removal potentials of 72 g Cd and 2.0 kg Zn ha(-1) y(-1), which is much higher than e.g. energy maize or rapeseed grown on the same soil Cd and Zn removal can be increased by 40% if leaves are harvested as well. Nevertheless, nowadays the wood price remains the most critical factor in order to implement SRC as an acceptable, economically feasible alternative crop on metal-contaminated agricultural soils.

  20. Influence of a riparian wetland on nitrate and herbicides exported from an agricultural field.

    PubMed

    Angier, Jonathan T; McCarty, Gregory W; Rice, Clifford P; Bialek, Krystyna

    2002-07-17

    Agrochemicals are a major source of nonpoint pollution. Forested corridors along stream channels (riparian zones) are thought to be potential sites for removal of agricultural contaminants from ground and surface waters. First-order riparian wetlands are reputed to be especially effective at groundwater remediation. The study site is a fairly typical (for eastern Maryland) small, first-order stream in an agricultural watershed. Preferential flow supplies most of the stream water within the riparian headwater wetland. This upstream area also contains the highest average stream N and pesticide loads in the entire first-order riparian system. Zones of active groundwater emergence onto the surface display high concentrations of nitrate throughout the soil profile and in the exfiltrating water, whereas inactive areas (where there is no visible upwelling) show rapid attenuation of nitrate with decreasing depths. Atrazine degradation products appear to penetrate more readily through the most active upwelling zones, and there is a correlation between zones of high nitrate and high atrazine metabolite levels. Deethylatrazine/atrazine ratios (DAR) seem to indicate that stream flow is dominated by ground water and that much of the ground water may have reached the stream via preferential flow. Remediative processes appear to be very complex, heterogeneous, and variable in these systems, so additional research is needed before effective formulation and application of riparian zone initiatives and guidelines can be accomplished.

  1. Phosphorus Transport at the Field Scale by Monitoring Groundwater and Interflow Discharge in Hydrologically Sensitive Areas in Agricultural Fields

    NASA Astrophysics Data System (ADS)

    Flores-Lopez, F.; Geohring, L.; Steenhuis, T.

    2004-05-01

    Quantification of nonpoint source of phosphorus losses through agricultural land is important because hydrologically active areas can significantly affect water quality. In this study we examined phosphorus concentration and phosphorus losses from hydrologically sensitive areas and upland areas located in valley soils in the Cannosville basin in Catskill Mountains. Phosphorus concentrations as low as 0.01 - 0.02 mg/L in water increase the algael bloom in lakes and reservoirs and the Cannosville basin is currently restricted to 0.02mg/L. We measured grab surface water samples taken along the creeks to study the phosphorus concentration in the sub-superficial runoff that drains water from the surrounding hills. Also we installed two different transects of piezometers, one line upstream and one line downstream, to study the role of the groundwater component and its effect in the hydrologically sensitive areas. We generally found low phosphorus concentration in the grab surface water samples and the groundwater samples taken in the piezometers. Sampling during the highest creek flow has resulted in the highest concentrations, generally near 0.05 mg/L of dissolved reactive phosphorus. These concentrations were slightly higher than the concentrations in most of the wells, which were around 0.03 mg/L. Sampling is ongoing to determine the effects snow melt contributions. Results will be presented to show the seasonal effects of phosphorus in the hydrologically sensitive areas.

  2. Comparison of ARAC calculations with surface and airborne measurements for the ACE field trials

    SciTech Connect

    Foster, K.T.; Pobanz, B.

    1996-11-01

    These Atmospheric Collection Equipment (ACE) trials were sponsored by the Air Force Technical Applications Center (AFTAC) for the purpose of investigating specific tracer monitoring methods and equipment. Three different tracers (sulfur hexafluoride and two particulate tracers) were released simultaneously for each experiment. This document provides a brief summary of the sulfur hexafluoride modeling results for three of the remaining four ACE trials (the tracer plume from the fifth trial was not located by the monitoring teams and provided no tracer measurements for model comparison). This summary is followed by a discussion of model results for the two particulate tracers which were co-released with sulfur hexafluoride.

  3. Screening of willow species for resistance to heavy metals: comparison of performance in a hydroponics system and field trials.

    PubMed

    Watson, C; Pulford, I D; Riddell-Black, D

    2003-01-01

    The aim of this study was to ascertain whether metal resistance in willow (Salix) clones grown in a hydroponics screening test correlated with data from the same clones grown independently in a field trial. If so, results from a short-term, glasshouse-based system could be extrapolated to the field, allowing rapid identification of willows suitable for planting in metal-contaminated substrates without necessitating longterm field trials. Principal Components Analysis was used to show groups of clones and to assess the relative importance of the parameters measured in both the hydroponics system and the field; including plant response factors such as increase in stem height, as well as metal concentrations in plant tissues. The clones tested fell into two distinct groups. Salix viminalis clones and the basket willow Black Maul (S. triandra) were less resistant to elevated concentrations of heavy metals than a group of hardier clones, including S. burjatica 'Germany,' S.x dasyclados, S. candida and S. spaethii. The more resistant clones produced more biomass in the glasshouse and field, and had higher metal concentrations in the wood. The less resistant clones had greater concentrations of Cu and Ni in the bark, and produced less biomass in the glasshouse and field. Significant relationships were found between the response of the same clones grown the in short-term glasshouse hydroponics system and in the field.

  4. Biochar decelerates soil organic nitrogen cycling but stimulates soil nitrification in a temperate arable field trial.

    PubMed

    Prommer, Judith; Wanek, Wolfgang; Hofhansl, Florian; Trojan, Daniela; Offre, Pierre; Urich, Tim; Schleper, Christa; Sassmann, Stefan; Kitzler, Barbara; Soja, Gerhard; Hood-Nowotny, Rebecca Clare

    2014-01-01

    Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N) cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem) in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50-80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers) and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies. PMID:24497947

  5. Full Scale Field Trial of the Low Temperature Mercury Capture Process

    SciTech Connect

    Locke, James; Winschel, Richard

    2012-05-21

    CONSOL Energy Inc., with partial funding from the Department of Energy (DOE) National Energy Technology Laboratory, designed a full-scale installation for a field trial of the Low-Temperature Mercury Control (LTMC) process, which has the ability to reduce mercury emissions from coal-fired power plants by over 90 percent, by cooling flue gas temperatures to approximately 230°F and absorbing the mercury on the native carbon in the fly ash, as was recently demonstrated by CONSOL R&D on a slip-stream pilot plant at the Allegheny Energy Mitchell Station with partial support by DOE. LTMC has the potential to remove over 90 percent of the flue gas mercury at a cost at least an order of magnitude lower (on a $/lb mercury removed basis) than activated carbon injection. The technology is suitable for retrofitting to existing and new plants, and, although it is best suited to bituminous coal-fired plants, it may have some applicability to the full range of coal types. Installation plans were altered and moved from the original project host site, PPL Martins Creek plant, to a second host site at Allegheny Energy's R. Paul Smith plant, before installation actually occurred at the Jamestown (New York) Board of Public Utilities (BPU) Samuel A. Carlson (Carlson) Municipal Generating Station Unit 12, where the LTMC system was operated on a limited basis. At Carlson, over 60% mercury removal was demonstrated by cooling the flue gas to 220-230°F at the ESP inlet via humidification. The host unit ESP operation was unaffected by the humidification and performed satisfactorily at low temperature conditions.

  6. Field trial of a new aeration system for enhancing biodegradation in a biopile.

    PubMed

    Li, L; Cunningham, C J; Pas, Valerie; Philp, J C; Barry, D A; Anderson, P

    2004-01-01

    The influence of a new aeration system on the biopile performance was investigated. The purpose was to increase biodegradation efficiency by optimising airflow through the pile. During a 1-month field trial, the performance of a new system using two perforated vertical pipes with wind-driven turbines was compared with that of a standard pile configuration with two horizontal perforated pipes. Both piles were composed of a similar mix of diesel-contaminated soils, woodchips, compost and NPK fertiliser. Hydrocarbons were recovered using solvent extraction, and determined both gravimetrically and by gas chromatography. Total heterotrophs, pH and moisture content were also assessed. Air pressure measurements were made to compare the efficiency of suction in the pipes. Results at the end of the experiment showed that there was no significant difference between the two piles in the total amount of hydrocarbon biodegradation. The normalised degradation rate was, however, considerably higher in the new system than in the standard one, suggesting that the vertical venting method may have improved the efficiency of the biological reactions in the pile. The pressure measurements showed a significant improvement in the suction produced by the new aeration system. However, many factors other than the airflow (oxygen supply) may influence and limit the biodegradation rates, including moisture content, age of contaminants and the climatic conditions. Additional experiments and modelling need to be carried out to explore further the new aeration method and to develop criteria and guidelines for engineering design of optimal aeration schemes in order to achieve maximum biodegradation in biopiles. PMID:14761751

  7. Field trial of a new aeration system for enhancing biodegradation in a biopile.

    PubMed

    Li, L; Cunningham, C J; Pas, Valerie; Philp, J C; Barry, D A; Anderson, P

    2004-01-01

    The influence of a new aeration system on the biopile performance was investigated. The purpose was to increase biodegradation efficiency by optimising airflow through the pile. During a 1-month field trial, the performance of a new system using two perforated vertical pipes with wind-driven turbines was compared with that of a standard pile configuration with two horizontal perforated pipes. Both piles were composed of a similar mix of diesel-contaminated soils, woodchips, compost and NPK fertiliser. Hydrocarbons were recovered using solvent extraction, and determined both gravimetrically and by gas chromatography. Total heterotrophs, pH and moisture content were also assessed. Air pressure measurements were made to compare the efficiency of suction in the pipes. Results at the end of the experiment showed that there was no significant difference between the two piles in the total amount of hydrocarbon biodegradation. The normalised degradation rate was, however, considerably higher in the new system than in the standard one, suggesting that the vertical venting method may have improved the efficiency of the biological reactions in the pile. The pressure measurements showed a significant improvement in the suction produced by the new aeration system. However, many factors other than the airflow (oxygen supply) may influence and limit the biodegradation rates, including moisture content, age of contaminants and the climatic conditions. Additional experiments and modelling need to be carried out to explore further the new aeration method and to develop criteria and guidelines for engineering design of optimal aeration schemes in order to achieve maximum biodegradation in biopiles.

  8. Biochar Decelerates Soil Organic Nitrogen Cycling but Stimulates Soil Nitrification in a Temperate Arable Field Trial

    PubMed Central

    Prommer, Judith; Wanek, Wolfgang; Hofhansl, Florian; Trojan, Daniela; Offre, Pierre; Urich, Tim; Schleper, Christa; Sassmann, Stefan; Kitzler, Barbara; Soja, Gerhard; Hood-Nowotny, Rebecca Clare

    2014-01-01

    Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N) cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem) in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50–80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers) and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies. PMID:24497947

  9. Phytoextraction of Cd-contaminated soil by carambola (Averrhoa carambola) in field trials.

    PubMed

    Li, J T; Liao, B; Dai, Z Y; Zhu, R; Shu, W S

    2009-08-01

    Use of metal-accumulating woody species to extract metals from heavy metal contaminated soil has received more attention. While considerable studies have focused on the phytoextraction potential of willow (Salix spp.) and poplar (Populus spp.), similar information is rare for other woody species. Carambola (Averrhoa carambola) is a high-biomass tree and has been identified as a new Cd-accumulating species. The present study aimed to evaluate the Cd phytoextraction potential of carambola under field condition. After growing in a slightly Cd-contaminated site for about 170 d, the carambola stand initiated by seed-seedling with high planting density (encoded with "HD-1yr") attained a high shoot biomass yield of 18.6 t ha(-1) and extracted 213 g Cdha(-1), resulting in a 1.6-fold higher Cd removal efficiency than that of a contrasting stand established by grafted-seedling with low planting density (5.3% vs. 2%). That is, "HD-1yr" would remove 50% of the total soil Cd with 13yr, assuming that the Cd removal efficiency would not change over time. Further, one crop of "HD-1yr" significantly decreased (63-69%) the Cd uptake by subsequent vegetables. Among the four carambola stands established using grafted-seedling, the 2-yr-old stand exhibited the highest annual Cd removal efficiency (3.7%), which was yet lower than that of "HD-1yr". These results suggested that phytoextraction of Cd by carambola (especially for "HD-1yr" stand) presented a feasible option to clean up agricultural soils slightly contaminated by Cd.

  10. Towards the Development of a Smart Flying Sensor: Illustration in the Field of Precision Agriculture.

    PubMed

    Hernandez, Andres; Murcia, Harold; Copot, Cosmin; De Keyser, Robin

    2015-01-01

    Sensing is an important element to quantify productivity, product quality and to make decisions. Applications, such as mapping, surveillance, exploration and precision agriculture, require a reliable platform for remote sensing. This paper presents the first steps towards the development of a smart flying sensor based on an unmanned aerial vehicle (UAV). The concept of smart remote sensing is illustrated and its performance tested for the task of mapping the volume of grain inside a trailer during forage harvesting. Novelty lies in: (1) the development of a position-estimation method with time delay compensation based on inertial measurement unit (IMU) sensors and image processing; (2) a method to build a 3D map using information obtained from a regular camera; and (3) the design and implementation of a path-following control algorithm using model predictive control (MPC). Experimental results on a lab-scale system validate the effectiveness of the proposed methodology. PMID:26184205

  11. Towards the Development of a Smart Flying Sensor: Illustration in the Field of Precision Agriculture

    PubMed Central

    Hernandez, Andres; Murcia, Harold; Copot, Cosmin; De Keyser, Robin

    2015-01-01

    Sensing is an important element to quantify productivity, product quality and to make decisions. Applications, such as mapping, surveillance, exploration and precision agriculture, require a reliable platform for remote sensing. This paper presents the first steps towards the development of a smart flying sensor based on an unmanned aerial vehicle (UAV). The concept of smart remote sensing is illustrated and its performance tested for the task of mapping the volume of grain inside a trailer during forage harvesting. Novelty lies in: (1) the development of a position-estimation method with time delay compensation based on inertial measurement unit (IMU) sensors and image processing; (2) a method to build a 3D map using information obtained from a regular camera; and (3) the design and implementation of a path-following control algorithm using model predictive control (MPC). Experimental results on a lab-scale system validate the effectiveness of the proposed methodology. PMID:26184205

  12. A persistent scatterer interpolation for retrieving accurate ground deformation over InSAR-decorrelated agricultural fields

    NASA Astrophysics Data System (ADS)

    Chen, Jingyi; Zebker, Howard A.; Knight, Rosemary

    2015-11-01

    Interferometric synthetic aperture radar (InSAR) is a radar remote sensing technique for measuring surface deformation to millimeter-level accuracy at meter-scale resolution. Obtaining accurate deformation measurements in agricultural regions is difficult because the signal is often decorrelated due to vegetation growth. We present here a new algorithm for retrieving InSAR deformation measurements over areas with severe vegetation decorrelation using adaptive phase interpolation between persistent scatterer (PS) pixels, those points at which surface scattering properties do not change much over time and thus decorrelation artifacts are minimal. We apply this algorithm to L-band ALOS interferograms acquired over the San Luis Valley, Colorado, and the Tulare Basin, California. In both areas, the pumping of groundwater for irrigation results in deformation of the land that can be detected using InSAR. We show that the PS-based algorithm can significantly reduce the artifacts due to vegetation decorrelation while preserving the deformation signature.

  13. Towards the Development of a Smart Flying Sensor: Illustration in the Field of Precision Agriculture.

    PubMed

    Hernandez, Andres; Murcia, Harold; Copot, Cosmin; De Keyser, Robin

    2015-07-10

    Sensing is an important element to quantify productivity, product quality and to make decisions. Applications, such as mapping, surveillance, exploration and precision agriculture, require a reliable platform for remote sensing. This paper presents the first steps towards the development of a smart flying sensor based on an unmanned aerial vehicle (UAV). The concept of smart remote sensing is illustrated and its performance tested for the task of mapping the volume of grain inside a trailer during forage harvesting. Novelty lies in: (1) the development of a position-estimation method with time delay compensation based on inertial measurement unit (IMU) sensors and image processing; (2) a method to build a 3D map using information obtained from a regular camera; and (3) the design and implementation of a path-following control algorithm using model predictive control (MPC). Experimental results on a lab-scale system validate the effectiveness of the proposed methodology.

  14. Natural establishment of woody species on abandoned agricultural fields in the lower Mississippi Valley: first- and second-year results

    USGS Publications Warehouse

    Allen, J.A.; McCoy, J.W.; Keeland, B.D.

    1998-01-01

    The natural establishment of woody seedlings on abandoned agricultural fields was investigated at sites in Louisiana and Mississippi. Series of disked and undisked plots originating at forest edges and oriented in cardinal directions were established on fields at each site. During the firest 2 years, seedling recruitment was dominated by sweetgum, sugarberry, and elms at both sites. Seedling establishment was strongly affected by direction from mature forest and disking, and to a slightly lesser degree by distance from mature forest. Slightly under half of the variation in seedling numbers per plot was explained by the effects of direction, distance, and disking, indicating that other factors also may play an important role in seedling recruitment.

  15. Metabolite Profiles of Maize Leaves in Drought, Heat, and Combined Stress Field Trials Reveal the Relationship between Metabolism and Grain Yield.

    PubMed

    Obata, Toshihiro; Witt, Sandra; Lisec, Jan; Palacios-Rojas, Natalia; Florez-Sarasa, Igor; Yousfi, Salima; Araus, Jose Luis; Cairns, Jill E; Fernie, Alisdair R

    2015-12-01

    The development of abiotic stress-resistant cultivars is of premium importance for the agriculture of developing countries. Further progress in maize (Zea mays) performance under stresses is expected by combining marker-assisted breeding with metabolite markers. In order to dissect metabolic responses and to identify promising metabolite marker candidates, metabolite profiles of maize leaves were analyzed and compared with grain yield in field trials. Plants were grown under well-watered conditions (control) or exposed to drought, heat, and both stresses simultaneously. Trials were conducted in 2010 and 2011 using 10 tropical hybrids selected to exhibit diverse abiotic stress tolerance. Drought stress evoked the accumulation of many amino acids, including isoleucine, valine, threonine, and 4-aminobutanoate, which has been commonly reported in both field and greenhouse experiments in many plant species. Two photorespiratory amino acids, glycine and serine, and myoinositol also accumulated under drought. The combination of drought and heat evoked relatively few specific responses, and most of the metabolic changes were predictable from the sum of the responses to individual stresses. Statistical analysis revealed significant correlation between levels of glycine and myoinositol and grain yield under drought. Levels of myoinositol in control conditions were also related to grain yield under drought. Furthermore, multiple linear regression models very well explained the variation of grain yield via the combination of several metabolites. These results indicate the importance of photorespiration and raffinose family oligosaccharide metabolism in grain yield under drought and suggest single or multiple metabolites as potential metabolic markers for the breeding of abiotic stress-tolerant maize.

  16. Metabolite Profiles of Maize Leaves in Drought, Heat, and Combined Stress Field Trials Reveal the Relationship between Metabolism and Grain Yield.

    PubMed

    Obata, Toshihiro; Witt, Sandra; Lisec, Jan; Palacios-Rojas, Natalia; Florez-Sarasa, Igor; Yousfi, Salima; Araus, Jose Luis; Cairns, Jill E; Fernie, Alisdair R

    2015-12-01

    The development of abiotic stress-resistant cultivars is of premium importance for the agriculture of developing countries. Further progress in maize (Zea mays) performance under stresses is expected by combining marker-assisted breeding with metabolite markers. In order to dissect metabolic responses and to identify promising metabolite marker candidates, metabolite profiles of maize leaves were analyzed and compared with grain yield in field trials. Plants were grown under well-watered conditions (control) or exposed to drought, heat, and both stresses simultaneously. Trials were conducted in 2010 and 2011 using 10 tropical hybrids selected to exhibit diverse abiotic stress tolerance. Drought stress evoked the accumulation of many amino acids, including isoleucine, valine, threonine, and 4-aminobutanoate, which has been commonly reported in both field and greenhouse experiments in many plant species. Two photorespiratory amino acids, glycine and serine, and myoinositol also accumulated under drought. The combination of drought and heat evoked relatively few specific responses, and most of the metabolic changes were predictable from the sum of the responses to individual stresses. Statistical analysis revealed significant correlation between levels of glycine and myoinositol and grain yield under drought. Levels of myoinositol in control conditions were also related to grain yield under drought. Furthermore, multiple linear regression models very well explained the variation of grain yield via the combination of several metabolites. These results indicate the importance of photorespiration and raffinose family oligosaccharide metabolism in grain yield under drought and suggest single or multiple metabolites as potential metabolic markers for the breeding of abiotic stress-tolerant maize. PMID:26424159

  17. Metabolite Profiles of Maize Leaves in Drought, Heat, and Combined Stress Field Trials Reveal the Relationship between Metabolism and Grain Yield1[OPEN

    PubMed Central

    Witt, Sandra; Lisec, Jan; Palacios-Rojas, Natalia; Yousfi, Salima; Araus, Jose Luis; Fernie, Alisdair R.

    2015-01-01

    The development of abiotic stress-resistant cultivars is of premium importance for the agriculture of developing countries. Further progress in maize (Zea mays) performance under stresses is expected by combining marker-assisted breeding with metabolite markers. In order to dissect metabolic responses and to identify promising metabolite marker candidates, metabolite profiles of maize leaves were analyzed and compared with grain yield in field trials. Plants were grown under well-watered conditions (control) or exposed to drought, heat, and both stresses simultaneously. Trials were conducted in 2010 and 2011 using 10 tropical hybrids selected to exhibit diverse abiotic stress tolerance. Drought stress evoked the accumulation of many amino acids, including isoleucine, valine, threonine, and 4-aminobutanoate, which has been commonly reported in both field and greenhouse experiments in many plant species. Two photorespiratory amino acids, glycine and serine, and myoinositol also accumulated under drought. The combination of drought and heat evoked relatively few specific responses, and most of the metabolic changes were predictable from the sum of the responses to individual stresses. Statistical analysis revealed significant correlation between levels of glycine and myoinositol and grain yield under drought. Levels of myoinositol in control conditions were also related to grain yield under drought. Furthermore, multiple linear regression models very well explained the variation of grain yield via the combination of several metabolites. These results indicate the importance of photorespiration and raffinose family oligosaccharide metabolism in grain yield under drought and suggest single or multiple metabolites as potential metabolic markers for the breeding of abiotic stress-tolerant maize. PMID:26424159

  18. Investigating summer flow paths in a Dutch agricultural field using high frequency direct measurements

    NASA Astrophysics Data System (ADS)

    Delsman, J. R.; Waterloo, M. J.; Groen, M. M. A.; Groen, J.; Stuyfzand, P. J.

    2014-11-01

    The search for management strategies to cope with projected water scarcity and water quality deterioration calls for a better understanding of the complex interaction between groundwater and surface water in agricultural catchments. We separately measured flow routes to tile drains and an agricultural ditch in a deep polder in the coastal region of the Netherlands, characterized by exfiltration of brackish regional groundwater flow and intake of diverted river water for irrigation and water quality improvement purposes. We simultaneously measured discharge, electrical conductivity and temperature of these separate flow routes at hourly frequencies, disclosing the complex and time-varying patterns and origins of tile drain and ditch exfiltration. Tile drainage could be characterized as a shallow flow system, showing a non-linear response to groundwater level changes. Tile drainage was fed primarily by meteoric water, but still transported the majority (80%) of groundwater-derived salt to surface water. In contrast, deep brackish groundwater exfiltrating directly in the ditch responded linearly to groundwater level variations and is part of a regional groundwater flow system. We could explain the observed salinity of exfiltrating drain and ditch water from the interaction between the fast-responding pressure distribution in the subsurface that determined groundwater flow paths (wave celerity), and the slow-responding groundwater salinity distribution (water velocity). We found water demand for maintaining water levels and diluting salinity through flushing to greatly exceed the actual sprinkling demand. Counterintuitively, flushing demand was found to be largest during precipitation events, suggesting the possibility of water savings by operational flushing control.

  19. Assessment of soil redistribution rates by (137)Cs and (210)Pbex in a typical Malagasy agricultural field.

    PubMed

    Rabesiranana, N; Rasolonirina, M; Solonjara, A F; Ravoson, H N; Raoelina Andriambololona; Mabit, L

    2016-02-01

    Soil degradation processes affect more than one-third of the Malagasy territory and are considered as the major environmental threat impacting the natural resources of the island. This innovative study reports about a pioneer test and use of radio-isotopic techniques (i.e. Cs-137 and Pb-210ex) under Madagascar agroclimatic condition to evaluate soil erosion magnitude. This preliminary investigation has been conducted in a small agricultural field situated in the eastern central highland of Madagascar, 40 km East from Antananarivo. Both anthropogenic Cs-137 and geogenic Pb-210 soil tracers provided similar results highlighting soil erosion rates reaching locally 18 t ha(-1) yr(-1,) a level almost two times higher than the sustainable soil loss rate under Madagascar agroclimatic condition. The sediment delivery ratio established with both radiotracers was above 80% indicating that most of the mobilized sediment exits the field. Assessing soil erosion rate through fallout radionuclides in Madagascar is a first step towards an efficient land and water resource management policy to optimise the effectiveness of future agricultural soil conservation practices. PMID:26691498

  20. Assessment of soil redistribution rates by (137)Cs and (210)Pbex in a typical Malagasy agricultural field.

    PubMed

    Rabesiranana, N; Rasolonirina, M; Solonjara, A F; Ravoson, H N; Raoelina Andriambololona; Mabit, L

    2016-02-01

    Soil degradation processes affect more than one-third of the Malagasy territory and are considered as the major environmental threat impacting the natural resources of the island. This innovative study reports about a pioneer test and use of radio-isotopic techniques (i.e. Cs-137 and Pb-210ex) under Madagascar agroclimatic condition to evaluate soil erosion magnitude. This preliminary investigation has been conducted in a small agricultural field situated in the eastern central highland of Madagascar, 40 km East from Antananarivo. Both anthropogenic Cs-137 and geogenic Pb-210 soil tracers provided similar results highlighting soil erosion rates reaching locally 18 t ha(-1) yr(-1,) a level almost two times higher than the sustainable soil loss rate under Madagascar agroclimatic condition. The sediment delivery ratio established with both radiotracers was above 80% indicating that most of the mobilized sediment exits the field. Assessing soil erosion rate through fallout radionuclides in Madagascar is a first step towards an efficient land and water resource management policy to optimise the effectiveness of future agricultural soil conservation practices.

  1. Spectral properties of agricultural crops and soils measured from space, aerial, field, and laboratory sensors

    NASA Technical Reports Server (NTRS)

    Bauer, M. E. (Principal Investigator); Vanderbilt, V. C.; Robinson, B. F.; Daughtry, C. S. T.

    1981-01-01

    Investigations of the multispectral reflectance characteristics of crops and soils as measured from laboratory, field, aerial, and satellite sensor systems are reviewed. The relationships of important biological and physical characteristics to the spectral properties of crops and soils are addressed.

  2. Waterfowl density on agricultural fields managed to retain water in winter

    USGS Publications Warehouse

    Twedt, D.J.; Nelms, C.O.

    1999-01-01

    Managed water on private and public land provides habitat for wintering waterfowl in the Mississippi Valley, where flood control projects have reduced the area of natural flooding. We compared waterfowl densities on rice, soybean, and moist-soil fields under cooperative agreements to retain water from 1 November through 28 February in Arkansas and Mississippi and assessed temporal changes in waterfowl density during winter in 1991-1992 and 1992-1993. Fields flooded earlier in Arkansas, but retained water later in Mississippi. Over winter, waterfowl densities decreased in Arkansas and increased in Mississippi. Densities of waterfowl, including mallard (Anas platyrhynchos), the most abundant species observed, were greatest on moist-soil fields. However, soybean fields had the greatest densities of northern shoveler (Spatula clypeata).

  3. GeoLab in NASA's Pressurized Excursion Module: First Results from the 2010 Field Trials

    NASA Technical Reports Server (NTRS)

    Evans, Cynthia A.; Calaway, Michael; Bell, Mary Sue; Graff, Trevor

    2010-01-01

    Before humans explore other planets, NASA must develop advanced techniques for collection, preservation and return of unique extraterrestrial samples. To help evaluate hardware requirements and operational concepts for future sample-return missions, we designed and built GeoLab our first generation lab for geological samples into NASA s Habitat Demonstration Unit in the Pressurized Excursion Module (HDU1-PEM). The center of GeoLab is a glovebox for the examination of samples in a shirt-sleeve environment. As part of a deployable habitat, GeoLab can participate in NASA s analog missions that simulate planetary exploration activities and support the testing of relevant technologies for collecting and handling geological samples. Over time, these tests will evaluate sample handling environments (field and lab), sampling tools and analytical instruments, and different scenarios involving both robotic and human procedures. The GeoLab design supports evolving tests and configurations. The glovebox is mounted on the habitat bulkhead, with three sample pass-though chambers that allow for direct sample transfer into the glovebox from the outside. The glovebox design and construction (low-particle shedding, minimally off-gassing materials) provides a clean environment to reduce sample contamination; in the future, we will integrate a positive pressure, enriched nitrogen atmosphere. The glovebox is equipped with configurable instrument ports. The 2010 test included a mass balance, a stereomicroscope with a HD camera for detailed imaging of samples, and a handheld XRF analyzer for preliminary geochemical characterization of samples. Network cameras provided context imagery and sample handling activities. We present early results from the initial field trial of GeoLab during the 2010 Desert Research and Technology Studies (D-RATS) planetary analog test near Flagstaff AZ. The 2010 D-RATS mission involved two rovers, the habitat with GeoLab, four crew members, and a team of

  4. Predation by carabid beetles on the invasive slug Arion vulgaris in an agricultural semi-field experiment.

    PubMed

    Pianezzola, E; Roth, S; Hatteland, B A

    2013-04-01

    Arion vulgaris Moquin-Tandon 1855 is one of the most important invasive species in Europe, affecting both biodiversity and agriculture. The species is spreading in many parts of Europe, inflicting severe damage to horticultural plants and cultivated crops partly due to a lack of satisfactory and effective management solutions. Molluscicides have traditionally been used to manage slug densities, although the effects are variable and some have severe side-effects on other biota. Thus, there is a need to explore potential alternatives such as biological control. The nematode Phasmarhabditis hermaphrodita is the only biological agent that has been applied commercially so far. However, other biological control agents such as carabid beetles have also been found to be promising. In addition, some carabid species have been shown to feed on A. vulgaris in the field as well as in the laboratory. Two species in particular have been found to be important predators of A. vulgaris, and these species are also common in agricultural environments: Pterostichus melanarius and Carabus nemoralis. This study is the first to use semi-field experiments in a strawberry field, manipulating densities, to investigate how P. melanarius and C. nemoralis affect densities of A. vulgaris eggs and juveniles, respectively. Gut contents of C. nemoralis were analysed using multiplex PCR methods to detect DNA of juvenile slugs. Results show that both P. melanarius and C. nemoralis significantly affect densities of slug eggs and juvenile slugs under semi-field conditions and that C. nemoralis seems to prefer slugs smaller than one gram. Carabus nemoralis seems to be especially promising in reducing densities of A. vulgaris, and future studies should investigate the potential of using this species as a biological control agent.

  5. Enhancement of the Initial Growth Rate of Agricultural Plants by Using Static Magnetic Fields.

    PubMed

    Kim, Seung C; Mason, Alex; Im, Wooseok

    2016-01-01

    Electronic devices and high-voltage wires induce magnetic fields. A magnetic field of 1,300-2,500 Gauss (0.2 Tesla) was applied to Petri dishes containing seeds of Garden Balsam (Impatiens balsamina), Mizuna (Brassica rapa var. japonica), Komatsuna (Brassica rapa var. perviridis), and Mescluns (Lepidium sativum). We applied magnets under the culture dish. During the 4 days of application, we observed that the stem and root length increased. The group subjected to magnetic field treatment (n = 10) showed a 1.4 times faster rate of growth compared with the control group (n = 11) in a total of 8 days (p <0.0005). This rate is 20% higher than that reported in previous studies. The tubulin complex lines did not have connecting points, but connecting points occur upon the application of magnets. This shows complete difference from the control, which means abnormal arrangements. However, the exact cause remains unclear. These results of growth enhancement of applying magnets suggest that it is possible to enhance the growth rate, increase productivity, or control the speed of germination of plants by applying static magnetic fields. Also, magnetic fields can cause physiological changes in plant cells and can induce growth. Therefore, stimulation with a magnetic field can have possible effects that are similar to those of chemical fertilizers, which means that the use of fertilizers can be avoided.

  6. Enhancement of the Initial Growth Rate of Agricultural Plants by Using Static Magnetic Fields.

    PubMed

    Kim, Seung C; Mason, Alex; Im, Wooseok

    2016-01-01

    Electronic devices and high-voltage wires induce magnetic fields. A magnetic field of 1,300-2,500 Gauss (0.2 Tesla) was applied to Petri dishes containing seeds of Garden Balsam (Impatiens balsamina), Mizuna (Brassica rapa var. japonica), Komatsuna (Brassica rapa var. perviridis), and Mescluns (Lepidium sativum). We applied magnets under the culture dish. During the 4 days of application, we observed that the stem and root length increased. The group subjected to magnetic field treatment (n = 10) showed a 1.4 times faster rate of growth compared with the control group (n = 11) in a total of 8 days (p <0.0005). This rate is 20% higher than that reported in previous studies. The tubulin complex lines did not have connecting points, but connecting points occur upon the application of magnets. This shows complete difference from the control, which means abnormal arrangements. However, the exact cause remains unclear. These results of growth enhancement of applying magnets suggest that it is possible to enhance the growth rate, increase productivity, or control the speed of germination of plants by applying static magnetic fields. Also, magnetic fields can cause physiological changes in plant cells and can induce growth. Therefore, stimulation with a magnetic field can have possible effects that are similar to those of chemical fertilizers, which means that the use of fertilizers can be avoided. PMID:27500712

  7. Hydrological and erosion processes in terraced agricultural fields: observations from a wet Mediterranean region in northern Portugal

    NASA Astrophysics Data System (ADS)

    Nunes, João Pedro; Bernard-Jannin, Léonard; Rodriguez-Blanco, María Luz; Marisa Santos, Juliana; Oliveira Alves Coelho, Celeste; Keizer, Jan Jacob

    2015-04-01

    Traditional agriculture in the mountainous humid regions of the northwestern Iberian peninsula has relied on terraces for soil retention. In the last decades, a strong afforestation (in many cases with commercial species) has led to the appearance of large forest areas coexisting with traditional agricultural landscapes. Soil erosion research in this region has therefore focused on the impact of forest management practices and associated disturbances such as wildfires. However, there has been little research on the impacts of traditional terracing practices on erosion, and therefore it has been difficult to connect forest research with the wider issue of sediment connectivity in this complex agroforestry landscape. This work tried to address this research gap by monitoring an agricultural terrace in the Caramulo mountains, northern Portugal, during two years. The field site is located in a humid Mediterranean climate region, with c. 1500 mm/y rainfall, overlaying granite bedrock; agricultural practices are a traditional rotation between winter pasture and summer (irrigated) corn cultivation. During this period, the soil properties of the terrace were characterized, and there was a continuous monitoring of rainfall, soil moisture and surface runoff at the outlet, as well as 1 or 2-weekly collections of runoff to measure sediment yield. Occasional measurements of vegetation cover and erosion features (rills) within the plot were also made. Preliminary results indicate that runoff generation occurred mostly due to saturation-excess, possibly linked with the accumulation of groundwater in the lower layers of the soil. After one of the largest events, there was a clear inflow of runoff from outside the terrace, through either the irrigation network linking all terraces or by resurfacing of groundwater. Sediment yield was linked with runoff, but sediment concentration was linked with vegetation cover and was highest during the early stages of pasture growth. However

  8. Long-term monitoring of nitrate-N transport to drainage from three agricultural clayey till fields

    NASA Astrophysics Data System (ADS)

    Ernstsen, V.; Olsen, P.; Rosenbom, A. E.

    2015-01-01

    The application of nitrogen (N) fertilisers to crops grown on tile-drained fields is necessary to sustain most modern crop production, but poses a risk to the aquatic environment since tile drains facilitate rapid transport pathways with no significant reduction in nitrate. To maintain the water quality of the aquatic environment and the provision of food from highly efficient agriculture in line with the EU's Water Framework Directive and Nitrates Directive, field-scale knowledge is imperative if there is to be differentiated N-regulation in future. This study describes nitrate-N leaching to drainage based on coherent monitoring of nitrate-N concentrations, the climate, the groundwater table and crop-specific parameters obtained over eleven years (2001-2011) at three subsurface-drained clayey till fields (1.3-2.3 ha). The monitoring results showed significant field differences in nitrate-N transport to drainage. Not only were these caused by periods of bare soil after short-season crops and N-fixing crops (pea), which have been shown to generate high nitrate-N concentrations in drainage, but by the hydrogeological field conditions that were shown to be the controlling factor of nitrate-N transport to drainage. The fields had the following characteristics: (A) the lowest mass transport (13 kg N ha-1) and fertiliser input had short-term and low-intensity drainage with the highest nitrate-N concentrations detected, representing 40% of net precipitation (226 mm) combined with low air temperatures, (B) the medium mass transport (14 kg N ha-1) had medium-term and medium-intensity drainage, representing 42% of net precipitation (471 mm) combined with periods of both low and higher air temperatures, (C) the highest mass transport (19 kg N ha-1) had long-term drainage, representing 68% of net precipitation (617 mm), but had the highest potential for in-situ soil denitrification and post-treatment (e.g. constructed wetlands) due to long periods with both high water

  9. Intensive field measurements of nitrous oxide emissions from a tropical agricultural soil

    NASA Astrophysics Data System (ADS)

    Crill, P. M.; Keller, M.; Weitz, A.; Grauel, B.; Veldkamp, E.

    2000-03-01

    The amount of nitrous oxide (N2O) continues to increase in the atmosphere. Agricultural use of nitrogen fertilizers in the tropics is thought to be an important source of atmospheric N2O. High frequency, highly precise measurements of the N2O flux were made with an automated system deployed in N fertilized and unfertilized agricultural plots of papaya and corn in Costa Rica for an entire corn crop growth to harvest cycle. N2O fluxes were as high as 64 ng N-N2O cm-2 h-1 from fertilized versus 12 ng N-N2O cm-2 h-1 from unfertilized corn and 28 ng N-N2O cm-2 h-1 from fertilized versus 4.6 ng N-N2O cm-2 h-1 from unfertilized papaya. Fertilized corn released more N2O than fertilized papaya over the 125 days of the crop cycle, 1.83 kg N ha-1 versus 1.37 kg N ha-1. This represents a loss as N2O of 1.1 and 0.9% of the total N applied as ammonium nitrate to the corn and papaya, respectively. As has often been observed, N2O fluxes were highly variable. The fastest rates of emission were associated with fertilization and high soil moisture. A diurnal cycle in the fluxes was not evident probably due to the minimal day/night temperature fluctuations. Each chamber was measured between 509 and 523 times over the course of the experiment. This allows us to evaluate the effect on constructed mean fluxes of lowered sampling frequencies. Sampling each collar about once a day throughout the crop cycle (25% of the data set) could result in a calculated mean flux from any individual chamber that can vary by as much as 20% even though the calculated mean would probably be within 10% of the mean of the complete data set. The uncertainty increases very rapidly at lower sampling frequencies. For example, if only 10% of the data set were used which would be the equivalent of sampling every other day, a very high sampling frequency in terms of manual measurements, the calculated mean flux could vary by as much as 40% or more at any given site.

  10. Infrared-temperature variability in a large agricultural field. [Dunnigan, California

    NASA Technical Reports Server (NTRS)

    Millard, J. P.; Goettelman, R. C.; Leroy, M. L. (Principal Investigator)

    1980-01-01

    The combined effect of water carved gullies, varying soil color, moisture state of the soil and crop, nonuniform phenology, and bare spots was measured for commercially grown barley planted on varying terrain. For all but the most rugged terrain, over 80% of the area within 4, 16, 65, and 259 ha cells was at temperatures within 3 C of the mean cell temperature. The result of using relatively small, 4 ha instantaneous field of views for remote sensing applications is that either the worst or the best of conditions is often observed. There appears to be no great advantage in utilizing a small instantaneous field of view instead of a large one for remote sensing of crop canopy temperatures. The two alternatives for design purposes are then either a very high spatial resolution, of the order of a meter or so, where the field is very accurately temperature mapped, or a low resolution, where the actual size seems to make little difference.

  11. Polarization signatures for abandoned agricultural fields in the Manix Basin area of the Mojave Desert

    NASA Technical Reports Server (NTRS)

    Ray, Terrill W.; Farr, Tom G.; Vanzyl, Jakob J.

    1991-01-01

    Polarimetric signatures from abandoned circular alfalfa fields in the Manix Basin area of the Mojave desert show systematic changes with length of abandonment. The obliteration of circular planting rows by surface processes could account for the disappearance of bright 'spokes', which seems to be reflection patterns from remnants of the planting rows, with increasing length of abandonment. An observed shift in the location of the maximum L-band copolarization return away from VV, as well as an increase in surface roughness, both occurring with increasing age of abandonment, seems to be attributable to the formation of wind ripple on the relatively vegetationless fields. A Late Pleistocene/Holocene sand bar deposit, which can be identified in the radar images, is probably responsible for the failure of three fields to match the age sequence patterns in roughness and peak shift.

  12. Operation of agricultural test fields for study of stressed crops by remote sensing

    NASA Technical Reports Server (NTRS)

    Toler, R. W.

    1974-01-01

    A test site for the study of winter wheat development and collection of ERTS data was established in September of 1973. The test site is a 10 mile square area located 12.5 miles west of Amarillo, Texas on Interstate Hwy. 40, in Randall and Potter counties. The center of the area is the Southwestern Great Plains Research Center at Bushland, Texas. Within the test area all wheat fields were identified by ground truth and designated irrigated or dryland. The fields in the test area other than wheat were identified as to pasture or the crop that was grown. A ground truth area of hard red winter wheat was established west of Hale Center, Texas. Maps showing the location of winter wheat fields in excess of 40 acres in size within a 10 mile radius were supplied NASA. Satellite data was collected for this test site (ERTS-1).

  13. Field tracer investigation of unsaturated zone flow paths and mechanisms in agricultural soils of northwestern Mississippi, USA

    NASA Astrophysics Data System (ADS)

    Perkins, Kim S.; Nimmo, John R.; Rose, Claire E.; Coupe, Richard H.

    2011-01-01

    SummaryIn many farmed areas, intensive application of agricultural chemicals and withdrawal of groundwater for irrigation have led to water quality and supply issues. Unsaturated-zone processes, including preferential flow, play a major role in these effects but are not well understood. In the Bogue Phalia basin, an intensely agricultural area in the Delta region of northwestern Mississippi, the fine-textured soils often exhibit surface ponding and runoff after irrigation and rainfall as well as extensive surface cracking during prolonged dry periods. Fields are typically land-formed to promote surface flow into drainage ditches and streams that feed into larger river ecosystems. Downward flow of water below the root zone is considered minimal; regional groundwater models predict only 5% or less of precipitation recharges the heavily used alluvial aquifer. In this study transport mechanisms within and below the root zone of a fallow soybean field were assessed by performing a 2-m ring infiltration test with tracers and subsurface monitoring instruments. Seven months after tracer application, 48 continuous cores were collected for tracer extraction to define the extent of water movement and quantify preferential flow using a mass-balance approach. Vertical water movement was rapid below the pond indicating the importance of vertical preferential flow paths in the shallow unsaturated zone, especially to depths where agricultural disturbance occurs. Lateral flow of water at shallow depths was extensive and spatially non-uniform, reaching up to 10 m from the pond within 2 months. Within 1 month, the wetting front reached a textural boundary at 4-5 m between the fine-textured soil and sandy alluvium, now a potential capillary barrier which, prior to extensive irrigation withdrawals, was below the water table. Within 10 weeks, tracer was detectable at the water table which is presently about 12 m below land surface. Results indicate that 43% of percolation may be through

  14. Field tracer investigation of unsaturated zone flow paths and mechanisms in agricultural soils of northwestern Mississippi, USA

    USGS Publications Warehouse

    Perkins, K.S.; Nimmo, J.R.; Rose, C.E.; Coupe, R.H.

    2011-01-01

    In many farmed areas, intensive application of agricultural chemicals and withdrawal of groundwater for irrigation have led to water quality and supply issues. Unsaturated-zone processes, including preferential flow, play a major role in these effects but are not well understood. In the Bogue Phalia basin, an intensely agricultural area in the Delta region of northwestern Mississippi, the fine-textured soils often exhibit surface ponding and runoff after irrigation and rainfall as well as extensive surface cracking during prolonged dry periods. Fields are typically land-formed to promote surface flow into drainage ditches and streams that feed into larger river ecosystems. Downward flow of water below the root zone is considered minimal; regional groundwater models predict only 5% or less of precipitation recharges the heavily used alluvial aquifer. In this study transport mechanisms within and below the root zone of a fallow soybean field were assessed by performing a 2-m ring infiltration test with tracers and subsurface monitoring instruments. Seven months after tracer application, 48 continuous cores were collected for tracer extraction to define the extent of water movement and quantify preferential flow using a mass-balance approach. Vertical water movement was rapid below the pond indicating the importance of vertical preferential flow paths in the shallow unsaturated zone, especially to depths where agricultural disturbance occurs. Lateral flow of water at shallow depths was extensive and spatially non-uniform, reaching up to 10. m from the pond within 2. months. Within 1. month, the wetting front reached a textural boundary at 4-5. m between the fine-textured soil and sandy alluvium, now a potential capillary barrier which, prior to extensive irrigation withdrawals, was below the water table. Within 10. weeks, tracer was detectable at the water table which is presently about 12. m below land surface. Results indicate that 43% of percolation may be through

  15. Standardization of doctoral study in agricultural and extension education: is the field of study mature enough for achievement of the optimum degree of order?

    PubMed

    Briers, G E; Lindner, J R; Shinn, G C; Wingenbach, G W; Baker, M T

    2010-01-01

    Agricultural and extension education--or some derivative name--is a field of study leading to the doctoral degree in universities around the world. Is there are body of knowledge or a taxonomy of the knowledge--e.g., a knowledge domain--that one should possess with a doctorate in agricultural and extension education? The purpose of this paper was to synthesize the work of researchers who attempted to define the field of study, with a taxonomy comprising the knowledge domains (standards) and knowledge objects--structured interrelated sets of data, knowledge, and wisdom--of the field of study. Doctoral study in agricultural and extension education needs a document that provides for rules and guidelines--rules and guidelines that in turn provide for common and repeated use--all leading to achievement of an optimum degree of order in the context of academic, scholarly, and professional practice in agricultural and extension education. Thus, one would know in broad categories the knowledge, skills, and abilities possessed by one who holds a doctoral degree in agricultural and extension education. That is, there would exist a standard for doctoral degrees in agricultural and extension education. A content analysis of three previous attempts to categorize knowledge in agricultural and extension education served as the primary technique to create a new taxonomy--or to confirm an existing taxonomy--for doctoral study in agricultural and extension education. The following coalesced as nine essential knowledge domains for a doctorate in agricultural and extension education: (1) history, philosophy, ethics, and policy; (2) agricultural/rural development; (3) organizational development and change management; (4) planning, needs assessment, and evaluation; (5) learning theory; (6) curriculum development and instructional design; (7) teaching methods and delivery strategies; (8) research methods and tools; and, (9) scholarship and communications.

  16. Comparison of equations used for estimating agricultural crop evapotranspiration with field research

    SciTech Connect

    Hill, R.W.; Johns, E.L.; Frevert, D.K.

    1983-10-01

    Research data on alfalfa water use and related yields were obtained for 10 sites in the Western United States. Similar research data was obtained for corn at eight sites. Four different types of research studies were available: lysimeter, line source sprinkler, stress plots, and farm yield. Research alfalfa yields and corresponding ET (evapotranspiration) were assumed to be 20 percent greater than field attained yields and ET, based on experience. Similarly, corn research yields and ET were assumed to be 10 percent greater than field attained yields and ET. Yield versus ET relationships were derived from the available research data.

  17. Rapid field assessment of RO desalination of brackish agricultural drainage water.

    PubMed

    Thompson, John; Rahardianto, Anditya; Gu, Han; Uchymiak, Michal; Bartman, Alex; Hedrick, Marcos; Lara, David; Cooper, Jim; Faria, Jose; Christofides, Panagiotis D; Cohen, Yoram

    2013-05-15

    Rapid field evaluation of RO feed filtration requirements, selection of effective antiscalant type and dose, and estimation of suitable scale-free RO recovery level were demonstrated using a novel approach based on direct observation of mineral scaling and flux decline measurements, utilizing an automated Membrane Monitor (MeMo). The MeMo, operated in a stand-alone single-pass desalting mode, enabled rapid assessment of the adequacy of feed filtration by enabling direct observation of particulate deposition on the membrane surface. The diagnostic field study with RO feed water of high mineral scaling propensity revealed (via direct MeMo observation) that suspended particulates (even for feed water of turbidity <1 NTU) could serve as seeds for promoting surface crystal nucleation. With feed filtration optimized, a suitable maximum RO water recovery, with complete mineral scale suppression facilitated by an effective antiscalant dose, can be systematically and directly identified (via MeMo) in the field for a given feed water quality. Scale-free operating conditions, determined via standalone MeMo rapid diagnostic tests, were shown to be applicable to spiral-would RO system as validated via both flux decline measurements and ex-situ RO plant membrane scale monitoring. It was shown that the present approach is suitable for rapid field assessment of RO operability and it is particularly advantageous when evaluating water sources of composition that may vary both temporally and across the regions of interest. PMID:23538039

  18. Multi-scale satellite assessment of water availability and agricultural drought: from field to global scales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper discusses a multi-scale remote sensing modeling system that fuses flux assessments generated with TIR imagery collected by multiple satellite platforms to estimate daily surface fluxes from field to global scales. The Landsat series of polar orbiting systems has collected TIR imagery at 6...

  19. Quantifying variability in field scale evapotranspiration measurements in an irrigated agricultural region under advection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compares the evapotranspiration (ET) measurements from eddy covariance, lysimetry, and water balance using a network of neutron probe sensors and investigates the role of within-field variability in the vegetation density in explaining the differences among the ET estimates from the vario...

  20. Rapid field assessment of RO desalination of brackish agricultural drainage water.

    PubMed

    Thompson, John; Rahardianto, Anditya; Gu, Han; Uchymiak, Michal; Bartman, Alex; Hedrick, Marcos; Lara, David; Cooper, Jim; Faria, Jose; Christofides, Panagiotis D; Cohen, Yoram

    2013-05-15

    Rapid field evaluation of RO feed filtration requirements, selection of effective antiscalant type and dose, and estimation of suitable scale-free RO recovery level were demonstrated using a novel approach based on direct observation of mineral scaling and flux decline measurements, utilizing an automated Membrane Monitor (MeMo). The MeMo, operated in a stand-alone single-pass desalting mode, enabled rapid assessment of the adequacy of feed filtration by enabling direct observation of particulate deposition on the membrane surface. The diagnostic field study with RO feed water of high mineral scaling propensity revealed (via direct MeMo observation) that suspended particulates (even for feed water of turbidity <1 NTU) could serve as seeds for promoting surface crystal nucleation. With feed filtration optimized, a suitable maximum RO water recovery, with complete mineral scale suppression facilitated by an effective antiscalant dose, can be systematically and directly identified (via MeMo) in the field for a given feed water quality. Scale-free operating conditions, determined via standalone MeMo rapid diagnostic tests, were shown to be applicable to spiral-would RO system as validated via both flux decline measurements and ex-situ RO plant membrane scale monitoring. It was shown that the present approach is suitable for rapid field assessment of RO operability and it is particularly advantageous when evaluating water sources of composition that may vary both temporally and across the regions of interest.

  1. Simulation of water balance in a clayey, subsurface drained agricultural field with three-dimensional FLUSH model

    NASA Astrophysics Data System (ADS)

    Warsta, Lassi; Karvonen, Tuomo; Koivusalo, Harri; Paasonen-Kivekäs, Maija; Taskinen, Antti

    2013-01-01

    SummaryWater flow is a key component in the evaluation of soil erosion and nutrient loads from agricultural fields. Field cultivation is the main non-point pollution source threatening water quality of surface waters in Nordic and many other countries. Few models exist that can describe key hydrological processes in clayey soils, i.e. overland flow, preferential flow in macropores and soil shrinkage and swelling. A new three-dimensional (3-D) distributed numerical model called FLUSH is introduced in this study to simulate these processes. FLUSH describes overland flow with the diffuse wave simplification of the Saint Venant equations and subsurface flow with a dual-permeability approach using the Richards equation in both macropore and matrix pore systems. A method based on the pentadiagonal matrix algorithm solves flow in both macropore and matrix systems directly in a column of cells in the computational grid. Flow between the columns is solved with iteration accelerated with OpenMP parallelisation. The model validity is tested with data from a 3-D analytical model and a clayey subsurface drained agricultural field in southern Finland. According to the simulation results, over 99% of the drainflow originated from the macropore system and drainflow started in some cases within the same hour when precipitation started indicating preferential flow in the profile. The moisture content of the clay soil had a profound effect on runoff distribution between surface runoff and drainflow. In summer, when the soil was dry and cracked, drainflow dominated the total runoff, while in autumn, when the shrinkage crack network had swollen shut, surface runoff fraction clearly increased. Observed differences in surface runoff fraction before and after tillage indicated that the operation decreased hydraulic conductivity of the profile.

  2. Seasonal Dynamics in Runoff Generation, Flowpaths and Phosphorus Mobilization From Reduced-till Agricultural Fields in Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Macrae, M. L.; van Esbroeck, C.; Brunke, R.; McKague, K.

    2014-12-01

    Reduced tillage systems used in agriculture have been shown to decrease losses of particulate phosphorus (P), but may increase the risk of dissolved P transport in some landscapes. Most of our knowledge of P losses from agricultural systems is based on observations made during the frost-free season and little is known about winter processes. Given the magnitude of the spring freshet in many regions, it is important to characterize P dynamics during this period. Discharge and P transport in overland flow and subsurface (tile) drainage were monitored at three reduced-till fields in southern Ontario, Canada for 18 months to (1) quantify runoff and P loads from fields; (2) characterize seasonality in the relative contributions of tile drainage and overland flow to runoff and P loads, and (3) demonstrate variable responses among different event types. Transport pathways were active throughout the non-growing season (NGS) and this period accounted for the majority of annual P loads over the study period. Drainage tiles were the dominant hydrologic pathway from fields throughout the study period, but were a small source of P when compared to P loss in overland flow. Overland flow was predominantly observed during winter thaws when ground frost was present. However, the magnitude and speciation of P losses during individual winter events were variable, and, were governed by a combination of antecedent conditions and precipitation characteristics. Given the importance of the NGS to annual P losses, we suggest that management steps should be taken to minimize the risk of losses during this period.

  3. Assessment of soil erosion and deposition rates in a Moroccan agricultural field using fallout 137Cs and 210Pbex.

    PubMed

    Benmansour, M; Mabit, L; Nouira, A; Moussadek, R; Bouksirate, H; Duchemin, M; Benkdad, A

    2013-01-01

    In Morocco land degradation - mainly caused by soil erosion - is one of the most serious agroenvironmental threats encountered. However, only limited data are available on the actual magnitude of soil erosion. The study site investigated was an agricultural field located in Marchouch (6°42' W, 33° 47' N) at 68 km south east from Rabat. This work demonstrates the potential of the combined use of (137)Cs, (210)Pb(ex) as radioisotopic soil tracers to estimate mid and long term erosion and deposition rates under Mediterranean agricultural areas. The net soil erosion rates obtained were comparable, 14.3 t ha(-1) yr(-1) and 12.1 ha(-1) yr(-1) for (137)Cs and (210)Pb(ex) respectively, resulting in a similar sediment delivery ratio of about 92%. Soil redistribution patterns of the study field were established using a simple spatialisation approach. The resulting maps generated by the use of both radionuclides were similar, indicating that the soil erosion processes has not changed significantly over the last 100 years. Over the previous 10 year period, the additional results provided by the test of the prediction model RUSLE 2 provided results of the same order of magnitude. Based on the (137)Cs dataset established, the contribution of the tillage erosion impact has been evaluated with the Mass Balance Model 3 and compared to the result obtained with the Mass Balance Model 2. The findings highlighted that water erosion is the leading process in this Moroccan cultivated field, tillage erosion under the experimental condition being the main translocation process within the site without a significant and major impact on the net erosion.

  4. Effects of agricultural practices on greenhouse gas emissions (N2O, CH4 and CO2) from corn fields

    NASA Astrophysics Data System (ADS)

    Hui, D.; Wang, J.; Jima, T.; Dennis, S.; Stockert, C.; Smart, D.; Bhattarai, S.; Brown, K.; Sammis, T.; Reddy, C.

    2012-12-01

    The United States is, by far, the largest producer of corn (Zea mays L.) in the world. Recent increases in fertilizer cost and concerns over global climate change have farmers and others interested in more efficient fertilization management and greenhouse gas emissions reductions. To seek the best management practices, we conducted field experiments during the 2012 growing season at Tennessee State University Agricultural Research and Demonstration Center in Nashville, TN. Six treatments were applied including regular URAN application [2 times], multiple URAN applications [4 times], denitrification inhibitor with regular URAN application, and chicken litter plus regular URAN application in no-tilled plots, and URAN application plus bio-char in tilled plots, all compared to regular URAN application in conventional tilled plots. Each treatment was replicated six times (blocks). We measured N2O, CO2 and CH4 emissions using a closed chamber method after rainfall events, fertilizer applications or every two weeks whichever was shorter. Corresponding soil NH4+-N and NO3--N, soil temperature and moisture were also measured during the gas sampling. Plant physiology and growth were measured about every two weeks. While preliminary results indicate that N2O and CO2 fluxes were significantly influenced by the agricultural practices on some days, particularly after rainfall events, CH4 flux was not influenced by the treatments during most of the days. Plots with bio-char showed significantly lower N2O emissions. We also measured N2O flux in a commercial corn field using the Eddy Covariance (EC) technique to ground verify the chamber based N2O emissions at the field scale. Results obtained with the EC technique seem comparable with the chamber method.

  5. Aquatic Insect Emergence in Post-Harvest Flooded Agricultural Fields in the Southern San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Moss, R. C.; Blumenshine, S.; Fleskes, J.

    2005-05-01

    California's Southern San Joaquin Valley is one of the most important waterbird areas in North America, but has suffered a disproportionate loss of wetlands when compared to other California regions. This project analyzes the habitat value of post-harvest flooded cropland by measuring the emergence of aquatic insects across multiple crop types. Aquatic insect emergence was sampled from post-harvest flooded fields of four crop types (alfalfa, corn, tomato, wheat), August-October, 2003-2004. Emergence was measured using traps deployed with a stratified random distribution to sample between and within field variation. Emergence rate and emergent biomass was significantly higher in flooded tomato fields. Results from corn fields indicate that flooding depth was correlated (r=0.095) with both diel temperature fluctuation and emergence rate. Chironomus dilutus larvae were grown in environmental chambers, under two thermal treatments with the same mean but different amplitudes (high: 15°-32°C, low: 20°-26°C) to investigate thermal fluctuation effects on survival and biomass. Larval survival (4x) and biomass (2x) were significantly greater in the low versus high temperature fluctuation treatment. This research has the potential to affect agricultural management throughout the 12,600 km2 region, increase aquatic insect production and aid in the recovery of declining bird populations.

  6. Testing the Need for Replication of Eddy Covariance Carbon Dioxide Flux Measurements over Agricultural Fields

    NASA Astrophysics Data System (ADS)

    Taylor, A. M.; Amiro, B. D.; Gervais, M.

    2015-12-01

    The eddy covariance method directly measures carbon dioxide (CO2) fluxes for long periods of time and with footprints up to hundreds of meters in size. Any ecosystem process that alters how gases and energy move between the atmosphere and soil/vegetation can affect these fluxes. Eddy covariance is vulnerable to systematic errors and uncertainy, particular through relying on assumptions about surface characteristics. Additionally, spatial variation within a site can cause more uncertainty in these measurements and lack of replication in many eddy covariance studies makes statistical analysis of carbon fluxes challenging. We tested if there are significant differences between co-located and simultaneous CO2 flux measurements over a uniform crop surface, and if the differences increase if we measure different flux footprint areas over the same field. During the summer of 2014, three matched instrumented 2.5-m high towers were co-located and then periodically separated by moving at 50 m intervals along a north-south transect on an alfalfa/trefoil field and a spring wheat field in Southern Manitoba, Canada to compare CO­2 fluxes. Georeferenced leaf area index measurements were taken in 50 m grid of each field to establish uniformity of the source/sink within a footprint. Diurnal differences of similar magnitude in the CO2 ­fluxes were found in both the co-located experiment and the spatially separated intervals. Despite rigorous calibration during the experiment, some differences were caused by the measurement systems rather than by variation within the field. Interpretation of the spatial variation in leaf area index is being used to determine the contribution caused by difference in source/sink contributions to the flux footprint areas when the towers were spatially separated.

  7. 3-D modeling of water balance and soil erosion in a clayey subsurface drained agricultural field in boreal climate

    NASA Astrophysics Data System (ADS)

    Turunen, M.; Warsta, L.; Koivusalo, H. J.; Paasonen-Kivekäs, M.; Nurminen, J.; Myllys, M.; Alakukku, L.; Äijö, H.; Puustinen, M.

    2012-12-01

    Fluxes of nutrients and other substances from cultivated fields cause eutrophication and deterioration of water quality in aquatic ecosystems worldwide. In order to develop effective strategies to control the environmental impacts of crop cultivation, it is crucial to identify the main transport pathways and the effects of different water management methods on the loads. Reduction of sediment loads is essential since sediment particles typically carry nutrients (especially sorbed phosphorus) and other potentially harmful substances, e.g. pesticides, from the fields to the adjacent surface waters. The novel part of this study was the investigation of suspended sediment transport in soil macropores to the subsurface drains and to the deep groundwater. We applied a 3-D distributed dual-permeability model (FLUSH) using a dataset collected from a subsurface drained, clayey agricultural field (15 ha) to holistically assess water balance, soil erosion and sediment transport from the field to an adjacent stream. The data set included five years of hydrological and water quality measurements from four intensively monitored field sections with different soil properties, topography, drainage systems (drain spacing and drain depth), drain installation methods (trenchless and trench drainage) and drain envelope materials (gravel and fiber). The 3-D model allowed us to quantify how soil erosion and sediment transport differed between the field sections within the field area. The simulations were conducted during snow- and frost-free periods. The simulation results include closure of water balance of the cultivated field, distribution of soil erosion and sediment transport within the field area and the effects of different subsurface drainage systems on sediment loads. The 3-D dual-permeability subsurface flow model was able to reproduce the measured drainflows and sediment fluxes in the clayey field and according to the simulations over 90% of drainflow waters were conveyed to

  8. Rainwater lens dynamics and mixing between infiltrating rainwater and upward saline groundwater seepage beneath a tile-drained agricultural field

    NASA Astrophysics Data System (ADS)

    de Louw, P. G. B.; Eeman, S.; Oude Essink, G. H. P.; Vermue, E.; Post, V. E. A.

    2013-09-01

    Thin rainwater lenses (RW-lenses) near the land surface are often the only source of freshwater in agricultural areas with regionally-extensive brackish to saline groundwater. The seasonal and inter-annual dynamics of these lenses are poorly known. Here this knowledge gap is addressed by investigating the transient flow and mixing processes in RW-lenses beneath two tile-drained agricultural fields in the Netherlands. Evidence of RW-lens dynamics was systematically collected by monthly ground- and soil water sampling, in combination with daily observations of water table elevation, drain tile discharge and drain water salinity. Based on these data, and numerical modeling of the key lens characteristics, a conceptual model of seasonal lens dynamics is presented. It is found that variations in the position of the mixing zone and mixing zone salinities are small and vary on a seasonal timescale, which is attributed to the slow transient oscillatory flow regime in the deepest part of the lens. The flow and mixing processes are faster near the water table, which responds to recharge and evapotranspiration at a timescale less than a day. Variations of drain tile discharge and drain water salinity are also very dynamic as they respond to individual rain events. Salinities of soil water can become significantly higher than in the groundwater. This is attributed to the combined effect of capillary rise of saline groundwater during dry periods and incomplete flushing by infiltrating freshwater due to preferential flow through cracks in the soil. The results of this study are the key to understanding the potential impact of future climate change and to designing effective mitigating measures such as adapting tile-drainage systems to ensure the future availability of freshwater for agriculture.

  9. Chemical and biological characterization of products of incomplete combustion from the simulated field burning of agricultural plastic.

    PubMed

    Linak, W P; Ryan, J V; Perry, E; Williams, R W; DeMarini, D M

    1989-06-01

    Chemical and biological analyses were performed to characterize products of incomplete combustion emitted during the simulated open field burning of agricultural plastic. A small utility shed equipped with an air delivery system was used to simulate pile burning and forced-air-curtain incineration of a nonhalogenated agricultural plastic that reportedly consisted of polyethylene and carbon black. Emissions were analyzed for combustion gases; volatile, semi-volatile, and particulate organics; and toxic and mutagenic properties. Emission samples, as well as samples of the used (possibly pesticide-contaminated) plastic, were analyzed for the presence of several pesticides to which the plastic may have been exposed. Although a variety of alkanes, alkenes, and aromatic and polycyclic aromatic hydrocarbon (PAH) compounds were identified in the volatile, semi-volatile, and particulate fractions of these emissions, a substantial fraction of higher molecular weight organic material was not identified. No pesticides were identified in either combustion emission samples or dichloromethane washes of the used plastic. When mutagenicity was evaluated by exposing Salmonella bacteria (Ames assay) to whole vapor and vapor/particulate emissions, no toxic or mutagenic effects were observed. However, organic extracts of the particulate samples were moderately mutagenic. This mutagenicity compares approximately to that measured from residential wood heating on a revertant per unit heat release basis. Compared to pile burning, forced air slightly decreased the time necessary to burn a charge of plastic. There was not a substantial difference, however, in the variety or concentrations of organic compounds identified in samples from these two burn conditions. This study highlights the benefits of a combined chemical/biological approach to the characterization of complex, multi-component combustion emissions. These results may not reflect those of other types of plastic that may be used

  10. Prehistoric Agriculture and Soil Fertility on Lava Flows in Northern Arizona, USA: Results from the San Francisco Volcanic Field REU

    NASA Astrophysics Data System (ADS)

    Broadman, E.; Anderson, K. C.

    2013-12-01

    The San Francisco Volcanic Field in northern Arizona is home to ~600 cinder cones, the youngest of which is Sunset Crater (erupted ~AD 1100). This study documents trends in available phosphate and nitrate content with time, testing whether lowered soil pH from the addition of Sunset cinders increased soil fertility and became a factor in Anasazi agricultural success. Soil fertility is examined both before and after Sunset's eruption in soils of different ages that have developed from eolian deposition on top of lava flows. An increase in phosphate and nitrate levels following acidification would suggest that the presence of Sunset cinders brought the soils to the optimal pH for mobilization of these nutrients. The combined effects of the cinder layer retaining nutrients and water, wetter climates, and increases in phosphate and nitrate (both limiting nutrients for plant growth), would have contributed to Anasazi agricultural success after Sunset's eruption. Samples for this study were taken from eolian-derived soils of different ages atop lava flows in the San Francisco Volcanic Field. OSL data from these soils on Strawberry and SP Craters' lava flows yielded age estimates of ~12.3 ka (Strawberry) and ~32.7 ka (SP), on which a soil chronosequence was based. Results from the chronosequence supported these OSL ages, indicating that soils on the SP flow are older than those on the Strawberry flow. Field descriptions, Harden Development Indices, particle size analysis, and nutrient content analysis were used for this aspect of the project. An experimental acid wash method will be used to simulate the addition of Sunset's acidic cinders, and will yield data for phosphate and nitrate content after Sunset erupted. Preliminary results indicate that phosphate and nitrate accumulate in upper, eolian-derived horizons (Av, Bw) and in more deeply buried carbonate horizons (Bk). Higher concentrations of phosphate and nitrate were found in older (SP) soils than younger

  11. Agricultural terraces montoring and modeling: a field survey in Chianti region, Firenze, Italy – Second part

    NASA Astrophysics Data System (ADS)

    Preti, Federico; Caruso, Marco; Dani, Andrea; Cassiani, Giorgio; Romano, Nunzio; Tarolli, Paolo

    2015-04-01

    sustainable management of erosion processes in agricultural land and hilly-mountainous area

  12. Evaluation of the effects of varying moisture contents on microwave thermal emissions from agriculture fields

    NASA Technical Reports Server (NTRS)

    Burke, H. H. K.

    1980-01-01

    Three tasks related to soil moisture sensing at microwave wavelengths were undertaken: (1) analysis of data at L, X and K sub 21 band wavelengths over bare and vegetated fields from the 1975 NASA sponsored flight experiment over Phoenix, Arizona; (2) modeling of vegetation canopy at microwave wavelengths taking into consideration both absorption and volume scattering effects; and (3) investigation of overall atmospheric effects at microwave wavelengths that can affect soil moisture retrieval. Data for both bare and vegetated fields are found to agree well with theoretical estimates. It is observed that the retrieval of surface and near surface soil moisture information is feasible through multi-spectral and multi-temporal analysis. It is also established that at long wavelengths, which are optimal for surface sensing, atmospheric effects are generally minimal. At shorter wavelengths, which are optimal for atmosheric retrieval, the background surface properties are also established.

  13. Exposure to sulfosulfuron in agricultural drainage ditches: field monitoring and scenario-based modelling.

    PubMed

    Brown, Colin D; Dubus, Igor G; Fogg, Paul; Spirlet, Marie; Gustin, Christophe

    2004-08-01

    Field monitoring and scenario-based modelling were used to assess exposure of small ditches in the UK to the herbicide sulfosulfuron following transport via field drains. A site in central England on a high pH, clay soil was treated with sulfosulfuron, and concentrations were monitored in the single drain outfall and in the receiving ditch 1 km downstream. Drainflow in the nine months following application totalled 283 mm. Pesticide lost in the first 12.5 mm of flow was 99% of the total loading to drains (0.5% of applied). Significant dilution was observed in the receiving ditch and quantifiable residues were only detected in one sample (0.06 microg litre(-1)). The MACRO model was evaluated against the field data with minimal calibration. The parameterisation over-estimated the importance of macropore flow at the site. As a consequence, the maximum concentration in drainflow (2.3 microg litre(-1)) and the total loading to drains (0.76 g) were over-estimated by factors of 2.4 and 5, respectively. MACRO was then used to simulate long-term fate of the herbicide for each of 20 environmental scenarios. Resulting estimates for concentrations of sulfosulfuron in a receiving ditch were weighted according to the prevalence of each scenario to produce a probability distribution of daily exposure. PMID:15307668

  14. Remote sensing for precision agriculture: Within-field spatial variability analysis and mapping with aerial digital multispectral images

    NASA Astrophysics Data System (ADS)

    Gopalapillai, Sreekala

    2000-10-01

    Advances in remote sensing technology and biological sensors provided the motivation for this study on the applications of aerial multispectral remote sensing in precision agriculture. The feasibility of using high-resolution multispectral remote sensing for precision farming applications such as soil type delineation, identification of crop nitrogen levels, and modeling and mapping of weed density distribution and yield potential within a crop field was explored in this study. Some of the issues such as image calibration for variable lighting conditions and soil background influence were also addressed. Intensity normalization and band ratio methods were found to be adequate image calibration methods to compensate for variable illumination and soil background influence. Several within-field variability factors such as growth stage, field conditions, nutrient availability, crop cultivar, and plant population were found to be dominant in different periods. Unsupervised clustering of color infrared (CIR) image of a field soil was able to identify soil mapping units with an average accuracy of 76%. Spectral reflectance from a crop field was highly correlated to the chlorophyll reading. A regression model developed to predict nitrogen stress in corn identified nitrogen-stressed areas from nitrogen-sufficient areas with a high accuracy (R2 = 0.93). Weed density was highly correlated to the spectral reflectance from a field. One month after planting was found to be a good time to map spatial weed density. The optimum range of resolution for weed mapping was 4 m to 4.5 m for the remote sensing system and the experimental field used in this study. Analysis of spatial yield with respect to spectral reflectance showed that the visible and NIR reflectance were negatively correlated to yield and crop population in heavily weed-infested areas. The yield potential was highly correlated to image indices, especially to normalized brightness. The ANN model developed for one of the

  15. Review of the findings of the Ignik Sikumi CO2-CH4 gas hydrate exchange field trial

    SciTech Connect

    Anderson, Brian J.; Boswell, Ray; Collett, Tim S.; Farrell, Helen; Ohtsuka, Satoshi; White, Mark D.

    2014-08-01

    The Ignik Sikumi Gas Hydrate Exchange Field Trial was conducted by ConocoPhillips in partnership with the U.S. Department of Energy, the Japan Oil, Gas, and Metals National Corporation, and the U.S. Geological Survey within the Prudhoe Bay Unit on the Alaska North Slope (ANS) during 2011 and 2012. The 2011 field program included drilling the vertical test well and performing extensive wireline logging through a thick section of gas-hydrate-bearing sand reservoirs that provided substantial new insight into the nature of ANS gas hydrate occurrences. The 2012 field program involved an extended, scientific field trial conducted within a single vertical well (“huff-and-puff” design) through three primary operational phases: 1) injection of a gaseous phase mixture of CO2, N2, and chemical tracers; 2) flowback conducted at down-hole pressures above the stability threshold for native CH4-hydrate, and 3) extended (30-days) flowback at pressures below the stability threshold of native CH4-hydrate. Ignik Sikumi represents the first field investigation of gas hydrate response to chemical injection, and the longest-duration field reservoir response experiment yet conducted. Full descriptions of the operations and data collected have been fully reported by ConocoPhillips and are available to the science community. The 2011 field program indicated the presence of free water within the gas hydrate reservoir, a finding with significant implications to the design of the exchange trial – most notably the use of a mixed gas injectant. While this decision resulted in a complex chemical environment within the reservoir that greatly tests current experimental and modeling capabilities – without such a mixture, it is apparent that injection could not have been achieved. While interpretation of the field data are continuing, the primary scientific findings and implications of the program are: 1) gas hydrate destabilizing is self-limiting, dispelling any notion of the potential for

  16. Controls on Nitrogen Fluxes from Agricultural Fields: Differing Conclusions Based on Choice of Sensitivity Analysis Method

    NASA Astrophysics Data System (ADS)

    Ahrens, T.; Matson, P.; Lobell, D.

    2006-12-01

    Sensitivity analyses (SA) of biogeochemical and agricultural models are often used to identify the importance of input variables for variance in model outputs, such as crop yield or nitrate leaching. Identification of these factors can aid in prioritizing efforts in research or decision support. Many types of sensitivity analyses are available, ranging from simple One-At-A-Time (OAT) screening exercises to more complex local and global variance-based methods (see Saltelli et al 2004). The purpose of this study was to determine the influence of the type of SA on factor prioritization in the Yaqui Valley, Mexico using the Water and Nitrogen Management Model (WNMM; Chen et al 2005). WNMM, a coupled plant-growth - biogeochemistry simulation model, was calibrated to reproduce crop growth, soil moisture, and gaseous N emission dynamics in experimental plots of irrigated wheat in the Yaqui Valley, Mexico from 1994-1997. Three types of SA were carried out using 16 input variables, including parameters related to weather, soil properties and crop management. Methods used for SA were local OAT, Monte Carlo (MC), and a global variance-based method (orthogonal input; OI). Results of the SA were based on typical interpretations used for each test: maximum absolute ratio of variation (MAROV) for OAT analyses; first- and second-order regressions for MC analyses; and a total effects index for OI. The three most important factors identified by MC and OI methods were generally in agreement, although the order of importance was not always consistent and there was little agreement for variables of less importance. OAT over-estimated the importance of two factors (planting date and pH) for many outputs. The biggest differences between the OAT results and those from MC and OI were likely due to the inability of OAT methods to account for non-linearity (eg. pH and ammonia volatilization), interactions among variables (eg. pH and timing of fertilization) and an over-reliance on baseline

  17. Nitrate transport and fluxes during storm-event discharge from a 12 ha tile-drained dryland agricultural field

    NASA Astrophysics Data System (ADS)

    Kelley, C. J.; Keller, C. K.; Brooks, E. S.; Smith, J. L.; Orr, C. H.; Evans, R. D.

    2012-12-01

    Tile drains shortcut natural soil hydrology and decrease the capacity of soils to buffer water and nutrient fluxes during storm events. Previous research at the Cook Agronomy Farm near Pullman, WA. found seasonal patterns for nutrient and water fluxes, larger during the winter and smaller during the summer. The objective of this study was to determine the effects storm events have on tile-drain water and nutrient fluxes from a dryland agricultural field. Our first hypothesis is that winter storm events activate shallow soil-water flow paths, resulting in rapid transport of precipitation and younger soil pore-water through the tile-drain system. These storm-event flow paths result in a decrease in tile-drain water electrical conductivity from a baseline of approximately 260 μS/cm to as low as 20 μS/ cm. Data suggest that storm events increase hydraulic conductivities in the upper profile as soil approaches saturation, increasing the contributions of relatively young soil water and possibly current storm-event precipitation to tile-drain discharge. Our second hypothesis is that the observed increase in discharge during storm events does not decrease nitrate concentrations in discharged water, because the storm-event flow paths also transport additional nitrate from the upper soil profile through the tile-drain system. If this hypothesis is correct, during storm events nitrate fluxes should increase, indicating rapid mobilization and potential flushing of soil nutrients through the vadose zone and tile-drain. If nitrate fluxes remain constant during storm events, then decreased tile-drain nitrate concentrations may be caused by the addition of low-nitrate or nitrate-free water. This would suggest that the nitrate leached from the system is present at the depth of the tile-drain and is not transported from near the soil surface to the tile-drain during storm-events, indicating flushing of soil nutrients from the rooting zone is not occurring at these temporal scales

  18. Experimental monitoring and numerical study of pesticide (carbofuran) transfer in an agricultural soil at a field site

    NASA Astrophysics Data System (ADS)

    Hmimou, Abderrahim; Maslouhi, Abdellatif; Tamoh, Karim; Candela, Lucila

    2014-09-01

    We studied the transport of a pesticide at field scale, namely carbofuran molecule, which is known for its high mobility, especially in sandy soils with high hydraulic conductivity and low organic matter. To add to our knowledge of the future of this high-mobility molecule in this type of soils, we developed a mechanistic numerical model allowing the simulation of hydric and solute transfers (bromide and carbofuran) in the soil. We carried out this study in an agricultural plot in the region of Mnasra in Morocco. Confrontation of the measured and simulated values allowed the calibration of the parameters of hydric transfer and carbofuran. The developed model accurately reproduces the measured values. Despite a weak irrigation and precipitation regime, carbofuran was practically leached beyond the root zone. Prospective simulations show that under a more important irrigation regime, carbofuran reaches a 100-cm depth, whereas it does not exceed 60 cm under a deficit regime.

  19. Temporal variability of colloidal material in agricultural storm runoff from managed grassland using flow field-flow fractionation.

    PubMed

    Gimbert, Laura J; Worsfold, Paul J

    2009-12-25

    This paper reports the use of flow field-flow fractionation (FlFFF) to determine the temporal variability of colloidal (<1mum) particle size distributions in agricultural runoff waters in a small managed catchment in SW England during storm events. Three storm events of varying intensity were captured and the colloidal material in the runoff analysed by FlFFF. The technique had sufficient sensitivity to determine directly the changing colloidal profile over the 0.08-1.0mum size range in the runoff waters during these storm events. Rainfall, total phosphorus and suspended solids in the bulk runoff samples were also determined throughout one storm and showed significant correlation (P<0.01) with the amount of colloidal material. Whilst there are some uncertainties in the resolution and absolute calibration of the FlFFF profiles, the technique has considerable potential for the quantification of colloidal material in storm runoff waters. PMID:19577239

  20. Influences of suspended particles on the runoff of pesticides from an agricultural field at Askim, SE-Norway.

    PubMed

    Wu, Q; Riise, G; Lundekvam, H; Mulder, J; Haugen, L E

    2004-01-01

    Field and laboratory experiments were conducted to study the loss of particles from agricultural fields, and the role of suspended particles in carrying pesticides in surface runoff and drainage water. Propiconazole, a widely used fungicide was applied to experimental fields located at Askim, SE-Norway. Samples from surface runoff and drainage water were collected and analyzed for sediment mass, pesticides, particulate and dissolved organic carbon through a whole year. The surface soil and the runoff material were characterized by its particle size distribution, organic carbon content in size fractions and its ability to bind propiconazole. The results show that (1) particle runoff mostly occurred during the rainfall event shortly after harrowing in autumn. The highest particle concentration observed in the surface runoff water was 4600 mg l(-1), and in the drainage water 1130 mg l(-1); (2) the erosion of surface soil is size selective. The runoff sediment contained finer particle/aggregates rich in organic matter compared to its original surface soil; (3) the distribution coefficient (Kd) of propiconazole was significantly higher in the runoff sediment than in the parent soil. According to our calculation, particle-bound propiconazole can represent up to 23% of the total amount of propiconazole in a water sample with a sediment concentration of 7600 mg l(-1), which will significantly influence the transport behavior of the pesticide.

  1. Thresholds of copper phytotoxicity in field-collected agricultural soils exposed to copper mining activities in Chile.

    PubMed

    Verdejo, José; Ginocchio, Rosanna; Sauvé, Sébastien; Salgado, Eduardo; Neaman, Alexander

    2015-12-01

    It has been argued that the identification of the phytotoxic metal thresholds in soil should be based on field-collected soil rather than on artificially-contaminated soils. However, the use of field-collected soils presents several difficulties for interpretation because of mixed contamination and unavoidable covariance of metal contamination with other soil properties that affect plant growth. The objective of this study was to estimate thresholds of copper phytotoxicity in topsoils of 27 agricultural areas historically contaminated by mining activities in Chile. We performed emergence and early growth (21 days) tests (OECD 208 and ISO 11269-2) with perennial ryegrass (Lolium perenne L.). The total Cu content in soils was the best predictor of plant growth and shoot Cu concentrations, while soluble Cu and pCu(2+) did not well correlate with these biological responses. The effects of Pb, Zn, and As on plant responses were not significant, suggesting that Cu is a metal of prime concern for plant growth in soils exposed to copper mining activities in Chile. The effects of soil nutrient availability and shoot nutrient concentrations on ryegrass response were not significant. It was possible to determine EC10, EC25 and EC50 of total Cu in the soil of 327 mg kg(-1), 735 mg kg(-1) and 1144 mg kg(-1), respectively, using the shoot length as a response variable. However, the derived 95% confidence intervals for EC10, EC25 and EC50 values of total soil Cu were wide, and thus not allowing a robust assessment of metal toxicity for agricultural crops, based on total soil Cu concentrations. Thus, plant tests might need to be performed for metal toxicity assessment. This study suggests shoot length of ryegrass as a robust response variable for metal toxicity assessment in contaminated soils with different nutrient availability.

  2. Thresholds of copper phytotoxicity in field-collected agricultural soils exposed to copper mining activities in Chile.

    PubMed

    Verdejo, José; Ginocchio, Rosanna; Sauvé, Sébastien; Salgado, Eduardo; Neaman, Alexander

    2015-12-01

    It has been argued that the identification of the phytotoxic metal thresholds in soil should be based on field-collected soil rather than on artificially-contaminated soils. However, the use of field-collected soils presents several difficulties for interpretation because of mixed contamination and unavoidable covariance of metal contamination with other soil properties that affect plant growth. The objective of this study was to estimate thresholds of copper phytotoxicity in topsoils of 27 agricultural areas historically contaminated by mining activities in Chile. We performed emergence and early growth (21 days) tests (OECD 208 and ISO 11269-2) with perennial ryegrass (Lolium perenne L.). The total Cu content in soils was the best predictor of plant growth and shoot Cu concentrations, while soluble Cu and pCu(2+) did not well correlate with these biological responses. The effects of Pb, Zn, and As on plant responses were not significant, suggesting that Cu is a metal of prime concern for plant growth in soils exposed to copper mining activities in Chile. The effects of soil nutrient availability and shoot nutrient concentrations on ryegrass response were not significant. It was possible to determine EC10, EC25 and EC50 of total Cu in the soil of 327 mg kg(-1), 735 mg kg(-1) and 1144 mg kg(-1), respectively, using the shoot length as a response variable. However, the derived 95% confidence intervals for EC10, EC25 and EC50 values of total soil Cu were wide, and thus not allowing a robust assessment of metal toxicity for agricultural crops, based on total soil Cu concentrations. Thus, plant tests might need to be performed for metal toxicity assessment. This study suggests shoot length of ryegrass as a robust response variable for metal toxicity assessment in contaminated soils with different nutrient availability. PMID:26233921

  3. Estimation of spatio-temporal variability of soil water content in agricultural fields with ground penetrating radar

    NASA Astrophysics Data System (ADS)

    Wijewardana, Y. G. N. S.; Galagedara, L. W.

    2010-09-01

    SummaryEfficient water management, crop yield variability estimation and prediction of contaminant transport require some measurement of soil water content variation through time and space. This study focused on the estimation of spatio-temporal variability of volumetric soil water content ( θ v) in raised bed agricultural fields using ground penetrating radar (GPR), comparison of GPR method with gravimetric sampling data and development of 2D maps of θ v. The GPR system (pulse EKKO Pro) with 200 MHz antennas was used to collect data on approximately 1.0 m wide and 13.0 m long raised beds of about 0.1 m height cultivated with vegetables. Transillumination Zero Offset Profile (Trans ZOP) and Transillumination Multiple Offset Gather (Trans MOG) GPR survey modes which are classically used as borehole GPR method were employed as a surface GPR method. In each of these survey modes, the direct ground wave travel time was measured. The θ v at each Trans ZOP and Trans MOG location was calculated by first converting the electromagnetic (EM) wave velocity into soil dielectric permittivity and then to θ v using a standard empirical relationship. The results revealed that the spatio-temporal variability of θ v in raised bed agricultural fields could be estimated using the Trans ZOP and Trans MOG GPR survey modes. The GPR estimated θ v and gravimetrically measured soil water content ( θ g) were not significantly different ( P = 0.272). The correlation coefficient was 0.87, the root mean square error was 0.0184 m 3/m 3 and the average error was 0.20% between the two methods. The Trans MOG survey data allowed us to create plan view maps (2D) of the θ v variation which could not be obtained from the Trans ZOP data. No statistical difference ( P = 0.053) was found between the Trans ZOP and average Trans MOG values.

  4. Explaining Feast or Famine in Randomized Field Trials: Medical Science and Criminology Compared.

    ERIC Educational Resources Information Center

    Shepherd, Jonathan P.

    2003-01-01

    Discusses the contrast between the frequency of randomized clinical trials in the health sciences and the relative famine of such studies in criminology. Attributes this difference to the contexts in which research is done and the difference in the status of situational research in the two disciplines. (SLD)

  5. High School Geography Project. Introductory Unit. ETS Evaluation Report, Limited Field Trials.

    ERIC Educational Resources Information Center

    Bogatz, Gerry Ann; And Others

    This unit is one of several being prepared as a part of a geography course based on a settlement theme provisionally planned for tenth grade students. The materials are part of a larger proto unit on "A Structure of Geography." The original unit was tried out during the spring of 1965, then revised for the limited school trials. The regional…

  6. Building Development, Food and Population Issues in the Field of Agriculture with Rural Development in the Arab Countries (16-21 January 1993). Panel discussion (seminar).

    PubMed

    Morcos, M E

    1993-01-01

    The UN Organization for Food and Agriculture bureau held a panel discussion during January 16-21, 1993, to stress the importance of the joint relation between population issues, food, and nutrition in the fields of agriculture and rural development. Policymakers and individuals responsible for activities and programs on population, food, nutrition, and rural development in Egypt, Tunisia, Morocco, Jordan, Yemen, and Sudan participated in the seminar. The seminar was also attended by academic institutions and participants from the ministries of agriculture and health, the National Population Council, and the committees of the countries involved. Synopses of panel proceedings are presented.

  7. Controlling factors of nitrous oxide (N2O) emissions at the field-scale in an agricultural slope

    NASA Astrophysics Data System (ADS)

    Vilain, Guillaume; Garnier, Josette; Tallec, Gaëlle; Tournebize, Julien; Cellier, Pierre; Flipo, Nicolas

    2010-05-01

    Agricultural practices widely contribute to the atmospheric nitrous oxide (N2O) concentration increase and are the major source of N2O which account for 24% of the global annual emission (IPCC, 2007). Soil nitrification and denitrification are the microbial processes responsible for the production of N2O, which also depends on soil characteristics and management. Besides their control by various factors, such as climate, soil conditions and management (content of NO3- and NH4+, soil water content, presence of degradable organic material…), the role of topography is less known although it can play an important role on N2O emissions (Izaurralde et al., 2004). Due to the scarcity of data on N2O direct vs. indirect emission rate from agriculture in the Seine Basin (Garnier et al., 2009), one of the objectives of the study conducted here was to determine the N2O emission rates of the various land use representative for the Seine Basin, in order to better assess the direct N2O emissions, and to explore controlling factor such as meteorology, topography, soil properties and crop successions. The main objective of this study was at the same time to characterize N2O fluxes variability along a transect from an agricultural plateau to a river and to analyze the influence of landscape position on these emissions. We conducted this study in the Orgeval catchment (Seine basin, France; between 48°47' and 48°55' N, and 03°00' and 03°55' E) from May 2008 to August 2009 on two agricultural fields cropped with wheat, barley, oats, corn. N2O fluxes were monitored from weekly to bimonthly using static manual chambers placed along the chosen transect in five different landscape positions from the plateau to the River. This study has shown that soil moisture (expressed as Water Filled Pore Space) and NO3- soil concentrations explained most of the N2O flux variability during the sampling period. Most of N2O was emitted directly after N fertilization application during a relatively

  8. Pen and field trials of a new anticoagulant rodenticide flocoumafen against the house mouse (Mus musculus L.).

    PubMed

    Rowe, F P; Bradfield, A; Swinney, T

    1985-12-01

    The efficacy of flocoumafen, a novel anticoagulant rodenticide, was evaluated in feeding tests on confined and free-living populations of house mice (Mus musculus L.). In four pen trials, family groups of laboratory-reared wild mice were conditioned to feeding on plain foods and then offered flocoumafen at 0.005% in pinhead oatmeal bait. All 68 mice, comprising juvenile and adult animals, died within 10 days. Ten field trials were carried out, using the same formulated poison bait, against mice infesting farm buildings. Mean treatment success, estimated from live-capture and mortality data, ranged between 87.1 and 100%. The performance of flocoumafen is compared with that of difenacoum, bromadiolone and brodifacoum used at the same concentration in oatmeal bait. Flocoumafen gave an equally effective but quicker kill of mice. It is concluded that flocoumafen is a promising new rodenticide for the control of M. musculus. PMID:3841547

  9. Pen and field trials of a new anticoagulant rodenticide flocoumafen against the house mouse (Mus musculus L.).

    PubMed Central

    Rowe, F. P.; Bradfield, A.; Swinney, T.

    1985-01-01

    The efficacy of flocoumafen, a novel anticoagulant rodenticide, was evaluated in feeding tests on confined and free-living populations of house mice (Mus musculus L.). In four pen trials, family groups of laboratory-reared wild mice were conditioned to feeding on plain foods and then offered flocoumafen at 0.005% in pinhead oatmeal bait. All 68 mice, comprising juvenile and adult animals, died within 10 days. Ten field trials were carried out, using the same formulated poison bait, against mice infesting farm buildings. Mean treatment success, estimated from live-capture and mortality data, ranged between 87.1 and 100%. The performance of flocoumafen is compared with that of difenacoum, bromadiolone and brodifacoum used at the same concentration in oatmeal bait. Flocoumafen gave an equally effective but quicker kill of mice. It is concluded that flocoumafen is a promising new rodenticide for the control of M. musculus. PMID:3841547

  10. Measurements of the effectiveness of conservation agriculture at the field scale using radioisotopic techniques and runoff plots

    NASA Astrophysics Data System (ADS)

    Mabit, L.; Klik, A.; Toloza, A.; Benmansour, M.; Geisler, A.; Gerstmann, U. C.

    2009-04-01

    Growing evidence of the cost of soil erosion on agricultural land and off site impact of associated processes has emphasized the needs for quantitative assessment of erosion rates to develop and assess erosion control technology and to allocate conservation resources and development of conservation regulation, policies and programmes. Our main study goal was to assess the magnitude of deposition rates using Fallout Radionuclides ‘FRNs' (137-Cs and 210-Pb) and the mid-term (13 years) erosion rates using conventional runoff plot measurements in a small agricultural watershed under conventional and conservation tillage practices. The tillage treatments were conventional tillage system (CT), mechanical plough to 30 cm depth (the most common tillage system within the watershed); conservation tillage (CS) with cover crops during winter; and direct seeding (DS) no tillage with cover crops during winter. The experimental design - located in Mistelbach watershed 60 km north of Vienna/Austria - consists of one 3-metre-wide and 15-metre-long runoff plot (silt loam - slope of 14%) for each tillage system (CT, CS and DS) with the plots placed in the upper part of an agricultural field. 76 soil samples were collected to evaluate the initial fallout of 137-Cs and 210-Pb in a small forested area close to the experimental field, along a systematic multi-grid design,. In the sedimentation area of the watershed and down slope the agricultural field, 2 additional soil profiles were collected to 1 m depth. All soil samples were air dried, sieved to 2mm and analysed for their 137-Cs and 210-Pb contents using gamma detector. The main results and conclusion can be summarised as following: i) The initial 137-Cs fallout as measured in the 76 forested soil samples ranged from 1123 to 3354 Bq/m2 for an average of 1954 Bq/m2 with a coefficient of variation of 20.4 %. ii) Long-term erosion measurements (1994-2006) from runoff plots located in the upper part of the agricultural field just up

  11. Experimental and Numerical Investigation of Guest Molecule Exchange Kinetics based on the 2012 Ignik Sikumi Gas Hydrate Field Trial

    NASA Astrophysics Data System (ADS)

    Ruprecht Yonkofski, C. M.; Horner, J.; White, M. D.

    2015-12-01

    In 2012 the U.S. DOE/NETL, ConocoPhillips Company, and Japan Oil, Gas and Metals National Corporation jointly sponsored the first field trial of injecting a mixture of N2-CO2 into a CH4-hydrate bearing formation beneath the permafrost on the Alaska North Slope. Known as the Ignik Sikumi #1 Gas Hydrate Field Trial, this experiment involved three stages: 1) the injection of a N2-CO2 mixture into a targeted hydrate-bearing layer, 2) a 4-day pressurized soaking period, and 3) a sustained depressurization and fluid production period. Data collected during the three stages of the field trial were made available after a thorough quality check. The Ignik Sikumi #1 data set is extensive, but contains no direct evidence of the guest-molecule exchange process. This study uses numerical simulation to provide an interpretation of the CH4/CO2/N2 guest molecule exchange process that occurred at Ignik Sikumi #1. Simulations were further informed by experimental observations. The goal of the scoping experiments was to understand kinetic exchange rates and develop parameters for use in Iġnik Sikumi history match simulations. The experimental procedure involves two main stages: 1) the formation of CH4 hydrate in a consolidated sand column at 750 psi and 2°C and 2) flow-through of a 77.5/22.5 N2/CO2 molar ratio gas mixture across the column. Experiments were run both above and below the hydrate stability zone in order to observe exchange behavior across varying conditions. The numerical simulator, STOMP-HYDT-KE, was then used to match experimental results, specifically fitting kinetic behavior. Once this behavior is understood, it can be applied to field scale models based on Ignik Sikumi #1.

  12. Runoff of pharmaceuticals and personal care products following application of biosolids to an agricultural field.

    PubMed

    Topp, Edward; Monteiro, Sara C; Beck, Andrew; Coelho, Bonnie Ball; Boxall, Alistair B A; Duenk, Peter W; Kleywegt, Sonya; Lapen, David R; Payne, Michael; Sabourin, Lyne; Li, Hongxia; Metcalfe, Chris D

    2008-06-15

    Municipal biosolids are a source of nutrients for crop production. Beneficial Management Practices (BMPs) can be used to minimize the risk of contamination of adjacent water resources with chemical or microbial agents that are of public or environmental health concern. In this field study, we applied biosolids slurry at a commercial rate using either subsurface injection or broadcast application followed by incorporation. Precipitation was simulated at 1, 3, 7, 22, 36 and 266 days post-application on 2 m(2) microplots to evaluate surface runoff of 9 model pharmaceuticals and personal care products (PPCPs), atenolol, carbamazepine, cotinine, gemfibrozil, naproxen, ibuprofen, acetaminophen, sulfamethoxazole and triclosan. In runoff from the injected plots, concentrations of the model PPCPs were generally below the limits of quantitation. In contrast, in the broadcast application treatment, the concentrations of atenolol, carbamazepine, cotinine, gemfibrozil, naproxen, sulfamethoxazole and triclosan on the day following application ranged from 70-1477 ng L(-1) in runoff and generally declined thereafter with first order kinetics. The total mass of PPCPs mobilized in surface runoff per m(2) of the field ranged from 0.63 microg for atenolol to 21.1 microg for ibuprofen. For ibuprofen and acetaminophen, concentrations in runoff first decreased and then increased, suggesting that these drugs were initially chemically or physically sequestered in the biosolids slurry, and subsequently released in the soil. Carbamazepine and triclosan were detected at low concentrations in a runoff event 266 days after broadcast application. Overall, this study showed that injection of biosolids slurry below the soil surface could effectively eliminate surface runoff of PPCPs. PMID:18377955

  13. Multi-frequency SAR data for soil surface moisture estimation over agricultural fields

    NASA Astrophysics Data System (ADS)

    Zribi, Mehrez; Baghdadi, Nicolas

    2015-04-01

    Soil moisture plays a crucial role in the continental water cycle, in particular through its influence on the distribution of precipitation between surface runoff and infiltration, which is the main driver behind most hydrological and geomorphologic processes. Although there is now a good understanding of soil hydrodynamics and water transfer in porous media, the development of reliable techniques allowing field heterogeneities to be fully analyzed in space and time remains a key issue. In recent decades, various inversion models have been proposed for the retrieval of surface parameters (mainly soil moisture and surface roughness) from Synthetic Aperture Radar (SAR) high resolution measurements. The proposed techniques depend particularly on two instrumental parameters: the radar system's spatial resolution and the number of configurations measured during satellite acquisitions (mainly incidence angle and polarization). In this paper, our objective is to illustrate different applications of SAR data to estimate soil moisture over bare soil and vegetation cover areas (wheat, olive groves, meadows ...). Potential of very high resolution data, with the availability of TerraSAR-X and COSMO-SkyMed constellations is also discussed. This study is based on different experimental campaigns organized over different sites in humid and semi-arid regions. Ground measurements (soil moisture, soil roughness, vegetation description) over test fields were carried out simultaneously to SAR measurements. Effect of vegetation attenuation on radar signal is considered through a synergy with optical remote sensing. Soil moisture precision for all proposed applications is generally ranged between 3 and 5% of volumetric moisture. These methodologies are developed in the context of the preparation for having a high soil moisture operational product, with SENTINEL and/or the other planned constellations. After an analysis of radar data sensitivity (C and X bands) to surface parameters

  14. Nitrogen Cycle Modeling: a Mechanistic Estimate of N-losses From Agricultural Fields Over the Seasonal Time Period

    NASA Astrophysics Data System (ADS)

    Maggi, F.; Gu, C.; Venterea, R.; Riley, W.; Oldenburg, C.

    2007-12-01

    The biogeochemical cycle of nitrogen and production of NO, N2O, and CO2 gas and NO2- and NO3- ions in nutrient-enriched agricultural fields is mediated by soil microbial activity, the hydrological cycle, plant dynamics, and climatic forcing. Understanding how NO, N2O, CO2 gases and NO2- and NO3- ions are released from agricultural fields to the environment is a key factor in controlling the green-house effect and water contamination, and assumes ever greater importance in view of the foreseen increase in biofuel, food, and fiber production. To address these issues we have developed a mechanistic model (TOUGHREACT-N) for various nitrification and denitrification pathways, multiple microbial biomass dynamics, heat and water flows, and various chemical reactions at local and kinetic equilibrium. The soil column is represented in a 1D framework, with hydraulic properties described by a water tension-saturation model. Biotic and abiotic reactions are assumed to follow Michaelis-Menten kinetics, while a consortium of several micro-organismal strains is assumed to follow multiple Monod growth kinetics accounting for electron donor, electron acceptor, and inhibitor concentrations. Water flow is modeled with the Darcy-Richards equation, while nutrient transport is modeled by Fickian advective and diffusive processes in both gaseous and liquid phases. Heat flow is modeled with the Fourier equation. Plant dynamics is taken into account by coupling TOUGHREACT-N with CERES to determine water and nutrient uptake, and soil carbon accumulation. TOUGHREACT-N was calibrated against field measurements to assess pathways of N losses following fertilization. A good agreement between field observations and model predictions was found. We identified two dominant time scales in the system response that depended on plants dynamics. Before plants have substantial impact on soil nutrients and moisture content, N losses are characterized by rapid increases as a function of water application

  15. Nutrient uptake by agricultural crops from biochar-amended soils: results from two field experiments in Austria

    NASA Astrophysics Data System (ADS)

    Karer, Jasmin; Zehetner, Franz; Kloss, Stefanie; Wimmer, Bernhard; Soja, Gerhard

    2013-04-01

    The use of biochar as soil amendment is considered as a promising agricultural soil management technique, combining carbon sequestration and soil fertility improvements. These expectations are largely founded on positive experiences with biochar applications to impoverished or degraded tropical soils. The validity of these results for soils in temperate climates needs confirmation from field experiments with typical soils representative for intensive agricultural production areas. Frequently biochar is mixed with other organic additives like compost. As these two materials interact with each other and each one may vary considerably in its basic characteristics, it is difficult to attribute the effects of the combined additive to one of its components and to a specific physico-chemical parameter. Therefore investigations of the amendment efficacy require the study of the pure components to characterize their specific behavior in soil. This is especially important for adsorption behavior of biochar for macro- and micronutrients because in soil there are multiple nutrient sinks that compete with plant roots for vital elements. Therefore this contribution presents results from a field amendment study with pure biochar that had the objective to characterize the macro- and microelement uptake of crops from different soils in two typical Austrian areas of agricultural production. At two locations in North and South-East Austria, two identical field experiments on different soils (Chernozem and Cambisol) were installed in 2011 with varying biochar additions (0, 30 and 90 t/ha) and two nitrogen levels. The biochar was a product from slow pyrolysis of wood (SC Romchar SRL). During the installation of the experiments, the biochar fraction of <2 mm was mixed with surface soil to a depth of 15 cm in plots of 33 m2 each (n=4). Barley (at the Chernozem soil) and maize (at the Cambisol) were cultivated according to standard agricultural practices. The highest crop yields at both

  16. Discrimination of conventional and organic white cabbage from a long-term field trial study using untargeted LC-MS-based metabolomics.

    PubMed

    Mie, Axel; Laursen, Kristian Holst; Åberg, K Magnus; Forshed, Jenny; Lindahl, Anna; Thorup-Kristensen, Kristian; Olsson, Marie; Knuthsen, Pia; Larsen, Erik Huusfeldt; Husted, Søren

    2014-05-01

    The influence of organic and conventional farming practices on the content of single nutrients in plants is disputed in the scientific literature. Here, large-scale untargeted LC-MS-based metabolomics was used to compare the composition of white cabbage from organic and conventional agriculture, measuring 1,600 compounds. Cabbage was sampled in 2 years from one conventional and two organic farming systems in a rigidly controlled long-term field trial in Denmark. Using Orthogonal Projection to Latent Structures-Discriminant Analysis (OPLS-DA), we found that the production system leaves a significant (p = 0.013) imprint in the white cabbage metabolome that is retained between production years. We externally validated this finding by predicting the production system of samples from one year using a classification model built on samples from the other year, with a correct classification in 83 % of cases. Thus, it was concluded that the investigated conventional and organic management practices have a systematic impact on the metabolome of white cabbage. This emphasizes the potential of untargeted metabolomics for authenticity testing of organic plant products.

  17. Instantaneous and daily values of the surface energy balance over agricultural fields using remote sensing and a reference field in an arid environment

    USGS Publications Warehouse

    Kustas, W.P.; Moran, M.S.; Jackson, R. D.; Gay, L.W.; Duell, L.F.W.; Kunkel, K.E.; Matthias, A.D.

    1990-01-01

    Remotely sensed surface temperature and reflectance in the visible and near infrared wavebands along with ancilliary meteorological data provide the capability of computing three of the four surface energy balance components (i.e., net radiation, soil heat flux, and sensible heat flux) at different spatial and temporal scales. As a result, under nonadvective conditions, this enables the estimation of the remaining term (i.e., the latent heat flux). One of the practical applications with this approach is to produce evapotranspiration (ET) maps for agricultural regions which consist of an array of fields containing different crops at varying stages of growth and soil moisture conditions. Such a situation exists in the semiarid southwest at the University of Arizona Maricopa Agricultural Center, south of Phoenix. For one day (14 June 1987), surface temperature and reflectance measurements from an aircraft 150 m above ground level (agl) were acquired over fields from zero to nearly full cover at four times between 1000 MST and 1130 MST. The diurnal pattern of the surface energy balance was measured over four fields, which included alfalfa at 60% cover, furrowed cotton at 20% and 30% cover, and partially plowed what stubble. Instantaneous and daily values of ET were estimated for a representative area around each flux site with an energy balance model that relies on a reference ET. This reference value was determined with remotely sensed data and several meteorological inputs. The reference ET was adjusted to account for the different surface conditions in the other fields using only remotely sensed variables. A comparison with the flux measurements suggests the model has difficulties with partial canopy conditions, especially related to the estimation of the sensible heat flux. The resulting errors for instantaneous ET were on the order of 100 W m-2 and for daily values of order 2 mm day-1. These findings suggest future research should involve development of methods to

  18. Keeping agricultural soil out of rivers: evidence of sediment and nutrient accumulation within field wetlands in the UK.

    PubMed

    Ockenden, Mary C; Deasy, Clare; Quinton, John N; Surridge, Ben; Stoate, Chris

    2014-03-15

    Intensification of agriculture has resulted in increased soil degradation and erosion, with associated pollution of surface waters. Small field wetlands, constructed along runoff pathways, offer one option for slowing down and storing runoff in order to allow more time for sedimentation and for nutrients to be taken up by plants or micro-organisms. This paper describes research to provide quantitative evidence for the effectiveness of small field wetlands in the UK landscape. Ten wetlands were built on four farms in Cumbria and Leicestershire, UK. Annual surveys of sediment and nutrient accumulation in 2010, 2011 and 2012 indicated that most sediment was trapped at a sandy site (70 tonnes over 3 years), compared to a silty site (40 tonnes over 3 years) and a clay site (2 tonnes over 3 years). The timing of rainfall was more important than total annual rainfall for sediment accumulation, with most sediment transported in a few intense rainfall events, especially when these coincided with bare soil or poor crop cover. Nutrient concentration within sediments was inversely related to median particle size, but the total mass of nutrients trapped was dependent on the total mass of sediment trapped. Ratios of nutrient elements in the wetland sediments were consistent between sites, despite different catchment characteristics across the individual wetlands. The nutrient value of sediment collected from the wetlands was similar to that of soil in the surrounding fields; dredged sediment was considered to have value as soil replacement but not as fertiliser. Overall, small field wetlands can make a valuable contribution to keeping soil out of rivers.

  19. Keeping agricultural soil out of rivers: evidence of sediment and nutrient accumulation within field wetlands in the UK.

    PubMed

    Ockenden, Mary C; Deasy, Clare; Quinton, John N; Surridge, Ben; Stoate, Chris

    2014-03-15

    Intensification of agriculture has resulted in increased soil degradation and erosion, with associated pollution of surface waters. Small field wetlands, constructed along runoff pathways, offer one option for slowing down and storing runoff in order to allow more time for sedimentation and for nutrients to be taken up by plants or micro-organisms. This paper describes research to provide quantitative evidence for the effectiveness of small field wetlands in the UK landscape. Ten wetlands were built on four farms in Cumbria and Leicestershire, UK. Annual surveys of sediment and nutrient accumulation in 2010, 2011 and 2012 indicated that most sediment was trapped at a sandy site (70 tonnes over 3 years), compared to a silty site (40 tonnes over 3 years) and a clay site (2 tonnes over 3 years). The timing of rainfall was more important than total annual rainfall for sediment accumulation, with most sediment transported in a few intense rainfall events, especially when these coincided with bare soil or poor crop cover. Nutrient concentration within sediments was inversely related to median particle size, but the total mass of nutrients trapped was dependent on the total mass of sediment trapped. Ratios of nutrient elements in the wetland sediments were consistent between sites, despite different catchment characteristics across the individual wetlands. The nutrient value of sediment collected from the wetlands was similar to that of soil in the surrounding fields; dredged sediment was considered to have value as soil replacement but not as fertiliser. Overall, small field wetlands can make a valuable contribution to keeping soil out of rivers. PMID:24509365

  20. Clove oil as an anaesthetic for adult sockeye salmon: Field trials

    USGS Publications Warehouse

    Woody, C.A.; Nelson, Jack L.; Ramstad, K.

    2002-01-01

    Wild migrating sockeye salmon Oncorhynchus nerka exposed to 20, 50 and 80 mg 1-1 of clove oil could be handled within 3 min, recovered within 10 min, and survived 15 min exposure trials. Fish tested at 110 mg 1-1 did not recover from 15 min exposure trials. Response curves developed for induction and recovery time considered the following predictors: clove oil concentration, sex, fish length and depth. A significant positive dependence was observed between induction time and fish length for 20, 50 and 80 mg 1-1 test concentrations; no dependence was observed between induction time and length at 110 and 140 mg 1-1. Recovery time differed as a function of clove oil concentration, but not fish size. A concentration of 50 mg 1-1 is recommended for anaesthetizing sockeye salmon ranging in length from 400 to 550 mm at water temperatures averaging 9-10??C.

  1. Leaching of glyphosate and amino-methylphosphonic acid from Danish agricultural field sites.

    PubMed

    Kjaer, Jeanne; Olsen, Preben; Ullum, Marlene; Grant, Ruth

    2005-01-01

    Pesticide leaching is an important process with respect to contamination risk to the aquatic environment. The risk of leaching was thus evaluated for glyphosate (N-phosphonomethyl-glycine) and its degradation product AMPA (amino-methylphosphonic acid) under field conditions at one sandy and two loamy sites. Over a 2-yr period, tile-drainage water, ground water, and soil water were sampled and analyzed for pesticides. At a sandy site, the strong soil sorption capacity and lack of macropores seemed to prevent leaching of both glyphosate and AMPA. At one loamy site, which received low precipitation with little intensity, the residence time within the root zone seemed sufficient to prevent leaching of glyphosate, probably due to degradation and sorption. Minor leaching of AMPA was observed at this site, although the concentration was generally low, being on the order of 0.05 microg L(-1) or less. At another loamy site, however, glyphosate and AMPA leached from the root zone into the tile drains (1 m below ground surface [BGS]) in average concentrations exceeding 0.1 microg L(-1), which is the EU threshold value for drinking water. The leaching of glyphosate was mainly governed by pronounced macropore flow occurring within the first months after application. AMPA was frequently detected more than 1.5 yr after application, thus indicating a minor release and limited degradation capacity within the soil. Leaching has so far been confined to the depth of the tile drains, and the pesticides have rarely been detected in monitoring screens located at lower depths. This study suggests that as both glyphosate and AMPA can leach through structured soils, they thereby pose a potential risk to the aquatic environment.

  2. Government regulation and public opposition create high additional costs for field trials with GM crops in Switzerland.

    PubMed

    Bernauer, Thomas; Tribaldos, Theresa; Luginbühl, Carolin; Winzeler, Michael

    2011-12-01

    Field trials with GM crops are not only plant science experiments. They are also social experiments concerning the implications of government imposed regulatory constraints and public opposition for scientific activity. We assess these implications by estimating additional costs due to government regulation and public opposition in a recent set of field trials in Switzerland. We find that for every Euro spent on research, an additional 78 cents were spent on security, an additional 31 cents on biosafety, and an additional 17 cents on government regulatory supervision. Hence the total additional spending due to government regulation and public opposition was around 1.26 Euros for every Euro spent on the research per se. These estimates are conservative; they do not include additional costs that are hard to monetize (e.g. stakeholder information and dialogue activities, involvement of various government agencies). We conclude that further field experiments with GM crops in Switzerland are unlikely unless protected sites are set up to reduce these additional costs.

  3. Effects of soil amendments and EDTA on lead uptake by Chromolaena odorata: greenhouse and field trial experiments.

    PubMed

    Tanhan, Phanwimol; Pokethitiyook, Prayad; Kruatrachue, Maleeya; Chaiyarat, Rattanawat; Upatham, Suchart

    2011-10-01

    Greenhouse and field trial experiments were performed to evaluate the use of Chromolaena odorata with various soil amendments for phytoextraction of Pb contaminated soil Pb mine soils contain low amount of nutrients, so the additions of organic (cow manure) and inorganic (Osmocote and NH4NO3 and KCl) fertilizers with EDTA were used to enhance plant growth and Pb accumulation. Greenhouse study showed that cow manure decreased available Pb concentrations and resulted in the highest Pb concentration in roots (4660 mg kg(-1)) and shoots (389.2 mg kg(-1)). EDTA increased Pb accumulation in shoots (17-fold) and roots (11-fold) in plants grown in soil with Osmocote with Pb uptake up to 203.5 mg plant(-1). Application of all fertilizers had no significant effects on relative growth rates of C. odorata. Field trial study showed that C. odorata grown in soil with 99545 mg kg(-1) total Pb accumulated up to 3730.2 and 6698.2 mg kg(-1) in shoots and roots, respectively, with the highest phytoextraction coefficient (1.25) and translocation factor (1.18). These results indicated that C. odorata could be used for phytoextraction of Pb contaminated soil. In addition, more effective Pb accumulation could be enhanced by Osmocote fertilizer. However, the use of EDTA in the field should be concerned with their leaching problems.

  4. Field-based evidence for consistent responses of bacterial communities to copper contamination in two contrasting agricultural soils

    PubMed Central

    Li, Jing; Ma, Yi-Bing; Hu, Hang-Wei; Wang, Jun-Tao; Liu, Yu-Rong; He, Ji-Zheng

    2015-01-01

    Copper contamination on China's arable land could pose severe economic, ecological and healthy consequences in the coming decades. As the drivers in maintaining ecosystem functioning, the responses of soil microorganisms to long-term copper contamination in different soil ecosystems are still debated. This study investigated the impacts of copper gradients on soil bacterial communities in two agricultural fields with contrasting soil properties. Our results revealed consistent reduction in soil microbial biomass carbon (SMBC) with increasing copper levels in both soils, coupled by significant declines in bacterial abundance in most cases. Despite of contrasting bacterial community structures between the two soils, the bacterial diversity in the copper-contaminated soils showed considerably decreasing patterns when copper levels elevated. High-throughput sequencing revealed copper selection for major bacterial guilds, in particular, Actinobacteria showed tolerance, while Acidobacteria and Chloroflexi were highly sensitive to copper. The thresholds that bacterial communities changed sharply were 800 and 200 added copper mg kg−1 in the fluvo-aquic soil and red soil, respectively, which were similar to the toxicity thresholds (EC50 values) characterized by SMBC. Structural equation model (SEM) analysis ascertained that the shifts of bacterial community composition and diversity were closely related with the changes of SMBC in both soils. Our results provide field-based evidence that copper contamination exhibits consistently negative impacts on soil bacterial communities, and the shifts of bacterial communities could have largely determined the variations of the microbial biomass. PMID:25699026

  5. Field trials of various molluscicides (chiefly sodium pentachlorophenate) for the control of aquatic intermediate hosts of human bilharziasis *†

    PubMed Central

    Wright, Willard H.; Dobrovolny, Charles G.; Berry, Elmer G.

    1958-01-01

    Field trials of various molluscicides—notably sodium pentachlorophenate, copper sulfate and dinitro-o-cyclohexylphenol—were carried out in Brazil in order to test their effectiveness against the aquatic intermediate hosts of human bilharziasis. Sodium pentachlorophenate was found to be the most effective in relation to cost and availability. Subsequent tests in Egypt, using sodium pentachlorophenate alone, while confirming the effectiveness of this molluscicide in bilharziasis control, have shown that the dosage and methods of application must be adapted to environmental conditions. PMID:13573120

  6. Report of a joint DMRQC/Organon field trial to detect hepatitis A IgM by ELISA.

    PubMed

    Supran, E M; Craske, J; Hart, R J; Kurtz, J B; Parry, J V; Skidmore, S J; Gardner, P S

    1983-10-01

    The results of a field trial of a joint DMRQC/Organon ELISA kit for the detection of hepatitis A IgM antibody are reported. The participating laboratories were asked to use the kit to test a panel of 360 specimens consisting of duplicate coded samples of 180 sera. The panel was also tested by MACRIA in the Virus Reference Laboratory, Colindale. The ELISA was shown to be specific and sensitive giving good discrimination between acute and late convalescent hepatitis A sera. It was proposed that the same cut-off control as is used in the RIA (equivalent to 10 RIA units) should be adopted for the ELISA also.

  7. An improvement of Gurson-type models of porous materials by using Eshelby-like trial velocity fields

    NASA Astrophysics Data System (ADS)

    Monchiet, Vincent; Charkaluk, Eric; Kondo, Djimedo

    2007-01-01

    New expressions of the macroscopic criteria of perfectly plastic rigid matrix containing prolate and oblate cavities are presented. The proposed approach, derived in the framework of limit analysis, consists in the consideration of Eshelby-like trial velocity fields for the determination of the macroscopic dissipation. It is shown that the obtained results significantly improve existing criteria for ductile porous media. Moreover, for low stress triaxialities, these new results also agree perfectly with the (nonlinear) Hashin-Shtrikhman bound established by Ponte-Castañeda and Suquet. To cite this article: V. Monchiet et al., C. R. Mecanique 335 (2007).

  8. Chemical and biological characterization of products of incomplete combustion from the simulated field burning of agricultural plastic

    SciTech Connect

    Linak, W.P.; Ryan, J.V.; Perry, E.; Williams, R.W.; DeMarini, D.M.

    1989-06-01

    Chemical and biological analyses were performed to characterize products of incomplete combustion emitted during the simulated open field burning of agricultural plastic. A small utility shed equipped with an air delivery system was used to simulate pile burning and forced-air-curtain incineration of a nonhalogenated agricultural plastic that reportedly consisted of polyethylene and carbon black. Emissions were analyzed for combustion gases; volatile, semi-volatile, and particulate organics; and toxic and mutagenic properties. Emission samples, as well as samples of the used (possibly pesticide-contaminated) plastic, were analyzed for the presence of several pesticides to which the plastic may have been exposed. Although a variety of alkanes, alkenes, and aromatic and polycyclic aromatic hydrocarbon (PAH) compounds were identified in the volatile, semi-volatile, and particulate fractions of these emissions, a substantial fraction of higher molecular weight organic material was not identified. No pesticides were identified in either combustion emission samples or dichloromethane washes of the used plastic. When mutagenicity was evaluated by exposing Salmonella bacteria (Ames assay) to whole vapor and vapor/particulate emissions, no toxic or mutagenic effects were observed. However, organic extracts of the particulate samples were moderately mutagenic. This mutagenicity compares approximately to that measured from residential wood heating on a revertant per unit heat release basis. Compared to pile burning, forced air slightly decreased the time necessary to burn a charge of plastic. There was not a substantial difference, however, in the variety or concentrations of organic compounds identified in samples from these two burn conditions. This study highlights the benefits of a combined chemical/biological approach to the characterization of complex, multi-component combustion emissions.

  9. COMBAT: Initial experience with a randomized clinical trial of plasma-based resuscitation in the field for traumatic hemorrhagic shock

    PubMed Central

    Chapman, Michael P.; Moore, Ernest E.; Chin, Theresa L; Ghasabyan, Arsen; Chandler, James; Stringham, John; Gonzalez, Eduardo; Moore, Hunter B.; Banerjee, Anirban; Silliman, Christopher C; Sauaia, Angela

    2015-01-01

    The existing evidence shows great promise for plasma as the first resuscitation fluid in both civilian and military trauma. We embarked on the Control of Major Bleeding After Trauma (COMBAT) trial with the support of the Department of Defense, in order to determine if plasma-first resuscitation yields hemostatic and survival benefits. The methodology of the COMBAT study represents not only three years of development work, but the integration of nearly two-decades of technical experience with the design and implementation of other clinical trials and studies. Herein, we describe the key features of the study design, critical personnel and infrastructural elements, and key innovations. We will also briefly outline the systems engineering challenges entailed by this study. COMBAT is a randomized, placebo controlled, semi-blinded prospective Phase IIB clinical trial, conducted in a ground ambulance fleet based at a Level I trauma center, and part of a multicenter collaboration. The primary objective of COMBAT is to determine the efficacy of field resuscitation with plasma first, compared to standard of care (normal saline). To date we have enrolled 30 subjects in the COMBAT study. The ability to achieve intervention with a hemostatic resuscitation agent in the closest possible temporal proximity to injury is critical and represents an opportunity to forestall the evolution of the “bloody vicious cycle”. Thus, the COMBAT model for deploying plasma in first response units should serve as a model for RCTs of other hemostatic resuscitative agents. PMID:25784527

  10. A least-squares inversion technique for identification of a point release: Application to Fusion Field Trials 2007

    NASA Astrophysics Data System (ADS)

    Singh, Sarvesh Kumar; Rani, Raj

    2014-08-01

    Identification of a point release is a parametric estimation problem associated with the estimation of its parameters namely, location and strength. A least-squares inversion algorithm, free from initial guess of release parameters, is utilized here for the source identification in eleven trials of single continuous point releases conducted during Fusion Field Trials 2007. The source locations are retrieved within an average error of 23 m from their true locations. The maximum and minimum errors in the retrieval of the source location are obtained as 57.3 m and 3 m respectively. The source strength is retrieved within a factor of 1.6 in all the trials. The sensitivity of the source estimation is analysed with respect to (i) variation of grid sizes in discretized space, (ii) inclusion of zero measurements and (iii) addition of new measurements. Posterior uncertainty is mentioned in terms of variance of the source parameters, approximated by using the Hessian of the cost function. In addition, an attempt is made to obtain the minimum number of measurements for a successful source inversion. The study explores the future applicability of this least-squares inversion technique for point source identification.

  11. Pilot Evaluation of an Internet Educational Module for Agricultural Safety

    ERIC Educational Resources Information Center

    Schwab, Charles V.; Freeman, Steven A.

    2011-01-01

    An important component of the safe operation of agricultural equipment is the ability to read and understand universal symbols. The Internet educational module is designed to help participants recognize these symbols. The impact of using it was evaluated using a field trial study. Assessment consisted of pre- and post-tests. Youth who had access…

  12. Pilot Field Trial of the EG95 Vaccine Against Ovine Cystic Echinococcosis in Rio Negro, Argentina: Second Study of Impact

    PubMed Central

    Larrieu, Edmundo; Mujica, Guillermo; Gauci, Charles G.; Vizcaychipi, Katherina; Seleiman, Marcos; Herrero, Eduardo; Labanchi, José Luis; Araya, Daniel; Sepúlveda, Luis; Grizmado, Claudia; Calabro, Arnoldo; Talmon, Gabriel; Poggio, Thelma Verónica; Crowley, Pablo; Cespedes, Graciela; Santillán, Graciela; García Cachau, Mariela; Lamberti, Roberto; Gino, Lilia; Donadeu, Meritxell; Lightowlers, Marshall W.

    2015-01-01

    Background Cystic echinococcosis (CE) is an important zoonotic disease caused by the cestode parasite Echinococcus granulosus. It occurs in many parts of the world where pastoral activities predominate, including the Rio Negro province of Argentina. Although CE control activities have been undertaken in the western regions of Rio Negro for more than two decades, the disease continues to remain prevalent in both the human and livestock animal populations. Vaccination of animal intermediate hosts of CE with the EG95 vaccine may provide a new opportunity to improve the effectiveness of CE control measures, although data are lacking about field application of the vaccine. Aims Evaluate the impact of EG95 vaccination in sheep on the transmission of Echinococcus granulosus in a field environment. Methodology Two trial sites were established in western Rio Negro province within indigenous communities. Vaccination of lambs born into one trial site was introduced and continued for 6 years. Prior to initiation of the trial, and at the end of the trial, the prevalence of CE in sheep was determined by necropsy. Weaned lambs received two injections of EG95 vaccine, approximately one month apart, and a single booster injection one year later. Vaccination was not implemented at the second trial site. A total of 2725 animals were vaccinated in the first year. Animals from this cohort as well as age-matched sheep from the control area were evaluated by necropsy. Key results Introduction of the vaccine led to a statistically significant in the number and size of hydatid cysts in comparison to the situation prior to the introduction of the vaccine, or compared to CE prevalence in the control area where the vaccine was not applied. The prevalence of infection in the vaccinated area was also significantly reduced by 62% compared to the re-intervention level, being lower than the prevalence seen in the control area, although the difference from the control area after the intervention

  13. Pulsed electromagnetic fields after arthroscopic treatment for osteochondral defects of the talus: double-blind randomized controlled multicenter trial

    PubMed Central

    van Bergen, Christiaan JA; Blankevoort, Leendert; de Haan, Rob J; Sierevelt, Inger N; Meuffels, Duncan E; d'Hooghe, Pieter RN; Krips, Rover; van Damme, Geert; van Dijk, C Niek

    2009-01-01

    Background Osteochondral talar defects usually affect athletic patients. The primary surgical treatment consists of arthroscopic debridement and microfracturing. Although this is mostly successful, early sport resumption is difficult to achieve, and it can take up to one year to obtain clinical improvement. Pulsed electromagnetic fields (PEMFs) may be effective for talar defects after arthroscopic treatment by promoting tissue healing, suppressing inflammation, and relieving pain. We hypothesize that PEMF-treatment compared to sham-treatment after arthroscopy will lead to earlier resumption of sports, and aim at 25% increase in patients that resume sports. Methods/Design A prospective, double-blind, randomized, placebo-controlled trial (RCT) will be conducted in five centers throughout the Netherlands and Belgium. 68 patients will be randomized to either active PEMF-treatment or sham-treatment for 60 days, four hours daily. They will be followed-up for one year. The combined primary outcome measures are (a) the percentage of patients that resume and maintain sports, and (b) the time to resumption of sports, defined by the Ankle Activity Score. Secondary outcome measures include resumption of work, subjective and objective scoring systems (American Orthopaedic Foot and Ankle Society – Ankle-Hindfoot Scale, Foot Ankle Outcome Score, Numeric Rating Scales of pain and satisfaction, EuroQol-5D), and computed tomography. Time to resumption of sports will be analyzed using Kaplan-Meier curves and log-rank tests. Discussion This trial will provide level-1 evidence on the effectiveness of PEMFs in the management of osteochondral ankle lesions after arthroscopy. Trial registration Netherlands Trial Register (NTR1636) PMID:19591674

  14. Are BVOC exchanges in agricultural ecosystems overestimated? Insights from fluxes measured in a maize field over a whole growing season

    NASA Astrophysics Data System (ADS)

    Bachy, Aurélie; Aubinet, Marc; Schoon, Niels; Amelynck, Crist; Bodson, Bernard; Moureaux, Christine; Heinesch, Bernard

    2016-04-01

    Although maize is the second most important crop worldwide, and the most important C4 crop, no study on biogenic volatile organic compounds (BVOCs) has yet been conducted on this crop at ecosystem scale and over a whole growing season. This has led to large uncertainties in cropland BVOC emission estimations. This paper seeks to fill this gap by presenting, for the first time, BVOC fluxes measured in a maize field at ecosystem scale (using the disjunct eddy covariance by mass scanning technique) over a whole growing season in Belgium. The maize field emitted mainly methanol, although exchanges were bi-directional. The second most exchanged compound was acetic acid, which was taken up mainly in the growing season. Bi-directional exchanges of acetaldehyde, acetone and other oxygenated VOCs also occurred, whereas the terpenes, benzene and toluene exchanges were small, albeit significant. Surprisingly, BVOC exchanges were of the same order of magnitude on bare soil and on well developed vegetation, suggesting that soil is a major BVOC reservoir in agricultural ecosystems. Quantitatively, the maize BVOC emissions observed were lower than those reported in other maize, crops and grasses studies. The standard emission factors (SEFs) estimated in this study (231 ± 19 µg m-2 h-1 for methanol, 8 ± 5 µg m-2 h-1 for isoprene and 4 ± 6 µg m-2 h-1 for monoterpenes) were also much lower than those currently used by models for C4 crops, particularly for terpenes. These results suggest that maize fields are small BVOC exchangers in north-western Europe, with a lower BVOC emission impact than that modelled for growing C4 crops in this part of the world. They also reveal the high variability in BVOC exchanges across world regions for maize and suggest that SEFs should be estimated for each region separately.

  15. Effects of agricultural tillage practise on green house gas balance of an arable soil in a long term field experiment

    NASA Astrophysics Data System (ADS)

    Munch, Jean Charles; Schilling, Rolf; Ruth, Bernhard; Fuss, Roland

    2010-05-01

    Soils are an important part of the global carbon cycle. A large proportion of global carbon dioxide (CO2) emissions is released from soils, though carbon sequestration occurs. Nitrous oxide (N2O) emissions of soils are also believed to contribute significantly to the green house effect as well as the stratospheric ozone depletion. An important source of N2O emissions is denitrification of nitrate from nitrogen fertilized soils. Although it is desirable to minimize these emissions while maintaining high crop yields it is still poorly understood how green house gas emissions may be steered by agricultural management practise, i.e. tillage and fertilization systems . In an ongoing long term field experiment at the research farm Scheyern, Bavaria, a arable field with one homogenous soil formation was transformed into plots in a randomized design 14 years ago. Since then, they are managed using conventional tillage (CT) and no tillage (NT) as well as low and high fertilization. A conventional crop rotation is maintained on the field. Starting 2007, CO2 and N2O emissions were monitored continuously for 2.5 years. Furthermore water content, temperature and redox potential were measured in-situ as they are major factors on microbial activity and denitrification. Soil was sampled from the Ap horizons of the plots about twice a month and extracts from these soil samples were analyzed for dissolved organic carbon (DOC), ammonium, nitrate/nitrite, and dissolved organic nitrogen (DON). According to the results soil density and hydrology are clearly affected by tillage practise. DOC is more affected by tillage while concentration of nitrogen species is controlled mainly by fertilization. There are distinct differences in redox potential between CT and NT plots with CT plots having more anaerobic periods. CO2 and N2O emissions exhibit a clear seasonal pattern and are affected by both tillage system and fertilization

  16. Spatial variability of nitrous oxide emissions and their soil-related determining factors in an agricultural field.

    PubMed

    Yanai, Junta; Sawamoto, Takuji; Oe, Taku; Kusa, Kanako; Yamakawa, Keisuke; Sakamoto, Kazunori; Naganawa, Takahiko; Inubushi, Kazuyuki; Hatano, Ryusuke; Kosaki, Takashi

    2003-01-01

    To evaluate spatial variability of nitrous oxide (N2O) emissions and to elucidate their determining factors on a field-scale basis, N2O fluxes and various soil properties were evaluated in a 100- x 100-m onion (Allium cepa L.) field. Nitrous oxide fluxes were determined by a closed chamber method from the one-hundred 10- x 10-m plots. Physical (e.g., bulk density and water content), chemical (e.g., total N and pH), and biological (e.g., microbial biomass C and N) properties were determined from surface soil samples (0-0.1 m) of each plot. Geostatistical analysis was performed to examine spatial variability of both N2O fluxes and soil properties. Multivariate analysis was also conducted to elucidate relationships between soil properties and observed fluxes. Nitrous oxide fluxes were highly variable (average 331 microg N m(-2) h(-1), CV 217%) and were log-normally distributed. Log-transformed N2O fluxes had moderate spatial dependence with a range of >75 m. High N2O fluxes were observed at sites with relatively low elevation. Multivariate analysis indicated that an organic matter factor and a pH factor of the principal component analysis were the main soil-related determining factors of log-transformed N2O fluxes. By combining multivariate analysis with geostatistics, a map of predicted N2O fluxes closely matched the spatial pattern of measured fluxes. The regression equation based on the soil properties explained 56% of the spatially structured variation of the log-transformed N2O fluxes. Site-specific management to regulate organic matter content and water status of a soil could be a promising means of reducing N2O emissions from agricultural fields. PMID:14674518

  17. Demonstration and validation of automated agricultural field extraction from multi-temporal Landsat data for the majority of United States harvested cropland

    NASA Astrophysics Data System (ADS)

    Yan, L.; Roy, D. P.

    2014-12-01

    The spatial distribution of agricultural fields is a fundamental description of rural landscapes and the location and extent of fields is important to establish the area of land utilized for agricultural yield prediction, resource allocation, and for economic planning, and may be indicative of the degree of agricultural capital investment, mechanization, and labor intensity. To date, field objects have not been extracted from satellite data over large areas because of computational constraints, the complexity of the extraction task, and because consistently processed appropriate resolution data have not been available or affordable. A recently published automated methodology to extract agricultural crop fields from weekly 30 m Web Enabled Landsat data (WELD) time series was refined and applied to 14 states that cover 70% of harvested U.S. cropland (USDA 2012 Census). The methodology was applied to 2010 combined weekly Landsat 5 and 7 WELD data. The field extraction and quantitative validation results are presented for the following 14 states: Iowa, North Dakota, Illinois, Kansas, Minnesota, Nebraska, Texas, South Dakota, Missouri, Indiana, Ohio, Wisconsin, Oklahoma and Michigan (sorted by area of harvested cropland). These states include the top 11 U.S states by harvested cropland area. Implications and recommendations for systematic application to global coverage Landsat data are discussed.

  18. Phase I Trial of Simultaneous In-Field Boost With Helical Tomotherapy for Patients With One to Three Brain Metastases

    SciTech Connect

    Rodrigues, George; Yartsev, Slav; Yaremko, Brian; Perera, Francisco; Dar, A. Rashid; Hammond, Alex; Lock, Michael; Yu, Edward; Ash, Robert; Caudrelier, Jean-Michelle; Khuntia, Deepak; Bailey, Laura; Bauman, Glenn

    2011-07-15

    Purpose: Stereotactic radiosurgery is an alternative to surgical resection for selected intracranial lesions. Integrated image-guided intensity-modulated-capable radiotherapy platforms such as helical tomotherapy (HT) could potentially replace traditional radiosurgery apparatus. The present study's objective was to determine the maximally tolerated dose of a simultaneous in-field boost integrated with whole brain radiotherapy for palliative treatment of patients with one to three brain metastases using HT. Methods and Materials: The inclusion/exclusion criteria and endpoints were consistent with the Radiation Therapy Oncology Group 9508 radiosurgery trial. The cohorts were constructed with a 3 + 3 design; however, additional patients were enrolled in the lower dose tolerable cohorts during the toxicity assessment periods. Whole brain radiotherapy (30 Gy in 10 fractions) was delivered with a 5-30-Gy (total lesion dose of 35-60 Gy in 10 fractions) simultaneous in-field boost delivered to the brain metastases. The maximally tolerated dose was determined by the frequency of neurologic Grade 3-5 National Cancer Institute Common Toxicity Criteria, version 3.0, dose-limiting toxicity events within each Phase I cohort. Results: A total of 48 patients received treatment in the 35-Gy (n = 3), 40-Gy (n = 16), 50-Gy (n = 15), 55-Gy (n = 8), and 60-Gy (n = 6) cohorts. No patients experienced dose-limiting toxicity events in any of the trial cohorts. The 3-month RECIST assessments available for 32 of the 48 patients demonstrated a complete response in 2, a partial response in 16, stable disease in 6, and progressive disease in 8 patients. Conclusion: The delivery of 60 Gy in 10 fractions to one to three brain metastases synchronously with 30 Gy whole brain radiotherapy was achieved without dose-limiting central nervous system toxicity as assessed 3 months after treatment. This approach is being tested in a Phase II efficacy trial.

  19. Efficacy of a piglet-specific commercial inactivated vaccine against Porcine circovirus type 2 in clinical field trials

    PubMed Central

    Han, Kiwon; Seo, Hwi Won; Oh, Yeonsu; Park, Changhoon; Kang, Ikjae; Jang, Hyun; Chae, Chanhee

    2013-01-01

    The efficacy of a piglet-specific inactivated Porcine circovirus type 2 (PCV2) vaccine was evaluated with clinical field trials, as recommended by the Republic of Korea’s Animal, Plant & Fisheries Quarantine & Inspection Agency. Three farms were selected on the basis of their history of postweaning multisystemic wasting syndrome. On each farm 60, 1-week-old pigs were randomly allocated to 1 of 2 treatment groups: vaccination at 1 and 3 wk of age or no vaccination. The 2-dose schedule of vaccination with inactivated PCV2 vaccine improved the average daily weight gain from birth to 16 wk of age, the PCV2 load in the blood, and the frequency and severity of lymph node lesions. Inactivated PCV2 vaccine seems to be very effective in controlling PCV2 infection under field conditions. PMID:24101803

  20. National Atmospheric Release Advisory Center Dispersion Modeling of the Full-scale Radiological Dispersal Device (FSRDD) Field Trials.

    PubMed

    Neuscamman, Stephanie; Yu, Kristen

    2016-05-01

    The results of the National Atmospheric Release Advisory Center (NARAC) model simulations are compared to measured data from the Full-Scale Radiological Dispersal Device (FSRDD) field trials. The series of explosive radiological dispersal device (RDD) experiments was conducted in 2012 by Defence Research and Development Canada (DRDC) and collaborating organizations. During the trials, a wealth of data was collected, including a variety of deposition and air concentration measurements. The experiments were conducted with one of the stated goals being to provide measurements to atmospheric dispersion modelers. These measurements can be used to facilitate important model validation studies. For this study, meteorological observations recorded during the tests are input to the diagnostic meteorological model, ADAPT, which provides 3-D, time-varying mean wind and turbulence fields to the LODI dispersion model. LODI concentration and deposition results are compared to the measured data, and the sensitivity of the model results to changes in input conditions (such as the particle activity size distribution of the source) and model physics (such as the rise of the buoyant cloud of explosive products) is explored. The NARAC simulations predicted the experimentally measured deposition results reasonably well considering the complexity of the release. Changes to the activity size distribution of the modeled particles can improve the agreement of the model results to measurement. PMID:27023036

  1. National Atmospheric Release Advisory Center dispersion modeling of the Full-scale Radiological Dispersal device (FSRDD) field trials

    DOE PAGES

    Neuscamman, Stephanie J.; Yu, Kristen L.

    2016-05-01

    The results of the National Atmospheric Release Advisory Center (NARAC) model simulations are compared to measured data from the Full-Scale Radiological Dispersal Device (FSRDD) field trials. The series of explosive radiological dispersal device (RDD) experiments was conducted in 2012 by Defence Research and Development Canada (DRDC) and collaborating organizations. During the trials, a wealth of data was collected, including a variety of deposition and air concentration measurements. The experiments were conducted with one of the stated goals being to provide measurements to atmospheric dispersion modelers. These measurements can be used to facilitate important model validation studies. For this study, meteorologicalmore » observations recorded during the tests are input to the diagnostic meteorological model, ADAPT, which provides 3–D, time-varying mean wind and turbulence fields to the LODI dispersion model. LODI concentration and deposition results are compared to the measured data, and the sensitivity of the model results to changes in input conditions (such as the particle activity size distribution of the source) and model physics (such as the rise of the buoyant cloud of explosive products) is explored. The NARAC simulations predicted the experimentally measured deposition results reasonably well considering the complexity of the release. Lastly, changes to the activity size distribution of the modeled particles can improve the agreement of the model results to measurement.« less

  2. Field trial assessment of biological, chemical, and physical responses of soil to tillage intensity, fertilization, and grazing.

    PubMed

    Vargas Gil, Silvina; Becker, Analia; Oddino, Claudio; Zuza, Mónica; Marinelli, Adriana; March, Guillermo

    2009-08-01

    Soil microbial populations can fluctuate in response to environmental changes and, therefore, are often used as biological indicators of soil quality. Soil chemical and physical parameters can also be used as indicators because they can vary in response to different management strategies. A long-term field trial was conducted to study the effects of different tillage systems (NT: no tillage, DH: disc harrow, and MP: moldboard plough), P fertilization (diammonium phosphate), and cattle grazing (in terms of crop residue consumption) in maize (Zea mays L.), sunflower (Heliantus annuus L.), and soybean (Glycine max L.) on soil biological, chemical, and physical parameters. The field trial was conducted for four crop years (2000/2001, 2001/2002, 2002/2003, and 2003/2004). Soil populations of Actinomycetes, Trichoderma spp., and Gliocladium spp. were 49% higher under conservation tillage systems, in soil amended with diammonium phosphate (DAP) and not previously grazed. Management practices also influenced soil chemical parameters, especially organic matter content and total N, which were 10% and 55% higher under NT than under MP. Aggregate stability was 61% higher in NT than in MP, 15% higher in P-fertilized soil, and also 9% higher in not grazed strips, bulk density being 12% lower in NT systems compared with MP. DAP application and the absence of grazing also reduced bulk density (3%). Using conservation tillage systems, fertilizing crops with DAP, and avoiding grazing contribute to soil health preservation and enhanced crop production. PMID:19533217

  3. Field Trial Assessment of Biological, Chemical, and Physical Responses of Soil to Tillage Intensity, Fertilization, and Grazing

    NASA Astrophysics Data System (ADS)

    Vargas Gil, Silvina; Becker, Analia; Oddino, Claudio; Zuza, Mónica; Marinelli, Adriana; March, Guillermo

    2009-08-01

    Soil microbial populations can fluctuate in response to environmental changes and, therefore, are often used as biological indicators of soil quality. Soil chemical and physical parameters can also be used as indicators because they can vary in response to different management strategies. A long-term field trial was conducted to study the effects of different tillage systems (NT: no tillage, DH: disc harrow, and MP: moldboard plough), P fertilization (diammonium phosphate), and cattle grazing (in terms of crop residue consumption) in maize ( Zea mays L.), sunflower ( Heliantus annuus L.), and soybean ( Glycine max L.) on soil biological, chemical, and physical parameters. The field trial was conducted for four crop years (2000/2001, 2001/2002, 2002/2003, and 2003/2004). Soil populations of Actinomycetes, Trichoderma spp., and Gliocladium spp. were 49% higher under conservation tillage systems, in soil amended with diammonium phosphate (DAP) and not previously grazed. Management practices also influenced soil chemical parameters, especially organic matter content and total N, which were 10% and 55% higher under NT than under MP. Aggregate stability was 61% higher in NT than in MP, 15% higher in P-fertilized soil, and also 9% higher in not grazed strips, bulk density being 12% lower in NT systems compared with MP. DAP application and the absence of grazing also reduced bulk density (3%). Using conservation tillage systems, fertilizing crops with DAP, and avoiding grazing contribute to soil health preservation and enhanced crop production.

  4. National Atmospheric Release Advisory Center Dispersion Modeling of the Full-scale Radiological Dispersal Device (FSRDD) Field Trials.

    PubMed

    Neuscamman, Stephanie; Yu, Kristen

    2016-05-01

    The results of the National Atmospheric Release Advisory Center (NARAC) model simulations are compared to measured data from the Full-Scale Radiological Dispersal Device (FSRDD) field trials. The series of explosive radiological dispersal device (RDD) experiments was conducted in 2012 by Defence Research and Development Canada (DRDC) and collaborating organizations. During the trials, a wealth of data was collected, including a variety of deposition and air concentration measurements. The experiments were conducted with one of the stated goals being to provide measurements to atmospheric dispersion modelers. These measurements can be used to facilitate important model validation studies. For this study, meteorological observations recorded during the tests are input to the diagnostic meteorological model, ADAPT, which provides 3-D, time-varying mean wind and turbulence fields to the LODI dispersion model. LODI concentration and deposition results are compared to the measured data, and the sensitivity of the model results to changes in input conditions (such as the particle activity size distribution of the source) and model physics (such as the rise of the buoyant cloud of explosive products) is explored. The NARAC simulations predicted the experimentally measured deposition results reasonably well considering the complexity of the release. Changes to the activity size distribution of the modeled particles can improve the agreement of the model results to measurement.

  5. Phytostabilization of a Pb-contaminated mine tailing by various tree species in pot and field trial experiments.

    PubMed

    Meeinkuirt, Weeradej; Pokethitiyook, Prayad; Kruatrachue, Maleeya; Tanhan, Phanwimol; Chaiyarat, Rattanawat

    2012-10-01

    The potential of 6 tree species (Leucaena leucocephala, Acacia mangium, Peltophorum pterocarpum, Pterocarpus macrocarpus, Lagerstroemia floribunda, Eucalyptus camaldulensis) for phytoremediation of Pb in sand tailings (total Pb >9850 mg kg(-1)) from KEMCO Pb mine in Kanchanaburi province, Thailand, were investigated employing a pot experiment (3 months) and field trial experiment (12 months). In pot study E. camaldulensis treated with Osmocote fertilizer attained the highest total biomass (15.3 g plant(-1)) followed by P. pterocarpum (12.6 g plant(-1)) and A. mangium (10.8 g plant(-1)) both treated with cow manure. Cow manure application resulted in the highest root Pb accumulation (>10000 mg kg(-1)) in L. floribunda and P. macrocarpus. These two species also exhibited the highest Pb uptake (85-88 mg plant(-1)). Results from field trial also showed that Osmocote promoted the best growth performance in E. camaldulensis (biomass 385.7 g plant(-1), height 141.7 cm) followed by A. mangium (biomass 215.9 g plant(-1), height 102.7 cm), and they also exhibited the highest Pb uptake (600-800 microg plant(-1)). A. mangium with the addition of organic fertilizer was the best option for phytostabilization of Pb-contaminated mine tailing because it retained higher Pb concentration in the roots. PMID:22908655

  6. Field Trial of LANL On-Line Advanced Enrichment Monitor for UF6 GCEP

    SciTech Connect

    Ianakiev, Kiril D.; Lombardi, Marcie; MacArthur, Duncan W.; Parker, Robert F.; Smith, Morag K.; Keller, Clifford; Friend, Peter; Dunford, Andrew

    2012-07-13

    The outline of this presentation is: (1) Technology basis of on-line enrichment monitoring; (2) Timescale of trial; (3) Description of installed equipment; (4) Photographs; (5) Results; (6) Possible further development; and (7) Conclusions. Summary of the good things about the Advanced Enrichment Monitor (AEM) performance is: (1) High accuracy - normally better than 1% relative, (2) Active system as accurate as passive system, (3) Fast and accurate detection of enrichment changes, (4) Physics is well understood, (5) Elegant method for capturing pressure signal, and (6) Data capture is automatic, low cost and fast. A couple of negative things are: (1) Some jumps in measured passive enrichment - of around +2% relative (due to clock errors?); and (2) Data handling and evaluation is off-line, expensive and very slow. Conclusions are: (1) LANL AEM is being tested on E23 plant at Capenhurst; (2) The trial is going very well; (3) AEM could detect production of HEU at potentially much lower cost than existing CEMO; (4) AEM can measure {sup 235}U assay accurately; (5) Active system using X-Ray source would avoid need for pressure measurement; (6) Substantial work lies ahead to go from current prototype to a production instrument.

  7. The Future of Field Trials in Europe: Establishing a Network Beyond Boundaries.

    PubMed

    Stützel, Hartmut; Brüggemann, Nicolas; Inzé, Dirk

    2016-02-01

    We propose the establishment of a European Consortium for Open Field Experimentation (ECOFE) that will allow easy access of European plant and soil scientists to experimental field stations that cover all major climatological regions. Coordination and quality control of data extraction and management systems will greatly impact on our ability to cope with grand challenges such as climate change and food security. PMID:26776473

  8. Fate of synthetic musks in a domestic wastewater treatment plant and in an agricultural field amended with biosolids.

    PubMed

    Yang, Jian-Jun; Metcalfe, Chris D

    2006-06-15

    Synthetic musks are widely used as fragrance ingredients in personal care products, and they enter domestic wastewater treatment plants (WWTPs) through discharges into municipal sewage systems. Samples of aqueous sewage and biosolids collected from the Peterborough Wastewater Treatment Plant (WWTP), Ontario, Canada were analyzed for 11 synthetic musk compounds using GC/MS. The results showed that 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta[g]-2-benzopyrane (HHCB, 173.1+/-43.4 ng/L) and 7-acetyl-1,1,3,4,4,6-hexamethyl-tetrahydronaphthalene (AHTN, 41.6+/-15.8 ng/L) were the dominant fragrances in sewage, but other polycyclic musks and nitro musks were present at lower concentrations. The concentrations of HHCB and AHTN in the aqueous phase of the sewage were highly correlated with both BOD5 and TOC. The overall removal efficiency of synthetic musks from the aqueous sewage in the WWTP ranged from 43.3% to 56.9%, but removal occurred mainly by partitioning into the biosolids. Based on a mass balance model, the daily input and output of HHCB and AHTN in the Peterborough WWTP were 47 g and 46 g, respectively. In an agricultural field amended with biosolids from the Peterborough WWTP, HHCB and AHTN were detected in soil immediately after application at mean concentrations of 1.0 and 1.3 mug/kg, respectively, but concentrations declined relatively rapidly over the next 6 weeks, post-application.

  9. A finite element model for simulating runoff and soil erosion from mechanically treated agricultural lands: 2. Field validation and applications

    NASA Astrophysics Data System (ADS)

    Sharda, V. N.; Singh, Sita Ram; Sastry, G.; Dhruvanarayana, V. V.

    1994-07-01

    The finite element model for simulation of runoff and soil erosion as developed by Sharda and Singh (this issue) is evaluated using data collected from agricultural land treated with major mechanical soil and water conservation measures, namely, contour bunding, graded bunding, bench terracing, and conservation bench terracing. The simulated and experimentally realized hydrographs and soil loss values are in reasonably good agreement for various measures. Probable reasons for discrepancies between the predicted and observed values are discussed. The model has the potential of being used on a single storm or a continuous basis provided the soil, crop, and climatic parameters are precisely known or estimated for a given location and for the period under consideration. The model logically simulates the effects of flow, topographic, soil, and crop parameters such as antecedent moisture level, roughness coefficient, saturated hydraulic conductivity, slope, depth of impoundment, size of outlet, longitudinal slope of the channel, vertical interval, and cropping management factor. The model is found to be quite sensitive to changes in roughness coefficient, rainfall excess rate, and cover management factor, and hence these parameters need to be assessed carefully in the field. The general applicability of the model as a planning tool for soil conservation measures and the scope for future development are also discussed.

  10. Development of a field worthy sensor system to monitor gaseous nitrogen transfer from agricultural cropland. Phase 1, Final report

    SciTech Connect

    Not Available

    1992-11-01

    Nitrogen fertilizer accounts for 25 to 33% of the energy requirements in modern crop agriculture in the world today. Energy input for the manufacture of these N fertilizers is in the range of 460 {times} 10{sup 12} Btu per year. Unfortunately, for some N sources up to 70% of this energy in the form of NK can be lost through improper application techniques and poor N management strategies. Anhydrous NH{sub 3} may be lost to the atmosphere during and after placement due to soil conditions placement. Measurement of volatile N is difficult, especially under field conditions. A precise and convenient method of measuring gaseous NH{sub 3} near and above the soil surface is prerequisite to the development and evaluation of altemative fertilizer management strategies and application techniques which can reduce the potential for significant loss. Recent advances in integrated-optic (IO) based sensing offers the potential of measuring low levels of NH{sub 3} loss from a cropping system in the range of 100 ppB. The integrated design of an IO system allows for a more durable device that can be mass produced at low cost. Under Phase I of this project, two IO devices were designed and tested: an absorption device using an oxazine dye as a waveguide coating and an interferometric device using an anilinium salt as a waveguide coating.

  11. Transcranial pulsed electromagnetic fields for multiple chemical sensitivity: study protocol for a randomized, double-blind, placebo-controlled trial

    PubMed Central

    2013-01-01

    Background Multiple chemical sensitivity (MCS) is a chronic condition of unknown etiology. MCS is characterized by recurrent nonspecific symptoms from multiple organ systems in response to chemical exposures in concentrations that are normally tolerated by the majority of the population. The symptoms may have severe impact on patients’ lives, but an evidence-based treatment for the condition is nonexisting. The pathophysiology is unclarified, but several indicators point towards abnormal processing of sensory signals in the central nervous system. Pulsed electromagnetic fields (PEMF) offer a promising new treatment for refractory depression and can be targeted at the brain, thereby activating biochemical cell processes. Methods/Design In a parallel, randomized, double-blind, placebo-controlled trial conducted at the Danish Research Centre for Chemical Sensitivities, the effects of PEMF in MCS patients will be assessed using the Re5 Independent System. Based on sample size estimation, 40 participants will be randomized to either PEMF therapy or placebo. The allocation sequence will be generated by computer. All involved parties (that is, participants, investigators, the research nurse, and the statistician) will be blinded to group allocation. The participants will receive PEMF therapy or placebo applied transcranially 30 minutes twice a day for 7 days a week over 6 consecutive weeks. Outcomes will be measured at baseline, once weekly during treatment, post treatment, and at 2.5-month and 4.5-month follow-up according to a predefined timetable. The primary outcome will be a measurement of the impact of MCS on everyday life. The secondary outcomes will be measurements of MCS symptoms, psychological distress (stress, anxiety or depressive symptoms), capsaicin-induced secondary punctate hyperalgesia, immunological markers in serum, and quality of life. Discussion This trial will assess the effects of PEMF therapy for MCS. Currently, there is no treatment with a

  12. Spatiotemporal characterization of soil moisture fields in agricultural areas using cosmic-ray neutron probes and data fusion

    NASA Astrophysics Data System (ADS)

    Franz, Trenton; Wang, Tiejun

    2015-04-01

    Approximately 40% of global food production comes from irrigated agriculture. With the increasing demand for food even greater pressures will be placed on water resources within these systems. In this work we aimed to characterize the spatial and temporal patterns of soil moisture at the field-scale (~500 m) using the newly developed cosmic-ray neutron rover near Waco, NE USA. Here we mapped soil moisture of 144 quarter section fields (a mix of maize, soybean, and natural areas) each week during the 2014 growing season (May to September). The 12 by 12 km study domain also contained three stationary cosmic-ray neutron probes for independent validation of the rover surveys. Basic statistical analysis of the domain indicated a strong relationship between the mean and variance of soil moisture at several averaging scales. The relationships between the mean and higher order moments were not significant. Scaling analysis indicated strong power law behavior between the variance of soil moisture and averaging area with minimal dependence of mean soil moisture on the slope of the power law function. In addition, we combined the data from the three stationary cosmic-ray neutron probes and mobile surveys using linear regression to derive a daily soil moisture product at 1, 3, and 12 km spatial resolutions for the entire growing season. The statistical relationships derived from the rover dataset offer a novel set of observations that will be useful in: 1) calibrating and validating land surface models, 2) calibrating and validating crop models, 3) soil moisture covariance estimates for statistical downscaling of remote sensing products such as SMOS and SMAP, and 4) provide daily center-pivot scale mean soil moisture data for optimal irrigation timing and volume amounts.

  13. Field trials to evaluate effects of continuously planted transgenic insect-resistant cottons on soil invertebrates.

    PubMed

    Li, Xiaogang; Liu, Biao; Wang, Xingxiang; Han, Zhengmin; Cui, Jinjie; Luo, Junyu

    2012-03-01

    Impacts on soil invertebrates are an important aspect of environmental risk assessment and post-release monitoring of transgenic insect-resistant plants. The purpose of this study was to research and survey the effects of transgenic insect-resistant cottons that had been planted over 10 years on the abundance and community structure of soil invertebrates under field conditions. During 3 consecutive years (2006-2008), eight common taxa (orders) of soil invertebrates belonging to the phylum Arthropoda were investigated in two different transgenic cotton fields and one non-transgenic cotton field (control). Each year, soil samples were taken at four different growth stages of cotton (seedling, budding, boll forming and boll opening). Animals were extracted from the samples using the improved Tullgren method, counted and determined to the order level. The diversity of the soil fauna communities in the different fields was compared using the Simpson's, Shannon's diversity indices and evenness index. The results showed a significant sampling time variation in the abundance of soil invertebrates monitored in the different fields. However, no difference in soil invertebrate abundance was found between the transgenic cotton fields and the control field. Both sampling time and cotton treatment had a significant effect on the Simpson's, Shannon's diversity indices and evenness index. They were higher in the transgenic fields than the control field at the growth stages of cotton. Long-term cultivation of transgenic insect-resistant cottons had no significant effect on the abundance of soil invertebrates. Collembola, Acarina and Araneae could act as the indicators of soil invertebrate in this region to monitor the environmental impacts of transgenic plants in the future.

  14. Scanning Lidar Measurements of the Full-Scale RDD Field Trial Puff Plumes.

    PubMed

    Cao, Xiaoying; Roy, Gilles

    2016-05-01

    A vertically scanning lidar (light/radar) was used to measure the time evolution of clouds generated by a small explosive device. Vertical sweeps were performed at a downwind distance of 105 m from the detonation. The measured quantity obtained from the lidar was the light extinction coefficient. This quantity is directly proportional to the aerosol concentration. The background aerosol value was set to 0.0001 m (-1) (assuming a visibility of 40 km), and assuming the scattering properties of the explosively generated cloud is the same as the background aerosol, the authors found that the instantaneous maximal local concentration of aerosol in the cloud did not exceed 500 times the background aerosol value, and the instantaneous concentration was typically less than five times the background aerosol value. In the two trials that were done, the volumes of the clouds were reasonably close at 2,700 m(3) and 4,000 m(3), respectively.

  15. Field trials of second-generation anticoagulants against difenacoum-resistant Norway rat populations.

    PubMed

    Greaves, J H; Shepherd, D S; Quy, R

    1982-10-01

    Trials of rodenticidal baits containing 50 p.p.m. difenacoum, 50 p.p.m. bromadiolone or 20 p.p.m. brodifacoum were carried out on farmsteads against populations of Rattus norvegicus containing difenacoum-resistant individuals. Six difenacoum treatments failed in 14--42 days of baiting. Two treatments with bromadiolone succeeded in 23 and 33 days, but four further treatments lasting 35--56 days failed to eradicate the populations. Brodifacoum gave virtually complete control of six populations in 21--73 days and of the ten residual populations left behind by the other two compounds, after baiting for a further 11--85 days. The performance of both bromadiolone and brodifacoum was well below that reported by previous investigators, indicating the possibility of low-grade resistance to these compounds in the difenacoum-resistant strain. PMID:7130704

  16. Scanning Lidar Measurements of the Full-Scale RDD Field Trial Puff Plumes.

    PubMed

    Cao, Xiaoying; Roy, Gilles

    2016-05-01

    A vertically scanning lidar (light/radar) was used to measure the time evolution of clouds generated by a small explosive device. Vertical sweeps were performed at a downwind distance of 105 m from the detonation. The measured quantity obtained from the lidar was the light extinction coefficient. This quantity is directly proportional to the aerosol concentration. The background aerosol value was set to 0.0001 m (-1) (assuming a visibility of 40 km), and assuming the scattering properties of the explosively generated cloud is the same as the background aerosol, the authors found that the instantaneous maximal local concentration of aerosol in the cloud did not exceed 500 times the background aerosol value, and the instantaneous concentration was typically less than five times the background aerosol value. In the two trials that were done, the volumes of the clouds were reasonably close at 2,700 m(3) and 4,000 m(3), respectively. PMID:27023031

  17. Field trials of second-generation anticoagulants against difenacoum-resistant Norway rat populations.

    PubMed Central

    Greaves, J. H.; Shepherd, D. S.; Quy, R.

    1982-01-01

    Trials of rodenticidal baits containing 50 p.p.m. difenacoum, 50 p.p.m. bromadiolone or 20 p.p.m. brodifacoum were carried out on farmsteads against populations of Rattus norvegicus containing difenacoum-resistant individuals. Six difenacoum treatments failed in 14--42 days of baiting. Two treatments with bromadiolone succeeded in 23 and 33 days, but four further treatments lasting 35--56 days failed to eradicate the populations. Brodifacoum gave virtually complete control of six populations in 21--73 days and of the ten residual populations left behind by the other two compounds, after baiting for a further 11--85 days. The performance of both bromadiolone and brodifacoum was well below that reported by previous investigators, indicating the possibility of low-grade resistance to these compounds in the difenacoum-resistant strain. PMID:7130704

  18. Polyoxyethylene Tallow Amine, a Glyphosate Formulation Adjuvant: Soil Adsorption Characteristics, Degradation Profile, and Occurrence on Selected Soils from Agricultural Fields in Iowa, Illinois, Indiana, Kansas, Mississippi, and Missouri.

    PubMed

    Tush, Daniel; Meyer, Michael T

    2016-06-01

    Polyoxyethylene tallow amine (POEA) is an inert ingredient added to formulations of glyphosate, the most widely applied agricultural herbicide. POEA has been shown to have toxic effects to some aquatic organisms making the potential transport of POEA from the application site into the environment an important concern. This study characterized the adsorption of POEA to soils and assessed its occurrence and homologue distribution in agricultural soils from six states. Adsorption experiments of POEA to selected soils showed that POEA adsorbed much stronger than glyphosate; calcium chloride increased the binding of POEA; and the binding of POEA was stronger in low pH conditions. POEA was detected on a soil sample from an agricultural field near Lawrence, Kansas, but with a loss of homologues that contain alkenes. POEA was also detected on soil samples collected between February and early March from corn and soybean fields from ten different sites in five other states (Iowa, Illinois, Indiana, Missouri, Mississippi). This is the first study to characterize the adsorption of POEA to soil, the potential widespread occurrence of POEA on agricultural soils, and the persistence of the POEA homologues on agricultural soils into the following growing season. PMID:27163278

  19. Vertical distribution of heavy metals in soil profile in a seasonally waterlogging agriculture field in Eastern Ganges Basin.

    PubMed

    Rajmohan, N; Prathapar, S A; Jayaprakash, M; Nagarajan, R

    2014-09-01

    The accumulation of heavy metals in soil and water is a serious concern due to their persistence and toxicity. This study investigated the vertical distribution of heavy metals, possible sources and their relation with soil texture in a soil profile from seasonally waterlogged agriculture fields of Eastern Ganges basin. Fifteen samples were collected at ~0.90-m interval during drilling of 13.11 mbgl and analysed for physical parameters (moisture content and grain size parameters: sand, silt, clay ratio) and heavy metals (Fe, Mn, Cr, Cu, Pb, Zn, Co, Ni and Cd). The average metal content was in the decreasing order of Fe > Mn > Cr > Zn > Ni > Cu > Co > Pb > Cd. Vertical distribution of Fe, Mn, Zn and Ni shows more or less similar trends, and clay zone records high concentration of heavy metals. The enrichment of heavy metals in clay zone with alkaline pH strongly implies that the heavy metal distributions in the study site are effectively regulated by soil texture and reductive dissolution of Fe and Mn oxy-hydroxides. Correlation coefficient analysis indicates that most of the metals correlate with Fe, Mn and soil texture (clay and silt). Soil quality assessment was carried out using geoaccumulation index (I(geo)), enrichment factor (EF) and contamination factor (CF). The enrichment factor values were ranged between 0.66 (Mn) and 2.34 (Co) for the studied metals, and the contamination factor values varied between 0.79 (Mn) and 2.55 (Co). Results suggest that the elements such as Cu and Co are categorized as moderate to moderately severe contamination, which are further confirmed by I(geo) values (0.69 for Cu and 0.78 for Co). The concentration of Ni exceeded the effects-range median values, and the biological adverse effect of this metal is 87%. The average concentration of heavy metals was compared with published data such as concentration of heavy metals in Ganga River sediments, Ganga Delta sediments and upper continental crust (UCC

  20. Vertical distribution of heavy metals in soil profile in a seasonally waterlogging agriculture field in Eastern Ganges Basin.

    PubMed

    Rajmohan, N; Prathapar, S A; Jayaprakash, M; Nagarajan, R

    2014-09-01

    The accumulation of heavy metals in soil and water is a serious concern due to their persistence and toxicity. This study investigated the vertical distribution of heavy metals, possible sources and their relation with soil texture in a soil profile from seasonally waterlogged agriculture fields of Eastern Ganges basin. Fifteen samples were collected at ~0.90-m interval during drilling of 13.11 mbgl and analysed for physical parameters (moisture content and grain size parameters: sand, silt, clay ratio) and heavy metals (Fe, Mn, Cr, Cu, Pb, Zn, Co, Ni and Cd). The average metal content was in the decreasing order of Fe > Mn > Cr > Zn > Ni > Cu > Co > Pb > Cd. Vertical distribution of Fe, Mn, Zn and Ni shows more or less similar trends, and clay zone records high concentration of heavy metals. The enrichment of heavy metals in clay zone with alkaline pH strongly implies that the heavy metal distributions in the study site are effectively regulated by soil texture and reductive dissolution of Fe and Mn oxy-hydroxides. Correlation coefficient analysis indicates that most of the metals correlate with Fe, Mn and soil texture (clay and silt). Soil quality assessment was carried out using geoaccumulation index (I(geo)), enrichment factor (EF) and contamination factor (CF). The enrichment factor values were ranged between 0.66 (Mn) and 2.34 (Co) for the studied metals, and the contamination factor values varied between 0.79 (Mn) and 2.55 (Co). Results suggest that the elements such as Cu and Co are categorized as moderate to moderately severe contamination, which are further confirmed by I(geo) values (0.69 for Cu and 0.78 for Co). The concentration of Ni exceeded the effects-range median values, and the biological adverse effect of this metal is 87%. The average concentration of heavy metals was compared with published data such as concentration of heavy metals in Ganga River sediments, Ganga Delta sediments and upper continental crust (UCC

  1. Use of accelerometers as an ergonomic assessment method for arm acceleration-a large-scale field trial.

    PubMed

    Estill, C F; MacDonald, L A; Wenzl, T B; Petersen, M R

    2000-09-01

    Ergonomists need easy-to-use, quantitative job evaluation methods to assess risk factors for upper extremity work-related musculoskeletal disorders in field-based epidemiology studies. One device that may provide an objective measure of exposure to arm acceleration is a wrist-worn accelerometer or activity monitor. A field trial was conducted to evaluate the performance of a single-axis accelerometer using an industrial population (n=158) known to have diverse upper limb motion characteristics. The second phase of the field trial involved an examination of the relationship between more traditional observation-based ergonomic exposure measures and the monitor output among a group of assembly-line production employees (n=48) performing work tasks with highly stereotypic upper limb motion patterns. As expected, the linear acceleration data obtained from the activity monitor showed statistically significant differences between three occupational groups known observationally to have different upper limb motion requirements. Among the assembly-line production employees who performed different short-cycle assembly work tasks, statistically significant differences were also observed. Several observation-based ergonomic exposure measures were found to explain differences in the acceleration measure among the production employees who performed different jobs: hand and arm motion speed, use of the hand as a hammer, and, negatively, resisting forearm rotation from the torque of a power tool. The activity monitors were found to be easy to use and non-intrusive, and to be able to distinguish arm acceleration among groups with diverse upper limb motion characteristics as well as between different assembly job tasks where arm monitors were performed repeatedly at a fixed rate.

  2. Effects of Gentle Human Touch and Field Massage on Urine Cortisol Level in Premature Infants: A Randomized, Controlled Clinical Trial

    PubMed Central

    Asadollahi, Malihe; Jabraeili, Mahnaz; Mahallei, Majid; Asgari Jafarabadi, Mohammad; Ebrahimi, Sakine

    2016-01-01

    Introduction: Hospitalization in neonatal intensive care unit may leads to many stresses for premature infants. Since premature infants cannot properly process stressors, identifying interventions that reduce the stress level for them is seems necessary. The aim of present study was to compare the effects of Field massage and Gentle Human Touch (GHT) techniques on the urine level of cortisol, as an indicator of stress in preterm infants. Methods: This randomized, controlled clinical trial was carried out in Al-Zahra hospital, Tabriz. A total of 84 premature infants were randomly assigned into three groups. First groups were touched by their mothers three times a day (15 minutes in each session) for 5 days by GHT technique. The second group was received 15 minutes Field massage with sunflower oil three times a day by their mothers for 5 days. The third group received routine care. In all groups, 24-hours urine samples were collected in the first and sixth day after the intervention and analyzed for cortisol level. Data were analyzed by SPSS software. Results: There were significant differences between mean of changes in cortisol level between GHT and control groups and Field massage and control groups (0.026). Conclusion: Although the massage with Field technique resulted in a significant reduction in blood cortisol level, but the GHT technique have also a similar effect. So, both methods are recommended for decreasing of stress in preterm infants. PMID:27752484

  3. Thresholds of arsenic toxicity to Eisenia fetida in field-collected agricultural soils exposed to copper mining activities in Chile.

    PubMed

    Bustos, Víctor; Mondaca, Pedro; Verdejo, José; Sauvé, Sébastien; Gaete, Hernán; Celis-Diez, Juan L; Neaman, Alexander

    2015-12-01

    Several previous studies highlighted the importance of using field-collected soils-and not artificially-contaminated soils-for ecotoxicity tests. However, the use of field-collected soils presents several difficulties for interpretation of results, due to the presence of various contaminants and unavoidable differences in the physicochemical properties of the tested soils. The objective of this study was to estimate thresholds of metal toxicity in topsoils of 24 agricultural areas historically contaminated by mining activities in Chile. We performed standardized earthworm reproduction tests (OECD 222 and ISO 11268-2) with Eisenia fetida. Total soil concentrations of Cu, As, Zn, and Pb were in the ranges of 82-1295 mg kg(-1), 7-41 mg kg(-1), 86-345 mg kg(-1), and 25-97 mg kg(-1), respectively. In order to differentiate between the effects of different metals, we used regression analysis between soil metal concentrations and earthworm responses, as well as between metal concentrations in earthworm tissues and earthworm responses. Based on regression analysis, we concluded that As was a metal of prime concern for Eisenia fetida in soils affected by Cu mining activities, while Cu exhibited a secondary effect. In contrast, the effects of Zn and Pb were not significant. Soil electrical conductivity was another significant contributor to reproduction toxicity in the studied soils, forcing its integration in the interpretation of the results. By using soils with electrical conductivity ≤ 0.29 dS m(-1) (which corresponds to EC50 of salt toxicity to Eisenia fetida), it was possible to isolate the effect of soil salinity on earthworm reproduction. Despite the confounding effects of Cu, it was possible to determine EC10, EC25 and EC50 values for total soil As at 8 mg kg(-1), 14 mg kg(-1) and 22 mg kg(-1), respectively, for the response of the cocoon production. However, it was not possible to determine these threshold values for juvenile production. Likewise, we were able to

  4. Thresholds of arsenic toxicity to Eisenia fetida in field-collected agricultural soils exposed to copper mining activities in Chile.

    PubMed

    Bustos, Víctor; Mondaca, Pedro; Verdejo, José; Sauvé, Sébastien; Gaete, Hernán; Celis-Diez, Juan L; Neaman, Alexander

    2015-12-01

    Several previous studies highlighted the importance of using field-collected soils-and not artificially-contaminated soils-for ecotoxicity tests. However, the use of field-collected soils presents several difficulties for interpretation of results, due to the presence of various contaminants and unavoidable differences in the physicochemical properties of the tested soils. The objective of this study was to estimate thresholds of metal toxicity in topsoils of 24 agricultural areas historically contaminated by mining activities in Chile. We performed standardized earthworm reproduction tests (OECD 222 and ISO 11268-2) with Eisenia fetida. Total soil concentrations of Cu, As, Zn, and Pb were in the ranges of 82-1295 mg kg(-1), 7-41 mg kg(-1), 86-345 mg kg(-1), and 25-97 mg kg(-1), respectively. In order to differentiate between the effects of different metals, we used regression analysis between soil metal concentrations and earthworm responses, as well as between metal concentrations in earthworm tissues and earthworm responses. Based on regression analysis, we concluded that As was a metal of prime concern for Eisenia fetida in soils affected by Cu mining activities, while Cu exhibited a secondary effect. In contrast, the effects of Zn and Pb were not significant. Soil electrical conductivity was another significant contributor to reproduction toxicity in the studied soils, forcing its integration in the interpretation of the results. By using soils with electrical conductivity ≤ 0.29 dS m(-1) (which corresponds to EC50 of salt toxicity to Eisenia fetida), it was possible to isolate the effect of soil salinity on earthworm reproduction. Despite the confounding effects of Cu, it was possible to determine EC10, EC25 and EC50 values for total soil As at 8 mg kg(-1), 14 mg kg(-1) and 22 mg kg(-1), respectively, for the response of the cocoon production. However, it was not possible to determine these threshold values for juvenile production. Likewise, we were able to

  5. Dual-permeability modeling of preferential bromide leaching from a tile-drained glacial till agricultural field

    NASA Astrophysics Data System (ADS)

    Gerke, Horst H.; Maximilian Köhne, J.

    2004-04-01

    A tile-drained agricultural field can be regarded as a 'field-scale' lysimeter that may be used to study soil water and chemical transport under relatively natural conditions. Tile discharge and effluent bromide concentrations measured in a previous field tracer experiment for a structured clayey loam at Bokhorst, Northern Germany, indicated strong preferential flow. Simulation using single domain HYDRUS numerical flow and transport model could nevertheless explain water outflow, however, completely failed to describe tile-drain leaching patterns of the conservative tracer. The objective of this paper was to analyze whether the nonequilibrium-type dual-permeability model concept could better capture soil structure related principle mechanisms of preferential leaching in the unsaturated soil at that study site. The dual-permeability model (DUAL) describes for soil matrix and fracture pore systems Darcian flow with coupled Richards' equations and convective-dispersive (CD) solute transport with coupled CD equations. The hydraulic parameters of the dual-permeability model were obtained from standard soil hydraulic measurements by adopting a bimodal fitting procedure, whereas transport parameters were inferred from soil column tracer experiments and geometrical transfer term parameters were derived using qualitative soil structure descriptions. The hydraulic conductivity Ka in the inter-domain water transfer term and the effective diffusion coefficient Da in the solute mass transfer term were calibrated by comparing simulated with measured tile flow and effluent concentrations. The DUAL approach described water flow similarly well as the single-domain model. Bromide concentrations in the tile effluent could be approximated with DUAL when decreasing the Ka and Da values by three orders of magnitude compared with the values of the soil matrix domain. The dual-permeability approach seems to reflect nonequilibrium transport mechanisms at this structured soil since it not

  6. A field trial to evaluate the efficacy of a combined rotavirus-coronavirus/Escherichia coli vaccine in dairy cattle.

    PubMed Central

    Waltner-Toews, D; Martin, S W; Meek, A H; McMillan, I; Crouch, C F

    1985-01-01

    A field trial was designed to determine the efficacy of a combination rotavirus-coronavirus/Escherichia coli vaccine on dairy farms in southwestern Ontario. In Part A of the trial, 321 cows on 15 farms were randomly assigned to either vaccination or placebo groups. On eight farms, 50% of the dams were vaccinated, while on the other seven farms, 80% of the dams were vaccinated. In Part B of the trial, 26 farms were randomly assigned to either a total vaccination program or to no vaccination program. Mortality, disease occurrence and weight gains were recorded on all calves for the first two weeks of life. In Part A, 23.5% of all calves were treated in the first two weeks of life, 20.9% were treated specifically for scours and 3.6% of live-born calves died. Enteropathogenic E. coli was identified on 13 of the 15 farms, rotavirus on 11 and coronavirus on ten. At least one of the three potential pathogens was found on every farm. There were no significant differences between calves from placebo-treated and vaccine-treated dams with regard to the proportion treated for all diseases, or for scours, or the proportion which died. Neither were there differences in days to first treatment for all diseases (seven days on average), days to first scour (6.7 days), duration of treatments (3.9 days for all diseases, 3.7 days for scours), or estimated weight gains (0.5 kg/day to 14 days). These results were not altered when the presence or absence of enteropathogenic E. coli, rotavirus or coronavirus on the premises was accounted for.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2985213

  7. Sutureless Adult Voluntary Male Circumcision with Topical Anesthetic: A Randomized Field Trial of Unicirc, a Single-Use Surgical Instrument

    PubMed Central

    2016-01-01

    Introduction The World Health Organization has solicited rapid and minimally invasive techniques to facilitate scale-up of voluntary medical male circumcision (VMMC). Study design Non-blinded randomized controlled field trial with 2:1 allocation ratio. Participants 75 adult male volunteers. Setting Outpatient primary care clinic. Intervention Open surgical circumcision under local anesthetic with suturing vs. Unicirc disposable instrument under topical anesthetic and wound sealing with cyanoacrylate tissue adhesive. Primary Outcome Intraoperative duration. Secondary Outcomes Intraoperative and postoperative pain; adverse events; time to healing; patient satisfaction; cosmetic result. Results The intraoperative time was less with the Unicirc technique (median 12 vs. 25 min, p < 0.001). Wound healing and cosmetic results were superior in the Unicirc group. Adverse events were similar in both groups. Conclusions VMMC with Unicirc under topical anesthetic and wound sealing with cyanoacrylate tissue adhesive is rapid, heals by primary intention with superior cosmetic results, and is potentially safer and more cost-effective than open surgical VMMC. Trial Registration Clinicaltrials.gov NCT02443792 PMID:27299735

  8. A large-scale field trial of malathion as an insecticide for antimalarial work in southern Uganda

    PubMed Central

    Najera, J. A.; Shidrawi, G. R.; Gibson, F. D.; Stafford, J. S.

    1967-01-01

    Malathion shows promise as a substitute for chlorinated-hydrocarbon insecticides in the control of malaria whenever the latter are unsuitable because of Anopheles resistance or other reasons. A field trial of malathion was carried out in 1963-64, covering an area of about 500 km2 with a population of about 26 000, in Masaka District, southern Uganda. All houses and animal shelters were sprayed with malathion at 2 g/m2 at roughly 4-month intervals. The average combined densities of the females of the two main malaria vectors, Anopheles funestus and An. gambiae, fell from an average of 66 per shelter per day in a pre-trial survey in 1960-61 to 0.0011 at the end of 1964 in the sprayed area; no significant changes were noted in unsprayed comparison areas. The transmission of the infection in humans was apparently interrupted when allowance was made for imported cases. The presence of unsprayed surfaces in houses which had recently been built or altered interfered somewhat with complete coverage. Case detection was reliable and achieved excellent coverage. No toxic effects of malathion in humans were noted, while the effect on mosquitos was considerable even in the absence of direct contact. This effect of malathion lasted for a considerably shorter period of time in houses roofed with corrugated iron than with thatch; this should be borne in mind in the design of spraying programmes. PMID:5299860

  9. Development and field trial of a FBG-based magnetic sensor for large hydrogenerators

    NASA Astrophysics Data System (ADS)

    Fracarolli, João. P. V.; Rosolem, João. B.; Tomiyama, Elias K.; Floridia, Claudio; Penze, Rivael S.; Peres, Rodrigo; Dini, Danilo C.; Hortencio, Claudio A.; Dilli, Paulo I. G.; da Silva, Erlon V.; dos Santos, Marcéu. C.; Fruett, Fabiano

    2016-05-01

    We propose a passive optical sensor for online magnetic field monitoring in large hydrogenerators, based on FBG (Fiber Bragg Grating) technology and a magnestostrictive material (Terfenol-D). The objective of this sensor is to detect faults in the rotor windings due to inter turn short-circuits. This device is packaged in a novel rod-shaped enclosure, allowing it to be easily installed on the ventilation ducts of the stator of the machine. This sensor was developed and tested in laboratory and it has been evaluated in a field test on a 200 MVA, 60 poles hydrogenerator.

  10. Laboratory trials of three anticoagulant rodenticides for use against the Indian field mouse, Mus booduga Gray.

    PubMed Central

    Balasubramanyam, M.; Christopher, M. J.; Purushotham, K. R.

    1984-01-01

    The efficacy of three anticoagulant rodenticides for use against the Indian field mouse, Mus booduga, was evaluated in the laboratory. The poisons, namely warfarin, bromadiolone and brodifacoum, were all found to be toxic enough at the concentrations normally used against other commensal and field rodents. With brodifacoum (0.001 25%), bromadiolone (0.005%) and warfarin (0.025%), 83% of the animals died respectively after 1, 1 and 6 days' feeding. It is suggested that brodifacoum and bromadiolone might be more economical than warfarin for use in practical rodent control. PMID:6512257

  11. Escherichia coli O157:H7 vaccine field trial in 9 feedlots in Alberta and Saskatchewan.

    PubMed

    Van Donkersgoed, Joyce; Hancock, Dale; Rogan, Dragan; Potter, Andrew A

    2005-08-01

    A feedlot trial was conducted to assess the efficacy of an Escherichia coli O157:H7 vaccine in reducing fecal shedding of E. coli O157:H7 in 218 pens of feedlot cattle in 9 feedlots in Alberta and Saskatchewan. Pens of cattle were vaccinated once at arrival processing and again at reimplanting with either the E. coli O157:H7 vaccine or a placebo. The E. coli O157:H7 vaccine included 50 microg of type III secreted proteins. Fecal samples were collected from 30 fresh manure patties within each feedlot pen at arrival processing, revaccination at reimplanting, and within 2 wk of slaughter. The mean pen prevalence of E. coli O157:H7 in feces was 5.0%; ranging in pens from 0% to 90%, and varying significantly (P < 0.001) among feedlots. There was no significant association (P > 0.20) between vaccination and pen prevalence of fecal E. coli O157:H7 following initial vaccination, at reimplanting, or prior to slaughter.

  12. Explaining feast or famine in randomized field trials. Medical science and criminology compared.

    PubMed

    Shepherd, Jonathan P

    2003-06-01

    A feast of randomized controlled trials (RCTs) in medical science and comparative famine in criminology can be explained in terms of cultural and structural factors. Of central importance is the context in which the evaluation of interventions is done and the difference in status of situational research in the two disciplines. Evaluation of medical interventions has traditionally been led by practitioner (clinical) academics. This is not the case in criminal justice, where theory has had higher status than intervention research. Medical science has advanced in, or closely associated with, university teaching hospitals, but links between criminology and criminal justice services are far more tenuous. The late development of situational crime prevention seems extraordinary from a medical perspective, as does the absence of university police schools in the United Kingdom and elsewhere. These structural and cultural factors explain concentration of expectation, resource, and RCT productivity in medical science. The Campbell Collaboration and the Academy of Experimental Criminology are forces which are reducing this polarization of feast and famine in RCTs. But unless scientific criminology is embedded in university schools which are responsible for the education and training of law, probation, and police practitioners, convergence in terms of RCTs and implementation of findings in practice seems unlikely.

  13. A field trial of a survey method for estimating the coverage of selective feeding programmes.

    PubMed Central

    Myatt, Mark; Feleke, Teshome; Sadler, Kate; Collins, Steve

    2005-01-01

    OBJECTIVE: To test a survey method for estimating the coverage of selective feeding programmes in humanitarian emergencies. METHODS: The trial survey used a stratified design with strata that were defined using the centric systematic area sample method. Thirty 100 km2 quadrats were sampled. The communities located closest to the centre of each quadrat were sampled using a case-finding approach. FINDINGS: The method proved simple and rapid to implement and allowed overall and per-quadrat coverage to be estimated. Overall coverage was 20.0% (95% confidence intervals, 13.8-26.3%). Per-quadrat coverage ranged from zero (in nine quadrats) to 50% (in one quadrat). Coverage was highest in the quadrats closest to therapeutic feeding centres and in quadrats containing major roads leading to the towns in which therapeutic feeding centres were located. CONCLUSION: The method should be used, in preference to WHO Expanded Programme on Immunization (EPI)-derived survey methods, for estimating the coverage of selective feeding programmes. Its use should also be considered when evaluating the coverage of other selective entry programmes or when coverage is likely to be spatially inhomogeneous. PMID:15682245

  14. Vertically averaged velocities in the North Atlantic Current from field trials of a Lagrangian electric-field float

    NASA Astrophysics Data System (ADS)

    Szuts, Zoltan B.; Sanford, Thomas B.

    2013-01-01

    A subsurface Lagrangian float that utilizes motional induction to calculate vertically averaged velocities was tested in the North Atlantic Current (NAC), taking advantage of existing cruises and infrastructure. The Electric Field Float (EFF) is a RAFOS float with horizontal electrodes that measures its own velocity by RAFOS tracking and calculates vertically averaged velocities when merged with the electrode system. The observations showed depth-averaged velocities that were fast in the core of the NAC (0.6-0.9 m s -1) and moderate in adjacent recirculations and eddies (0.3-0.4 m s-1). A float at 850 dbar moved at close to the depth-averaged velocity, while shallower floats followed surface intensified flow on top of the depth-averaged motion. Integral time scales of depth-averaged velocity (1.3-1.6±0.4 d) are slightly shorter than time scales of float velocity (1.6-2.0±0.3 d), while integral length scales of depth-averaged water velocity (35±10 km for u, 18±6 km for v) are slightly shorter than length scales of float motion (53±12 km for u, 28±6 km for v). Velocity spectra of depth-averaged velocity show significant variance at inertial periods. Quantitative and qualitative validation with multiple independent data sets confirms the accuracy of the instrument and sampling strategy in the NAC, advancing the limited observational knowledge of depth-averaged circulation in subpolar regions.

  15. Short-term temporal and spatial variability of soil hydrophobicity in an abandoned agriculture field in Lithuania

    NASA Astrophysics Data System (ADS)

    Pereira, Paulo; Burguet, Maria; Cerdà, Artemi

    2013-04-01

    Soil water repellency (SWR) is a natural property of soils. Among other factors, SWR depends on soil moisture, mineralogy, texture, pH, organic matter, aggregate stability, fungal and microbiological activity and plant cover. It has implications on plant growth, superficial and subsurface hydrology and soil erosion. It is well known that SWR is temporarily, increasing when soils are dry and decreasing when moist. In agriculture, soil micro-topography is very heterogeneous with implications on surface water distribution and wettability. Normally, SWR studies are focused on large interval time (e.g, monthly or seasonally). The objective of this work is the study of SWR in a temporal scale and its variability in an abandoned agriculture field in Lithuania. An experimental plot with 21 m2 (07x03 m) was designed in a flat area. Inside this plot SWR was measured in the field, placing three droplets of water on the soil surface and counting the time that takes to infiltrate. A total of 105 sampling points were measured per sampling period. Soil water repellency was measured after a period of 14 days without rainfall and in the seven consequent weeks (one measurement per week between 28th May and 07th of July 2012). The results showed that in this small plot, SWR was observed in the first (May 28), third and fourth measurements (08th of June and 16th). It was observed an increasing of the percentage of hydrophobic points (Water Drop Penetration Test ≥5 seconds) between the first and the fourth measurement, decreasing thereafter. Significant differences of SWR were observed among all periods (F=78.32, p<0.0001). The coefficient of variation (CV%) changed strikingly, 361.10 % (8th of May), 151.78 % (01st of June), 83.77% (08th of June), 125.87% (16th of June), 0.45 (22nd of June), 121%(31st of June) and 67.13% (7th of July). The correlation between the mean SWR and the CV% is 0.75, p<0.05. The changes were attributed to different soil moisture conditions. The differences

  16. 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

  17. Manufacture of Optacons for a Field Trial Within Elementary and Secondary Schools. Final Report.

    ERIC Educational Resources Information Center

    Brugler, J. Stephen; Bliss, James C.

    Telesensory Systems, Inc. (TSI) was awarded a contract to design, develop, and test Optacons (Optical-to-Tactile Converter) and perepheral equipment. Optacons are direct-translation reading aids for the blind. The text summarizes the engineering design, manufacturing activities, field test procedure and results, and it provides recommendations for…

  18. Anatomy of a field trial: Wood-based biochar and compost influences a Pacific Northwest soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar land application research in elevated rainfall areas (980 millimeters of annual rainfall) of the U.S. Pacific Northwest is lacking. A proof-of-concept field study examined the effects of spruce-pine-fir wood chip biochar (slow pyrolysis; 450-500 degrees Celsius; 35 megagrams per hectare), d...

  19. The European Ultrasonic Planetary Core Drill: Preliminary Results from Field Trials at the Haughton Mars Project

    NASA Astrophysics Data System (ADS)

    Worrall, K.; Timoney, R.; Li, X.; Harkness, P.; Lucas, M.

    2016-09-01

    This paper presents the findings of a recent field trip by the Ultrasonic Planetary Core Drill team to the Mars analog site at the Haughton Mars Project. Results of this trip are compared to results obtained drilling permafrost simulant in the lab.

  20. A comparison of rating and dating techniques to estimate the threat of soil erosion to archaeological monuments under agricultural fields

    NASA Astrophysics Data System (ADS)

    van Soest, Maud; Huisman, Hans; Schoorl, Jeroen; Reimann, Tony; Temme, Arnaud; Wallinga, Jakob; de Kort, Jan-Willem; van der Heiden, Menno; van Os, Bertil; van Egmond, Fenny; Ketteren, Michael

    2015-04-01

    For the protection of Dutch archaeological sites against degradation, the TOPsites project is investigating the rate, extent and mitigation of the most important processes involved. One of these processes is soil translocation or soil redistribution. For many Dutch archaeological sites the actual extent and rate of soil erosion is not yet known. In this study different techniques for dating and estimating rates have been compared on three archaeological sites on tilled fields with gentle slopes: (multi-temporal LiDar, profiles and spatial distribution of 137Cs, anthropogenic Pb, and 239+240Pu, and moreover OSL. In addition, the added value of the combination of several of these techniques together will be evaluated. Preliminary results show evidence for colluvium formation (deposition) on two of the sites. Lead contents in a buried soil on one of these sites suggest a subrecent to recent date. 137Cs profiles and spatial mapping, however, do not show clear evidence for recent erosion or re-deposition patterns. These first results suggest that in these agricultural settings with typical Dutch gentle slopes, erosion may only occur in rare, catastrophic, events with local high erosion and re-deposition rates instead of a more or less continuous process with lower rates. Consequently, the impact of ploughing might be limited to mixing of the plough layer, while the effect of damaging soil translocation, for these selected archaeological sites, seems less important. Forthcoming analysis and results of Pu and OSL will provide enough data for further discussion and possible falsification of these preliminary conclusions.

  1. Field trial on removal of petroleum-hydrocarbon pollutants using a microbial consortium for bioremediation and rhizoremediation.

    PubMed

    Pizarro-Tobías, Paloma; Niqui, José L; Roca, Amalia; Solano, Jennifer; Fernández, Matilde; Bastida, Felipe; García, Carlos; Ramos, Juan L

    2015-02-01

    Petroleum waste sludges are toxic and dangerous that is why environmental protection agencies have declared their treatment top priority. Physicochemical treatments are expensive and environmentally unfriendly, while alternative biological treatments are less costly but, in general, work at a slower pace. An in situ bioremediation and rhizoremediation field scale trial was performed in an area contaminated with oil refinery sludge under semiarid climate. The bioremediation and rhizoremediation treatments included the use of an artificial consortium made up of plant growth-promoting rhizobacteria and polycyclic aromatic hydrocarbon-degrading bacteria,and the combined use of the mentioned consortium along with pasture plants respectively. Rhizoremediation revealed that the development of vegetation favoured the evolution of indigenous microbiota with potential to remove petroleum wastes. This was inferred as the decline of total petroleum hydrocarbons 7 months after the biological treatment.

  2. Elimination of Taenia solium transmission to pigs in a field trial of the TSOL18 vaccine in Cameroon.

    PubMed

    Assana, Emmanuel; Kyngdon, Craig T; Gauci, Charles G; Geerts, Stanny; Dorny, Pierre; De Deken, Redgi; Anderson, Garry A; Zoli, André P; Lightowlers, Marshall W

    2010-04-01

    A pilot field trial of the TSOL18 vaccine was undertaken in Cameroon. Two hundred and forty, 2-3 month-old piglets were distributed to 114 individual households in pairs. Vaccinated animals received three immunisations with 200 microg TSOL18 plus 5 mg Quil A and 30 mg/kg oxfendazole at the time of the second immunisation. Necropsies were undertaken when the pigs were approximately 12 months of age. Viable Taenia solium cysticerci were identified in 20 control pigs (prevalence 19.6%); no cysticerci were found in any of the vaccinated animals (P<0.0001). Combined application of TSOL18 vaccination and a single oxfendazole treatment in pigs may be a relatively simple and sustainable procedure that has the potential to control T. solium transmission in endemic areas and, indirectly, reduce the number of new cases of neurocysticercosis in humans.

  3. The use of toxoid for the prevention of tetanus neonatorum. Final report of a double-blind controlled field trial.

    PubMed

    Newell, K W; Dueñas Lehmann, A; LeBlanc, D R; Garces Osorio, N

    1966-01-01

    With a view to determining the effectiveness of a method for the control of tetanus neonatorum which would be independent of medical examination or care, a double-blind field trial covering 1618 women was conducted between 1961 and 1966 in a rural area of Colombia with an estimated existing tetanus neonatorum death rate of 11.6 per 100 births. The study group was given 1-3 injections of 1 ml of an aluminium-phosphate-adsorbed tetanus toxoid more than 6 weeks apart, and the control group a similar number of injections of an influenza-virus vaccine.There was no statistically significant difference between those in the two groups given one injection. Those in the control group given 2 or 3 injections had a tetanus neonatorum death rate of 7.8 deaths per 100 births, and the corresponding subjects in the study group had none. This difference is unlikely to have occurred by chance.

  4. Field trial on removal of petroleum-hydrocarbon pollutants using a microbial consortium for bioremediation and rhizoremediation.

    PubMed

    Pizarro-Tobías, Paloma; Niqui, José L; Roca, Amalia; Solano, Jennifer; Fernández, Matilde; Bastida, Felipe; García, Carlos; Ramos, Juan L

    2015-02-01

    Petroleum waste sludges are toxic and dangerous that is why environmental protection agencies have declared their treatment top priority. Physicochemical treatments are expensive and environmentally unfriendly, while alternative biological treatments are less costly but, in general, work at a slower pace. An in situ bioremediation and rhizoremediation field scale trial was performed in an area contaminated with oil refinery sludge under semiarid climate. The bioremediation and rhizoremediation treatments included the use of an artificial consortium made up of plant growth-promoting rhizobacteria and polycyclic aromatic hydrocarbon-degrading bacteria,and the combined use of the mentioned consortium along with pasture plants respectively. Rhizoremediation revealed that the development of vegetation favoured the evolution of indigenous microbiota with potential to remove petroleum wastes. This was inferred as the decline of total petroleum hydrocarbons 7 months after the biological treatment. PMID:25870876

  5. Elimination of Taenia solium transmission to pigs in a field trial of the TSOL18 vaccine in Cameroon

    PubMed Central

    Assana, Emmanuel; Kyngdon, Craig T.; Gauci, Charles G.; Geerts, Stanny; Dorny, Pierre; De Deken, Redgi; Anderson, Garry A.; Zoli, André P.; Lightowlers, Marshall W.

    2010-01-01

    A pilot field trial of the TSOL18 vaccine was undertaken in Cameroon. Two hundred and forty, 2–3 month-old piglets were distributed to 114 individual households in pairs. Vaccinated animals received three immunisations with 200 μg TSOL18 plus 5 mg Quil A and 30 mg/kg oxfendazole at the time of the second immunisation. Necropsies were undertaken when the pigs were approximately 12 months of age. Viable Taenia solium cysticerci were identified in 20 control pigs (prevalence 19.6%); no cysticerci were found in any of the vaccinated animals (P < 0.0001). Combined application of TSOL18 vaccination and a single oxfendazole treatment in pigs may be a relatively simple and sustainable procedure that has the potential to control T. solium transmission in endemic areas and, indirectly, reduce the number of new cases of neurocysticercosis in humans. PMID:20138046

  6. An updated doubled haploid oat linkage map and QTL mapping of agronomic and grain quality traits from Canadian field trials.

    PubMed

    Tanhuanpää, Pirjo; Manninen, Outi; Beattie, Aaron; Eckstein, Peter; Scoles, Graham; Rossnagel, Brian; Kiviharju, Elina

    2012-04-01

    The first doubled haploid oat linkage map constructed at MTT Agrifood Research Finland was supplemented with additional microsatellites and Diversity Array Technology (DArT) markers to produce a map containing 1058 DNA markers and 34 linkage groups. The map was used to locate quantitative trait loci (QTLs) for 11 important breeding traits analyzed from Finnish and Canadian field trials. The new markers enabled most of the linkage groups to be anchored to the 'Kanota' × 'Ogle' oat ( Avena sativa L.) reference map and allowed comparison of the QTLs located in this study with those found previously. Two to 12 QTLs for each trait were discovered, of which several were expressed consistently across several environments.

  7. Improving time-lapse seismic repeatability: CO2CRC Otway site permanent geophone array field trials

    NASA Astrophysics Data System (ADS)

    Pevzner, Roman; Dupuis, Christian; Shulakova, Valeriya; Urosevic, Milovan; Lumley, David

    2013-04-01

    The proposed Stage 2C of the CO2CRC Otway project involves injection of a small amount (around 15,000 tonnes) of CO2/CH4 gas mixture into saline acquifer (Paaratte formation) at the depth of ~1.5 km. The seismic time-lapse signal will depend largely on the formation properties and the injection scenario, but is likely to be relatively weak. In order to improve time-lapse seismic monitoring capabilities by decreasing the noise level, a buried receiver arrays can be used. A small-scale trial of such an array was conducted at Otway site in June 2012. A set of 25 geophones was installed in 3 m deep boreholes in parallel to the same number of surface geophones. In addition, four geophones were placed into boreholes of 1 to 12 m depth. In order to assess the gain in the signal-to-noise ratio and repeatability, both active and passive seismic surveys were carried out. The surveys were conducted in relatively poor weather conditions, with rain, strong wind and thunderstorms increasing the noise level. We found that noise level for buried geophones is on average 20 dB lower compared to the surface ones. Furthermore, the combination of active and passive experiments has allowed us to perform a detailed classification of various noise sources. Acknowledgement The authors acknowledge the funding provided by the Australian government through its CRC program to support this CO2CRC research project. We also acknowledge the CO2CRC's corporate sponsors and the financial assistance provided through Australian National Low Emissions Coal Research and Development (ANLEC R&D). ANLEC R&D is supported by Australian Coal Association Low Emissions Technology Limited and the Australian Government through the Clean Energy Initiative.

  8. Cocaine phenomenology study: results of a third in a series of field trials

    NASA Astrophysics Data System (ADS)

    Su, Chih-Wu; Rigdon, Stephen W.; Ricard, Steve; Hoglund, David E.; Drolet, Gerry; Neudorfl, Pavel; Hupe, Michael; Kunz, Terry D.; Ulvick, Sydney J.; Demirgian, Jack C.; Shier, Patrick; Wingo, Jeff J.

    1997-01-01

    To form an understanding of the environment in which non- intrusive detection and inspection technologies are required to operate, the Narcotic Detection Technology assessment Team has undertaken a series of field studies. These field studies have focused on the phenomenology, fate and behavior of narcotic residue in real world environments. The overall goal of the tests is to give Law Enforcement officers the ability to accurately differentiate between individuals involved in the smuggling process and individuals innocently contaminated with narcotics. The latest filed study in this series was conducted in Miami, FL in February 1996. The field study comprised several individual tests. The first was a contamination and transfer study which focuses on human contamination resulting from contact with actual kilos of cocaine and the mechanism by which this contamination transfers to surrounding objects, if at all. The second was a secondary contamination study which focused on determining the conditions under which cocaine contamination transfers from objects touched by individuals who handled narcotics to innocent passerbys. The third was a persistence study which focused on the persistence of cocaine contamination on people under a variety of conditions. An overview of the tests and their preliminary results will be discussed.

  9. Field Trial of a Low-Cost, Distributed Plug Load Monitoring System

    SciTech Connect

    Auchter, B.; Cautley, D.; Ahl, D.; Earle, L.; Jin, X.

    2014-03-01

    Researchers have struggled to inventory and characterize the energy use profiles of the ever-growing category of so-called miscellaneous electric loads (MELs) because plug-load monitoring is cost-prohibitive to the researcher and intrusive to the homeowner. However, these data represent a crucial missing link to understanding how homes use energy. Detailed energy use profiles would enable the nascent automated home energy management (AHEM) industry to develop effective control algorithms that target consumer electronics and other plug loads. If utility and other efficiency programs are to incent AHEM devices, they need large-scale datasets that provide statistically meaningful justification of their investments by quantifying the aggregate energy savings achievable. To address this need, NREL researchers investigated a variety of plug-load measuring devices available commercially and tested them in the laboratory to identify the most promising candidates for field applications. This report centers around the lessons learned from a field validation of one proof-of-concept system, called Smartenit (formerly SimpleHomeNet). The system was evaluated based on the rate of successful data queries, reliability over a period of days to weeks, and accuracy. This system offers good overall performance when deployed with up to 10 end nodes in a residential environment, although deployment with more nodes and in a commercial environment is much less robust. NREL concludes that the current system is useful in selected field research projects, with the recommendation that system behavior is observed over time.

  10. Vertical Chlorophyll Canopy Structure Affects the Remote Sensing Based Predictability of LAI, Chlorophyll and Leaf Nitrogen in Agricultural Fields

    NASA Astrophysics Data System (ADS)

    Boegh, E.; Houborg, R.; Bienkowski, J.; Braban, C. F.; Dalgaard, T.; van Dijk, N.; Dragosits, U.; Holmes, E.; Magliulo, V.; Schelde, K.; Di Tommasi, P.; Vitale, L.; Theobald, M.; Cellier, P.; Sutton, M.

    2012-12-01

    Leaf nitrogen and leaf surface area influence the exchange of gases between terrestrial ecosystems and the atmosphere, and they play a significant role in the global cycles of carbon, nitrogen and water. Remote sensing can be used to estimate leaf area index (LAI), chlorophyll content (CHL) and leaf nitrogen (N), but methods are often developed using plot-scale data and not verified over extended regions characterized by variations in environmental boundary conditions (soil, atmosphere) and canopy structures. Estimation of N can be indirect due to its association with CHL, however N is also included in pigments such as carotenoids and anthocyanin which have different spectral signatures than CHL. Photosynthesis optimization theory suggests that plants will distribute their N resources in proportion to the light gradient within the canopy. Such vertical variation in CHL and N complicates the evaluation of remote sensing-based methods. Typically remote sensing studies measure CHL of the upper leaf, which is then multiplied by the green LAI to represent canopy chlorophyll content, or random sampling is used. In this study, field measurements and high spatial resolution (10-20 m) remote sensing images acquired from the HRG and HRVIR sensors aboard the SPOT satellites were used to assess the predictability of LAI, CHL and N in five European agricultural landscapes located in Denmark, Scotland (United Kingdom), Poland, The Netherlands and Italy . All satellite images were atmospherically using the 6SV1 model with atmospheric inputs estimated by MODIS and AIRS data. Five spectral vegetation indices (SVIs) were calculated (the Normalized Difference Vegetation index, the Simple Ratio, the Enhanced Vegetation Index-2, the Green Normalized Difference Vegetation Index, and the green Chlorophyll Index), and an image-based inverse canopy radiative transfer modelling system, REGFLEC (REGularized canopy reFLECtance) was applied to each of the five European landscapes. While the

  11. 3D Extended Logging for Geothermal Resources: Field Trials with the Geo-Bilt System

    SciTech Connect

    Mallan, R; Wilt, M; Kirkendall, B; Kasameyer, P

    2002-05-29

    Geo-BILT (Geothermal Borehole Induction Logging Tool) is an extended induction logging tool designed for 3D resistivity imaging around a single borehole. The tool was developed for deployment in high temperature geothermal wells under a joint program funded by the California Energy Commission, Electromagnetic Instruments (EMI) and the U.S. Department of Energy. EM1 was responsible for tool design and manufacture, and numerical modeling efforts were being addressed at Lawrence Livermore Laboratory (LLNL) and other contractors. The field deployment was done by EM1 and LLNL. The tool operates at frequencies from 2 to 42 kHz, and its design features a series of three-component magnetic sensors offset at 2 and 5 meters from a three-component magnetic source. The combined package makes it possible to do 3D resistivity imaging, deep into the formation, from a single well. The manufacture and testing of the tool was completed in spring of 2001, and the initial deployment of Geo-BILT occurred in May 2001 at the Lost Hills oil field in southern California at leases operated by Chevron USA. This site was chosen for the initial field test because of the favorable geological conditions and the availability of a number of wells suitable for tool deployment. The second deployment occurred in April 2002 at the Dixie Valley geothermal field, operated by Caithness Power LLC, in central Nevada. This constituted the first test in a high temperature environment. The Chevron site features a fiberglass-cased observation well in the vicinity of a water injector. The injected water, which is used for pressure maintenance and for secondary sweep of the heavy oil formation, has a much lower resistivity than the oil bearing formation. This, in addition to the non-uniform flow of this water, creates a 3D resistivity structure, which is analogous to conditions produced from flowing fractures adjacent to geothermal boreholes. Therefore, it is an excellent site for testing the 3D capability of

  12. Field Trial of a Low-Cost, Distributed Plug Load Monitoring System

    SciTech Connect

    Auchter, B.; Cautley, D.; Ahl, D.; Earle, L.; Jin, X.

    2014-03-01

    Researchers have struggled to inventory and characterize the energy use profiles of the ever-growing category of so-called miscellaneous electric loads (MELs) because plug-load monitoring is cost-prohibitive to the researcher and intrusive to the homeowner. However, these data represent a crucial missing link to our understanding of how homes use energy, and we cannot control what we do not understand. Detailed energy use profiles would enable the nascent automated home energy management (AHEM) industry to develop effective control algorithms that target consumer electronics and other plug loads. If utility and other efficiency programs are to incent AHEM devices, they need large-scale datasets that provide statistically meaningful justification of their investments by quantifying the aggregate energy savings achievable. To address this need, we have investigated a variety of plug-load measuring devices available commercially and tested them in the laboratory to identify the most promising candidates for field applications. The scope of this report centers around the lessons learned from a field validation of one proof-of-concept system, called Smartenit (formerly SimpleHomeNet). The system was evaluated based on the rate of successful data queries, reliability over a period of days to weeks, and accuracy. This system offers good overall performance when deployed with up to ten end nodes in a residential environment, although deployment with more nodes and in a commercial environment is much less robust. We conclude that the current system is useful in selected field research projects, with the recommendation that system behavior is observed over time.

  13. Improving community development by linking agriculture, nutrition and education: design of a randomised trial of “home-grown” school feeding in Mali

    PubMed Central

    2013-01-01

    Background Providing food through schools has well documented effects in terms of the education, health and nutrition of school children. However, there is limited evidence in terms of the benefits of providing a reliable market for small-holder farmers through “home-grown” school feeding approaches. This study aims to evaluate the impact of school feeding programmes sourced from small-holder farmers on small-holder food security, as well as on school children’s education, health and nutrition in Mali. In addition, this study will examine the links between social accountability and programme performance. Design This is a field experiment planned around the scale-up of the national school feeding programme, involving 116 primary schools in 58 communities in food insecure areas of Mali. The randomly assigned interventions are: 1) a school feeding programme group, including schools and villages where the standard government programme is implemented; 2) a “home-grown” school feeding and social accountability group, including schools and villages where the programme is implemented in addition to training of community based organisations and local government; and 3) the control group, including schools and household from villages where the intervention will be delayed by at least two years, preferably without informing schools and households. Primary outcomes include small-holder farmer income, school participation and learning, and community involvement in the programme. Other outcomes include nutritional status and diet-diversity. The evaluation will follow a mixed method approach, including household, school and village level surveys as well as focus group discussions with small-holder farmers, school children, parents and community members. The impact evaluation will be incorporated within the national monitoring and evaluation (M&E) system strengthening activities that are currently underway in Mali. Baselines surveys are planned for 2012. A monthly

  14. Human Habitation in a Lunar Electric Rover During a 14-Day Field Trial

    NASA Technical Reports Server (NTRS)

    Litaker, Harry, Jr.; Thompson, Shelby; Howard, Robert, Jr.

    2010-01-01

    Various military and commercial entities, as well as the National Aeronautics and Space Administration (NASA), have conducted space cabin confinement studies. However, after an extensive literature search, only one study was found using a simulated lunar rover (LUNEX II), under laboratory conditions, with a crew of two for an eighteen day lunar mission. Forty-three years later, NASA human factors engineers conducted a similar study using the Lunar Electric Rover (LER) in a dynamic real-world lunar simulation at the Black Point Lava Flow in Arizona. The objective of the study was to obtain human-in-the-loop performance data on the vehicle s interior volume with respect to human-system interfaces, crew accommodations, and habitation over a 14-day mission. Though part of a larger study including 212 overall operational elements, this paper will discuss only the performance of fifty different daily habitational elements within the confines of the vehicle carried out by two male subjects. Objective timing data and subjective questionnaire data were collected. Results indicate, much like the LUNEX II study, the LER field study suggest that a crew of two was able to maintain a satisfactory performance of tasks throughout the 14-day field trail within a relative small vehicle volume.

  15. Field trial of vaccination against American trypanosomiasis (Chagas' disease) in domestic guinea pigs.

    PubMed

    Basombrío, M A; Arredes, H; Uncos, D A; Rossi, R; Alvarez, E

    1987-07-01

    Domestically bred South American guinea pigs received 3 to 5 immunizing intradermal inocula of 28 X 10(6) live attenuated Trypanosoma cruzi epimastigotes (TCC strain) per kg. These inocula were unable to produce patent infections or to propagate through vectors. Groups of experimental and control guinea pigs were exposed to natural T. cruzi infection in a field yard for periods of up to 551 days. Xenodiagnoses were applied periodically to all animals. This showed that the incidence of natural T. cruzi infection was significantly lowered at various periods post-exposure. The final proportion of infected animals was 39% (20/51) among vaccinees vs. 63% (32/51) among controls (P less than 0.02). The protective effect was exerted particularly upon males and lasted for over a year in one experimental series (infection in 1/7 vaccinees vs. 6/7 controls, P = 0.014). Vaccination reduced vector transmission rates from 38% to 18% (P less than 0.001). These results agree with previous laboratory experiments in showing a partial resistance which does not eliminate residual T. cruzi infection. However, the field work indicates that even this kind of resistance may have epidemiological impact, reducing both the number of reservoirs spreading the disease and the rate of vector transmission. PMID:3111281

  16. Laboratory and field trial of developing medicinal local Thai plant products against four species of mosquito vectors.

    PubMed

    Trongtokit, Yuwadee; Rongsriyam, Yupha; Komalamisra, Narumon; Krisadaphong, Panvipa; Apiwathnasorn, Chamnarn

    2004-06-01

    Oils of Syzygium aromaticum (clove) and Zanthoxylum limonella (makaen), widely used essential oils for dental caries or flavoring of food in Thailand, were prepared as 10 experimental repellent products in gel or cream form against Aedes aegypti, Culex quinquefasciatus, and Anopheles dirus under laboratory conditions, using the human-arm-in-cage method. Two products that gave the longest-lasting complete protection were selected to examine their repellency against a variety of mosquito species under field conditions. In laboratory tests, 0.1 g of each product was applied to 3x10 cm of exposed area on a volunteer's forearm, while in field trials, 1.0 g was applied to each volunteer's leg (from knee to ankle). In the laboratory, the gel dosage form contained 20% clove oil (Gel B) or 10% clove plus 10% makaen oil mixture (Gel E) were promising plant-based repellents against three mosquito species and gave significantly longer complete protection times of 4-5 hours than all other developing products. Therefore, their efficacy in the field was evaluated. Under field conditions, Gel E showed complete protection for 4 hours and gave 95.7% repellency after 5 hours application, whereas Gel B and 20% deet (di-methyl benzamide) provided only 86.8 and 82.7% repellency after treatment, respectively against Ae. aegypti, daytime-biting mosquitos. For nighttime-biting, the 3 repellents under development yielded equally excellent (average 97.1%) repellency for 5 hours against the predominant Cx. quinquefasciatus and Mansonia uniformis, but they gave 89.0% repellency against Cx. tritaeniorhynchus and Cx. gelidus. This finding demonstrated the effectiveness of Gel B and Gel E products for possible use by low-income rural communities against various mosquito species. PMID:15691131

  17. 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 ...

  18. The first field trials of the chemically synthesized malaria vaccine SPf66: safety, immunogenicity and protectivity.

    PubMed

    Amador, R; Moreno, A; Valero, V; Murillo, L; Mora, A L; Rojas, M; Rocha, C; Salcedo, M; Guzman, F; Espejo, F

    1992-01-01

    This paper reports the results of the first field study performed to assess the safety, immunogenicity and protectivity of the synthetic malaria vaccine SPf66 directed against the asexual blood stages of Plasmodium falciparum. Clinical and laboratory tests were performed on all volunteers prior to and after each immunization, demonstrating that no detectable alteration was induced by the immunization process. The vaccines were grouped as high, intermediate or low responders according to their antibody titres directed against the SPf66 molecule. Two of the 185 (1.08%) SPf66-vaccinated and nine of the 214 (4.20%) placebo-vaccinated volunteers developed P. falciparum malaria. The efficacy of the vaccine was calculated as 82.3% against P. falciparum and 60.6% against Plasmodium vivax.

  19. GeoLab's First Field Trials, 2010 Desert RATS: Evaluating Tools for Early Sample Characterization

    NASA Technical Reports Server (NTRS)

    Evans, Cindy A.; Bell, M. S.; Calaway, M. J.; Graff, Trevor; Young, Kelsey

    2011-01-01

    As part of an accelerated prototyping project to support science operations tests for future exploration missions, we designed and built a geological laboratory, GeoLab, that was integrated into NASA's first generation Habitat Demonstration Unit-1/Pressurized Excursion Module (HDU1-PEM). GeoLab includes a pressurized glovebox for transferring and handling samples collected on geological traverses, and a suite of instruments for collecting preliminary data to help characterize those samples. The GeoLab and the HDU1-PEM were tested for the first time as part of the 2010 Desert Research and Technology Studies (DRATS), NASA's analog field exercise for testing mission technologies. The HDU1- PEM and GeoLab participated in two weeks of joint operations in northern Arizona with two crewed rovers and the DRATS science team.

  20. Drivers of nitrogen dynamics in ecologically based agriculture revealed by long-term, high-frequency field measurements.

    PubMed

    Finney, Denise M; Eckert, Sara E; Kaye, Jason P

    2015-12-01

    Nitrogen (N) loss from agriculture impacts ecosystems worldwide. One strategy to mitigate these losses, ecologically based nutrient management (ENM), seeks to recouple carbon (C) and N cycles to reduce environmental losses and supply N to cash crops. However, our capacity to apply ENM is limited by a lack of field-based high-resolution data on N dynamics in actual production contexts. We used data from a five-year study of organic cropping systems to investigate soil inorganic N (SIN) variability and nitrate (NO3-) leaching in ENM. Four production systems initiated in 2007 and 2008 in central Pennsylvania varied in crop rotation, timing and intensity of tillage, inclusion of fallow periods, and N inputs. Extractable SIN was measured fortnightly from March through November throughout the experiment, and NO3- N concentration below the rooting zone was sampled with lysimeters during the first year of the 2008 start. We used recursive partitioning models to assess the importance of management and environmental factors to SIN variability and NO3- leaching and identify intera