WorldWideScience

Sample records for irrigation field experiment

  1. [Runoff Pollution Experiments of Paddy Fields Under Different Irrigation Patterns].

    Science.gov (United States)

    Zhou, Jing-wen; Su, Bao-lin; Huang, Ning-bo; Guan, Yu-tang; Zhao, Kun

    2016-03-15

    To study runoff and non-point source pollution of paddy fields and to provide a scientific basis for agricultural water management of paddy fields, paddy plots in the Jintan City and the Liyang City were chosen for experiments on non-point source pollution, and flood irrigation and intermittent irrigation patterns were adopted in this research. The surface water level and rainfall were observed during the growing season of paddies, and the runoff amount from paddy plots and loads of total nitrogen (TN) and total phosphorus (TP) were calculated by different methods. The results showed that only five rain events of totally 27 rainfalls and one artificially drainage formed non-point source pollution from flood irrigated paddy plot, which resulted in a TN export coefficient of 49.4 kg · hm⁻² and a TP export coefficient of 1.0 kg · hm⁻². No any runoff event occurred from the paddy plot with intermittent irrigation even in the case of maximum rainfall of 95.1 mm. Runoff from paddy fields was affected by water demands of paddies and irrigation or drainage management, which was directly correlated to surface water level, rainfall amount and the lowest ridge height of outlets. Compared with the flood irrigation, intermittent irrigation could significantly reduce non-point source pollution caused by rainfall or artificial drainage.

  2. How Patients Experience Antral Irrigation

    Directory of Open Access Journals (Sweden)

    Karin Blomgren

    2015-01-01

    Full Text Available Background Antral irrigation earlier had an important role in the diagnosis and treatment of rhinosinusitis. Nowadays, it is often considered too unpleasant. However, the experience of patients of this procedure has been very seldom evaluated. Nor has the effect on pain in rhinosinusitis been evaluated. The aim of this study was to evaluate patients’ experience of discomfort and pain during antral irrigation. We also assessed facial pain caused by rhinosinusitis before the procedure and pain soon after the procedure. Methods Doctors and 121 patients completed their questionnaires independently after antral irrigation in a university clinic, in a private hospital, and at a communal health center. Results Patients experienced mild pain during antral irrigation (mean and median visual analog scale score: <3. Their experience of pain during antral irrigation was closely comparable to pain during dental calculus scaling. Facial pain assessed before antral irrigation decreased quickly after the procedure. Conclusions Antral irrigation was well tolerated as an outpatient procedure. The procedure seems to relieve facial pain caused by the disease quickly. The role of antral irrigation in the treatment of acute rhinosinusitis will need further investigation.

  3. Field evaluation of deficit irrigation effects on tomato growth ...

    African Journals Online (AJOL)

    Two field experiments were conducted using a common tomato cultivar (GS12) to assess the effect of deficit irrigation (DI) regimes on tomato growth performance, and on root-knot nematode Meloidogyne javanica galling and abundance. Irrigation treatments consisted of five irrigation regimes: 20%, 40%, 60%, 80% and ...

  4. Addressing water scarcity through limited irrigation cropping: Field experiments and modeling

    Science.gov (United States)

    Population growth in urbanizing areas such as the Front Range of Colorado has led to increased pressure to transfer water from agriculture to municipalities. In many cases this has led to complete dry up of productive irrigated lands. An option to complete dry-up is the practice of limited or defi...

  5. Water movement through a shallow unsaturated zone in an inland arid region: Field drip irrigation experiment under matrix potential control

    Science.gov (United States)

    Zhou, T.; Han, D.; Song, X.

    2017-12-01

    It is vital to study soil water movement in unsaturated zone for evaluating and improving current irrigation mode for prevention and control of soil secondary salinization, especially in inland arid area, where is characterized by strong evaporation, poor drainage system and shallow water table depth. In this study, we investigated the applicability of drip irrigation under matrix potential control during cotton growth seasons in an inland arid region of northwest China. Combined physical observation with stable isotopes tracing method, we studied soil water flow system and recharge sources of shallow groundwater in heavy (Pilot 1) and light (Pilot 2) saline-alkali cotton fields. Evaporation depths (about 50-60 cm) are about the same for both pilots, but infiltration depths (about 60 cm for Pilot 1 and 150 cm for Pilot 2) are very different due to different soil texture, soil structure and soil salt content. Middle layer (about 100 cm thick) is a critical barrier for water exchange between surface and deep layer. Irrigation water is the major source (about 79.6% for Pilot 1 and 81.6% for Pilot 2), while evapotranspiration is the major sink (about 80.7% for Pilot 1 and 83.1% for Pilot 2) of unsaturated zone. The increase of soil water storage is not enough to make up the water shortage of middle layer and thus drip irrigation water doesn't recharge into groundwater for both pilots. Water table rise (about 60 cm for Pilot 1 and 50 cm for Pilot 2) could be caused by lateral groundwater flow instead of vertical infiltration. This irrigation mode could retard the water table rise in this region. However, improving horizontal drainage system may be indispensable for sustainable agriculture development. The study can provide important basis for soil secondary salinization prevention and agricultural water management in inland arid areas.

  6. Influence of season growth, soils and irrigation water composition on the concentration of uranium in two lettuce (Lactuca sativa L.) varieties. Field experiments

    Science.gov (United States)

    Abreu, M. M.; Neves, O.; Marcelino, M.

    2012-04-01

    Former uranium mines areas are frequently the sources of environmental radionuclides problems even many years after the closure of mining operations. A concern for inhabitants from mining areas is the use of contaminated land or irrigation water for agriculture, and the potential transfer of metals from soils to vegetables, and to humans through the food chain. The main aim of this study was to compare the uranium concentration in lettuce (Lactuca sativa L. varieties Marady and Romana) grown in different seasons (autumn and summer) and exposed to high and low uranium concentrations both in irrigation water and agricultural soil. The content of uranium in irrigation water, soil (total and available fraction) and in lettuce leaf samples was analyzed in a certified laboratory. In the field experiments, two agricultural soils were divided into two plots (four replicates each); one of them was irrigated with uranium contaminated water (0.94 to 1.14 mg/L) and the other with uncontaminated water (< 0.02 mg/L). Irrigation with contaminated water together with highest soil uranium available concentration (10 to 13 mg/kg) had negative effects on both studied lettuce varieties, namely yield reduction (up to 53% and 87% in autumn and summer experiments, respectively) and increase of uranium leaf concentration (up to 1.4 and 7 fold in autumn and summer, respectively). Effect on lettuce yield was mainly due to the high soil salinity (1.01 to 6.31 mS/cm) as a consequence of high irrigation water electrical conductivity (up to 1.82 mS/cm) and low lettuce soil salinity tolerance (1 to 3 mS/cm). The highest lettuce uranium concentration (dry weight) observed was 2.13 and 5.37 mg/kg for Marady and Romana variety, respectively. The highest uranium lettuce concentration in Romana variety was also the effect of its growing in summer season when it was subject to greatest frequency and amount of water irrigation. The consumption by an adult of the lettuce that concentrate more uranium

  7. Breakthrough of two pesticides into tile drain and shallow groundwater: comparison of tile drain reaction and soil profiles within a field scale irrigation experiment

    Science.gov (United States)

    Klaus, Julian; Zehe, Erwin; Elsner, Martin; Palm, Juliane; Schneider, Dorothee; Schröder, Boris; Steinbeiss, Sibylle; West, Stephanie

    2010-05-01

    Preferential flow in macropores is a key process which strongly affects infiltration and may cause rapid transport of pesticides into depths of 80 to 150 cm. At these depths they experience a much slower degradation, may leach into shallow groundwater or enter a tile-drain and are transported into surface water bodies. Therefore, preferential transport might be an environmental problem, if the topsoil is bypassed, which has been originally thought to act as a filter to protect the subsoil and shallow groundwater. To investigate the behaviour of two pesticides with different chemical characteristics and to compare their transport behaviour in soil and into the tile drain an irrigation experiment was performed on a 400 m² field site. The experimental plot is located in the Weiherbach valley, south-west Germany, which basic geology consists of Loess and Keuper layers, the soil at the test site is a gleyic Colluvisol. The distance of the irrigation site to the Weiherbach brook is approximately 12 m, the field is drained with a tile-drain in about 1.2 m depth and shows discharge over the entire year. Three hours before the irrigation started, the farmer applied a pesticide solution consisting of Isoproturon (80 g) and Flufenacet (20 g) (IPU and FLU) according to conventional agricultural practice on the field plot. The irrigation took place in three time blocks (80 min, 60 min, 80 min) with in total 33.6 mm of precipitation. During the first block 1600 g of Bromide were mixed in the irrigation water. The drainage outlet was instrumented with a pressure probe. About 50 water samples ware taken during the experimental day, and several samples more the days after the experiment. They were analysed for the pesticides, bromide and water isotopes. In the two days after the experiment three soil profiles were excavated and soil samples were taken on a 10x10 cm² scheme. One week after the experiment two additional profiles were excavated. The soil was analysed for IPU, FLU

  8. Regional Advection Perturbations in an Irrigated Desert (RAPID) Experiment

    NARCIS (Netherlands)

    Debruin, H.A.R.; Hartogensis, O.K.; Allen, R.G.; Kramer, J.W.J.L.

    2005-01-01

    The RAPID field experiment took place in August - September 1999 at a site 25km south of Twin Falls, Idaho, USA. The experiment concerned micrometeorological observations over extensive, well-irrigated fields covered with the fast-growing crop alfalfa. During daytime, on a number of days the

  9. Surge flow irrigation under short field conditions in Egypt

    NARCIS (Netherlands)

    Ismail, S.M.; Depeweg, H.; Schultz, E.

    2004-01-01

    Several studies carried out in long furrows have shown that surge flow irrigation offers the potential of increasing the efficiency of irrigation. The effects of surge flow in short fields, such as in Egypt, are still not well known, however. To investigate the effect of surge flow irrigation in

  10. Effects of irrigation strategies and soils on field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Plauborg, Finn; Andersen, Mathias Neumann

    2011-01-01

    Root distribution of field grown potatoes (cv. Folva) was studied in 4.32m2 lysimeters and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. Drip irrigation was applied for all irrigations. Irrigations were run in three different soils: coarse sand......, loamy sand, and sandy loam. Irrigation treatments started after tuber bulking and lasted until final harvest with PRD and DI receiving 65% of FI. Potatoes irrigated with water-saving irrigation techniques (PRD and DI) did not show statistically different dry root mass and root length density (RLD, cm...... density in the furrow. Most roots accumulated in the surface layers of coarse sand as compared to the other soil types. In the deep soil profile (30–70 cm) a higher root density was found in loamy sand compared with the sandy loam and coarse sand. Approximately twice the amounts of roots were found below...

  11. Irrigation ponds: Possibility and potentials for the treatment of drainage water from paddy fields in Zhanghe Irrigation System

    Institute of Scientific and Technical Information of China (English)

    DONG Bin; MAO Zhi; BROWN Larry; CHEN XiuHong; PENG LiYuan; WANG JianZhang

    2009-01-01

    Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and un-recycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China.With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious.Traditional ir-rigation and drainage systems only focus on issues concerning water quantity, i.e.the capacity of irri-gation in drought and drainage in waterlogging period, yet have no requirement on water quality im-provement, how to clean the water quality of farmland drainage through remodeling the existing irriga-tion and drainage systems has a very important realistic meaning.Pond is an important irrigation facil-ity in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use.Such water storage features of pond provide the possibility and potential capacity for drainage water treat-ment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system.To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site.The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water.Other issues, e.g.how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.

  12. Irrigation ponds:Possibility and potentials for the treatment of drainage water from paddy fields in Zhanghe Irrigation System

    Institute of Scientific and Technical Information of China (English)

    BROWN; Larry

    2009-01-01

    Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and unrecycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China. With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious. Traditional irrigation and drainage systems only focus on issues concerning water quantity, i.e. the capacity of irrigation in drought and drainage in waterlogging period, yet have no requirement on water quality improvement. how to clean the water quality of farmland drainage through remodeling the existing irrigation and drainage systems has a very important realistic meaning. Pond is an important irrigation facility in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use. Such water storage features of pond provide the possibility and potential capacity for drainage water treatment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system. To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site. The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water. Other issues, e.g. how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.

  13. Comparison of Manual and Automatic Irrigation of Pot Experiments

    DEFF Research Database (Denmark)

    Haahr, Vagner

    1975-01-01

    An air-lift principle for transport of water was adapted for automatic irrigation of experimental pots originally constructed for manual irrigation by the weighing method. The two irrigation techniques were compared in an experiment with increasing amounts of nitrogen fertilizer to spring barley....... Productions of grain and straw and chemical composition were almost the same after the two irrigation methods, and it was concluded that the laborious manual watering could be replaced by automatic irrigation. Comparison of the yield from individual plants in the pots showed a large difference between centre...... plants and border plants independent of irrigation principle. The increase in yield per pot with increasing N fertilization was at the highest N level caused only by an increase in yield of the border plants....

  14. Dual permeability soil water dynamics and water uptake by roots in irrigated potato fields

    DEFF Research Database (Denmark)

    Dolezal, Frantisek; Zumr, David; Vacek, Josef

    2007-01-01

    Water movement and uptake by roots in a drip-irrigated potato field was studied by combining field experiments, outputs of numerical simulations and summary results of an EU project (www.fertorganic.org). Detailed measurements of soil suction and weather conditions in the Bohemo-Moravian highland...

  15. Global field experiments for potato simulations

    DEFF Research Database (Denmark)

    Raymundo, Rubí; Asseng, Senthold; Prasad, Rishi

    2018-01-01

    A large field potato experimental dataset has been assembled for simulation modeling. The data are from temperate, subtropical, and tropical regions across the world and include 87 experiments with 204 treatments. Treatments include nitrogen fertilizer, irrigation, atmospheric CO2 levels, tempera......A large field potato experimental dataset has been assembled for simulation modeling. The data are from temperate, subtropical, and tropical regions across the world and include 87 experiments with 204 treatments. Treatments include nitrogen fertilizer, irrigation, atmospheric CO2 levels...

  16. TRANSPORT OF SOLUTES IN THE FIELD AS AFFECTED BY IRRIGATION

    Directory of Open Access Journals (Sweden)

    Alessandro Comegna

    2007-09-01

    Full Text Available This study documents and compares the transport of a conservative solute in near saturated soil profiles under flood and sprinkler irrigation. The experiments were carried out on a clay Vertic-Usthortens soil located near Potenza (Italy. Two 2x2 m2 plots were clipped of their native grass vegetation. After spraying on the surface a Cl- pulse as KCl salt; water was applied in five increments over two months as flood irrigation on the first plot and as sprinkler irrigation on the second one. Chloride resident concentration Cr, was sampled by soil coring at four different days after chemical application. Cr(z,t profiles were analyzed by spatial moment method. The recovered mass of Cl- and location of center of mass were comparable for the two types of irrigation. The spread around the center of mass, however, was higher for the flood-irrigated plot. In the flood-irrigated plot, more mass leached below the depth of 90 cm. The velocity of the center of mass was consistently 10-20% larger than the piston displacement velocity. To evaluate the nature of transport, the Cr(z,t distributions were modelled using quasi-steady solution of convection-dispersion equation(CDE. At the scale of our experiments the profiles of Cl- resident concentration are well-simulated.

  17. Nuclear techniques to assess irrigation schedules for field crops. Results of a co-ordinated research programme

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    This TECDOC summarizes the results of a Co-ordinated Research Programme on The Use of Nuclear and Related Techniques in Assessment of Irrigation Schedules of Field Crops to Increase Effective Use of Water in Irrigation Projects. The programme was carried out between 1990 and 1995 through the technical co-ordination of the Soil Fertility, Irrigation and Crop Production Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture of the International Atomic Energy Agency. Fourteen Member States of the IAEA and FAO carried out a series of field experiments aimed at improving irrigation water use efficiency through a type of irrigation scheduling known as deficit irrigation. Refs, figs, tabs.

  18. Nuclear techniques to assess irrigation schedules for field crops. Results of a co-ordinated research programme

    International Nuclear Information System (INIS)

    1996-06-01

    This TECDOC summarizes the results of a Co-ordinated Research Programme on The Use of Nuclear and Related Techniques in Assessment of Irrigation Schedules of Field Crops to Increase Effective Use of Water in Irrigation Projects. The programme was carried out between 1990 and 1995 through the technical co-ordination of the Soil Fertility, Irrigation and Crop Production Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture of the International Atomic Energy Agency. Fourteen Member States of the IAEA and FAO carried out a series of field experiments aimed at improving irrigation water use efficiency through a type of irrigation scheduling known as deficit irrigation. Refs, figs, tabs

  19. Evaluation of mulched drip irrigation for cotton in arid Northwest China

    NARCIS (Netherlands)

    Wang, Z.; Jin, M.; Simunek, J.; van Genuchten, M.T.

    2014-01-01

    Field experiments were conducted in arid Southern Xinjiang, Northwest China, for 3 years to evaluate sustainable irrigation regimes for cotton. The experiments involved mulched drip irrigation during the growing season and flood irrigation afterward. The drip irrigation experiments included control

  20. The phenology of malaria mosquitos in irrigated rice fields in Mali

    NARCIS (Netherlands)

    Klinkenberg, E.; Takken, W.; Huibers, F.P.; Touré, Y.T.

    2003-01-01

    A field study was carried out in the large-scale rice irrigation scheme of the Office du Niger in Mali to investigate the relation between anopheline mosquito larval development and small-scale differences in irrigation practices, such as water level, irrigation application and irrigation frequency.

  1. Arsenic transport in irrigation water across rice-field soils in Bangladesh

    International Nuclear Information System (INIS)

    Polizzotto, Matthew L.; Lineberger, Ethan M.; Matteson, Audrey R.; Neumann, Rebecca B.; Badruzzaman, A. Borhan M.; Ashraf Ali, M.

    2013-01-01

    Experiments were conducted to analyze processes impacting arsenic transport in irrigation water flowing over bare rice-field soils in Bangladesh. Dissolved concentrations of As, Fe, P, and Si varied over space and time, according to whether irrigation water was flowing or static. Initially, under flowing conditions, arsenic concentrations in irrigation water were below well-water levels and showed little spatial variability across fields. As flowing-water levels rose, arsenic concentrations were elevated at field inlets and decreased with distance across fields, but under subsequent static conditions, concentrations dropped and were less variable. Laboratory experiments revealed that over half of the initial well-water arsenic was removed from solution by oxidative interaction with other water-column components. Introduction of small quantities of soil further decreased arsenic concentrations in solution. At higher soil-solution ratios, however, soil contributed arsenic to solution via abiotic and biotic desorption. Collectively, these results suggest careful design is required for land-based arsenic-removal schemes. -- Highlights: •We analyzed the processes impacting arsenic transport in flowing irrigation water. •Arsenic in Bangladesh rice-field irrigation water varied over space and time. •Arsenic was correlated with Fe, P, and Si in flowing and static water. •Oxidation, adsorption and desorption reactions controlled arsenic concentrations. •Land-based arsenic removal from water will be impacted by hydraulic conditions. -- Arsenic concentrations in flowing and static irrigation water in Bangladesh varied over space and time, suggesting careful design is required for land-based pre-treatment schemes that aim to remove As from solution

  2. Field Comparison of Fertigation Vs. Surface Irrigation of Cotton Crop

    International Nuclear Information System (INIS)

    Janat, M.

    2004-01-01

    Based on previous results of the same nature, one nitrogen rate 180 kg N ha -1 was tested under two-irrigation methods, surface irrigation and drip fertigation of cotton (Cultivar Rakka-5) for two consecutive seasons 2000 and 2001. The study aimed to answer various questions regarding the applicability of drip fertigation at farm level and the effect of its employment on yield and growth parameters, compared to surface irrigation. Nitrogen fertilizer was either injected in eight equally split applications for the drip fertigated cotton or divided in four unequally split applications as recommend by Ministry of Agriculture (20% before planting, 40% at thinning, 20% after 60 days from planting and 20% after 75 days after planting). 15 N labeled urea was used to evaluate nitrogen fertilizer efficiency. The experimental design was randomized block design with seven replicates. Results showed that drip fertigation led to water saving exceeding 50% in some cases. Field germination percentage was highly increased under drip- fertigated cotton relative to surface-irrigated cotton. Dry matter and seed cotton yield of surface-irrigated cotton was slightly higher than that of drip-fertigated cotton in the first growing season. The reason for that was due to the hot spill that occurred in the region, which exposed the cotton crop to water stress and consequently pushed the cotton into early flowering. Lint properties were not affected by the introduction of drip-fertigation. Actually some properties were improved relative to the standard properties identified by the cotton Bureau.Nitrogen uptake was slightly increased under drip fertigation whereas nitrogen use efficiencies were not constant along the growing seasons. The reason for that could be lateral leaching and root proliferation into the labeled and unlabeled subplots. Field water use efficiency was highly increased for both growing seasons under drip fertigation practice. The rate of field water use efficiencies

  3. Column leaching experiments of a uranium ore by atomizing irrigation technique

    International Nuclear Information System (INIS)

    Zeng Yingying; Lei Zeyong; Chen Haihui

    2007-01-01

    Column leaching experiments ora uranium ore were made by atomizing irrigation technique. The leaching results are compared with the results obtained by spray irrigation and drip irrigation techniques respectively under the same conditions of column leaching experiments. The results show that the atomizing irrigation technique has more uniform solution distribution, higher leaching rate, shorter leaching period, and less ratio of liquid to solid. Consequently, the atomizing irrigation technique is suitable to the ore. (authors)

  4. Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

    NARCIS (Netherlands)

    Urrutia Cobo, N.

    2006-01-01

    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands

  5. Transfer of radioactive and chemical pollutants into irrigated rice fields

    International Nuclear Information System (INIS)

    Myttenaere, C.; Mousny, J.-M.; Dabin, P.; Bittel, R.

    1975-01-01

    In a general study on the consequences of radioactive and chemical releases in continental waters, flooded rice fields must be considered as a very important ecosystem due to the very large quantities of water used. In order to approach as much as possible to the natural conditions (irrigated rice fields of Northern Italy) ''mini-rice fields'' were built and local practices were respected. The behavior of activation and fission products ( 137 Cs, 60 Co, 65 Zn, 51 Cr...) and heavy metals pollutants (Cd, Cr, Sn) was studied and the transfer from water to soil and plant was followed. Concentration factors were calculated for the different organs of the plant and the impact of rice ingested to the dose delivered to man was evaluated [fr

  6. Global field experiments for potato simulations

    NARCIS (Netherlands)

    Raymundo, Rubi; Asseng, Senthold; Prasad, Rishi; Kleinwechter, Ulrich; Condori, Bruno; Bowen, Walter; Wolf, Joost; Olesen, Jørgen E.; Dong, Qiaoxue; Zotarelli, Lincoln; Gastelo, Manuel; Alva, Ashok; Travasso, Maria; Arora, Vijay

    2018-01-01

    A large field potato experimental data set has been assembled for simulation modeling. The data are from temperate, subtropical, and tropical regions across the world and include 87 experiments with 204 treatments. Treatments include nitrogen fertilizer, irrigation, atmospheric CO2 levels,

  7. Effect of sequential surface irrigations on field-scale emissions of 1,3-dichloropropene.

    Science.gov (United States)

    Yates, S R; Knuteson, J; Ernst, F F; Zheng, W; Wang, Q

    2008-12-01

    A field experiment was conducted to measure subsurface movement and volatilization of 1,3-dichloropropene (1,3-D) after shank injection to an agricultural soil. The goal of this study was to evaluate the effect of sprinkler irrigation on the emissions of 1,3-D to the atmosphere and is based on recent research that has shown that saturating the soil pore space reduces gas-phase diffusion and leads to reduced volatilization rates. Aerodynamic, integrated horizontal flux, and theoretical profile shape methods were used to estimate fumigant volatilization rates and total emission losses. These methods provide estimates of the volatilization rate based on measurements of wind speed, temperature, and 1,3-D concentration in the atmosphere. The volatilization rate was measured continuously for 16 days, and the daily peak volatilization rates for the three methods ranged from 18 to 60 microg m(-2) s(-1). The total 13-D mass entering the atmosphere was approximately 44-68 kg ha(-1), or 10-15% of the applied active ingredient This represents approximately 30-50% reduction in the total emission losses compared to conventional fumigant applications in field and field-plot studies. Significant reduction in volatilization of 1,3-D was observed when five surface irrigations were applied to the field, one immediately after fumigation followed by daily irrigations.

  8. Development of fine and coarse roots of Thuja occidentalis 'Brabant' in non-irrigated and drip irrigated field plots

    NARCIS (Netherlands)

    Pronk, A.A.; Willigen, de P.; Heuvelink, E.; Challa, H.

    2002-01-01

    Aboveground dry mass, total root dry mass and root length density of the fine roots of Thuja occidentalis `Brabant' were determined under non- and drip-irrigated field conditions. Two-dimensional diffusion parameters for dynamic root growth were estimated based on dry mass production of the fine

  9. Effects of irrigation strategies and soils on field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Andersen, Mathias Neumann; Plauborg, Finn

    2010-01-01

    Yield and water productivity of potatoes grown in 4.32 m2 lysimeters were measured in coarse sand, loamy sand, and sandy loam and imposed to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments received 65% of FI after...

  10. Studying Geographical Distribution Map of Weeds of Irrigated Wheat Fields of Ardabil Province

    OpenAIRE

    B Soheili

    2013-01-01

    In order to identify the density and abundance of weeds in irrigated wheat fields of Ardabil Province, 76 samples of irrigated wheat fields based on cultivation area from all counties of Ardabil province for six years (2001-2006) were selected. The genus and species of weeds from each sampling fields and their population indices density, frequency and uniformity of each species were calculated by using Thomas method. Geographic coordinates of field (Latitude, Altitude and Elevation) were the ...

  11. Field trials show the fertilizer value of nitrogen in irrigation water

    Directory of Open Access Journals (Sweden)

    Mike Cahn

    2017-04-01

    Full Text Available Increased regulatory activity designed to protect groundwater from degradation by nitrate-nitrogen (NO3-N is focusing attention on the efficiency of agricultural use of nitrogen (N. One area drawing scrutiny is the way in which growers consider the NO3-N concentration of irrigation water when determining N fertilizer rates. Four drip-irrigated field studies were conducted in the Salinas Valley evaluating the impact of irrigation water NO3-N concentration and irrigation efficiency on the N uptake efficiency of lettuce and broccoli crops. Irrigation with water NO3-N concentrations from 2 to 45 milligrams per liter were compared with periodic fertigation of N fertilizer. The effect of irrigation efficiency was determined by comparing an efficient (110% to 120% of crop evapotranspiration, ETc and an inefficient (160% to 200% of ETc irrigation treatment. Across these trials, NO3-N from irrigation water was at least as efficiently used as fertilizer N; the uptake efficiency of irrigation water NO3-N averaged approximately 80%, and it was not affected by NO3-N concentration or irrigation efficiency.

  12. Expanding the Annual Irrigation Maps (AIM) Product to the entire High Plains Aquifer (HPA): Addressing the Challenges of Cotton and Deficit-Irrigated Fields

    Science.gov (United States)

    Rapp, J. R.; Deines, J. M.; Kendall, A. D.; Hyndman, D. W.

    2017-12-01

    The High Plains Aquifer (HPA) is the most extensively irrigated aquifer in the continental United States and is the largest major aquifer in North America with an area of 500,000 km2. Increased demand for agricultural products has led to expanded irrigation extent, but brought with it declining groundwater levels that have made irrigation unsustainable in some locations. Understanding these irrigation dynamics and mapping irrigated areas through time are essential for future sustainable agricultural practices and hydrological modeling. Map products using remote sensing have only recently been able to track annual dynamics at relatively high spatial resolution (30 m) for a large portion of the northern HPA. However follow-on efforts to expand these maps to the entire HPA have met with difficulty due to the challenge of distinguishing irrigation in crop types that are commonly deficit- or partially-irrigated. Expanding these maps to the full HPA requires addressing unique features of partially irrigated fields and irrigated cotton, a major water user in the southern HPA. Working in Google Earth Engine, we used all available Landsat imagery to generate annual time series of vegetation indices. We combined this information with climate covariables, planting dates, and crop specific training data to algorithmically separate fully irrigated, partially irrigated, and non-irrigated field locations. The classification scheme was then applied to produce annual maps of irrigation across the entire HPA. The extensive use of ancillary data and the "greenness" time series for the algorithmic classification generally increased accuracy relative to previous efforts. High-accuracy, representative map products of irrigation extent capable of detecting crop type and irrigation intensity within aquifers will be an essential tool to monitor the sustainability of global aquifers and to provide a scientific bases for political and economic decisions affecting those aquifers.

  13. Water saving at the field scale with Irrig-OH, an open-hardware environment device for soil water potential monitoring and irrigation management

    Science.gov (United States)

    Masseroni, Daniele; Facchi, Arianna; Gandolfi, Claudio

    2015-04-01

    Sustainability of irrigation practices is an important objective which should be pursued in many countries, especially in areas where water scarcity causes strong conflicts among the different water uses. The efficient use of water is a key factor in coping with the food demand of an increasing world population and with the negative effects of the climate change on water resources availability in many areas. In this complex context, it is important that farmers adopt instruments and practices that enable a better management of water at the field scale, whatever the irrigation method they adopt. This work presents the hardware structure and the functioning of an open-hardware microstation based on the Arduino technology, called Irrig-OH, which allows the continuous and low-cost monitoring of the soil water potential (SWP) in the root zone for supporting the irrigation scheduling at the field scale. In order to test the microstation, an experiment was carried out during the agricultural season 2014 at Lodi (Italy), with the purpose of comparing the farmers' traditional management of irrigation of a peach variety and the scheduling based on the SWP measurements provided by the microstation. Additional measurements of leaf water potential (LWP), stomatal resistance, transpiration (T), crop water stress index (CWSI) and fruit size evolution were performed respectively on leafs and fruits for verifying the plant physiological responses on different SWP levels in soil. At the harvesting time, the peach production in term of quantity and quality (sucrose content was measured by a rifractometer over a sample of one hundred fruits) of the two rows were compared. Irrigation criteria was changed with respect to three macro-periods: up to the endocarp hardening phase (begin of May) soil was kept well watered fixing the SWP threshold in the first 35 cm of the soil profile at -20 kPa, during the pit hardening period (about the entire month of May) the allowed SWP threshold was

  14. Technical Evaluation of Sprinkler Irrigation Systems which were Implemented in Tea Fields of the Guilan Province

    Directory of Open Access Journals (Sweden)

    kourosh majdsalimi

    2016-02-01

    Full Text Available Introduction: Designing and management of sprinkler irrigation systems depend on the situation and location of its implementation and often rely on professional and long-term tests (9. Having a good irrigation system depends on knowledge of the relationship between soil, water, plants, irrigation scheduling, the required amount of irrigation water to the water-holding capacity of soil, climate and plant growth (6.The less use of sprinkler irrigation systems and less performed research projects in the Guilan province, lack of correct design parameters due to shortage of the required parameters for local and regional planning, has led to reliance on charts and tables. Therefore, planning water resources cannot be performed well and with accurate details. According to many researchers (8, the technical evaluation should be a regular and short-term process to review the problems and possible performance of irrigation systems. Merriam and Keller (10 defined the assessment of an irrigation system analysis, based on field measurements in real terms during the normal work of the system. Therefore, to develop these systems over the next few years, it is essential to evaluate the use of irrigation systems and review the performance of existing problems and utilizing the results to improve it. The aim of this study was to assess the current status of implemented irrigation systems in the tea plantations of Guilan and evaluate their performance. Materials and Methods: In this study, six classic sprinkler irrigation systems in tea fields of Guilan province were evaluated during two years. Sprinkler irrigation systems of semi-portable, solid-set and solid-set (hand-move sprinkler were selected randomly. To evaluate this irrigation systems, Christiansen’s uniformity coefficient (CU, distribution uniformity (DU, potential application efficiency of low-quarter (PELQ and application efficiency of low-quarter (AELQ in the form of trial blocks were estimated by

  15. Design of a pot experiment to study the effect of irrigation with ...

    African Journals Online (AJOL)

    Municipal water was used to irrigate the control treatment of each soil. .... experiment. RESULTS AND DISCUSSION. Since only ... deeper horizons were considered to be irrelevant. With the ... irrigation water uniformly over the soil surface, the four micro- .... of selected vineyard soils and a critical assessment of methods to.

  16. Treated wastewater and Nitrate transport beneath irrigated fields near Dodge city, Kansas

    Science.gov (United States)

    Sophocleous, M.; Townsend, M.A.; Vocasek, F.; Ma, Liwang; Ashok, K.C.

    2010-01-01

    Use of secondary-treated municipal wastewater for crop irrigation south of Dodge City, Kansas, where the soils are mainly of silty clay loam texture, has raised a concern that it has resulted in high nitratenitrogen concentrations (10-50 mg/kg) in the soil and deeper vadose zone, and also in the underlying deep (20-45 m) ground water. The goal of this field-monitoring project was to assess how and under what circumstances nitrogen (N) nutrients under cultivated corn that is irrigated with this treated wastewater can reach the deep ground water of the underlying High Plains aquifer, and what can realistically be done to minimize this problem. We collected 15.2-m-deep cores for physical and chemical properties characterization; installed neutron moisture-probe access tubes and suction lysimeters for periodic measurements; sampled area monitoring, irrigation, and domestic wells; performed dye-tracer experiments to examine soil preferential-flow processes through macropores; and obtained climatic, crop, irrigation, and N-application rate records. These data and additional information were used in the comprehensive Root Zone Water Quality Model (RZWQM2) to identify key parameters and processes that influence N losses in the study area. We demonstrated that nitrate-N transport processes result in significant accumulations of N in the thick vadose zone. We also showed that nitrate-N in the underlying ground water is increasing with time and that the source of the nitrate is from the wastewater applications. RZWQM2 simulations indicated that macropore flow is generated particularly during heavy rainfall events, but during our 2005-06 simulations the total macropore flow was only about 3% of precipitation for one of two investigated sites, whereas it was more than 13% for the other site. Our calibrated model for the two wastewater-irrigated study sites indicated that reducing current levels of corn N fertilization by half or more to the level of 170 kg/ha substantially

  17. Studying Geographical Distribution Map of Weeds of Irrigated Wheat Fields of Ardabil Province

    Directory of Open Access Journals (Sweden)

    B Soheili

    2013-12-01

    Full Text Available In order to identify the density and abundance of weeds in irrigated wheat fields of Ardabil Province, 76 samples of irrigated wheat fields based on cultivation area from all counties of Ardabil province for six years (2001-2006 were selected. The genus and species of weeds from each sampling fields and their population indices density, frequency and uniformity of each species were calculated by using Thomas method. Geographic coordinates of field (Latitude, Altitude and Elevation were the main coverage and were determined by using GPS. These data were used for producing weed maps using GIS in irrigated wheat fields of Ardabil province. Results showed that bedstraw (Galium tricurnatum, Fumitory(Fumaria vaillantiand wildradish (Raphanus raphanistrum were dominant broad leaf weed species and wild oats (Avena fatua, rye (Secale cereal and mouse foxtail(Alopecurus myosuroides dominant grassy weeds species in irrigated wheat fields of Ardabil province. Bindweed (Convolvulus arvensis, Canada thistle(Cirsium arvenseand Acroptilon repens were the most important disturbing plants prior to harvesting in irrigated wheat fields of Ardabil province.

  18. Modeling and assessing field irrigation water use in a canal system of Hetao, upper Yellow River basin: Application to maize, sunflower and watermelon

    Science.gov (United States)

    Ren, Dongyang; Xu, Xu; Hao, Yuanyuan; Huang, Guanhua

    2016-01-01

    Water saving in irrigation is a key issue in the upper Yellow River basin. Excessive irrigation leads to water waste, water table rising and increased salinity. Land fragmentation associated with a large dispersion of crops adds to the agro-hydrological complexity of the irrigation system. The model HYDRUS-1D, coupled with the FAO-56 dual crop coefficient approach (dualKc), was applied to simulate the water and salt movement processes. Field experiments were conducted for maize, sunflower and watermelon crops in the command area of a typical irrigation canal system in Hetao Irrigation District during 2012 and 2013. The model was calibrated and validated in three crop fields using two-year experimental data. Simulations of soil moisture, salinity concentration and crop yield fitted well with the observations. The irrigation water use was then evaluated and results showed that large amounts of irrigation water percolated due to over-irrigation but their reuse through capillary rise was also quite large. That reuse was facilitated by the dispersion of crops throughout largely fragmented field, thus with fields reusing water percolated from nearby areas due to the rapid lateral migration of groundwater. Beneficial water use could be improved when taking this aspect into account, which was not considered in previous researches. The non-beneficial evaporation and salt accumulation into the root zone were found to significantly increase during non-growth periods due to the shallow water tables. It could be concluded that when applying water saving measures, close attention should be paid to cropping pattern distribution and groundwater control in association with irrigation scheduling and technique improvement.

  19. Coordinated research project of the use of nuclear and related techniques in assessment of irrigation schedules of field crops to increase effective use of water in irrigation projects

    International Nuclear Information System (INIS)

    Anac, M.S.; Tuzel, I.H.; Anac, D.

    1995-01-01

    The study aimed at determining the followings; water consumptions. irrigation water requirements of new cotton variety N 84; specific growth stages of cotton which are less sensitive to stress so that the irrigation could be avoided without significant yield decrease; and interactions between deficit irrigation and nitrogen fertilizer use. The experiment was set up with 6 irrigation and three nitrogen fertilizer (0.60 , 120 kg.ha sup -1 ) treatments. The irrigation treatments employed single stress at vegetative, flowering and boll formation stages, in addition to full irrigation, continuous stress and the traditional practice. In stress conditions available soil water depleted to 75 - 80 %, whereas in normal irrigation the depletion was 40 % in 0.90 m. of root zone. In full irrigation treatment 8 irrigations were applied, whereas 3 or 4 irrigations were needed in continuous stress conditions. The number of irrigations were 6 or 7 for other stress treatments. Irrigation water applications varied form 424 to 751 mm. Seasonal ET were ranged between 659 and 899 mm. The highest monthly ET in august for all of the treatments. Daily ET were found to vary from 2.2 to 12.1 mm/day. The seed cotton yields, ky values and yield - N indices have indicated that the vegetative state was more sensitive to water stress. The stress at boll formation stage had slight effects on these parameters. Under limited water resource conditions, vegetative growth period of cotton should be given preference for irrigation, followed by flowering period. Omitting irrigation in boll formation period would result in 4.3 to 9.1 % water savings. Yield changes with respect to N rates showed that high N doses are accompanied by high yields. Nitrogen recoveries either from fertilizers or soil revealed high uptakes in full irrigation conditions. Nitrogen use efficiencies were also high in these conditions. Average of three years put forth that 19% of N in stress conditions and 29% in full irrigation were

  20. Interaction of different irrigation strategies and soil textures on the nitrogen uptake of field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, S.H.; Andersen, Mathias Neumann; Lærke, Poul Erik

    2011-01-01

    Nitrogen (N) uptake (kg ha-1) of field-grown potatoes was measured in 4.32 m2 lysimeters that were filled with coarse sand, loamy sand, and sandy loam and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments...... in the loamy sand had the highest amount of N uptake. The interaction between irrigation treatments and soil textures was significant, and implied that under non-limiting water conditions, loamy sand is the suitable soil for potato production because plants can take up sufficient amounts of N and it could...... potentially lead to higher yield. However, under limited water conditions and applying water-saving irrigation strategies, sandy loam and coarse sand are better growth media because N is more available for the potatoes. The simple yield prediction model was developed that could explains ca. 96...

  1. Nuclear techniques to evaluate the water use of field crops irrigated in different stages of their cycles

    International Nuclear Information System (INIS)

    Libardi, P.L.; Moraes, S.O.; Saad, M.A.; Jong Van Lier, Q.; Vieira, O.; Luis Tuon, R.

    1995-01-01

    The search for soil - water management systems that rationalize the water use of field crops should always be emphasized. The present coordinated research programme of the joint division FAO/ AEA has the objective to contribute to a better understanding of this subject by improving the use efficiency of water resources in irrigated agriculture. This project is a contribution to this programme and consisted in the identification of specified development stages of bean ( phaseolus vulgaris, L ) and corn (Zea mays, L ) crops in which plants are less sensitive to water deficit. Experiments were carried out in a tropical soil of agricultural importance in a traditional irrigation field site of the state of Sao Paulo, Brazil. Neutron probe tensiometers were used to determine the soil water balance in different treatments. 3 tabs, 16 refs, (Author)

  2. Survey of Endodontic Irrigants Used by Dentists With Varying Years of Professional Experience

    Directory of Open Access Journals (Sweden)

    Sharkov Nikolai

    2018-03-01

    Full Text Available Background/Aim: The aim of the present study was to describe the use of irrigants by dentists in Bulgaria in relation to their years of professional experience. Material and Methods: The data were collected with the help of a questionnaire. The survey included questions concerning frequency of irrigants applied, their respective concentrations, as well as spectrum of disinfectants used in endodontics. In addition, information about respondents’ age, years of professional experience, gender, and main areas of continuing education was collected. The statistical analysis was performed with the help of IBM SPSS Statistics 22.0. Results: 219 replies were analysed (response rate 27,3%. The majority of the respondents (31.1% had 21 to 30 years of professional experience. 18.7% had over 30 years. Most of the practitioners reported their continuing education to be in the area of general dentistry - 52%, while about 1.2 % had specialised in endodontics. Dentists with long-standing professional experience use predominantly H2O2 - 78%. Dentists with least experience use 17% EDTA - 53.6%. No significant differences were established for the use of sodium hypochlorite and 2% chlorhexidine. 82% of the respondents use conventional needle 27G for intracanal irrigation; 60% never use ultrasonic irrigation. Conclusions: The analysis of the usage of irrigants shows that many general dental practitioners do not follow the quality recommended protocols for endodontic irrigation protocols.

  3. Optimal simulation based design of deficit irrigation experiments

    OpenAIRE

    Seidel, Sabine

    2012-01-01

    There is a growing societal concern about excessive water and fertilizer use in agricultural systems. High water productivity while maintaining high crop yields can be achieved with appropriate irrigation scheduling. Moreover, freshwater pollution through nitrogen (N) leaching due to the widespread use of N fertilizers demands for an efficient N fertilization management. However, sustainable crop management requires good knowledge of soil water and N dynamics as well as of crop water and N de...

  4. Field services experiences

    International Nuclear Information System (INIS)

    Colflesh, J.A.; Kruse, P.W.; Merluzzi, R.A.

    1985-01-01

    Combustion Engineering (C-E) is a large diversified manufacturer of products and services for the energy field. At this time, C-E has supplied the nuclear steam supply systems for eleven operating nuclear power plants with two additional units currently undergoing start-up testing. The focus of C-E's commitment in the nuclear power plant services area is the Nuclear Services organization within the Nuclear Power Systems Division. The Nuclear Services organization provides services on a timely cost efficient basis; and dedicates resources to developing new products and services which are truly responsive to the needs of operating power plants world wide. In the paper, C-E's capabilities and experience in the field of nuclear services are described. Highlighted are our capabilities in the areas of transition management services, operating services and engineering services

  5. Wake field acceleration experiments

    International Nuclear Information System (INIS)

    Simpson, J.D.

    1988-01-01

    Where and how will wake field acceleration devices find use for other than, possibly, accelerators for high energy physics? I don't know that this can be responsibly answered at this time. What I can do is describe some recent results from an ongoing experimental program at Argonne which support the idea that wake field techniques and devices are potentially important for future accelerators. Perhaps this will spawn expanded interest and even new ideas for the use of this new technology. The Argonne program, and in particular the Advanced Accelerator Test Facility (AATF), has been reported in several fairly recent papers and reports. But because this is a substantially new audience for the subject, I will include a brief review of the program and the facility before describing experiments. 10 refs., 7 figs

  6. Reducing Potential Disaster Impacts in Irrigated Rice Fields in West Java

    NARCIS (Netherlands)

    Sianturi, R.S.

    2018-01-01

    The increasing global population inevitably demands for stable food production. As an important food crop, rice plays a major role in maintaining food security. However, irrigated rice fields are increasingly suffered from natural hazard occurrences worldwide, disrupting livelihoods of millions of

  7. Agronomic and environmental aspects of diazotrophic bacteria in irrigated rice fields

    Science.gov (United States)

    This article provides an overview of the free-living and plant-associated nitrogen-fixing bacterial communities in irrigated rice fields, with a focus on describing the drivers affecting community assemblages in this soil-water-plant-atmosphere system. Theoretical and technical advances in non-legu...

  8. Cokriging of Electromagnetic Induction Soil Electrical Conductivity Measurements and Soil Textural Properties to Demarcate Sub-field Management Zones for Precision Irrigation.

    Science.gov (United States)

    Ding, R.; Cruz, L.; Whitney, J.; Telenko, D.; Oware, E. K.

    2017-12-01

    There is the growing need for the development of efficient irrigation management practices due to increasing irrigation water scarcity as a result of growing population and changing climate. Soil texture primarily controls the water-holding capacity of soils, which determines the amount of irrigation water that will be available to the plant. However, while there are significant variabilities in the textural properties of the soil across a field, conventional irrigation practices ignore the underlying variability in the soil properties, resulting in over- or under-irrigation. Over-irrigation leaches plant nutrients beyond the root-zone leading to fertilizer, energy, and water wastages with dire environmental consequences. Under-irrigation, in contrast, causes water stress of the plant, thereby reducing plant quality and yield. The goal of this project is to leverage soil textural map of a field to create water management zones (MZs) to guide site-specific precision irrigation. There is increasing application of electromagnetic induction methods to rapidly and inexpensively map spatially continuous soil properties in terms of the apparent electrical conductivity (ECa) of the soil. ECa is a measure of the bulk soil properties, including soil texture, moisture, salinity, and cation exchange capacity, making an ECa map a pseudo-soil map. Data for the project were collected from a farm site at Eden, NY. The objective is to leverage high-resolution ECa map to predict spatially dense soil textural properties from limited measurements of soil texture. Thus, after performing ECa mapping, we conducted particle-size analysis of soil samples to determine the textural properties of soils at selected locations across the field. We cokriged the high-resolution ECa measurements with the sparse soil textural data to estimate a soil texture map for the field. We conducted irrigation experiments at selected locations to calibrate representative water-holding capacities of each

  9. BIOMETRIC PARAMETERS OF FIELD GROWN SESAME INFLUENCED BY ARBUSCULAR MYCORRHIZAL INOCULATION, ROCK PHOSPHATE FERTILIZATION AND IRRIGATION

    Directory of Open Access Journals (Sweden)

    V.S. Harikumar

    2017-08-01

    Full Text Available The aim of the study was to assess the effect of inoculation with arbuscular mycorrhizal fungi (AMF and rock phosphate (RP fertilization on biometric parameters and mycorrhizal colonization of field grown sesame under rainfed and irrigated conditions. Inoculation of AMF Funneliformis dimorphicus improved the biometric parameters of the crop such as leaf area (LA, leaf area index (LAI, specific leaf weight (SLW, net assimilation rate (NAR, oil index (OI as well as mycorrhizal colonization (%F in roots. Mycorrhizal inoculation however, did not give any positive response on harvest index (HI. LA, LAI and OI and %F showed a general increment in treatments of no added P (P0, while the other parameters such as SLW and NAR were improved by the application of RP at half the recommended dose (P50. HI did not respond to RP fertilization. Most of the parameters (LA, LAI, NAR, %F showed higher values under rainfed condition than irrigated condition whereas, SLW, HI and OI improved significantly under irrigated condition. Results indicated that the inoculation of AMF to field grown sesame can compensate for 50% of the recommended P fertilizer under a need based irrigation schedule, without affecting the biometric parameters.

  10. Greenhouse and field-based studies on the distribution of dimethoate in cotton and its effect on Tetranychus urticae by drip irrigation.

    Science.gov (United States)

    He, Jiangtao; Zhou, Lijuan; Yao, Qiang; Liu, Bo; Xu, Hanhong; Huang, Jiguang

    2018-01-01

    The two-spotted spider mite, Tetranychus urticae Koch is an important pest of cotton. We investigated the efficacy of dimethoate in controlling T. urticae by drip irrigation. Greenhouse and field experiments were carried out to determine the efficacy of dimethoate to T. urticae and the absorption and distribution of dimethoate in cotton. Greenhouse results showed that cotton leaves received higher amounts of dimethoate compared with cotton roots and stems, with higher amounts in young leaves compared with old leaves and cotyledon having the lowest amounts among leaves. Field results showed the efficacy of dimethoate to T. urticae by drip irrigation varied by volume of dripping water, soil pH and dimethoate dosage. Dimethoate applied at 3.00 kg ha -1 with 200 m 3  ha -1 water at weak acidic soil pH (5.70-6.70) through drip irrigation can obtain satisfactory control efficacy (81.49%, 7 days) to T. urticae, without negatively impacting on its natural enemy Neoseiulus cucumeris. The residue of dimethoate in all cotton seed samples were not detectable. These results demonstrate the effectiveness of applying dimethoate by drip irrigation for control of T. urticae on cotton. This knowledge could aid in the applicability of dimethoate by drip irrigation for field management of T. urticae populations. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Integrating Field Spectra and Worldview-2 Data for Grapevine Productivity in Different Irrigation Treatments

    Science.gov (United States)

    Maimaitiyiming, M.; Bozzolo, A.; Wulamu, A.; Wilkins, J. L.

    2015-12-01

    Precision farming requires high spectral, spatial and temporal resolution remote sensing data to detect plant physiological changes. The higher spatial resolution is particularly as important as the spectral resolution for crop monitoring. It is important to develop data integration techniques between field or airborne hyperspectral data with spaceborne broad band multispectral images for plant productivity monitoring. To investigate varying rootstock and irrigation interactions, different irrigation treatments are implemented in a vineyard experimental site either i) unirrigated ii) full replacement of evapotranspiration (ET) iii) irrigated at 50 % of the potential ET. In summer 2014, we collected leaf and canopy spectra of the vineyard using field spectroscopy along with other plant physiological and nutritional variables. In this contribution, we integrate the field spectra and the spectral wavelengths of WorldView-2 to develop a predictive model for plant productivity,i.e., fruit quality and yield. First, we upscale field and canopy spectra to WorldView-2 spectral bands using radiative transfer simulations (e.g., MODTRAN). Then we develop remote sensing techniques to quantify plant productivity in different scenarios water stress by identifying the most effective and sensitive wavelengths, and indices that are capable of early detection of plant health and estimation of crop nutrient status. Finally we present predictive models developed from partial least square regression (PLSR) for plant productivity using spectral wavelengths and indices derived from integrated field and satellite remote sensing data.

  12. Ammonia volatilization losses from paddy fields under controlled irrigation with different drainage treatments.

    Science.gov (United States)

    He, Yupu; Yang, Shihong; Xu, Junzeng; Wang, Yijiang; Peng, Shizhang

    2014-01-01

    The effect of controlled drainage (CD) on ammonia volatilization (AV) losses from paddy fields under controlled irrigation (CI) was investigated by managing water table control levels using a lysimeter. Three drainage treatments were implemented, namely, controlled water table depth 1 (CWT1), controlled water table depth 2 (CWT2), and controlled water table depth 3 (CWT3). As the water table control levels increased, irrigation water volumes in the CI paddy fields decreased. AV losses from paddy fields reduced due to the increases in water table control levels. Seasonal AV losses from CWT1, CWT2, and CWT3 were 59.8, 56.7, and 53.0 kg N ha(-1), respectively. AV losses from CWT3 were 13.1% and 8.4% lower than those from CWT1 and CWT2, respectively. A significant difference in the seasonal AV losses was confirmed between CWT1 and CWT3. Less weekly AV losses followed by TF and PF were also observed as the water table control levels increased. The application of CD by increasing water table control levels to a suitable level could effectively reduce irrigation water volumes and AV losses from CI paddy fields. The combination of CI and CD may be a feasible water management method of reducing AV losses from paddy fields.

  13. Interannual variability and sensitivity analysis of manure-borne bacteria transport from irrigated fields.

    Science.gov (United States)

    Martinez, Gonzalo; Pachepsky, Yakov; Shelton, Daniel; Guber, Andrey; Yakirevich, Alexander; Dughtry, Craig; Goodrich, David

    2014-05-01

    Manure application has been implicated in deterioration of microbial quality of surface water utilized in recreation, irrigation, aquaculture, and various household- and agriculture-related processes. The model KINEROS2/STWIR has been recently developed for rainfall- or irrigation event-based simulations of manure-borne overland bacteria transport. Information on uncertainty in the model parameter values is essential for running sensitivity analysis, creating synthetic datasets, developing risk assessment projects, etc. The objective of this work was to analyze data obtained in multiple years when the status of soil surface, soil structure, and weed cover created palpably different conditions for overland microorganism transport. Experiments were carried out at the Beltsville USDA OPE3 site, which is a part of the Lower Chesapeake Long-term Agricultural Research Network Site. Manure was applied at typical Maryland rates and the two-hour irrigation was applied immediately after manure application and one week later. Escherichia coli and thermotolerant coliform concentrations in runoff and the bacteria contents in manure and soil before and after application were measured across the application area of about 100 m x 50 m on the 40-point grid. Bacteria contents in manure varied up to six orders of magnitude. No spatial structure in these contents was found at the support and spacing of this work. Parameters sets were substantially different for thermotolerant coliforms and E. coli. Bacteria adsorption and straining parameters varied by one order of magnitude over three year trials. Variability of Manning roughness coefficient, saturated hydraulic conductivity, net capillary drive, relative saturation, and solute dispersivity was substantially smaller. The hypothesis of applicability of uniform distributions to simulate the empirical distributions of above parameters could not be rejected at the 0.05 significance level. The Bradford-Schijven model was used to simulate

  14. Design of a pot experiment to study the effect of irrigation with ...

    African Journals Online (AJOL)

    Due to the intensification of environmental legislation, the wine industry is expected to find solutions for the treatment or re-use of winery wastewater. The objective of the study was to design and evaluate a pot experiment for determining the effects of irrigation with diluted winery wastewater on different soils.

  15. Assessment of soil moisture dynamics on an irrigated maize field using cosmic ray neutron sensing

    Science.gov (United States)

    Scheiffele, Lena Maria; Baroni, Gabriele; Oswald, Sascha E.

    2015-04-01

    In recent years cosmic ray neutron sensing (CRS) developed as a valuable, indirect and non-invasive method to estimate soil moisture at a scale of tens of hectares, covering the gap between point scale measurements and large scale remote sensing techniques. The method is particularly promising in cropped and irrigated fields where invasive installation of belowground measurement devices could conflict with the agricultural management. However, CRS is affected by all hydrogen pools in the measurement footprint and a fast growing biomass provides some challenges for the interpretation of the signal and application of the method for detecting soil moisture. For this aim, in this study a cosmic ray probe was installed on a field near Braunschweig (Germany) during one maize growing season (2014). The field was irrigated in stripes of 50 m width using sprinkler devices for a total of seven events. Three soil sampling campaigns were conducted throughout the growing season to assess the effect of different hydrogen pools on calibration results. Additionally, leaf area index and biomass measurements were collected to provide the relative contribution of the biomass on the CRS signal. Calibration results obtained with the different soil sampling campaigns showed some discrepancy well correlated with the biomass growth. However, after the calibration function was adjusted to account also for lattice water and soil organic carbon, thus representing an equivalent water content of the soil, the differences decreased. Soil moisture estimated with CRS responded well to precipitation and irrigation events, confirming also the effective footprint of the method (i.e., radius 300 m) and showing occurring water stress for the crop. Thus, the dynamics are in agreement with the soil moisture determined with point scale measurements but they are less affected by the heterogeneous moisture conditions within the field. For this reason, by applying a detailed calibration, CRS proves to be a

  16. Optimized Subsurface Irrigation System: The Future of Sugarcane Irrigation

    Directory of Open Access Journals (Sweden)

    M. H. J. P. Gunarathna

    2018-03-01

    Full Text Available Climate change may harm the growth and yield of sugarcane (Saccharum officinarum L. without the introduction of appropriate irrigation facilities. Therefore, new irrigation methods should be developed to maximize water use efficiency and reduce operational costs. OPSIS (optimized subsurface irrigation system is a new solar-powered automatic subsurface irrigation system that creates a phreatic zone below crop roots and relies on capillarity to supply water to the root zone. It is designed for upland crops such as sugarcane. We investigated the performance of OPSIS for irrigating sugarcane and evaluated its performance against sprinkler irrigation under subtropical conditions. We conducted field experiments in Okinawa, Japan, over the period from 2013 to 2016 and took measurements during spring- and summer-planted main crops and two ratoon crops of the spring-planted crop. Compared with sprinkler irrigation, OPSIS produced a significantly higher fresh cane yield, consumed less irrigation water and provided a higher irrigation water use efficiency. We conclude that OPSIS could be adopted as a sustainable solution to sugarcane irrigation in Okinawa and similar environments.

  17. FEATURES OF MINERAL NUTRITION FOR TOMATO PLANTS WITH DRIP IRRIGATION SYSTEM IN OPEN FIELD CONDITION

    Directory of Open Access Journals (Sweden)

    P. M. Akhmetova

    2017-01-01

    Full Text Available Dagestan is the largest region with irrigation system of agriculture in Russia. Irrigated lands provide 70% of total plant production. The field cultivation is carried on arable land in plain region of the republic. The drip irrigation as an ecologically safe technology for watering is regarded as major means for vegetable production farming. This approach maintains the propitious level of water and air in the soil without surface and deep drainage of irrigating water. These irrigated lands are expected to be used first of all for valuable and profitable crops such as tomato that is a leading crop in Dagestan. The experimental work was carried out at OOO ‘Dagagrocomplex’, Aleksandro-Nevskoye, in Tarumovskiy region. The aim of the study was to determinate the optimal dose of mineral fertilizers and the way of their application to improve the productivity without quality loss. The complex analysis of the technology for tomato production under drip irrigation through nontransplanting culture showed its high efficiency, because volume and quality of yield directly depended on soil moisture and precise supporting of mineral nutrition rates. The maximal yield of tomato fruits, 88.7-94.5 t/ha was observed with once mineral fertilizer application at a dose of N180P135K60 with soil humidity 70-80% (field moisture capacity, and also at the dose of N180P135K60 with basic application of N100 in nutrition rate. The result of the study showed that the optimization of two factors, namely soil water rate and mineral nutrition, enabled to produce additionally 39.2 t/ha. It was shown the tight connection between yielding and its quality; when yielding 95 t/ha, the increased contents of dry matter to 7.01%, sugar to 3.8% vitamin C to 18.46% were noticed. The high quality of produced output was supported by pre-watering threshold of moisture at 75-80% (field moisture capacity, when once fertilizer application at a dose of N180P135K60. 

  18. Unsaturated flow dynamics during irrigation with wastewater: field and modelling study

    Science.gov (United States)

    Martinez-Hernandez, V.; de Miguel, A.; Meffe, R.; Leal, M.; González-Naranjo, V.; de Bustamante, I.

    2012-04-01

    . Data from the lysimeter and soil moisture probes were used to calibrate the model. The overall simulation time period included the dry (irrigation as main source of water) and the wet season (precipitation as main source of water). Future investigation concerning groundwater affections and contaminant transport at the field site will be based on the results obtained through the flow model developed in this study.

  19. Carbon Balance in an Irrigated Corn Field after Inorganic Fertilizer or Manure Application

    Science.gov (United States)

    Lentz, R. D.; Lehrsch, G. A.

    2014-12-01

    Little is known about inorganic fertilizer or manure effects on organic carbon (OC) and inorganic C (IC) losses from a furrow irrigated field, particularly in the context of other system C gains or losses. In 2003 and 2004, we measured dissolved organic and inorganic C (DOC, DIC), particulate OC and IC (POC, PIC) concentrations in irrigation inflow, runoff, and percolation waters (6-7 irrigations/y); C inputs from soil amendments and crop biomass; harvested C; and gaseous C emissions from field plots cropped to silage corn (Zea mays L.) in southern Idaho. Annual treatments included: (M) 13 (y 1) and 34 Mg/ha (y 2) stockpiled dairy manure; (F) 78 (yr 1) and 195 kg N/ha (y 2) inorganic N fertilizer; or (NA) no amendment--control. The mean annual total C input into M plots averaged 16.1 Mg/ha, 1.4-times greater than that for NA (11.5 Mg/ha) or F (11.1 Mg/ha), while total C outputs for the three treatments were similar, averaging 11.8 Mg/ha. Thus, the manure plots ended each growing season with an average net gain of 3.8 Mg C/ha (a positive net C flux), while the control (-0.5 Mg C/ha) and fertilizer (-0.4 Mg C/ha) treatments finished the season with a net C loss. Atmospheric CO2 incorporated into the crop biomass contributed 96% of the mean annual C input to NA and F plots but only 68% to M plots. We conclude that nutrient amendments substantially influence the short-term carbon balance of our furrow-irrigated system. Amendments had both direct and indirect influences on individual C components, such as the losses of DIC and POC in runoff and DOC in percolation water, producing temporally complex outcomes which may depend on environmental conditions external to the field.

  20. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1978-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centers the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFC's with a major radius R = 2-6 cm, minor radius a approximately 2 cm, and a total length l approximately 35 cm. The observed temperatures are T/sub e/ approximately 100 eV and T/sub i/ = 150-350 eV with a peak density n approximately 2 x 10 15 cm -3 . After the plasma reaches equilibrium, the RFC remains stable for up to 30 μs followed by the rapid growth of the rotational m = 2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behavior of the m = 2 mode qualitatively agrees with the theoretically predicted instability for rotational velocities exceeding some critical value

  1. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1979-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centres the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFCs with a major radius R=2-6cm, a minor radius a approximately 2cm, and a total length l approximately 35cm. The observed temperatures are Tsub(e) approximately 100eV and Tsub(i)=150-350eV with a peak density n approximately 2x10 15 cm -3 . After the plasma has reached equilibrium, the RFC remains stable for up to 30μs, followed by the rapid growth of the rotational m=2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behaviour of the m=2 mode agrees qualitatively with the theoretically predicted instability for rotational velocities exceeding some critical value. (author)

  2. Study of Irrigation Interval and Mulch Effects on Pomological Characteristics and Yield of Sevillana Cultivar in Field Condition

    Directory of Open Access Journals (Sweden)

    rahmatollah gholami

    2018-03-01

    Full Text Available Introduction: Olive (Olea europaea L. is one of the drought tolerant ever green fruit trees. Olive is an economically important species of the Mediterranean area, so understanding the mechanisms by which olive plants face drought stress under environmental conditions is essential for the improvement of olive yield and oil quality. Olive is one of the fruit trees which become important in the Iranian fruit industry at the near future. Mulch is an optimizing strategy under which crops are allowed to sustain some degree of water deficit and yield reduction. Increasing crop water-use efficiency (WUE through water conservation in the soil is an important component of dry land farming. Mulching is among the water management practices for increasing WUE. Mulch is referred to as any material that is spread onto the surface of the soil for protection against solar radiation or evaporation. Different materials, such as wheat straw, rice straw, plastic film, grass, wood, and sand, are used as mulches. Materials and Methods: This experiment was conducted to study the effect of irrigation interval and mulch on Pomological characteristics and yield of 11-years old Sevillana olive cultivar. A factorial experiment was carried out in Dallaho Olive Research Station at Sarepole located in Kermanshah province. Field experiment based on randomized complete block design with three replications and two factors (irrigation interval and mulch were conducted in 2015. Each experiment unit consists of 4 trees and 108 trees were used. Irrigation treatments period for experiment were 3, 6 and 10 days interval and mulch treatments for experiment were polyethylene, organic materials and non-mulch (control. Geographical characters was longitude of 45˚, 51΄ E and latitude of 34˚, 30΄ N and the height of sea level 581m. The measured tree characteristics were: Fruit Weight, Pulp Fresh Weight, Pulp Dry Weight, Dry matter, Pulp/Pit ratio, Pit Length, Pit Diameter, Fruit Yield

  3. Long term continuous field survey to assess nutrient emission impact from irrigated paddy field into river catchment

    Science.gov (United States)

    Kogure, Kanami; Aichi, Masaatsu; Zessner, Matthias

    2017-04-01

    In order to achieve good river environment, it is very important to understand and to control nutrient behavior such as Nitrogen and Phosphorus. As we could reduce impact from urban and industrial activities by wastewater treatment, pollution from point sources are likely to be controlled. Besides them, nutrient emission from agricultural activity is dominant pollution source into the river system. In many countries in Asia and Africa, rice is widely cultivated and paddy field covers large areas. In Japan 54% of its arable land is occupied with irrigated paddy field. While paddy field can deteriorate river water quality due to fertilization, it is also suggested that paddy field can purify water. We carried out field survey in middle reach of the Tone River Basin with focus on a paddy field IM. The objectives of the research are 1) understanding of water and nutrient balance in paddy field, 2) data collection for assessing nutrient emission. Field survey was conducted from June 2015 to October 2016 covering two flooding seasons in summer. In our measurement, all input and output were measured regarding water, N and P to quantify water and nutrient balance in the paddy field. By measuring water quality and flow rate of inflow, outflow, infiltrating water, ground water and flooding water, we tried to quantitatively understand water, N and P cycle in a paddy field including seasonal trends, and changes accompanied with rainy events and agricultural activities like fertilization. Concerning water balance, infiltration rate was estimated by following equation. Infiltration=Irrigation water + Precipitation - Evapotranspiration -Outflow We estimated mean daily water balance during flooding season. Infiltration is 11.9mm/day in our estimation for summer in 2015. Daily water reduction depth (WRD) is sum of Evapotranspiration and Infiltration. WRD is 21.5mm/day in IM and agrees with average value in previous research. Regarding nutrient balance, we estimated an annual N and

  4. Reversed field pinch experiments

    International Nuclear Information System (INIS)

    Roberston, S.

    1991-05-01

    The Reversatron RFP is usually operated with toroidal field windings which are a continuous helix of 144 turns. These windings produce a poloidal current which is uniform around the torus. The distribution of current is fixed by the geometry so that the applied field has only an m = 0, n = 0 component. The windings cannot act to stabilize an m = 0 mode with |n| > 0 or any m = 1 mode because these modes will excite no current in the windings. It has recently been suggested that parallel connected field coils might act as a shell by forcing the flux within each winding to be the same. Coils connected in parallel must have the same voltage at their terminals and thus must enclose the same volt-seconds or flux. Data from ZT-40 show that the discharges are more quiescent when parallel or series-parallel connected windings are used

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

    Science.gov (United States)

    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. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  6. Soil water movement in the unsaturated zone of an inland arid region: Mulched drip irrigation experiment

    Science.gov (United States)

    Han, Dongmei; Zhou, Tiantian

    2018-04-01

    Agricultural irrigation with trans-basin water diversion can effectively relieve the water paucity in arid and semi-arid regions, however, this may be accompanied by eco-environmental problems (e.g., saline soils, rising groundwater levels, water quality problems). The mechanism of soil water movement under irrigation in the unsaturated zone of arid regions is a key scientific problem that should be solved in order to evaluate agricultural water management and further improve current irrigation practices. This study investigated the impact of drip irrigation on soil water movement in the unsaturated zone of a cotton field in an inland arid region (the Karamay Agricultural Development Area), northwest China. Combining in situ observational physical data with temporal variation in stable isotopic compositions of soil water, we described the soil water flow system and mechanism in severe (Plot 1) and mild (Plot 2) saline-alkali cotton fields. The infiltration depths are 0-150 cm for both plots. Drip irrigation scheduling makes no significant contribution to local groundwater recharge, however, groundwater can move into the unsaturated zone through capillary rise during cotton flowering and boll periods. Plot 2 is less prone to having secondary soil salinization than Plot 1 due to the existence of a middle layer (approximately 100 cm thick), which elongated the distance between the root zone and aquifer. Rise in the water table (approximately 60 cm for Plot 1 and 50 cm for Plot 2) could be caused by lateral groundwater flow instead of vertical infiltration. We estimated the soil water storage changes in the unsaturated zone and proposed a conceptual model for deciphering the movement process of soil water. This study provides a scientific basis for determining the rise of groundwater levels and potential development of saline soils and improving agricultural water management in arid regions.

  7. Estimation of local and regional components of drain - flow from an irrigated field

    International Nuclear Information System (INIS)

    Eching, S.O.; Hopmans, J.W.; Wallender, W.W.; Macyntyre, J.L.; Peters, D.

    1995-01-01

    The contribution of regional ground water and deep percolation from a furrow irrigated field to total drain flow was estimated using salt load analysis. It was found that 64% of the drain flow comes from regional ground water flow. The electrical conductivity of the drain water was highly correlated with the drain flow rate. From the field water balance with deep percolation as estimated from the salt load analysis, using yield function derived evapotranspiration, and measured changes in root zone water storage, it was shown that 14% of the crop evapotranspiration comes from ground water during the study period. 8 figs; 5 tabs; 15 refs ( Author )

  8. Heterogeneity of water flow in grassland soil during irrigation experiment

    Czech Academy of Sciences Publication Activity Database

    Lichner, Ľ.; Dušek, J.; Tesař, Miroslav; Czachor, H.; Mészároš, I.

    2014-01-01

    Roč. 69, č. 11 (2014), s. 1555-1561 ISSN 0006-3088 R&D Projects: GA TA ČR(CZ) TA0201451 Grant - others:ERDF ITMS26240120004 Institutional support: RVO:67985874 Keywords : degree of preferential flow * effective cross section * infiltration experiment * radioactive tracer technique * sandy soil Subject RIV: DA - Hydrology ; Limnology Impact factor: 0.827, year: 2014

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

    Science.gov (United States)

    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.

  10. Temporal changes of radiocesium in irrigated paddy fields and its accumulation in rice plants in Fukushima.

    Science.gov (United States)

    Yang, Baolu; Onda, Yuichi; Wakiyama, Yoshifumi; Yoshimura, Kazuya; Sekimoto, Hitoshi; Ha, Yiming

    2016-01-01

    About half of the total paddy field area, which is the dominant agricultural land in Fukushima Prefecture, was contaminated by radiocesium released by the Fukushima Daiichi Nuclear Power Plant accident. In this study, we investigated the temporal changes of radiocesium in soil, irrigation water, and rice plant in two adjacent rice paddies, with and without surface-soil-removal, in Fukushima Prefecture for over three years (2012-2014) after the nuclear accident. Our results showed that radiocesium migrated into 24-28 cm soil layers and that the activity concentration of radiocesium in paddy soils showed a significant reduction in 2014. The newly added radiocesium to paddies through irrigation water contributed only a maximum value of 0.15% and 0.75% of the total amount present in control and decontaminated paddies, respectively, throughout the study period. The radiocesium activity concentration in suspended sediment in irrigation water exponentially decreased, and the effective half-lives (Teff) for (137)Cs and (134)Cs were 1.3 and 0.9 years, respectively. Additionally, the average suspended sediment concentration in irrigation water increased between 2012 and 2014, suggesting that enhanced soil erosion had occurred in the surrounding environment. Radiocesium accumulation in rice plant also decreased with time in both paddies. However, the concentration ratio of radiocesium for rice plant in the decontaminated paddy increased compared with control paddy, despite approximately 96% of fallout radiocesium removed in paddy soil. Further analysis is required to clarify the reasons of high concentration ratio of radiocesium for rice plant in the decontaminated paddy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Field note: irrigation of tree stands with groundwater containing 1,4-dioxane.

    Science.gov (United States)

    Ferro, Ari M; Tammi, Carl E

    2009-07-01

    Coniferous and deciduous tree stands totaling 14 ha were recently planted on a closed landfill, and when mature, the stands are expected to be part of a natural treatment system for recovered groundwater. The trees would be irrigated at the rate of 189 L/min year-round with water containing 1,4-dioxane (trees. The water is moderately saline and contains elevated levels of manganese. This paper describes a concurrent series of preliminary studies, performed prior to the full-scale planting, to assess the feasibility of the phytoremediation system. Greenhouse experiments were carried out to identify tree species that can take up 1,4-dioxane and are tolerant of the water. Estimates were made of the area of the tree stand necessary to transpire the irrigation water plus precipitation. The landfill matrix was characterized in terms of its percolation rate and water holding capacity and based on those results salinity-modeling studies were carried out to estimate the fate and leaching potential of the various inorganic species that would accumulate in the root-zone of the trees. A pilot study, currently in progress on the landfill, suggested that the landfill cap is a suitable matrix for the establishment of large trees, and that the stands could be irrigated without the production of excess drainage.

  12. Effects of irrigation and plastic mulch on soil properties on semi-arid abandoned fields

    OpenAIRE

    van der Meulen, E.S.; Nol, L.; Cammeraat, L.H.

    2006-01-01

    The Guadalentín Basin in Spain is one of the driest areas of Europe and has problems with high evaporation rates, and high risks of desertification exist including soil quality loss and soil erosion. Farmers in this semi-arid region use polyethylene covers on their irrigated croplands to reduce evaporation in order to enhance crop yield. When farmers abandon the acres, they leave the plastic covers on the fields. Up to now research has been concentrating on the effects of plastic covers on cr...

  13. fields

    Directory of Open Access Journals (Sweden)

    Brad J. Arnold

    2014-07-01

    Full Text Available Surface irrigation, such as flood or furrow, is the predominant form of irrigation in California for agronomic crops. Compared to other irrigation methods, however, it is inefficient in terms of water use; large quantities of water, instead of being used for crop production, are lost to excess deep percolation and tail runoff. In surface-irrigated fields, irrigators commonly cut off the inflow of water when the water advance reaches a familiar or convenient location downfield, but this experience-based strategy has not been very successful in reducing the tail runoff water. Our study compared conventional cutoff practices to a retroactively applied model-based cutoff method in four commercially producing alfalfa fields in Northern California, and evaluated the model using a simple sensor system for practical application in typical alfalfa fields. These field tests illustrated that the model can be used to reduce tail runoff in typical surface-irrigated fields, and using it with a wireless sensor system saves time and labor as well as water.

  14. Study of the influence of stable cadmium on the transfer of zinc-65 in an ecosystem irrigated by submersion (irrigated rice field)

    International Nuclear Information System (INIS)

    Myttenaere, C.; Merlini, M.; Dabin, P.; Mousny, J.M.; Pozzi, G.; Bittel, R.

    1975-01-01

    Irrigation water contains varying amounts of stable cadmium from industrial disposal. The presence of this element is capable of modifying the transfer of and affecting the mechanisms of absorption of zinc-65, a radionuclide which is discharged into water by nuclear power stations. This type of interaction between a nuclear contaminant and a conventional contaminant was studied in a rice-field irrigated by submersion. This ecosystem was reproduced under controlled 'mini-rice-field' conditions: the water was enriched in stable zinc (1 ppm) and in stable cadmium (2,5x10 -3 ; 50x10 -3 ppm) so as to reproduce the actual conditions; the stable zinc was traced by means of zinc-65. Fish (20 Carassius auratus L.) were introduced into each compartment of the ecosystem. Samples of irrigation water and surface water were taken during cultivation, and at the end of cultivation the content of stable zinc, radioactive zinc and stable cadmium was determined in each component of the ecosystem. The results show the important influence of a conventional contaminant on the transfer of a radionuclide and justify the use of the term 'associate contaminant' to describe it. (author)

  15. Study on the quantitative relationship between Agricultural water and fertilization process and non-point source pollution based on field experiments

    Science.gov (United States)

    Wang, H.; Chen, K.; Wu, Z.; Guan, X.

    2017-12-01

    In recent years, with the prominent of water environment problem and the relative increase of point source pollution governance, especially the agricultural non-point source pollution problem caused by the extensive use of fertilizers and pesticides has become increasingly aroused people's concern and attention. In order to reveal the quantitative relationship between agriculture water and fertilizer and non-point source pollution, on the basis of elm field experiment and combined with agricultural drainage irrigation model, the agricultural irrigation water and the relationship between fertilizer and fertilization scheme and non-point source pollution were analyzed and calculated by field emission intensity index. The results show that the variation of displacement varies greatly under different irrigation conditions. When the irrigation water increased from 22cm to 42cm, the irrigation water increased by 20 cm while the field displacement increased by 11.92 cm, about 66.22% of the added value of irrigation water. Then the irrigation water increased from 42 to 68, irrigation water increased 26 cm, and the field displacement increased by 22.48 cm, accounting for 86.46% of irrigation water. So there is an "inflection point" between the irrigation water amount and field displacement amount. The load intensity increases with the increase of irrigation water and shows a significant power correlation. Under the different irrigation condition, the increase amplitude of load intensity with the increase of irrigation water is different. When the irrigation water is smaller, the load intensity increase relatively less, and when the irrigation water increased to about 42 cm, the load intensity will increase considerably. In addition, there was a positive correlation between the fertilization and load intensity. The load intensity had obvious difference in different fertilization modes even with same fertilization level, in which the fertilizer field unit load intensity

  16. Testing climate-smart irrigation strategies to reduce methane emissions from rice fields

    Science.gov (United States)

    Runkle, B.; Suvocarev, K.; Reba, M. L.

    2017-12-01

    Approximately 11% of the global 308 Tg CH4 anthropogenic emissions are currently attributed to rice cultivation. In this study, the impact of water conservation practices on rice field CH4 emissions was evaluated in Arkansas, the leading state in US rice cultivation. While conserving water, the Alternate Wetting and Drying (AWD) irrigation practice can also reduce CH4 emissions through the deliberate, periodic introduction of aerobic conditions. Seasonal CH4emissions from a pair of adjacent, production-sized rice fields were estimated and compared during the 2015 to 2017 growing seasons using the eddy covariance method on each field. The fields were alternately treated with continuous flood (CF) and AWD irrigation. In 2015, the seasonal cumulative carbon losses by CH4 emission were 30.3 ± 6.3 and 141.9 ± 8.6 kg CH4-C ha-1 for the AWD and CF treatments, respectively. Data from 2016 and 2017 will be analyzed and shown within this presentation; an initial view demonstrates consistent findings to 2015. When accounting for differences in field conditions and soils, the AWD practice is attributable to a 36-51% reduction in seasonal emissions. The substantial decrease in CH4 emissions by AWD supports previous chamber-based research and offers strong evidence for the efficacy of AWD in reducing CH4 emissions in Arkansas rice production. The AWD practice has enabled the sale of credits for carbon offsets trading and this new market could encourage CH4 emissions reductions on a national scale. These eddy covariance towers are being placed into a regional perspective including crop and forest land in the three states comprising the Mississippi Delta: Arkansas, Mississippi, and Louisiana.

  17. Use of Peristeen® transanal colonic irrigation for bowel management in children: a single-center experience.

    Science.gov (United States)

    Pacilli, Maurizio; Pallot, David; Andrews, Afiya; Downer, Angela; Dale, Louiza; Willetts, Ian

    2014-02-01

    Transanal colonic irrigation has been shown to be effective in bowel management program in adults. However, there exist limited data in children. We appraised the effectiveness of this technique in a series of children with incontinence or constipation and overflow soiling. Following ethical approval, a review of children with incontinence or constipation on a bowel management program with Peristeen® transanal colonic irrigation treated between 2007 and 2012 was performed. Irrigations were performed with a volume of 10-20 ml/kg of water with schedules depending on patient response. Data are reported as median (range). Twenty-three patients were reviewed. Median age at commencement of irrigations was 7 (2-15) years. Median follow-up is 2 (0.7-3.4) years. Diagnoses include the following: spina bifida (n=11), anorectal anomaly (n=6), Hirschsprung's (n=1), and other complex anomalies (n=5). Sixteen (70%) patients had associated anomalies. Twelve (52%) had constipation and overflow soiling, and 11 (48%) had fecal incontinence. Twenty (87%) had associated urinary wetting. Sixteen (70%) children used alternate-day irrigations, 4 (17%) daily irrigations, and 3 (13%) every third-day irrigations. Nine (39%) patients were taking oral laxatives. Sixteen (70%) reported to be clean and 3 (13%) reported a significant improvement, although were having occasional soiling. Four patients (17%) did not tolerate the irrigations and underwent subsequent colostomy formation for intractable soiling. In our experience, Peristeen® transanal colonic irrigation is an effective method of managing patients with focal soiling in childhood. Majority (83%) of children achieve social fecal continence or a significant improvement with occasional soiling. This was accompanied by high parental satisfaction. Peristeen® transanal colonic irrigation is a valid alternative to invasive surgical procedures and should be considered the first line of treatment for bowel management in children with soiling

  18. Microbial, physical and chemical properties of irrigation water in rice fields of Southern Brazil

    Directory of Open Access Journals (Sweden)

    MARIA HELENA L.R. RECHE

    2016-03-01

    Full Text Available ABSTRACT This paper presents the results of the statistical analysis of microbiological, physical and chemical parameters related to the quality of the water used in rice fields in Southern Brazil. Data were collected during three consecutive crop years, within structure of a comprehensive monitoring program. The indicators used were: potential hydrogen, electrical conductivity, turbidity, nitrogen, phosphorus, potassium, calcium, total and fecal coliforms. Principal Component and Discriminant Analysis showed consistent differences between the water irrigation and drainage, as the temporal variation demonstrated a clear reduction in the concentration of most of the variables analyzed. The pattern of this reduction is not the same in the two regions - that is, the importance of each of the different variables in the observed differentiation is modified in two locations. These results suggested that the variations in the water quality utilized for rice irrigation was influenced by certain specific aspects of each rice region in South Brazilian - such as anthropic action or soil/climate conditions in each hydrographic basin.

  19. Variation in energy sorghum hybrid TX08001 biomass composition and lignin chemistry during development under irrigated and non-irrigated field conditions

    Science.gov (United States)

    Olson, Sara N.; Ritter, Kimberley B.; Herb, Dustin W.; Karlen, Steven D.; Lu, Fachuang; Ralph, John; Rooney, William L.; Mullet, John E.

    2018-01-01

    This study was conducted to document the extent and basis of compositional variation of shoot biomass of the energy Sorghum bicolor hybrid TX08001 during development under field conditions. TX08001 is capable of accumulating ~40 Mg/ha of dry biomass under good growing conditions and this genotype allocates ~80% of its shoot biomass to stems. After 150 days of growth TX08001 stems had a fresh/dry weight ratio of ~3:1 and soluble biomass accounted for ~30% of stem biomass. A panel of diverse energy sorghum genotypes varied ~6-fold in the ratio of stem structural to soluble biomass after 150 days of growth. Near-infrared spectroscopic analysis (NIRS) showed that TX08001 leaves accumulated higher levels of protein, water extractives and ash compared to stems, which have higher sugar, cellulose, and lignin contents. TX08001 stem sucrose content varied during development, whereas the composition of TX08001 stem cell walls, which consisted of ~45–49% cellulose, ~27–30% xylan, and ~15–18% lignin, remained constant after 90 days post emergence until the end of the growing season (180 days). TX08001 and Della stem syringyl (S)/guaiacyl (G) (0.53–0.58) and ferulic acid (FA)/para-coumaric acid (pCA) ratios were similar whereas ratios of pCA/(S+G) differed between these genotypes. Additionally, an analysis of irrigated versus non-irrigated TX08001 revealed that non-irrigated hybrids exhibited a 50% reduction in total cell wall biomass, an ~2-fold increase in stem sugars, and an ~25% increase in water extractives relative to irrigated hybrids. This study provides a baseline of information to help guide further optimization of energy sorghum composition for various end-uses. PMID:29684037

  20. On the Control of Solute Mass Fluxes and Concentrations Below Fields Irrigated With Low-Quality Water: A Numerical Study

    Science.gov (United States)

    Russo, David

    2017-11-01

    The main goal of this study was to test the capability of irrigation water-based and soil-based approaches to control nitrate and chloride mass fluxes and concentrations below the root zone of agricultural fields irrigated with treated waste water (TWW). Using numerical simulations of flow and transport in relatively a fine-textured, unsaturated, spatially heterogeneous, flow domain, scenarios examined include: (i) irrigating with TWW only (REF); (ii) irrigation water is substituted between TWW and desalinized water (ADW); (iii) soil includes a capillary barrier (CB) and irrigating with TWW only (CB + TWW); and (iv) combination of (ii) and a CB (CB + ADW). Considering groundwater quality protection, plausible goals are: (i) to minimize solute discharges leaving the root zone, and, (ii) to maximize the probability that solute concentrations leaving the root zone will not exceed a prescribed, critical value. Results of the analyses suggest that in the case of a seasonal crop (a corn field) subject to irrigations only, with respect to the first goal, the CB + TWW and CB + ADW scenarios provide similar, excellent results, better than the ADW scenario; with respect to the second goal, however, the CB + ADW scenario gave substantially better results than the CB + TWW scenario. In the case a multiyear, perennial crop (a citrus orchard), subject to a sequence of irrigation and rainfall periods, for both solutes, and, particularly, nitrate, with respect to the two goals, both the ADW and CB + ADW scenarios perform better than the CB + TWW scenario. As compared with the REF and CB + TWW scenarios, the ADW and CB + ADW scenarios substantially reduce nitrogen mass fluxes to the groundwater and to the atmosphere, and, essentially, did not reduce nitrogen mass fluxes to the trees. Similar results, even better, were demonstrated for a relatively coarse-textured, spatially heterogeneous soil.

  1. Carbon balance of a plastic mulch and drip irrigated cotton field in an arid oasis of Northwest China

    Science.gov (United States)

    Ming, G.

    2017-12-01

    Carbon balance of a plastic mulch and drip irrigated cotton field in an arid oasis of Northwest ChinaGuanghui Ming1, Fuqiang Tian1*, Hongchang Hu11State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing, China,Abstracts: Agricultural ecosystems have the potential to offset rising CO2 concentration in the atmosphere but the potential is often altered by agricultural management. Plastic film mulching and drip irrigation (PMDI) have been widespread for saving water and improving crop yield worldwide. To comprehensively assess the carbon balance and to detect the controlling factors of the carbon flux in a PMDI cotton field, experiments combining eddy covariance (EC) system, chamber method and crop sampling were implemented in an arid oasis of Xinjiang from the year 2012 to 2016. The annual net ecosystem exchange (NEE) was -250.18 ± 80.41 g C m-2 in the five years, which indicated that the filed was a much stronger carbon sink. After removal of the harvest of cotton as seed oil (Ch) of 108.81±7.57 g C m-2, the field was still a moderate carbon sink with net biome productivity (NBP) of 141.37±73.7 g C m-2. Soil temperature can explain 82% of seasonal variation of nighttime NEE while PAR can explain 36-81% of daytime NEE varying with crop development and photosynthetic activity. NEE was separated into total ecosystem respiration (Reco, 1214.20±144.42 g C m-2) and gross primary productivity (GPP, 1464.38±122.78 g C m-2). Interannual Reco changed more drastically than GPP and respiration may be the main determinant of carbon balance in the PMDI field. Seasonal NPP measured by cop sampling method (NPPCS) agreed well with NPP calculated with EC (NPPEC), with the annual NPP of 708.86 ± 52.26 g C m-2, which indicated that our carbon flux measurements and separating methods reasonable. The PMDI cotton field induced more GPP and Reco than other croplands with larger light use efficiency (LUE) but relatively

  2. Diet and resource partitioning among anurans in irrigated rice fields in Pantanal, Brazil

    Directory of Open Access Journals (Sweden)

    L. Piatti

    Full Text Available Artificial ponds or irrigated systems scattered throughout farmlands can offer important habitats for anurans and can be interesting sites for research on species resources use in a changing landscape. This study describes the diet and resource partitioning among anurans inhabiting irrigated rice fields in the Pantanal region. Twenty categories of prey were found in the stomachs of Leptodactylus chaquensis, L. elenae, L. podicipinus and Rhinella bergi, the most frequent being Coleoptera, Hymenoptera, larvae of Hexapoda, Hemiptera, Diptera and Orthoptera. The great differences found in the diet of these species in rice fields compared to other locations, according to available records in the literature, was the increased importance of Hemipitera and Orthoptera and the decrease in importance of Hymenoptera in the diet of leptodactylids. These differences might be attributed to changes in the availability of resources in response to habitat modification. Although diet composition was very similar among species, niche overlap was larger than expected by chance, suggesting that the competition for food resources is not, or has not been, a significant force in determining the structure of this frog community. Two non-exclusive hypotheses could be considered as a justification for this result: 1 the high niche overlap could result from resource availability, which is sufficient to satisfy all species without any strong competition; 2 or the high values of niche overlap could be a selective force driving species to compete, but there has not been enough time to express a significant divergence in the species diet because the study area is characterised as a dynamic habitat influenced by frequent and cyclical changes.

  3. Field experiments in salt formations

    International Nuclear Information System (INIS)

    Kuehn, K.

    1986-01-01

    Field experiments in salt formations started as early as 1965 with Project Salt Vault in the Lyons Mine, Kansas, U.S.A., and with the purchase of the Asse salt mine by the German Federal Government. Underground tests concentrated on the heat dissipation around buried high-level radioactive wastes and the geomechanical consequences of their disposal. Near-field investigations cover the properties of water and gas release, radiolysis and corrosion. Further objectives of field experiments are the development and underground testing of a handling system for high-level wastes. The performance of an underground test disposal for such wastes is not only considered to be necessary for technical and scientific reasons but also for improving public acceptance of the concept of radioactive waste disposal. (author)

  4. Rice Field Geochemistry and Hydrology: An Explanation for Why Groundwater Irrigated Fields in Bangladesh are Net Sinks of Arsenic from Groundwater

    Science.gov (United States)

    Neumann, Rebecca B.; St. Vincent, Allison P.; Roberts, Linda C.; Badruzzaman, A. Borhan M.; Ali, M. Ashraf; Harvey, Charles F.

    2011-01-01

    Irrigation of rice fields in Bangladesh with arsenic-contaminated groundwater transfers tens of cubic kilometers of water and thousands of tons of arsenic from aquifers to rice fields each year. Here we combine observations of infiltration patterns with measurements of porewater chemical composition from our field site in Munshiganj Bangladesh to characterize the mobility of arsenic in soils beneath rice fields. We find that very little arsenic delivered by irrigation returns to the aquifer, and that recharging water mobilizes little, if any, arsenic from rice field subsoils. Arsenic from irrigation water is deposited on surface soils and sequestered along flow paths that pass through bunds, the raised soil boundaries around fields. Additionally, timing of flow into bunds limits the transport of biologically available organic carbon from rice fields into the subsurface where it could stimulate reduction processes that mobilize arsenic from soils and sediments. Together, these results explain why groundwater irrigated rice fields act as net sinks of arsenic from groundwater. PMID:21332196

  5. Field application of self-healing concrete with natural fibres as linings for irrigation canals in Ecuador

    NARCIS (Netherlands)

    Sierra Beltran, M.G.; Jonkers, H.M.; Mors, R.M.; Mera-Ortiz, W.

    2015-01-01

    This paper describes the first field application of self-healing concrete with alkaliphilic spore-forming bacteria and reinforced with natural fibres. The application took place in the highlands in Ecuador in July 2014. The concrete was cast as linings for an irrigation canal that transports water

  6. Study of capillary experiments and hydrologic factors under subsurface drip irrigation with fractal theory

    International Nuclear Information System (INIS)

    Zhou, W; Cao, L

    2012-01-01

    Soil spatial variability is one of the primary environmental factors that influences the hydraulic factors and technical indicators of subsurface drip irrigation (SDI), whose emitters are buried in the soil. This paper aimed at evaluating these effects of soil spatial variability on hydrologic factors under SDI. And some SDI emitter and capillary experiments were designed to obtain test data and distribution of pressure and emitter discharge. First, The results of labyrinth non-turbulent mosaic drip emitter test and fractal theory were used to research the fractal and quantitative relationship between single emitter hydrologic factors and soil physical parameters; and then, the capillary experiments and the relationship among hydrologic factors of capillary were used to analyze the fractal and quantitative relationship between hydrologic factors of capillary and soil physical parameters, which explained the inner relationship between spatial variability of soil and hydrologic factors of filed pipeline network under SDI, and provide theory support for the plan, design, management and production of SDI.

  7. AN INTERACTION MODEL BETWEEN ENVIRONMENTAL FACTORS AND BLACK RICE GROWTH IN IRRIGATED ORGANIC PADDY FIELD

    Directory of Open Access Journals (Sweden)

    Budiman

    2015-02-01

    Full Text Available Black rice production in organic farming system does not meet the demand of local customers because of its low productivity. This research aimed to set an interaction model using multivariate analysis via smartPLS to identify environmental factors which simultaneously affects the growth of black rice. The growth of black rice in two irrigated organic paddy field in Malang, Indonesia was observed during planting period from November 2011 to March 2012. In each rice field, the growth was periodically recorded during planting periods: 19-29 days after planting (dap, 41-45 dap, 62-66 dap, 77-81 dap, 90-94 dap and 104-106 dap. Environmental factors such as water quantities, soil conditions, weed communities and cultivation system around the black rice population were also measured. Black rice growth was influenced simultaneously by water quantities, soil, weed communities and cultivating systems with predictive-relevance value reaching 92.83%. Based on the model, water quantities in paddy field is a key factor which directly and indirectly determined the growth and productivity of black rice.

  8. Biomass Development in SRI Field Under Unmaintained Alternate Wetting-Drying Irrigation

    Science.gov (United States)

    Ardiansyah; Chusnul, A.; Krissandi, W.; Asna, M.

    2018-05-01

    The aim of this research is to observe biomass development of SRI on farmers practice in three plots with different level. This research observes the farmer practice of SRI and Non-SRI during the uncertainty of irrigation water supply and its effects on paddy biomass development during growth stages and final stage of crop. A farmer group that already understand the principle of SRI, applied this method into several plots of their rented paddy field. Researcher interventions were eliminated from their action, so it is purely on farmers decision on managing their SRI plots. Three plots from both SRI and Non-SRI were chosen based on the position of the plot related their access to water. First plots had direct access to water from tertiary irrigation channel (on farm). Second plots were received water from previous upper plots and drainage water into other plots. Third plots were in the bottom position, where they received water from upper plot, and drainage water into farm drainage channel. Result shows there are similar patterns of root, straw, and leaves of biomass during crop growth. On the other hand, during generative phase, grain development shows different pattern and resulting different biomass in harvest time. Second plot, (of SRI) that has water from first plot has the average of biomass grain per plant of 54.4, higher than first plot and third plot, which are 33.8 g and 38.4. Average biomass in second plot is 74.6 g, higher than first and third plot, which are 49.9 g and 52.3 g.

  9. Field Evidence Supporting Conventional Onion Curing Practices as a Strategy To Mitigate Escherichia coli Contamination from Irrigation Water.

    Science.gov (United States)

    Wright, Daniel; Feibert, Erik; Reitz, Stuart; Shock, Clint; Waite-Cusic, Joy

    2018-03-01

    The Produce Safety Rule of the U.S. Food Safety Modernization Act includes restrictions on the use of agricultural water of poor microbiological quality. Mitigation options for poor water quality include the application of an irrigation-to-harvest interval of onion production includes an extended irrigation-to-harvest interval (onion fields (randomized block design; n = 5) via drip tape on the final day of irrigation. Onions remained undisturbed for 7 days and were then lifted to the surface to cure for an additional 21 days before harvest. Water, onions, and soil were tested for presence of rifampin-resistant E. coli. One day after irrigation, 13.3% of onions (20 of 150) receiving the poorest quality water (3 log CFU/mL) tested positive for E. coli; this prevalence was reduced to 4% (6 of 150 onions) after 7 days. Regardless of inoculum level, E. coli was not detected on any onions beyond 15 days postirrigation. These results support conventional dry bulb onion curing practices as an effective strategy to mitigate microbiological concerns associated with poor quality irrigation water.

  10. Nuclide-migration field experiments

    International Nuclear Information System (INIS)

    Erdal, B.R.; Wolfsberg, K.; Johnstone, J.K.; Erickson, K.L.; Friedman, A.M.; Fried, S.; Hines, J.J.

    1981-03-01

    When considering groundwater flow and radionuclide retention in the complex flow systems that can occur in geologic formations, one has a serious problem in determining if laboratory studies are being performed under conditions appropriate to natural systems. This document is the project plan for a program designed to begin to address these problems. The project is being carried out jointly by the Los Alamos National Laboratory, Sandia National Laboratories, and Argonne National Laboratory. The work has three principal objectives: (1) to develop the experimental, instrumental, and safety techniques necessary to conduct controlled, small-scale radionuclide migration field experiments, including those involving actinides; (2) to use these techniques to define radionuclide migration through rock by performing generic, at-depth experiments under closely monitored conditions; and (3) to determine whether available lithologic, geochemical, and hydrologic properties together with existing or developing transport models are sufficient and appropriate to describe real field conditions

  11. Nuclide-migration field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Erdal, B.R.; Wolfsberg, K.; Johnstone, J.K.; Erickson, K.L.; Friedman, A.M.; Fried, S.; Hines, J.J.

    1981-03-01

    When considering groundwater flow and radionuclide retention in the complex flow systems that can occur in geologic formations, one has a serious problem in determining if laboratory studies are being performed under conditions appropriate to natural systems. This document is the project plan for a program designed to begin to address these problems. The project is being carried out jointly by the Los Alamos National Laboratory, Sandia National Laboratories, and Argonne National Laboratory. The work has three principal objectives: (1) to develop the experimental, instrumental, and safety techniques necessary to conduct controlled, small-scale radionuclide migration field experiments, including those involving actinides; (2) to use these techniques to define radionuclide migration through rock by performing generic, at-depth experiments under closely monitored conditions; and (3) to determine whether available lithologic, geochemical, and hydrologic properties together with existing or developing transport models are sufficient and appropriate to describe real field conditions.

  12. {sup 137}Cs in irrigation water and its effect on paddy fields in Japan after the Fukushima nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Natsuki [Institute of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Obara, Hitomi [Oriental Consultants, Sumitomo Fudosan Nishi Shinjuku Bldg. No. 6, 3-12-1 Honmachi, Shibuya-ku, Tokyo 151-0071 (Japan); Ogasa, Marie; Miyazu, Susumu [Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Harada, Naoki [Institute of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Nonaka, Masanori [Graduate School for Management of Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan)

    2014-05-01

    There is concern that radiocesium deposited in the environment after the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 will migrate to paddy fields through hydrological pathways and cause serious and long-lasting damage to the agricultural activities. This study was conducted in the Towa region of Nihonmatsu in the northern part of Fukushima Prefecture, Japan, (1) to quantify {sup 137}Cs in stream water used to irrigate paddy fields by separating the dissolved and particulate components in water samples and then fractionating the particulate components bonded in different ways using a sequential extraction procedure, and (2) to determine the amounts of radiocesium newly added to paddy fields in irrigation water relative to the amounts of radiocesium already present in the fields from the deposition of atmospheric fallout immediately after the FDNPP accident. Three catchments were studied, and the {sup 137}Cs activity concentrations in stream water samples were 79–198 mBq L{sup −1} under stable runoff conditions and 702–13,400 Bq L{sup −1} under storm runoff conditions. The residual fraction (F4, considered to be non-bioavailable) was dominant, accounting for 59.5–82.6% of the total {sup 137}Cs activity under stable runoff conditions and 69.4–95.1% under storm runoff conditions. The {sup 137}Cs newly added to paddy fields in irrigation water only contributed 0.03–0.05% of the amount already present in the soil (201–348 kBq m{sup −2}). This indicates that the {sup 137}Cs inflow load in irrigation water is negligible compared with that already in the soil. However, the contribution from the potentially bioavailable fractions (F1 + F2 + F3) was one order of magnitude larger, accounting for 0.20–0.59%. The increase in the dissolved and soluble radiocesium fraction (F1) was especially large (3.0% to infinity), suggesting that radiocesium migration in irrigation water is increasing the accumulation of radiocesium in rice

  13. Potato yield and yield structure depending on irrigation

    Directory of Open Access Journals (Sweden)

    Milić Stanko

    2010-01-01

    Full Text Available In the agroclimatic conditions of the Vojvodina Province, the application of an economic water regime and modern technology is necessary for stable and intensive potato production. A two-year experiment on calcareous chernozem was carried out to determine how irrigation and different pre-irrigation soil moisture affect potato yield and distribution of tuber fraction in the potato yield. The block-design trial had four replicates and was adapted for sprinkler irrigation conditions. It included four treatments: irrigation with pre-irrigation moisture levels of 60 % of field water capacity (FC, irrigation with pre-irrigation moisture levels of 70 % (FC, irrigation with pre-irrigation moisture levels of 80% (FC, and a non-irrigated control treatment. Irrigation significantly increased the yield of potato, which increased from 37.27 % to 75.86 %. Under irrigation, the percentage of small fractions decreased in favour of the 55 mm one, or fractions above the 45-55 mm range. On average, irrigated treatments produced significantly more tubers than the conditions of natural water supply. .

  14. Making the user visible: analysing irrigation practices and farmers’ logic to explain actual drip irrigation performance

    NARCIS (Netherlands)

    Benouniche, M.; Kuper, M.; Hammani, A.; Boesveld, H.

    2014-01-01

    The actual performance of drip irrigation (irrigation efficiency, distribution uniformity) in the field is often quite different from that obtained in experimental stations. We developed an approach to explain the actual irrigation performance of drip irrigation systems by linking measured

  15. Portable photovoltaic irrigation pumps

    Energy Technology Data Exchange (ETDEWEB)

    Furber, J. D.

    1980-07-01

    Experiences in developing a solar-powered irrigation pump to meet the needs of poor farmers in developing nations are summarized. The design which evolved is small and portable, employing a high-efficiency electric pump, powered by photovoltaic panels. Particular emphasis is placed on how the system works, and on early field problems experienced with the first prototypes. The resolution of these problems and the performance of actual systems in various countries is presented and user responses are noted.

  16. Rice evapotranspiration at the field and canopy scales under water-saving irrigation

    Science.gov (United States)

    Liu, Xiaoyin; Xu, Junzeng; Yang, Shihong; Zhang, Jiangang

    2018-04-01

    Evapotranspiration (ET) is an important process of land surface water and thermal cycling, with large temporal and spatial variability. To reveal the effect of water-saving irrigation (WSI) on rice ET at different spatial scales and understand the cross spatial scale difference, rice ET under WSI condition at canopy (ETCML) and field scale (ETEC) were measured simultaneously by mini-lysimeter and eddy covariance (EC) in the rice season of 2014. To overcome the shortage of energy balance deficit by EC system, and evaluate the influence of energy balance closure degree on ETEC, ETEC was corrected as {ET}_{EC}^{*} by energy balance closure correction according to the evaporative fraction. Seasonal average daily ETEC, {ET}_{EC}^{*} and ETCML of rice under WSI practice were estimated as 3.12, 4.03 and 4.35 mm day-1, smaller than the values reported in flooded paddy fields. Daily ETEC, {ET}_{EC}^{*} and ETCML varied in a similar trends and reached the maximum in late tillering, then decreased along with the crop growth in late season. The value of ETEC was much lower than ETCML, and was frequently 1-2 h lagged behind ETCML. It indicated that the energy balance deficit resulted in underestimation of crop ET by EC system. The corrected value of {ET}_{EC}^{*} matched ETCML much better than ETEC, with a smaller RMSE (0.086 mm h-1) and higher R 2 (0.843) and IOA (0.961). The time lapse between {ET}_{EC}^{*} and ETCML was mostly shortened to less than 0.5 h. The multiple stepwise regression analysis indicated that net radiation ( R n) is the dominant factor for rice ET, and soil moisture ( θ) is another significant factor ( p rice fields. The difference between ETCML and {ET}_{EC}^{*} ({ET}_{CML} - {ET}_{EC}^{*}) were significantly ( p rice ET in WSI fields, and for its cross scale conversion.

  17. SPOT-Based Sub-Field Level Monitoring of Vegetation Cover Dynamics: A Case of Irrigated Croplands

    Directory of Open Access Journals (Sweden)

    Olena Dubovyk

    2015-05-01

    Full Text Available Acquiring multi-temporal spatial information on vegetation condition at scales appropriate for site-specific agricultural management is often complicated by the need for meticulous field measurements. Understanding spatial/temporal crop cover heterogeneity within irrigated croplands may support sustainable land use, specifically in areas affected by land degradation due to secondary soil salinization. This study demonstrates the use of multi-temporal, high spatial resolution (10 m SPOT-4/5 image data in an integrated change vector analysis and spectral mixture analysis (CVA-SMA procedure. This procedure was implemented with the principal objective of mapping sub-field vegetation cover dynamics in irrigated lowland areas within the lowerlands of the Amu Darya River. CVA intensity and direction were calculated separately for the periods of 1998–2006 and 2006–2010. Cumulative change intensity and the overall directional trend were also derived for the entire observation period of 1998–2010. Results show that most of the vector changes were observed between 1998 and 2006; persistent conditions were seen within the study region during the 2006–2010 period. A decreasing vegetation cover trend was identified within 38% of arable land. Areas of decreasing vegetation cover were located principally in the irrigation system periphery where deficient water supply and low soil quality lead to substandard crop development. During the 2006–2010 timeframe, degraded crop cover conditions persisted in 37% of arable land. Vegetation cover increased in 25% of the arable land where irrigation water supply was adequate. This high sub-field crop performance spatial heterogeneity clearly indicates that current land management practices are inefficient. Such information can provide the basis for implementing and adapting irrigation applications and salt leaching techniques to site-specific conditions and thereby make a significant contribution to sustainable

  18. Simulating water and nitrogen loss from an irrigated paddy field under continuously flooded condition with Hydrus-1D model.

    Science.gov (United States)

    Yang, Rui; Tong, Juxiu; Hu, Bill X; Li, Jiayun; Wei, Wenshuo

    2017-06-01

    Agricultural non-point source pollution is a major factor in surface water and groundwater pollution, especially for nitrogen (N) pollution. In this paper, an experiment was conducted in a direct-seeded paddy field under traditional continuously flooded irrigation (CFI). The water movement and N transport and transformation were simulated via the Hydrus-1D model, and the model was calibrated using field measurements. The model had a total water balance error of 0.236 cm and a relative error (error/input total water) of 0.23%. For the solute transport model, the N balance error and relative error (error/input total N) were 0.36 kg ha -1 and 0.40%, respectively. The study results indicate that the plow pan plays a crucial role in vertical water movement in paddy fields. Water flow was mainly lost through surface runoff and underground drainage, with proportions to total input water of 32.33 and 42.58%, respectively. The water productivity in the study was 0.36 kg m -3 . The simulated N concentration results revealed that ammonia was the main form in rice uptake (95% of total N uptake), and its concentration was much larger than for nitrate under CFI. Denitrification and volatilization were the main losses, with proportions to total consumption of 23.18 and 14.49%, respectively. Leaching (10.28%) and surface runoff loss (2.05%) were the main losses of N pushed out of the system by water. Hydrus-1D simulation was an effective method to predict water flow and N concentrations in the three different forms. The study provides results that could be used to guide water and fertilization management and field results for numerical studies of water flow and N transport and transformation in the future.

  19. Development of services for irrigation management: the experience with the users

    Science.gov (United States)

    Vuolo, Francesco; Neugebauer, Nikolaus; D'Urso, Guido; De Michele, Carlo

    2014-05-01

    Irrigated agriculture is the main user of freshwater resources (30% in Central Europe, 60% in the South). Efficient water management is therefore of essential importance, especially where water scarcity and water quality are becoming severe challenges. To achieve a successful and effective use of resources, farmers and water managers require easy-to-use decision support tools and reliable information. Our approach is based on Earth observation (EO) techniques and decision support tools. Generally, the service concept is based on two main components: i) the processing of time-series of high spatial resolution (10-30-m pixel size) images from satellite, currently available from public and commercial data providers, to timely monitor the crop growth and to estimate the crop water requirements throughout the growing season; ii) the adaptation and integration in local management practices & tools of easy to use geo-spatial technologies to make the information available to users and to support the decision-making process in near-real-time. The participation and feedback we receive from the users is fundamental to develop and provide easy-to-use technologies that can be embedded in standard approaches. In this paper, we briefly describe some examples of pre- and fully operational applications at field and irrigation scheme level and report some success stories of cooperation between decision makers and scientists. The paper includes the outcomes of ongoing activities such as Irrisat (www.irrisat.it), a regional operational service supported by rural development funds in Southern Italy and EO4Water (www.eo4water.com), a case study of knowledge and technology transfer in Eastern Austria funded by the Austrian Space Application Programme. The new capacities we develop to assist farmers in monitoring their crops are a step towards a better integration of tools and production. More technical advice and recommendation regarding sustainable land and resource use could then be

  20. A coupled remote sensing and simplified surface energy balance approach to estimate actual evapotranspiration from irrigated fields

    Science.gov (United States)

    Senay, G.B.; Budde, Michael; Verdin, J.P.; Melesse, Assefa M.

    2007-01-01

    Accurate crop performance monitoring and production estimation are critical for timely assessment of the food balance of several countries in the world. Since 2001, the Famine Early Warning Systems Network (FEWS NET) has been monitoring crop performance and relative production using satellite-derived data and simulation models in Africa, Central America, and Afghanistan where ground-based monitoring is limited because of a scarcity of weather stations. The commonly used crop monitoring models are based on a crop water-balance algorithm with inputs from satellite-derived rainfall estimates. These models are useful to monitor rainfed agriculture, but they are ineffective for irrigated areas. This study focused on Afghanistan, where over 80 percent of agricultural production comes from irrigated lands. We developed and implemented a Simplified Surface Energy Balance (SSEB) model to monitor and assess the performance of irrigated agriculture in Afghanistan using a combination of 1-km thermal data and 250m Normalized Difference Vegetation Index (NDVI) data, both from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. We estimated seasonal actual evapotranspiration (ETa) over a period of six years (2000-2005) for two major irrigated river basins in Afghanistan, the Kabul and the Helmand, by analyzing up to 19 cloud-free thermal and NDVI images from each year. These seasonal ETa estimates were used as relative indicators of year-to-year production magnitude differences. The temporal water-use pattern of the two irrigated basins was indicative of the cropping patterns specific to each region. Our results were comparable to field reports and to estimates based on watershed-wide crop water-balance model results. For example, both methods found that the 2003 seasonal ETa was the highest of all six years. The method also captured water management scenarios where a unique year-to-year variability was identified in addition to water-use differences between

  1. Three-dimensional groundwater velocity field in an unconfined aquifer under irrigation

    International Nuclear Information System (INIS)

    Zlotnik, V.

    1990-01-01

    A method for three-dimensional flow velocity calculation has been developed to evaluate unconfined aquifer sensitivity to areal agricultural contamination of groundwater. The methodology of Polubarinova-Kochina is applied to an unconfined homogeneous compressible or incompressible anisotropic aquifer. It is based on a three-dimensional groundwater flow model with a boundary condition on the moving surface. Analytical solutions are obtained for a hydraulic head under the influence of areal sources of circular and rectangular shape using integral transforms. Two-dimensional Hantush formulas result from the vertical averaging of the three-dimensional solutions, and the asymptotic behavior of solutions is analyzed. Analytical expressions for flow velocity components are obtained from the gradient of the hydraulic head field. Areal and temporal variability of specific yield in groundwater recharge areas is also taken into account. As a consequence of linearization of the boundary condition, the operation of any irrigation system with respect to groundwater is represented by superposition of the operating wells and circular and rectangular source influences. Combining the obtained solutions with Dagan or Neuman well functions, one can develop computer codes for the analytical computation of the three-dimensional groundwater hydraulic head and velocity component distributions. Methods for practical implementation are discussed. (Author) (20 refs., 4 figs.)

  2. Magnetic field line reconnection experiments

    International Nuclear Information System (INIS)

    Gekelman, W.; Stenzel, R.L.; Wild, N.

    1982-01-01

    A laboratory experiment concerned with the basic physics of magnetic field line reconnection is discussed. Stimulated by important processes in space plasmas and anomalous transport in fusion plasmas the work addresses the following topics: Dynamic magnetic fields in a high beta plasma, magnetic turbulence, plasma dynamics and energy transport. First, the formation of magnetic neutral sheets, tearing and island coalescence are shown. Nonstationary magnetic fluctuations are statistically evaluated displaying the correlation tensor in the #betta#-k domain for mode identification. Then, the plasma properties are analyzed with particular emphasis on transport processes. Although the classical fluid flow across the separatrix can be observed, the fluctuation processes strongly modify the plasma dynamics. Direct measurements of the fluid force density and ion acceleration indicate the presence of an anomalous scattering process characterized by an effective scattering tensor. Turbulence also enhances the plasma resistivity by one to two orders of magnitude. Measurements of the three-dimensional electron distribution function using a novel energy analyzer exhibit the formation of runaway electrons in the current sheet. Associated micro-instabilities are observed. Finally, a macroscopic disruptive instability of the current sheet is observed. Excess magnetic field energy is converted at a double layer into particle kinetic energy and randomized through beam-plasma instabilities. These laboratory results are compared with related observations in space and fusion plasmas. (Auth.)

  3. The Kolar Gold Field experiment

    International Nuclear Information System (INIS)

    Sreekantan, B.V.

    1982-01-01

    Meson theory was propounded to explain the nuclear force which holds neutrons and protons inside the nucleus. Subsequently, quark theory was put forward to bring some order into an enormously large number of fundamental particles discovered in the hadron family. These two theories are briefly explained. The gravitational force, the electromagnetic force, the weak nuclear force and the strong nuclear force are the basic forces which determine the behaviour of fundamental particles when they are in close proximity. If the last three of the above-mentioned four forces are one or just different aspects of a single force, quarks and leptons can be mingled in the same theoretical framework indicating the non-conservation of baryon number and the spontaneous decay of the proton into leptons. In order to test the last possibility i.e. proton decay, an experiment has been set up in the Kolar Gold Field at a depth of 2300 metres in India. 1650 gas proportional counters are sandwiched between iron plates. The total amount of iron in the form of iron plates and walls of the counters is 140 tons. In this experiment, nuclei of iron are serving as the source of protons and neutrons and the depth eliminates the background events which mimic proton decay. The amount of iron used in the experiment i.e. 140 tons is more than enough to obtain evidence of 10 proton decay events in a year, assuming that the lifetime of proton is 10 30 years or below. (M.G.B.)

  4. IRRIGATION SCHEDULING CALCULATOR (ISC TO IMPROVE WATER MANAGEMENT ON FIELD LEVEL IN EGYPT

    Directory of Open Access Journals (Sweden)

    Samiha Abou El-Fetouh Hamed Ouda

    2017-10-01

    Full Text Available The developed model is MS excel sheet called “Irrigation Scheduling Calculator, ISC”. The model requires to input daily weather data to calculate daily evapotranspiration using Penman-Monteith equation. The model calculates water depletion from the root zone to determine when to irrigate and how much water should be applied. The charge from irrigation pump is used to calculate how many hours should the farmer run the pump to deliver the needed amount of water. ISC model was used to developed irrigation schedule for wheat and maize planted in El-Gharbia governorate. The developed schedules were compared to the actual schedules for both crops. Furthermore, CropSyst model was calibrated for both crops and run using the developed schedules by ISC model. The simulation results indicated that the calculated irrigation amount by ISC model for wheat was lower than actual schedule by 6.0 mm. Furthermore, the simulated wheat productivity by CropSyst was higher than measured grain and biological by 2%. Similarly, the calculated applied irrigation amount by ISC model for maize was lower than actual schedule by 79.0 mm and the productivity was not changed.

  5. Groundwater irrigation and its implications for water policy in semiarid countries: the Spanish experience

    Science.gov (United States)

    Garrido, Alberto; Martínez-Santos, Pedro; Llamas, M. Ramón

    2006-03-01

    Over the last decades, groundwater irrigation has become commonplace in many arid and semiarid regions worldwide, including Spain. This is largely a consequence of the advances in drilling and pumping technologies, and of the development of Hydrogeology. Compared with traditional surface water irrigation systems, groundwater irrigation offers more reliable supplies, lesser vulnerability to droughts, and ready accessibility for individual users. Economic forces influence the groundwater irrigation sector and its development. In Spain's Mediterranean regions, abstraction costs often amount to a very small fraction of the value of crops. In the inner areas, groundwater irrigation supports a more stable flow of farm income than rainfed agriculture. The social (jobs/m3) and economic (€/m3) value of groundwater irrigation generally exceeds that of surface water irrigation systems. However, poor groundwater management and legal controversies are currently at the base of Spain's social disputes over water. A thorough and transparent assessment of the relative socio-economic value of groundwater in relation to surface water irrigation might contribute to mitigate or avoid potential future conflicts. Enforcement of the European Union's Water Framework Directive may deliver better groundwater governance and a more sustainable use.

  6. Relationships between carbon fluxes and environmental factors in a drip-irrigated, film-mulched cotton field in arid region

    OpenAIRE

    Li, Xiaoyu; Liu, Lijuan; Yang, Huijin; Li, Yan

    2018-01-01

    Environmental factors and human activities play important roles in carbon fixation and emissions generated from croplands. Eddy covariance measurements in a drip-irrigated, film-mulched cotton field were used to analyze the relationships between carbon fluxes and environmental factors in Wulanwusu, northern Xinjiang, an arid region of Northwest China. Our results showed that the cumulative net carbon flux (NEE) was -304.8 g C m-2 (a strong sink) over the whole cotton growing season in 2012, w...

  7. Fladis field experiments. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, M.; Ott, S.

    1996-06-01

    The objective of the Fladis field experiments was to investigate dispersion of liquefied ammonia with equal attention to the near-source aerosol jet, the intermediate heavy gas dispersion phase, and the downstream transition to passive dispersion. The present report presents the sensor layout and gives an overview of the available experimental data. This is done for observations in a fixed frame of reference and relative to the instantaneous plume centre line. The moving frame statistics are expected to compare better with wind tunnel simulations and numerical models which do not include plume meandering. The plume mass flux is estimated from the observed plume profiles and compared to the release rate. Average surface concentrations are found with a special interpolation method, and this is used to study how the averaging period affects the plume footprint. The instantaneous plume is non-Gaussian, and this is demonstrated by Lidar measurements in the far field and thermocouple measurements in the near-source jet. Probability functions and a spatial correlation for the concentration are found. The heat budget of the plume shows signs of heat flux from the ground. The composition of the liquid aerosols was observed to change from almost pure ammonia to almost pure water. A new two-dimensional `shallow layer` type model SLAM is developed, and an existing `box` type model for heavy-gas dispersion on a uniform terrain is generalized. (au) 3 tabs., 19 ills., 29 refs.

  8. An integrated, multisensor system for the continuous monitoring of water dynamics in rice fields under different irrigation regimes.

    Science.gov (United States)

    Chiaradia, Enrico Antonio; Facchi, Arianna; Masseroni, Daniele; Ferrari, Daniele; Bischetti, Gian Battista; Gharsallah, Olfa; Cesari de Maria, Sandra; Rienzner, Michele; Naldi, Ezio; Romani, Marco; Gandolfi, Claudio

    2015-09-01

    The cultivation of rice, one of the most important staple crops worldwide, has very high water requirements. A variety of irrigation practices are applied, whose pros and cons, both in terms of water productivity and of their effects on the environment, are not completely understood yet. The continuous monitoring of irrigation and rainfall inputs, as well as of soil water dynamics, is a very important factor in the analysis of these practices. At the same time, however, it represents a challenging and costly task because of the complexity of the processes involved, of the difference in nature and magnitude of the driving variables and of the high variety of field conditions. In this paper, we present the prototype of an integrated, multisensor system for the continuous monitoring of water dynamics in rice fields under different irrigation regimes. The system consists of the following: (1) flow measurement devices for the monitoring of irrigation supply and tailwater drainage; (2) piezometers for groundwater level monitoring; (3) level gauges for monitoring the flooding depth; (4) multilevel tensiometers and moisture sensor clusters to monitor soil water status; (5) eddy covariance station for the estimation of evapotranspiration fluxes and (6) wireless transmission devices and software interface for data transfer, storage and control from remote computer. The system is modular and it is replicable in different field conditions. It was successfully applied over a 2-year period in three experimental plots in Northern Italy, each one with a different water management strategy. In the paper, we present information concerning the different instruments selected, their interconnections and their integration in a common remote control scheme. We also provide considerations and figures on the material and labour costs of the installation and management of the system.

  9. Effect of timing of joint application of hydroquinone and dicyandiamide on nitrous oxide emission from irrigated lowland rice paddy field.

    Science.gov (United States)

    Li, Xianglan; Zhang, Guangbin; Xu, Hua; Cai, Zucong; Yagi, Kazuyuki

    2009-06-01

    A field experiment was conducted to study the effect of timing of joint application of urease inhibitor hydroquinone (HQ) and nitrification inhibitor dicyandiamide (DCD) on N(2)O emission from irrigated lowland rice paddy field. Four treatments including Treatment CK (the control with urea alone), HQ/DCD-1 (application of HQ and DCD together with fertilizer before transplanting), HQ/DCD-2 (HQ and DCD with fertilizer at tillering stage) and HQ/DCD-3 (HQ and DCD with fertilizer at panicle initiation stage) were designed and implemented separately during rice growth period. Seasonal peaks of N(2)O flux occurred during midseason drainage and significant negative correlation between N(2)O flux and water layer depth was observed (r=-0.69 to -0.75, P<0.01). Mean N(2)O flux was the highest in the control with urea alone, while joint addition of HQ and DCD with urea lowered mean N(2)O flux considerably (P<0.05). Total N(2)O emission during rice growth season in Treatment CK, HQ/DCD-1, HQ/DCD-2 and HQ/DCD-3 was 3.90, 2.98, 1.73 and 3.23kgN(2)O-N ha(-1), respectively. Application of HQ and DCD together with basal fertilizer, tillering fertilizer and panicle initiation fertilizer decreased the total N(2)O emission by 24%, 56% and 17%, respectively, while increased grain yield by 10%, 18% and 6%, respectively. Effect of application of inhibitors on N(2)O emission during the continuous period from incorporation of HQ and DCD to rice harvest was also studied, where results indicating that the highest inhibiting efficiency of inhibitors on N(2)O emission was recorded when HQ and DCD applied with fertilizer at tillering stage.

  10. Nitrogen availability effects on gas exchange measurements in field-grown maize (Zea mays L.) under irrigated Mediterranean conditions

    Energy Technology Data Exchange (ETDEWEB)

    Isla, R.; Guillén, M.; Salmerón, M.

    2016-07-01

    There are limited studies about the effect of nitrogen (N) deficiency on leaf growth, N status, and photosynthetic capacity of maize grown under field conditions in a Mediterranean climate. The objective of this work was to evaluate the effect of different levels of mineral N availability on leaf gas exchange parameters of sprinkler irrigated maize. The experiment was conducted in a conventional maize field located in the central part of the Ebro valley (Spain) during two seasons. Using a portable LICOR-6400 equipment, instantaneous measurements and light response curves to gas exchange were conducted in plots with different levels of N supply ranging from deficient (no fertilized) to over-fertilized (300 kg N/ha). In addition to gas exchange measurements, mineral soil N content, chlorophyll meter readings (CMR), leaf N content, and grain yield were measured in the different plots. Results showed that grain yield reached a plateau (14.5 Mg/ha) when the mineral N available was about 179 kg/ha. CMR were linearly and highly related to total N in ear leaves. The relationship between light-saturated leaf photosynthesis measurements and CMR was significant but very weak (R2=0.13) at V8 and V14 stages but increased later in the growing season (R2=0.52). Plants with intermediate levels of N supply (48

  11. Nitrogen availability effects on gas exchange measurements in field-grown maize (Zea mays L.) under irrigated Mediterranean conditions

    International Nuclear Information System (INIS)

    Isla, R.; Guillén, M.; Salmerón, M.

    2016-01-01

    There are limited studies about the effect of nitrogen (N) deficiency on leaf growth, N status, and photosynthetic capacity of maize grown under field conditions in a Mediterranean climate. The objective of this work was to evaluate the effect of different levels of mineral N availability on leaf gas exchange parameters of sprinkler irrigated maize. The experiment was conducted in a conventional maize field located in the central part of the Ebro valley (Spain) during two seasons. Using a portable LICOR-6400 equipment, instantaneous measurements and light response curves to gas exchange were conducted in plots with different levels of N supply ranging from deficient (no fertilized) to over-fertilized (300 kg N/ha). In addition to gas exchange measurements, mineral soil N content, chlorophyll meter readings (CMR), leaf N content, and grain yield were measured in the different plots. Results showed that grain yield reached a plateau (14.5 Mg/ha) when the mineral N available was about 179 kg/ha. CMR were linearly and highly related to total N in ear leaves. The relationship between light-saturated leaf photosynthesis measurements and CMR was significant but very weak (R2=0.13) at V8 and V14 stages but increased later in the growing season (R2=0.52). Plants with intermediate levels of N supply (48< CMR<54) tended to have slightly higher assimilation rates than plants with higher CMR readings. As the available N increased, the saturation point, the light compensation point and significant increases of dark respiration rate were observed. Under the conditions of the study, leaf N contents of 1.9% in the ear leaf were enough to maximize leaf assimilation rates with no need to over-fertilize the maize crop.

  12. Interaction of different irrigation strategies and soil textures on the nitrogen uptake of field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, S.H.; Andersen, M.N.; Lærke, P.E.

    2011-01-01

    received 65% of FI after tuber bulking and lasted for six weeks until final harvest. Results showed that the irrigation treatments were not significantly different in terms of N uptake in the tubers, shoot, and whole crop. However, there was a statistical difference between the soil textures where plants...... in the loamy sand had the highest amount of N uptake. The interaction between irrigation treatments and soil textures was significant, and implied that under non-limiting water conditions, loamy sand is the suitable soil for potato production because plants can take up sufficient amounts of N and it could...... potentially lead to higher yield. However, under limited water conditions and applying water-saving irrigation strategies, sandy loam and coarse sand are better growth media because N is more available for the potatoes. The simple yield prediction model was developed that could explains ca. 96...

  13. Similarity index between irrigation water and soil saturation extract in the experimental field of Yachay University, Ecuador

    Science.gov (United States)

    Carrera-Villacrés, D. V.; Sánchez-Gómez, V. P.; Portilla-Bravo, O. A.; Bolaños-Guerrón, D. R.

    2017-08-01

    Soil monitoring is a job that demands a lot of time and money. therefore, measuring the same parameters in the water becomes simple because it can be done in situ. The objective of this work was to find a similarity index for the validation of mathematical correlation models based on physicochemical parameters to verify if there is a balance between irrigation water and soil saturation extract in the experimental field Yachay that is known as the city of knowledge that is located in Imbabura province, Ecuador, for which, the sampling of water was carried out in two representative periods (dry and rainy). Sampling of 10 soil profiles was also performed, covering the total area; these samples were obtained results of Electrical Conductivity (EC), pH and total dissolved salts (TDS). With correlation models between soils and water, it is possible to predict concentrations of elements in the irrigation water. It was concluded that there is a balance between soil and water, so that the salts present in the soil are highly soluble, in addition, there is a high probability that the elements in the irrigation water are in the soil. In sample water, the same concentrations were found in the soil, at their saturation point, and very close to the field capacity.

  14. THE EFFECT OF RICE CULTIVARS ON METHANE EMISSION FROM IRRIGATED RICE FIELD

    Directory of Open Access Journals (Sweden)

    P. Setyanto

    2016-10-01

    Full Text Available Rice plants have been reported to affect methane (CH4 emission from rice fields. The objectives of this study were to determine the effect of rice cultivars on CH4 emission from flooded rice and to develop crop management strategies with low emitting rice cultivars while sustaining high yield. The four rice cultivars studied were Memberamo, Cisadane, IR64, and Way Apoburu. The CH4 emissions were determined in the wet season of 2001/2002 (November-February using an automated closed chamber technique in an irrigated field condition. Farmyard manure at the rate of 5 t ha-1 was given to the plots to ensure carbon was not limited. Root weight, root length, biomass, and number of tillers were determined at 17, 36, and 57 days after transplanting (DAT. The results showed that the mean CH4 emission was highest in the plot planted with Cisadane (94.8 kg CH4 ha-1, and the lowest with IR64 (37.7 kg CH4 ha-1. The plots treated with emberamo and Way Apoburu resulted an intermediate CH4 emission at the average of 61.1 and 58.9 kg CH4 ha-1, respectively. There was no significant difference in yield between the cultivars tested. The yield of Memberamo, Cisadane, IR64, and Way Apoburu were 5.882, 5.764, 5.873 and 6.065 t ha-1, respectively. Statistical analysis showed that there were no significant differences in the root weight and root length among cultivars. However, Cisadane gave the highest dry matter weight (222 g hill-1 at 57 DAT compared to the other cultivars (175-190 g hill-1. Plant tillers did not show significant differences between the cultivars. Regression analysis showed that CH4 flux was significantly related with root weight, root length, aboveground biomass, and number of plant tillers. This finding shows that the use of selected cultivars, such as IR64, can potentially lower CH4 emission without scarifying yield.

  15. The Politics, Development and Problems of Small Irrigation Dams in Malawi: Experiences from Mzuzu ADD

    Directory of Open Access Journals (Sweden)

    Bryson Gwiyani Nkhoma

    2011-10-01

    Full Text Available The paper examines the progress made regarding the development of small irrigation dams in Malawi with the view of establishing their significance in improving rural livelihoods in the country. The paper adopts a political economy theory and a qualitative research approach. Evidence from Mzuzu Agricultural Development Division (ADD, where small reservoirs acquire specific relevance, shows that despite the efforts made, the development of small dams is making little progress. The paper highlights that problems of top-down planning, high investment costs, negligence of national and local interests, over-dependency on donors, and conflicts over the use of dams – which made large-scale dams unpopular in the 1990s – continue to affect the development of small irrigation dams in Malawi. The paper argues that small irrigation dams should not be simplistically seen as a panacea to the problems of large-scale irrigation dams. Like any other projects, small dams are historically and socially constructed through interests of different actors in the local settings, and can only succeed if actors, especially those from formal institutions, develop adaptive learning towards apparent conflicting relations that develop among them in the process of implementation. In the case of Mzuzu ADD, it was the failure of the government to develop this adaptive learning to the contestations and conflicts among these actors that undermined successful implementation of small irrigation dams. The paper recommends the need to consider local circumstances, politics, interests, rights and institutions when investing in small irrigation dams.

  16. Effect of Periods of Field Establishment and Irrigation on Growth and ...

    African Journals Online (AJOL)

    Two irrigation regimes on the growth and yield performance of Thevetia peruviana (Pers) Schum were evaluated during the 2010 and 2011 rainy seasons. The study was carried out at the Research Farms of the Bio-fuel and Alternate Renewable Energy Ltd, Edidi, Kwara State in the southern Guinea savannah of Nigeria.

  17. Using farmer knowledge to combat low productive spots in rice fields of a Sahelian irrigation scheme

    NARCIS (Netherlands)

    Asten, van P.J.A.; Barro, S.E.; Wopereis, M.C.S.; Defoer, T.

    2004-01-01

    In the oldest sections of Burkina Faso's largest irrigation scheme in the Sourou Valley (13degrees 10'N, 03degrees 30'W) rice (Oryza sativa L.) yields dropped from about 5 to 6 t ha(-1) in the early 1990s, shortly after establishment of the scheme, to 2 to 4 t ha(-1) from 1995 onwards. Farmers

  18. Effects of irrigation and plastic mulch on soil properties on semi-arid abandoned fields

    NARCIS (Netherlands)

    van der Meulen, E.S.; Nol, L.; Cammeraat, L.H.

    2006-01-01

    The Guadalentín Basin in Spain is one of the driest areas of Europe and has problems with high evaporation rates, and high risks of desertification exist including soil quality loss and soil erosion. Farmers in this semi-arid region use polyethylene covers on their irrigated croplands to reduce

  19. Mapping soil moisture across an irrigated field using electromagnetic conductivity imaging

    Science.gov (United States)

    The ability to measure and map volumetric soil water theta quickly and accurately is important in irrigated agriculture. However, the traditional approach of using thermogravimetric moisture (w) and converting this to theta using measurements of bulk density (theta – cm3/cm3) is laborious and time c...

  20. Relationships between carbon fluxes and environmental factors in a drip-irrigated, film-mulched cotton field in arid region.

    Directory of Open Access Journals (Sweden)

    Xiaoyu Li

    Full Text Available Environmental factors and human activities play important roles in carbon fixation and emissions generated from croplands. Eddy covariance measurements in a drip-irrigated, film-mulched cotton field were used to analyze the relationships between carbon fluxes and environmental factors in Wulanwusu, northern Xinjiang, an arid region of Northwest China. Our results showed that the cumulative net carbon flux (NEE was -304.8 g C m-2 (a strong sink over the whole cotton growing season in 2012, which was more than that in cotton cropland without plastic film mulching and drip-irrigation. Moreover, when time is scaled up from a half-hour to a month, the correlations of gross primary production (GPP to air temperature (Tair, net solar radiation (Rn and soil water content (SWC gradually become stronger due to ecosystem resistance and resilience as well as the protection of plastic film mulching. The GPP is more strongly correlated with Rn than Tair at time scales from minutes to days, while it reverses at time scales from days to weeks. This outcome is largely determined by the biochemical characteristics of photosynthesis. SWC and vapor pressure deficit (VPD at all time scales are weakly correlated with GPP because plastic film mulching and regularly drip-irrigation allow soil to maintain sufficient water.

  1. Review of WAG Field Experience

    DEFF Research Database (Denmark)

    Christensen, Jes Reimer; Stenby, Erling Halfdan; Skauge, A.

    2001-01-01

    well spacing is in the order of 1000 m. For the fields reviewed, a common trend for the successful injections is an increased oil recovery in the range of 5 to 10% of the oil initially in place (OIIP). Very few field trials have been reported as unsuccessful, but operational problems are often noted...

  2. The National Airborne Field Experiment Data Sets

    DEFF Research Database (Denmark)

    Walker, J. P.; Balling, Jan E.; Bell, M.

    2007-01-01

    The National Airborne Field Experiment's (NAFE) were a series of intensive experiments recently conducted in different parts of Australia. These hydrologic-focused experiments have been designed to answer a range of questions which can only be resolved through carefully planned and executed field...

  3. Traditional Irrigation Management in Betmera-Hiwane, Ethiopia: The Main Peculiarities for the Persistence of Irrigation Practices

    Institute of Scientific and Technical Information of China (English)

    Solomon Habtu; Kitamura Yoshinobu

    2006-01-01

    Traditional irrigation, as part of the ancient agricultural practices in northern Ethiopia (Tigray), has persisted for long time since 500 B.C.,while many newly introduced irrigation projects have usually failed there. The main objective of this study is thus to investigate the peculiarities pertinent to irrigation management and those having contributed for the persistence of traditional irrigation practices for a long period of time. The experience gained from such areas can definitely help make irrigation management system of new irrigation schemes sustainable. Betmera-Hiwane, one of the ancient traditional irrigation areas in Tigray region, was selected for the field study. Direct observations through field visits accompanied by interviews to farmers, local officials, local knowledgeable individuals and higher officials were made. After analyzing the collected primary and secondary information, the main peculiarities that contributed to the persistence of traditional irrigation areas were identified, and they are: the presence of communally constructed local rules, locally designed hydraulic control structures, ownership feeling of the irrigators and accountability of water distributors to the irrigation management, the culture for mobilizing communal resources and the culture of self-initiating local water management strategies.

  4. Seasonal Canopy Temperatures for Normal and Okra Leaf Cotton under Variable Irrigation in the Field

    Directory of Open Access Journals (Sweden)

    James R. Mahan

    2016-11-01

    Full Text Available Temperature affects a number of physiological factors in plants and is related to water use, yield and quality in many crop species. Seasonal canopy temperature, measured with infrared thermometers, is often used in conjunction with environmental factors (e.g., air temperature, humidity, solar radiation to assess crop stress and management actions in cotton. Normal and okra leaf shapes in cotton have been associated with differences in water use and canopy temperature. The okra leaf shape in cotton is generally expected to result in lower water use and lower canopy temperatures, relative to normal leaf, under water deficits. In this study canopy temperatures were monitored in okra and normal leaf varieties for a growing season at four irrigation levels. Differences in canopy temperature (<2 °C were measured between the two leaf shapes. As irrigation levels increased, canopy temperature differences between the leaf shapes declined. At the lowest irrigation level, when differences in sensible energy exchanges due to the okra leaf shape would be enhanced, the canopy temperature of the okra leaf was warmer than the normal leaf. This suggests that varietal differences that are not related to leaf shape may have more than compensated for leaf shape differences in the canopy temperature.

  5. Adubarroz: a brazilian experience for fertilization and liming recommendation of irrigated rice via computational system

    Directory of Open Access Journals (Sweden)

    Felipe de Campos Carmona

    Full Text Available ABSTRACT: Recommendations for fertilizing irrigated rice in southern Brazil have been constantly evolving over years. In this process, the influence of factors such as the development cycle of varieties and sowing period increased. Thus, computational tools that take these and others important aspects into account can potentiate the fertilization response of rice. This study describes the computer program "ADUBARROZ". The software provides recommendations of fertilizer rates and liming requirements of irrigated rice, based on information entered by the user. The system takes various factors that regulate the crop response to fertilization into account. A final report is established with the graphical representation of input management over time.

  6. Escherichia coli transfer from simulated wildlife feces to lettuce during foliar irrigation: A field study in the Northeastern United States.

    Science.gov (United States)

    Weller, Daniel L; Kovac, Jasna; Kent, David J; Roof, Sherry; Tokman, Jeffrey I; Mudrak, Erika; Kowalcyk, Barbara; Oryang, David; Aceituno, Anna; Wiedmann, Martin

    2017-12-01

    Wildlife intrusion has been associated with pathogen contamination of produce. However, few studies have examined pathogen transfer from wildlife feces to pre-harvest produce. This study was performed to calculate transfer coefficients for Escherichia coli from simulated wildlife feces to field-grown lettuce during irrigation. Rabbit feces inoculated with a 3-strain cocktail of non-pathogenic E. coli were placed in a lettuce field 2.5-72 h before irrigation. Following irrigation, the E. coli concentration on the lettuce was determined. After exclusion of an outlier with high E. coli levels (Most Probable Number = 5.94*10 8 ), the average percent of E. coli in the feces that transferred to intact lettuce heads was 0.0267% (Standard Error [SE] = 0.0172). Log-linear regression showed that significantly more E. coli transferred to outer leaves compared to inner leaves (Effect = 1.3; 95% Confidence Interval = 0.4, 2.1). Additionally, the percent of E. coli that transferred from the feces to the lettuce decreased significantly with time after fecal placement, and as the distance between the lettuce and the feces, and the lettuce and the sprinklers increased. These findings provide key data that may be used in future quantitative risk assessments to identify potential intervention strategies for reducing food safety risks associated with fresh produce. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Yield response of cotton, maize, soybean, sugar beet, sunflower and wheat to deficit irrigation

    International Nuclear Information System (INIS)

    Kirda, C.; Kanber, R.; Tulucu, K.

    1995-01-01

    Results of several field experiments on deficit irrigation programmes in Turkey are discussed. Deficit irrigation of sugar beet with water stress imposed (i e.,irrigation omitted)during ripening,stage saved nearly 22 % water, yet with no significant yield decrease. An experiment, conducted in Turkey Region, the European part of Turkey,and aimed at studying water production functions of sunflower(i e,yield vs water consumption), revealed that water stress imposed at either head forming or seed filling stags influence yield the least , and 40 % savings of irrigation water supply , compared with traditional practices in the region, can be achieved without significant yield reduction. Water stress imposed at vegetative and flowering stages of maize hindered the yield most significantly. The results showed that deficit irrigation can be a feasible option under limited supply of irrigation if stress occurs during yield formation stage. A four year field experiments aiming at developing deficit irrigation strategies for soybean showed that soybean was at the most sensitive to water stress during flowering and pod filling stages, and irrigation during these stages would ensure high yields. Results of experiments on cotton showed that irrigations omitted during yield formation stage did not significantly hinder the yield. Similarly wheat give good yield response if irrigated at booting,heading and milking stages, depending on w heather conditions. In areas where rainfall at planting is limited, supplementary irrigation during this period can ensure good establishment of wheat crop. 1 tab; 9 figs; 59 refs (Author)

  8. Online decision support system for surface irrigation management

    Science.gov (United States)

    Wang, Wenchao; Cui, Yuanlai

    2017-04-01

    Irrigation has played an important role in agricultural production. Irrigation decision support system is developed for irrigation water management, which can raise irrigation efficiency with few added engineering services. An online irrigation decision support system (OIDSS), in consist of in-field sensors and central computer system, is designed for surface irrigation management in large irrigation district. Many functions have acquired in OIDSS, such as data acquisition and detection, real-time irrigation forecast, water allocation decision and irrigation information management. The OIDSS contains four parts: Data acquisition terminals, Web server, Client browser and Communication system. Data acquisition terminals are designed to measure paddy water level, soil water content in dry land, ponds water level, underground water level, and canals water level. A web server is responsible for collecting meteorological data, weather forecast data, the real-time field data, and manager's feedback data. Water allocation decisions are made in the web server. Client browser is responsible for friendly displaying, interacting with managers, and collecting managers' irrigation intention. Communication system includes internet and the GPRS network used by monitoring stations. The OIDSS's model is based on water balance approach for both lowland paddy and upland crops. Considering basic database of different crops water demands in the whole growth stages and irrigation system engineering information, the OIDSS can make efficient decision of water allocation with the help of real-time field water detection and weather forecast. This system uses technical methods to reduce requirements of user's specialized knowledge and can also take user's managerial experience into account. As the system is developed by the Browser/Server model, it is possible to make full use of the internet resources, to facilitate users at any place where internet exists. The OIDSS has been applied in

  9. Experiments for obtaining field influence mass particles.

    CERN Document Server

    Yahalomi, E

    2010-01-01

    Analyzing time dilation experiments the existence of a universal field interacting with moving mass particles is obtained. It is found that mass particle changes its properties depend on its velocity relative to this universal scalar field and not on its velocity relative to the laboratory. High energy proton momentum, energy and mass were calculated obtaining new results. Experiments in high energy accelerators are suggested as additional proofs for the existence of this universal field. This universal field may explain some results of other high energy experiments.

  10. Effects of shallow groundwater management on the spatial and temporal variability of boron and salinity in an irrigated field

    NARCIS (Netherlands)

    Shouse, P.J.; Goldberg, S.; Skaggs, T.H.; Soppe, R.W.O.; Ayars, J.E.

    2006-01-01

    In some irrigated regions, the disposal of agricultural drainage waters poses significant environmental challenges. Efforts are underway to develop irrigation water management practices that reduce the volume of drainage generated. One such management strategy involves restricting flow in subsurface

  11. Towards the Development and Validation of a Global Field Size and Irrigation Map using Crowdsourcing, Mobile Apps and Google Earth Engine in support of GEOGLAM

    Science.gov (United States)

    Fritz, S.; Nordling, J.; See, L. M.; McCallum, I.; Perger, C.; Becker-Reshef, I.; Mucher, S.; Bydekerke, L.; Havlik, P.; Kraxner, F.; Obersteiner, M.

    2014-12-01

    The International Institute for Applied Systems Analysis (IIASA) has developed a global cropland extent map, which supports the monitoring and assessment activities of GEOGLAM (Group on Earth Observations Global Agricultural Monitoring Initiative). Through the European-funded SIGMA (Stimulating Innovation for Global Monitoring of Agriculture and its Impact on the Environment in support of GEOGLAM) project, IIASA is continuing to support GEOGLAM by providing cropland projections in the future and modelling environmental impacts on agriculture under various scenarios. In addition, IIASA is focusing on two specific elements within SIGMA: the development of a global field size and irrigation map; and mobile app development for in-situ data collection and validation of remotely-sensed products. Cropland field size is a very useful indicator for agricultural monitoring yet the information we have at a global scale is currently very limited. IIASA has already created a global map of field size at a 1 km resolution using crowdsourced data from Geo-Wiki as a first approximation. Using automatic classification of Landsat imagery and algorithms contained within Google Earth Engine, initial experimentation has shown that circular fields and landscape structures can easily be extracted. Not only will this contribute to improving the global map of field size, it can also be used to create a global map that contains a large proportion of the world's irrigated areas, which will be another useful contribution to GEOGLAM. The field size map will also be used to stratify and develop a global crop map in SIGMA. Mobile app development in support of in-situ data collection is another area where IIASA is currently working. An Android app has been built using the Open Data Toolkit (ODK) and extended further with spatial mapping capabilities called GeoODK. The app allows users to collect data on different crop types and delineate fields on the ground, which can be used to validate the

  12. Effects of irrigation strategies and soils on field-grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Andersen, Mathias Neumann; Plauborg, Finn

    2010-01-01

    Gas exchange was measured in potatoes (cv. Folva) grown in lysimeters (4.32 m2) in coarse sand, loamy sand, and sandy loam and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments received 65% of FI...... measurements showed that An reached peak values during mid-morning and midday, while gs were highest during the morning. Intrinsic water use efficiency (An/gs) correlated linearly well with the leaf to air vapor pressure deficit (VPD) and the slope of the line revealed the rate of An/gs increase per each k......Pa increase in VPD, i.e. approximately 10 μmol mol-1. Transpiration efficiency (An/T) of PRD was higher than DI, which shows slightly better efficient water use than DI. The slope of the linear relationship between transpiration efficiency and VPD decreased from -2.03 to -1.04 during the time course...

  13. Performance of the METRIC model in estimating evapotranspiration fluxes over an irrigated field in Saudi Arabia using Landsat-8 images

    Science.gov (United States)

    Madugundu, Rangaswamy; Al-Gaadi, Khalid A.; Tola, ElKamil; Hassaballa, Abdalhaleem A.; Patil, Virupakshagouda C.

    2017-12-01

    Accurate estimation of evapotranspiration (ET) is essential for hydrological modeling and efficient crop water management in hyper-arid climates. In this study, we applied the METRIC algorithm on Landsat-8 images, acquired from June to October 2013, for the mapping of ET of a 50 ha center-pivot irrigated alfalfa field in the eastern region of Saudi Arabia. The METRIC-estimated energy balance components and ET were evaluated against the data provided by an eddy covariance (EC) flux tower installed in the field. Results indicated that the METRIC algorithm provided accurate ET estimates over the study area, with RMSE values of 0.13 and 4.15 mm d-1. The METRIC algorithm was observed to perform better in full canopy conditions compared to partial canopy conditions. On average, the METRIC algorithm overestimated the hourly ET by 6.6 % in comparison to the EC measurements; however, the daily ET was underestimated by 4.2 %.

  14. Indirect Reciprocity; A Field Experiment.

    Science.gov (United States)

    van Apeldoorn, Jacobien; Schram, Arthur

    2016-01-01

    Indirect reciprocity involves cooperative acts towards strangers, either in response to their kindness to third parties (downstream) or after receiving kindness from others oneself (upstream). It is considered to be important for the evolution of cooperative behavior amongst humans. Though it has been widely studied theoretically, the empirical evidence of indirect reciprocity has thus far been limited and based solely on behavior in laboratory experiments. We provide evidence from an online environment where members can repeatedly ask and offer services to each other, free of charge. For the purpose of this study we created several new member profiles, which differ only in terms of their serving history. We then sent out a large number of service requests to different members from all over the world. We observe that a service request is more likely to be rewarded for those with a profile history of offering the service (to third parties) in the past. This provides clear evidence of (downstream) indirect reciprocity. We find no support for upstream indirect reciprocity (in this case, rewarding the service request after having previously received the service from third parties), however. Our evidence of downstream indirect reciprocity cannot be attributed to reputational effects concerning one's trustworthiness as a service user.

  15. Biological degradation of chernozems under irrigation

    Directory of Open Access Journals (Sweden)

    Oksana Naydyonova

    2014-12-01

    Full Text Available We studied the changes in the state of microbial cenosis of Ukraine’s chernozems under irrigation. Considerable part of Ukraine’s chernozems is located in the areas where humidification is insufficient and unstable. Irrigation is a soil-reclamation measure for chernozems of Ukrainian Forest-steppe and Steppe which enables getting the assured yield, especially vegetable and fodder crops. At the same time, irrigation is a powerful anthropogenic factor that affects the soil, causes a significant transformation of many of its properties and regimes including biological ones. Often these changes are negative. The purpose of our investigation was to identify changes in the state of microbial cenoses of chernozem soils under irrigation which depend on such factors as the quality of irrigation water, the duration and intensity of irrigation, the initial properties of soil, the structure of crop rotation, usage of fertilizing systems and agroameliorative techniques. We identified direction and evaluated a degree of changes in biological properties of chernozems under influence of irrigation in different agro-irrigational and soil-climatic conditions. In the long-term stationary field experiments we identified the following biological indices of irrigated soils and their non-irrigated analogues: a number of microorganisms which belong to main ecological-trophic groups, activity of soil enzymes (dehydrogenase, invertase, phenol oxidase, soil phytotoxic activity, cellulose destroying capacity of soil, indices of oligotrophy and mineralization, summary biological index (SBI and index of biological degradation (BDI. Results of researches showed that irrigation unbalanced the soil ecosystem and stipulated the forming of microbial cenosis with new parameters. Long-term intensive irrigation of typical chernozem (Kharkiv Region with fresh water under condition of 4-fields vegetable crop rotation led to the degradation changes of its microbial cenosis such as

  16. Field Experience Study in a Traditional Setting.

    Science.gov (United States)

    Perenich, Theresa A.

    1978-01-01

    A field experience in fashion marketing for Kansas State University students is described. The functions and responsibilities of the coordinator, the student, and the departmental supervisor are outlined, along with the evaluation processes used. (Author/LBH)

  17. Effects of arbuscular mycorrhizae on tomato yield, nutrient uptake, water relations, and soil carbon dynamics under deficit irrigation in field conditions.

    Science.gov (United States)

    Bowles, Timothy M; Barrios-Masias, Felipe H; Carlisle, Eli A; Cavagnaro, Timothy R; Jackson, Louise E

    2016-10-01

    Plant strategies to cope with future droughts may be enhanced by associations between roots and soil microorganisms, including arbuscular mycorrhizal (AM) fungi. But how AM fungi affect crop growth and yield, together with plant physiology and soil carbon (C) dynamics, under water stress in actual field conditions is not well understood. The well-characterized mycorrhizal tomato (Solanum lycopersicum L.) genotype 76R (referred to as MYC+) and the mutant nonmycorrhizal tomato genotype rmc were grown in an organic farm with a deficit irrigation regime and control regime that replaced evapotranspiration. AM increased marketable tomato yields by ~25% in both irrigation regimes but did not affect shoot biomass. In both irrigation regimes, MYC+ plants had higher plant nitrogen (N) and phosphorus (P) concentrations (e.g. 5 and 24% higher N and P concentrations in leaves at fruit set, respectively), 8% higher stomatal conductance (gs), 7% higher photosynthetic rates (Pn), and greater fruit set. Stem water potential and leaf relative water content were similar in both genotypes within each irrigation regime. Three-fold higher rates of root sap exudation in detopped MYC+ plants suggest greater capacity for water uptake through osmotic driven flow, especially in the deficit irrigation regime in which root sap exudation in rmc was nearly absent. Soil with MYC+ plants also had slightly higher soil extractable organic C and microbial biomass C at anthesis but no changes in soil CO2 emissions, although the latter were 23% lower under deficit irrigation. This study provides novel, field-based evidence for how indigenous AM fungi increase crop yield and crop water use efficiency during a season-long deficit irrigation and thus play an important role in coping with increasingly limited water availability in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Field Experiments in Behavioral and Public Economics

    OpenAIRE

    Bhanot, Syon Pandya

    2015-01-01

    The three essays in this dissertation present field experiments exploring phenomena in behavioral and public economics in real-world settings. The first essay outlines a field experiment that uses mailers with peer rank information to motivate water conservation. The essay contributes some of the first pieces of evidence on how comparisons with specific peers might influence behavior. The main finding is that while competitive framing of peer information has positive impacts on efficient h...

  19. An experimental study on the grape orchard: Effects comparison of two irrigation systems

    Directory of Open Access Journals (Sweden)

    Kadbhane Sharad J.

    2017-03-01

    Full Text Available Table grape (Vitis vinifera cultivars is a major cash crop in the Nashik district of India, which requires irrigation water throughout the year as per demand instantly. Canal irrigation is the adopted irrigation systems in the study area, but canal irrigation has got several serious disadvantages, such as mismatching rotation schedules and crop water demands, water allotment system and restrictions on the use of efficient irrigation methods. The storing the canal water in the farm pond instead of directly applying to the field using the free flooding method is alternate solution to overcome the disadvantages of the canal irrigation system. Once the canal water storing in the pond, it increases the possibilities to use the advance irrigation system like drip, subsurface, sprinkler etc. to enhance water use efficiency. The comparative study between the canal water directly applying for the field and canal water storing in the farm pond then use for irrigation, executed through the field experiments carried out on the grape orchard during a period April 2013 to March 2016. Results have been evaluated based on grape yield, water-productivity, berry size, and biomass. Water productivity (kg·m-3 with respect to water delivery to crop through the pond irrigation method was found 37% higher than the canal irrigation method during the study period. Based on the results, this study recommended the use of the farm pond to store the canal water and use it as per crop demand using advance irrigation systems.

  20. Using Case Studies to Enrich Field Experience.

    Science.gov (United States)

    Florio-Ruane, Susan; Clark, Christopher M.

    1990-01-01

    This paper discusses the use of field experience in teacher education and how it can be augmented by phenomenological case studies. It summarizes a particular case study involving three teacher education classes, noting that reflective analysis of cases can prepare students to observe in the field. (SM)

  1. Detecting the Spatio-temporal Distribution of Soil Salinity and Its Relationship to Crop Growth in a Large-scale Arid Irrigation District Based on Sampling Experiment and Remote Sensing

    Science.gov (United States)

    Ren, D.; Huang, G., Sr.; Xu, X.; Huang, Q., Sr.; Xiong, Y.

    2016-12-01

    Soil salinity analysis on a regional scale is of great significance for protecting agriculture production and maintaining eco-environmental health in arid and semi-arid irrigated areas. In this study, the Hetao Irrigation District (Hetao) in Inner Mongolia Autonomous Region, with suffering long-term soil salinization problems, was selected as the case study area. Field sampling experiments and investigations related to soil salt contents, crop growth and yields were carried out across the whole area, during April to August in 2015. Soil salinity characteristics in space and time were systematically analyzed for Hetao as well as the corresponding impacts on crops. Remotely sensed map of soil salinity distribution for surface soil was also derived based on the Landsat OLI data with a 30 m resolution. The results elaborated the temporal and spatial dynamics of soil salinity and the relationships with irrigation, groundwater depth and crop water consumption in Hetao. In addition, the strong spatial variability of salinization was clearly presented by the remotely sensed map of soil salinity. Further, the relationship between soil salinity and crop growth was analyzed, and then the impact degrees of soil salinization on cropping pattern, leaf area index, plant height and crop yield were preliminarily revealed. Overall, this study can provide very useful information for salinization control and guide the future agricultural production and soil-water management for the arid irrigation districts analogous to Hetao.

  2. Field experiments on airborne moisture transport

    NARCIS (Netherlands)

    Oldengarm, J.; Gids, W.F. de

    1990-01-01

    Within the framework of the Dutch participation in the IEA Annex XIV “Condensation” field experiments have been carried out to study airbome moisture transport in realistic circumstances. The experiments were done in an unoccupied 3-story dwelling in Leidschendam in the Netherlands. Some of the

  3. A Field Experiment in Motivating Employee Ideas

    NARCIS (Netherlands)

    M. Gibbs (Michael); S. Neckermann (Susanne); C. Siemroth (Christoph)

    2014-01-01

    markdownabstract__Abstract__ We study the effects of a field experiment designed to motivate employee ideas, at a large technology company. Employees were encouraged to submit ideas on process and product improvements via an online system. In the experiment, the company randomized 19 account

  4. CHANGE DETECTION OF CROPPING PATTERN IN PADDY FIELD USING MULTI SPECTRAL SATELLITE DATA FOR ESTIMATING IRRIGATION WATER NEEDS

    Directory of Open Access Journals (Sweden)

    Rizatus Shofiyati1

    2012-10-01

    Full Text Available This paper investigates the use of multi spectral satellite data for cropping pattern monitoring in paddy field. The southern coastal of Citarum watershed, West Java Province was selected as study sites. The analysis used in this study is identifying crop pattern based on growth stages of wetland paddy and other crops by investi-gating the characteristic of Normalized Differen-ce Vegetation Indices (NDVI and Wetness of Tasseled Cap Transformation (TCT derived from 14 scenes of Landsat TM date 1988 to 2001. In general, the phenological of growth stages of wetland paddy can be used to distinguish with other seasonal crops. The research results indicate that multi spectral satellite data has a great potential for identi-fication and monitoring cropping pattern in paddy field. Specific character of NDVI and Wetness can also produce a map of cropping pattern in paddy field that is useful to monitor agricultural land condition. The cropping pattern can also be used to estimate irrigation water needed of paddy field in the area. Expected implication of the information obtained from this analysis is useful for guiding more appropriate planning and better agricultural management.

  5. Minimizing Erosion and Agro-Pollutants Transport from Furrow Irrigated Fields to the Nearby Water Body Using Spatially-Explicit Agent Based Model and Decision Optimization Platform

    Science.gov (United States)

    Ghoveisi, H.; Al Dughaishi, U.; Kiker, G.

    2017-12-01

    Maintaining water quality in agricultural watersheds is a worldwide challenge, especially where furrow irrigation is being practiced. The Yakima River Basin watershed in south central Washington State, (USA) is an example of these impacted areas with elevated load of sediments and other agricultural products due to runoff from furrow-irrigated fields. Within the Yakima basin, the Granger Drain watershed (area of 75 km2) is particularly challenged in this regard with more than 400 flood-irrigated individual parcels (area of 21 km2) growing a variety of crops from maize to grapes. Alternatives for improving water quality from furrow-irrigated parcels include vegetated filter strip (VFS) implementation, furrow water application efficiency, polyacrylamide (PAM) application and irrigation scheduling. These alternatives were simulated separately and in combinations to explore potential Best Management Practices (BMPs) for runoff-related-pollution reduction in a spatially explicit, agent based modeling system (QnD:GrangerDrain). Two regulatory scenarios were tested to BMP adoption within individual parcels. A blanket-style regulatory scenario simulated a total of 60 BMP combinations implemented in all 409 furrow-irrigated parcels. A second regulatory scenario simulated the BMPs in 119 furrow-irrigated parcels designated as "hotspots" based on a standard 12 Mg ha-1 seasonal sediment load. The simulated cumulative runoff and sediment loading from all BMP alternatives were ranked using Multiple Criteria Decision Analysis (MCDA), specifically the Stochastic Multi-Attribute Acceptability Analysis (SMAA) method. Several BMP combinations proved successful in reducing loads below a 25 NTU (91 mg L-1) regulatory sediment concentration. The QnD:GrangerDrain simulations and subsequent MCDA ranking revealed that the BMP combinations of 5 m-VFS and high furrow water efficiency were highly ranked alternatives for both the blanket and hotspot scenarios.

  6. Environmental effects on proline accumulation and water potential in olive leaves (Olea europaea L. (cv Chemlali)) under saline water irrigated field conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ben Ahmed, C.; Ben Rouina, B.; Boukhris, M.

    2009-07-01

    In arid regions in Tunisia suffering from limited water resources, the olive extension to irrigated lands has led to the urgent use of saline water, the most readily available water in the these areas. Nevertheless, the effects of salt stress on olive tree seem to be reinforced by environmental conditions. The issue of this paper is to determine how does the olive tree respond to environmental stress in the Mediterranean climate under saline water irrigated field conditions with respect to leaf proline concentrations and water Status. (Author)

  7. Environmental effects on proline accumulation and water potential in olive leaves (Olea europaea L. CV Chemlali)) under saline water irrigated field conditions

    International Nuclear Information System (INIS)

    Ben Ahmed, C.; Ben Rouina, B.; Boukhris, M.

    2009-01-01

    In arid regions in Tunisia suffering from limited water resources, the olive extension to irrigated lands has led to the urgent use of saline water, the most readily available water in the these areas. Nevertheless, the effects of salt stress on olive tree seem to be reinforced by environmental conditions. The issue of this paper is to determine how does the olive tree respond to environmental stress in the Mediterranean climate under saline water irrigated field conditions with respect to leaf proline concentrations and water Status. (Author)

  8. [Effects of drip irrigation with plastic mulching on the net primary productivity, soil heterotrophic respiration, and net CO2 exchange flux of cotton field ecosystem in Xinjiang, Northwest China].

    Science.gov (United States)

    Li, Zhi-Guo; Zhang, Run-Hua; Lai, Dong-Mei; Yan, Zheng-Yue; Jiang, Li; Tian, Chang-Yan

    2012-04-01

    In April-October, 2009, a field experiment was conducted to study the effects of drip irrigation with plastic mulching (MD) on the net primary productivity (NPP), soil heterotrophic respiration (Rh) , and net CO2 exchange flux (NEF(CO2)) of cotton field ecosystem in Xinjiang, taking the traditional flood irrigation with no mulching (NF) as the control. With the increasing time, the NPP, Rh, and NEF(CO2) in treatments MD and NF all presented a trend of increasing first and decreased then. As compared with NF, MD increased the aboveground and belowground biomass and the NPP of cotton, and decreased the Rh. Over the whole growth period, the Rh in treatment MD (214 g C x m(-2)) was smaller than that in treatment NF (317 g C x m(-2)), but the NEF(CO2) in treatment MD (1030 g C x m(-2)) was higher than that in treatment NF (649 g C x m(-2)). Treatment MD could fix the atmospheric CO2 approximately 479 g C x m(-2) higher than treatment NF. Drip irrigation with plastic mulching could promote crop productivity while decreasing soil CO2 emission, being an important agricultural measure for the carbon sequestration and emission reduction of cropland ecosystems in arid area.

  9. Assessment of village-wise groundwater draft for irrigation: a field-based study in hard-rock aquifers of central India

    Science.gov (United States)

    Ray, R. K.; Syed, T. H.; Saha, Dipankar; Sarkar, B. C.; Patre, A. K.

    2017-12-01

    Extracted groundwater, 90% of which is used for irrigated agriculture, is central to the socio-economic development of India. A lack of regulation or implementation of regulations, alongside unrecorded extraction, often leads to over exploitation of large-scale common-pool resources like groundwater. Inevitably, management of groundwater extraction (draft) for irrigation is critical for sustainability of aquifers and the society at large. However, existing assessments of groundwater draft, which are mostly available at large spatial scales, are inadequate for managing groundwater resources that are primarily exploited by stakeholders at much finer scales. This study presents an estimate, projection and analysis of fine-scale groundwater draft in the Seonath-Kharun interfluve of central India. Using field surveys of instantaneous discharge from irrigation wells and boreholes, annual groundwater draft for irrigation in this area is estimated to be 212 × 106 m3, most of which (89%) is withdrawn during non-monsoon season. However, the density of wells/boreholes, and consequent extraction of groundwater, is controlled by the existing hydrogeological conditions. Based on trends in the number of abstraction structures (1982-2011), groundwater draft for the year 2020 is projected to be approximately 307 × 106 m3; hence, groundwater draft for irrigation in the study area is predicted to increase by ˜44% within a span of 8 years. Central to the work presented here is the approach for estimation and prediction of groundwater draft at finer scales, which can be extended to critical groundwater zones of the country.

  10. A Field Experiment in Motivating Employee Ideas

    OpenAIRE

    Susanne Neckermann; Michael Gibbs; Christoph Siemroth

    2014-01-01

    markdownabstract__Abstract__ We study the effects of a field experiment designed to motivate employee ideas, at a large technology company. Employees were encouraged to submit ideas on process and product improvements via an online system. In the experiment, the company randomized 19 account teams into treatment and control groups. Employees in treatment teams received rewards if their ideas were approved. Nothing changed for employees in control teams. Our main finding is that rewards substa...

  11. Effects of Residue Management on Decomposition in Irrigated Rice Fields Are Not Related to Changes in the Decomposer Community.

    Directory of Open Access Journals (Sweden)

    Anja Schmidt

    Full Text Available Decomposers provide an essential ecosystem service that contributes to sustainable production in rice ecosystems by driving the release of nutrients from organic crop residues. During a single rice crop cycle we examined the effects of four different crop residue management practices (rice straw or ash of burned straw scattered on the soil surface or incorporated into the soil on rice straw decomposition and on the abundance of aquatic and soil-dwelling invertebrates. Mass loss of rice straw in litterbags of two different mesh sizes that either prevented or allowed access of meso- and macro-invertebrates was used as a proxy for decomposition rates. Invertebrates significantly increased total loss of litter mass by up to 30%. Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season. We found no significant responses in microbial decomposition rates to management practices. The abundance of aquatic fauna was higher in fields with rice straw amendment, whereas the abundance of soil fauna fluctuated considerably. There was a clear separation between the overall invertebrate community structure in response to the ash and straw treatments. However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates. Our results indicate that invertebrates can contribute to soil fertility in irrigated paddy fields by decomposing rice straw, and that their abundance as well as efficiency in decomposition may be promoted by crop residue management practices.

  12. Effects of Residue Management on Decomposition in Irrigated Rice Fields Are Not Related to Changes in the Decomposer Community.

    Science.gov (United States)

    Schmidt, Anja; John, Katharina; Arida, Gertrudo; Auge, Harald; Brandl, Roland; Horgan, Finbarr G; Hotes, Stefan; Marquez, Leonardo; Radermacher, Nico; Settele, Josef; Wolters, Volkmar; Schädler, Martin

    2015-01-01

    Decomposers provide an essential ecosystem service that contributes to sustainable production in rice ecosystems by driving the release of nutrients from organic crop residues. During a single rice crop cycle we examined the effects of four different crop residue management practices (rice straw or ash of burned straw scattered on the soil surface or incorporated into the soil) on rice straw decomposition and on the abundance of aquatic and soil-dwelling invertebrates. Mass loss of rice straw in litterbags of two different mesh sizes that either prevented or allowed access of meso- and macro-invertebrates was used as a proxy for decomposition rates. Invertebrates significantly increased total loss of litter mass by up to 30%. Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season. We found no significant responses in microbial decomposition rates to management practices. The abundance of aquatic fauna was higher in fields with rice straw amendment, whereas the abundance of soil fauna fluctuated considerably. There was a clear separation between the overall invertebrate community structure in response to the ash and straw treatments. However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates. Our results indicate that invertebrates can contribute to soil fertility in irrigated paddy fields by decomposing rice straw, and that their abundance as well as efficiency in decomposition may be promoted by crop residue management practices.

  13. [Optimal irrigation index for cotton drip irrigation under film mulching based on the evaporation from pan with constant water level].

    Science.gov (United States)

    Shen, Xiao-Jun; Zhang, Ji-Yang; Sun, Jing-Sheng; Gao, Yang; Li, Ming-Si; Liu, Hao; Yang, Gui-Sen

    2013-11-01

    A field experiment with two irrigation cycles and two irrigating water quotas at squaring stage and blossoming-boll forming stage was conducted in Urumqi of Xinjiang Autonomous Region, Northwest China in 2008-2009, aimed to explore the high-efficient irrigation index of cotton drip irrigation under film mulching. The effects of different water treatments on the seed yield, water consumption, and water use efficiency (WUE) of cotton were analyzed. In all treatments, there was a high correlation between the cotton water use and the evaporation from pan installed above the plant canopy. In high-yield cotton field (including the treatment T4 which had 10 days and 7 days of irrigation cycle with 30.0 mm and 37.5 mm of irrigating water quota at squaring stage and blossoming-boll forming stage, respectively in 2008, and the treatment T1 having 7 days of irrigation cycle with 22.5 mm and 37.5 mm of irrigating water quota at squaring stage and blossoming-boll forming stage, respectively in 2009), the pan-crop coefficient (Kp) at seedling stage, squaring stage, blossoming-boll forming stage, and boll opening stage was 0.29-0.30, 0.52-0.53, 0.74-0.88, and 0.19-0.20, respectively. As compared with the other treatments, T4 had the highest seed cotton yield (5060 kg x hm(-2)) and the highest WUE (1.00 kg x m(-3)) in 2008, whereas T1 had the highest seed cotton yield (4467 kg x hm(-2)) and the highest WUE (0.99 kg x m(-3)) in 2009. The averaged cumulative pan evaporation in 7 days and 10 days at squaring stage was 40-50 mm and 60-70 mm, respectively, and that in 7 days at blossoming-boll forming stage was 40-50 mm. It was suggested that in Xinjiang cotton area, irrigating 45 mm water for seedling emergence, no irrigation both at seedling stage and at boll opening stage, and irrigation was started when the pan evaporation reached 45-65 mm and 45 mm at squaring stage and blossoming-boll stage, respectively, the irrigating water quota could be determined by multiplying cumulative

  14. Employee Recognition and Performance: A Field Experiment

    NARCIS (Netherlands)

    C. Bradler (Christiane); A.J. Dur (Robert); S. Neckermann (Susanne); J.A. Non (Arjan)

    2013-01-01

    textabstractThis paper reports the results from a controlled field experiment designed to investigate the causal effect of public recognition on employee performance. We hired more than 300 employees to work on a three-hour data-entry task. In a random sample of work groups, workers unexpectedly

  15. Employee recognition and performance: A field experiment

    NARCIS (Netherlands)

    Bradler, C.; Dur, R.; Neckermann, S.; Non, J.A.

    2013-01-01

    This paper reports the results from a controlled field experiment designed to investigate the causal effect of public recognition on employee performance. We hired more than 300 employees to work on a three-hour data-entry task. In a random sample of work groups, workers unexpectedly received

  16. Random Assignment: Practical Considerations from Field Experiments.

    Science.gov (United States)

    Dunford, Franklyn W.

    1990-01-01

    Seven qualitative issues associated with randomization that have the potential to weaken or destroy otherwise sound experimental designs are reviewed and illustrated via actual field experiments. Issue areas include ethics and legality, liability risks, manipulation of randomized outcomes, hidden bias, design intrusiveness, case flow, and…

  17. Contribution to the improvement of irrigation management practices through water - deficit irrigation

    International Nuclear Information System (INIS)

    Bazza, M.

    1995-01-01

    The study aimed at identifying irrigation management practices which could result in water savings through -water deficit irrigation. Two field experiments, one on wheat and the other on sugar beet, were conducted and consisted of refraining from supplying water during specific stages of the cycle so as to identy the period(s) during which water deficit would have a limited effect on crop production. In the case of wheat, high water deficit occurred during the early and during these stages was the most beneficial for the crop. However, one water application during the tillering stage allowed the yield to be lower only to that of the treatement with three irrigations. Irrigation during the stage of grain filling caused the kernel weight to be as high as under three irrigations. The lowest value corresponded to the treatement with one irrigation during grain filling and that under rainfed conditions. For sugar beet, when water stress was was applied early in the crop cycle, its effect could be almost entirely recovered with adequate watering during the rest of the growing season. On the opposite, good watering early in cycle, followed by a stress, resulted in the second lowest yield. Water deficit during the maturity stage had also a limited effect on yield. The most crucial periods for adequate watering were which correspond to late filiar development and root growth which coincided with the highest water requirements period. For the same amount of water savings through deficit irrigation, it was better to partition the stress throughout the cycle than during the critical stages of the crop. However, at the national level, it would have been more important to practice deficit irrigation and the irrigated area. For both crops, high yields as high as water - use efficiency values could have been obtained. 8 tabs; 5 refs ( Author )

  18. Mapping cropping patterns in irrigated rice fields in West Java: Towards mapping vulnerability to flooding using time-series MODIS imageries

    Science.gov (United States)

    Sianturi, Riswan; Jetten, V. G.; Sartohadi, Junun

    2018-04-01

    Information on the vulnerability to flooding is vital to understand the potential damages from flood events. A method to determine the vulnerability to flooding in irrigated rice fields using the Enhanced Vegetation Index (EVI) was proposed in this study. In doing so, the time-series EVI derived from time-series 8 day 500 m spatial resolution MODIS imageries (MOD09A1) was used to generate cropping patterns in irrigated rice fields in West Java. Cropping patterns were derived from the spatial distribution and phenology metrics so that it is possible to show the variation of vulnerability in space and time. Vulnerability curves and cropping patterns were used to determine the vulnerability to flooding in irrigated rice fields. Cropping patterns capture the shift in the vulnerability, which may lead to either an increase or decrease of the degree of damage in rice fields of origin and other rice fields. The comparison of rice field areas between MOD09A1 and ALOS PALSAR and MOD09A1 and Agricultural Statistics showed consistent results with R2 = 0.81 and R2 = 0.93, respectively. The estimated and observed DOYs showed RMSEs = 9.21, 9.29, and 9.69 days for the Start of Season (SOS), heading stage, and End of Season (EOS), respectively. Using the method, one can estimate the relative damage provided available information on the flood depth and velocity. The results of the study may support the efforts to reduce the potential damages from flooding in irrigated rice fields.

  19. Soil treatment technologies: Comparison of field experiences

    International Nuclear Information System (INIS)

    Hodges, H.I.; Jackson, D.W.; Kline, K.

    1992-01-01

    A number of on-site soil treatment technologies are available for closure of oil-field waste pits, leaking underground storage tank (LUST) sites, and general hydrocarbon contamination. This paper will contrast Separation Systems Consultants, Inc.'s (SSCI's) field experiences with the following soil restoration techniques: (1) Land Treatment using indigenous microbes; (2) Land Farming using commercial microbes; (3) Low Temperature Thermal Treatment; (4) Solidification. The technologies will be contrasted in terms of regulatory constraints and requirements, key set-up and maintenance consideration, selection factors. Included in the regulatory contrast is the authors' perception of regulatory attitudes toward the techniques. Because this paper is based on actual field experience and projects, the practical aspects of making the technologies work is emphasized

  20. A regional field-based assessment of organic C sequestration and GHG balances in irrigated agriculture in Mediterranean semi-arid land

    Science.gov (United States)

    Virto, Inigo; Antón, Rodrigo; Arias, Nerea; Orcaray, Luis; Enrique, Alberto; Bescansa, Paloma

    2016-04-01

    In a context of global change and increasing food demand, agriculture faces the challenge of ensuring food security making a sustainable use of resources, especially arable land and water. This implies in many areas a transition towards agricultural systems with increased and stable productivity and a more efficient use of inputs. The introduction of irrigation is, within this framework, a widespread strategy. However, the C cycle and the net GHG emissions can be significantly affected by irrigation. The net effect of this change needs to be quantified at a regional scale. In the region of Navarra (NE Spain) more than 22,300 ha of rainfed agricultural land have been converted to irrigation in the last years, adding to the previous existing irrigated area of 70,000 ha. In this framework the project Life+ Regadiox (LIFE12 ENV/ES/000426, http://life-regadiox.es/) has the objective of evaluating the net GHG balances and atmospheric CO2 fixation rates of different management strategies in irrigated agriculture in the region. The project involved the identification of areas representative of the different pedocllimatic conditions in the region. This required soil and climate characterizations, and the design of a network of agricultural fields representative of the most common dryland and irrigation managements in these areas. This was done from available public datasets on climate and soil, and from soil pits especially sampled for this study. Two areas were then delimited, mostly based on their degree of aridity. Within each of those areas, fields were selected to allow for comparisons at three levels: (i) dryland vs irrigation, (ii) soil and crop management systems for non-permanent crops, and (iii) soil management strategies for permanent crops (namely olive orchards and vineyards). In a second step, the objective of this work was to quantify net SOC variations and GHG balances corresponding to the different managements identified in the previous step. These

  1. Games for groundwater governance: field experiments in Andhra Pradesh, India

    Directory of Open Access Journals (Sweden)

    Ruth Meinzen-Dick

    2016-09-01

    Full Text Available Groundwater is a common-pool resource that is subject to depletion in many places around the world as a result of increased use of irrigation and water-demanding cash crops. Where state capacity to control groundwater use is limited, collective action is important to increase recharge and restrict highly water-consumptive crops. We present results of field experiments in hard rock areas of Andhra Pradesh, India, to examine factors affecting groundwater use. Two nongovernmental organizations (NGOs ran the games in communities where they were working to improve watershed and water management. Results indicate that, when the links between crop choice and groundwater depletion is made explicit, farmers can act cooperatively to address this problem. Longer NGO involvement in the villages was associated with more cooperative outcomes in the games. Individuals with more education and higher perceived community social capital played more cooperatively, but neither gender nor method of payment had a significantly effect on individual behavior. When participants could repeat the game with communication, similar crop choice patterns were observed. The games provided an entry point for discussion on the understanding of communities of the interconnectedness of groundwater use and crop choice.

  2. Clay pot irrigation for tomato (Lycopersicon esculentum Mill production in the north east semiarid region of Ethiopia

    Directory of Open Access Journals (Sweden)

    Kebede Woldetsadik

    2011-06-01

    Full Text Available Water shortage is one of the major constraints for production of horticultural crops in arid and semiarid regions. A field experiment was conducted to determine irrigation water and fertilizer use efficiency, growth and yield of tomato under clay pot irrigation at the experimental site of Sekota Dryland Agricultural Research Center, Lalibela, Ethiopia in 2009/10. The experiment comprised of five treatments including furrow irrigated control and clay pot irrigation with different plant population and fertilization methods, which were arranged in Randomized Complete Block Design with three replications. The highest total and marketable fruit yields were obtained from clay pot irrigation combined with application of nitrogen fertilizer with irrigation water irrespective of difference in plant population. The clay pot irrigation had seasonal water use of up to 143.71 mm, which resulted in significantly higher water use efficiency (33.62 kg m-3 as compared to the furrow irrigation, which had a seasonal water use of 485.50 mm, and a water use efficiency of 6.67 kg m-3. Application of nitrogen fertilizer with irrigation water in clay pots improved fertilizer use efficiency of tomato by up to 52% than band application with furrow or clay pot irrigation. Thus, clay pot irrigation with 33,333 plants ha-1 and nitrogen fertilizer application with irrigation water in clay pots was the best method for increasing the yield of tomato while economizing the use of water and nitrogen fertilizer in a semiarid environment.

  3. The Impact of Regular and Periodic Irrigation on the Fertility and Productivity of an Ordinary Chernozem of the Azov Irrigation System

    Science.gov (United States)

    Shchedrin, V. N.

    2016-02-01

    The effect of regular and periodic irrigation on the fertility and productivity of an ordinary chernozem cultivated under different conditions within the same cereal-fodder crop rotation is discussed. The investigation object is located in the area of the Azov irrigation system on the second terrace of the Don River in Rostov oblast. Irrigation water for the system is taken from the Veselovsk water reservoir. Its salinity is 1.7-2.1 g/dm3, and the salt composition is sulfate-sodium. The field experiments were performed in 2006-2013 on three experimental plots. Two of them were regularly irrigated; the third plot was periodically irrigated with alternation of 2-year-long periods with and without irrigation. Our study proved that periodic irrigation could be applied in the chernozemic zone. This new irrigation mode contributes to the preservation of the natural soil-forming process and stops the development of unfavorable processes typical of the lands irrigated with water of inadequate quality. In eight years of cultivation of the ordinary chernozem with periodic irrigation, the soil humus content increased by 10% (from 3.80 to 4.15%), and the yield reached 66.0 t/ha of fodder units. This was 9% higher than the yield obtained upon regular irrigation without agroameliorative measures and 12% lower than the yield upon regular irrigation in combination with soil-protective measures. Our data suggest that periodic irrigation is promising for the chernozemic zone, because it ensures lower water loads and preservation of the irrigated chernozems.

  4. Production of mungbean under reclaimed sandy soil and irrigation levels using N-15 labeled

    International Nuclear Information System (INIS)

    Abdallah, A.A.G.; Thabet, E.M.A.

    2000-01-01

    Field experiment were performed at the Atomic Energy Authority, Experimental farm, Inshas, Egypt. During 1998 growing season. In tafla and sand mixture soil (1:7 Wt./Wt.). The treatments were laid out using a single line source sprinkler irrigation system which allows a gradual variation of irrigation from excess to little irrigation in which the calculated amount of irrigation water levels were 2241, 1562 and 1093 m 3 / feddan (W 1 , W 2 and W 3 ). The obtained results indicated that, there was a clear relationship between adequate amount of irrigation water and both total seed yield and total green pods/plot as well as there were significant increase in both characters due to irrigation W 1 and W 2 compared with W 3 . The results also indicated that W 2 irrigation level could be used in irrigation under the same conditions. Water use efficiency was significantly increased with middle irrigation level than with other two irrigation treatments. The result concerned fertilizer use efficiency using N 15 labeled fertilizers and total seed protein content were increased with decreasing irrigation level

  5. Population dynamics and breeding patterns of multimammate mouse, Mastomys natalensis (Smith 1834), in irrigated rice fields in eastern Tanzania.

    Science.gov (United States)

    Mulungu, Loth S; Ngowo, Victoria; Mdangi, Mashaka; Katakweba, Abdul S; Tesha, Protas; Mrosso, Furaha P; Mchomvu, Mary; Sheyo, Paul M; Kilonzo, Bukhet S

    2013-03-01

    Multimammate mice are the most important vertebrate pests in Sub-Saharan Africa and are also reservoirs of many zoonotic diseases, including sylvan plague. This study investigated the population dynamics and breeding patterns of this mouse in irrigated rice cropping systems in eastern Tanzania. The multimammate mouse, Mastomys natalensis, population varied with habitat and months. Fallow land had a more abundant population than rice fields. The highest population peak was observed during the dry season from July to October. Mastomys natalensis is sexually active throughout the year in the study area, although it reaches the highest level in June and December when rice is at the maturity stage. This suggests that breeding is highly influenced by the presence of a rice crop in both seasons. More juvenile individuals were recorded in August and September, indicating that they were produced in the previous breeding months. The sex ratio of M. natalensis was not skewed to either males or females, indicating that it was at parity. Rodent population dynamics during the study periods in all habitats indicated that high birth rates accounted for the rapid population growth and turnover. Regular control and sustainable operations are thus essential if rodent pest populations are to be kept within tolerable limits. Copyright © 2012 Society of Chemical Industry.

  6. Effects of seed size and aging on field performance of lentil (Lens culinaris Medik. under different irrigation treatments

    Directory of Open Access Journals (Sweden)

    Kazem GHASSEMI-GOLEZANI

    2015-12-01

    Full Text Available A sub-sample of lentil (Lens culinaris ‘Kimia’ seeds was kept as bulk (S1 and another sample was separated to large (S2 and small (S3 seeds. A sub-sample of each size was kept as control or high vigor seed lot (A1 and the two other sub-samples were artificially aged for 2 and 4 days (A2 and A3, respectively. Field performance of these seeds was evaluated during 2011 and 2012. Yield components and grain yield of lentil decreased with decreasing water availability. The highest yield components (except 1000 grain weight and grain yield per unit area were obtained by plants from large seeds. The superiority of plants from large seeds in grain yield was more evident under limited irrigations than under well watering. Seed aging resulted in poor stand establishment and consequently low grain yield per unit area. Plants from aged large seeds showed the lowest reduction in grain yield per unit area, compared with those from aged small and bulk seeds. It seems that cultivation of large seeds somehow can reduce the deleterious effects of drought stress and seed aging on grain yield per unit area of lentil.

  7. Effects of waste water irrigation on soil properties and soil fauna of spinach fields in a West African urban vegetable production system.

    Science.gov (United States)

    Stenchly, Kathrin; Dao, Juliane; Lompo, Désiré Jean-Pascal; Buerkert, Andreas

    2017-03-01

    The usage of inadequately processed industrial waste water (WW) can lead to strong soil alkalinity and soil salinization of agricultural fields with negative consequences on soil properties and biota. Gypsum as a soil amendment to saline-sodic soils is widely used in agricultural fields to improve their soil physical, chemical and hence biological properties. This study aimed at analysing the effects of intensive WW irrigation on the structure and composition of soil-dwelling arthropods on spinach fields (Spinacia oleracea L.) in a West African urban vegetable production system. We used gypsum as a soil amendment with the potential to alleviate soil chemical stress resulting in a potentially positive impact on soil arthropods. A total of 32 plots were established that showed a gradient in soil pH ranging from slight to strong soil alkalinity and that were irrigated with WW (n = 12) or clean water (CW; n = 20), including eight plots into which gypsum was incorporated. Our study revealed a high tolerance of soil-dwelling arthropods for alkaline soils, but spinach fields with increased soil electrical conductivity (EC) showed a reduced abundance of Hymenoptera, Diptera and Auchenorrhyncha. Arthropod abundance was positively related to a dense spinach cover that in turn was not affected by WW irrigation or soil properties. Gypsum application reduced soil pH but increased soil EC. WW irrigation and related soil pH affected arthropod composition in the investigated spinach fields which may lead to negative effects on agronomical important arthropod groups such as pollinators and predators. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Utilizing Urban Environments for Effective Field Experiences

    Science.gov (United States)

    MacAvoy, S. E.; Knee, K.

    2014-12-01

    Research surveys suggest that students are demanding more applied field experiences from their undergraduate environmental science programs. For geoscience educators at liberal arts colleges without field camps, university vehicles, or even geology departments, getting students into the field is especially rewarding - and especially challenging. Here, we present strategies that we have used in courses ranging from introductory environmental science for non-majors, to upper level environmental methods and geology classes. Urban locations provide an opportunity for a different type of local "field-work" than would otherwise be available. In the upper-level undergraduate Environmental Methods class, we relied on a National Park area located a 10-minute walk from campus for most field exercises. Activities included soil analysis, measuring stream flow and water quality parameters, dendrochronology, and aquatic microbe metabolism. In the non-majors class, we make use of our urban location to contrast water quality in parks and highly channelized urban streams. Here we share detailed lesson plans and budgets for field activities that can be completed during a class period of 2.5 hours with a $75 course fee, show how these activities help students gain quantitative competency, and provide student feedback about the classes and activities.

  9. Employee Recognition and Performance: A Field Experiment

    OpenAIRE

    Bradler, Christiane; Dur, Robert; Neckermann, Susanne; Non, Arjan

    2014-01-01

    This discussion paper led to a publication in 'Management Science' . This paper reports the results from a controlled field experiment designed to investigate the causal effect of unannounced, public recognition on employee performance. We hired more than 300 employees to work on a three-hour data-entry task. In a random sample of work groups, workers unexpectedly received recognition after two hours of work. We find that recognition increases subsequent performance substantially, and particu...

  10. Water economy in the irrigation of family farmland in arid zones

    International Nuclear Information System (INIS)

    Mhiri, A.; Elloumi, M.J.; Laouini, M.

    1983-01-01

    A simple irrigation technique based on the use of polyethylene bags was developed and tested so as to achieve maximum water economy in family-scale farming in arid zones. It simulates localized irrigation and eliminates water losses due to evaporation and drainage. The method was tried out in the cultivation of tomatoes in glasshouses. In comparison with the control experiment in the field with furrow irrigation, the saving of water was 60%, with a 30% drop in production. There was thus a net improvement in efficiency in the utilization of the irrigation water. (author)

  11. The FIELDS experiment for Solar Probe Plus

    Science.gov (United States)

    Bale, S.; Spp/Fields Team

    2010-12-01

    Many of our basic ideas on the plasma physics of acceleration, energy flow, and dissipation, and structure of the solar wind have never been rigorously confronted by direct experimental measurements in the region where these processes are actually occurring. Although Alfven waves, shocks, and magnetic reconnection are often invoked as heating mechanisms, there have never been any direct measurements of Alfvenic waves nor the associated Poynting flux nor any measurements of ion or electron kinetic energy flux in the region from 10 R_s to 30 R_s where the final stages of wind acceleration are believed to occur. The radial profiles of both slow and fast solar wind acceleration are based on remote-sensing measurements and have been obtained for only a few selected events. Thus, the spatial radial and perpendicular scales of the acceleration process have been averaged by line-of-sight effects and the possibility of intense localized acceleration cannot be ruled out. The Solar Probe Plus (SPP) mission calls for the high quality fields and particles measurements required to solve the coronal heating and wind acceleration problem. The SPP 'FIELDS' experiment measures the electric and magnetic fields fundamental to the plasma physics of the structured and turbulent solar wind, flux ropes, collisionless shocks, and magnetic reconnection. FIELDS will make the first-ever measurements of the DC/Low-Frequency electric field inside of 1 AU allowing for in situ, high cadence measurements of the Poynting vector, the Elsasser variables, and E/B diagnostics of the wave spectrum to fce in the solar wind. SPP/FIELDS measures the radio wave (type III and II) signatures of microflares, energized electrons, and CME propagation. SPP/ FIELDS measures the plasma electron density to ~2% accuracy and the core electron temperature to ~5-10% accuracy more than 90% of the time at perihelion. FIELDS will also measure the in situ density fluctuation spectrum and structures at a very high cadence (

  12. Field accumulation risks of heavy metals in soil and vegetable crop irrigated with sewage water in western region of Saudi Arabia

    Science.gov (United States)

    Balkhair, Khaled S.; Ashraf, Muhammad Aqeel

    2015-01-01

    Wastewater irrigated fields can cause potential contamination with heavy metals to soil and groundwater, thus pose a threat to human beings . The current study was designed to investigate the potential human health risks associated with the consumption of okra vegetable crop contaminated with toxic heavy metals. The crop was grown on a soil irrigated with treated wastewater in the western region of Saudi Arabia during 2010 and 2011. The monitored heavy metals included Cd, Cr, Cu, Pb and Zn for their bioaccumulation factors to provide baseline data regarding environmental safety and the suitability of sewage irrigation in the future. The pollution load index (PLI), enrichment factor (EF) and contamination factor (CF) of these metals were calculated. The pollution load index of the studied soils indicated their level of metal contamination. The concentrations of Ni, Pb, Cd and Cr in the edible portions were above the safe limit in 90%, 28%, 83% and 63% of the samples, respectively. The heavy metals in the edible portions were as follows: Cr > Zn > Ni > Cd > Mn > Pb > Cu > Fe. The Health Risk Index (HRI) was >1 indicating a potential health risk. The EF values designated an enhanced bio-contamination compared to other reports from Saudi Arabia and other countries around the world. The results indicated a potential pathway of human exposure to slow poisoning by heavy metals due to the indirect utilization of vegetables grown on heavy metal-contaminated soil that was irrigated by contaminated water sources. The okra tested was not safe for human use, especially for direct consumption by human beings. The irrigation source was identified as the source of the soil pollution in this study. PMID:26858563

  13. Examining professionals' and parents' views of using transanal irrigation with children: Understanding their experiences to develop a shared health resource for education and practise.

    Science.gov (United States)

    Sanders, Caroline; Bray, Lucy

    2014-06-01

    Irrigation as a bowel management approach has been reportedly used with children for more than 20 years. Parents managing their child's chronic bowel problem have previously been shown to have increased emotional stress. The aim of this study was to explore professionals' (n = 24) understanding and parents' (n = 18) experiences of using transanal irrigation with children at home as a mid to longer term bowel management approach. This study was underpinned by action research methodology and used mixed methods determined by an action research group of parents, professionals, researchers, a voluntary sector worker, commercial representative and independent observer. Data informed the study outcome which was the development and evaluation of a shared health resource to support professionals in their holistic approach when prescribing transanal irrigation and guide parents in the areas of education, management, problem solving, support and goal setting. The resource includes constructed case studies from parents of their experiences to inform choice and decision-making between parents and professionals. The shared health resource provides an approach to initiating and evaluating transanal irrigation and is available in a paper format from key Internet sites across hospital, community and voluntary services. © The Author(s) 2013.

  14. Effect of irrigation frequency and application levels of sulphur ...

    African Journals Online (AJOL)

    A field experiment was conducted at Indian Agricultural Research Institute, New Delhi during the crop season of 2007 to 2008 and 2008 to 2009 to study the effect of irrigation and sulphur on yield and water use efficiency of Indian mustard (Brassica juncea var. PusaJagannath). The experiment was carried out in split plot ...

  15. Across the Arctic Teachers Experience Field Research

    Science.gov (United States)

    Warnick, W. K.; Warburton, J.; Wiggins, H. V.; Marshall, S. A.; Darby, D. A.

    2005-12-01

    From studying snow geese on the North Slope of Alaska to sediment coring aboard the U.S. Coast Guard Cutter Healy in the Arctic Ocean, K-12 teachers embark on scientific expeditions as part of a program that strives to make science in the Arctic a "virtual" reality. In the past two years, seventeen K-12 teachers have participated in Teachers and Researchers Exploring and Collaborating (TREC), a program that pairs teachers with researchers to improve science education through arctic field experiences. TREC builds on the scientific and cultural opportunities of the Arctic, linking research and education through topics that naturally engage students and the wider public. TREC includes expeditions as diverse as studying plants at Toolik Field Station, a research facility located 150 miles above the Arctic Circle; climate change studies in Norway's Svalbard archipelago; studying rivers in Siberia; or a trans-arctic expedition aboard the USCGC Healy collecting an integrated geophysical data set. Funded by the National Science Foundation Office of Polar Programs, TREC offers educators experiences in scientific inquiry while encouraging the public and students to become active participants in the scientific inquiry by engaging them virtually in arctic research. TREC uses online outreach elements to convey the research experience to a broad audience. While in remote field locations, teachers and researchers interact with students and the public through online seminars and live calls from the field, online journals with accompanying photos, and online bulletin boards. Since the program's inception in 2004, numerous visitors have posted questions or interacted with teachers, researchers, and students through the TREC website (http://www.arcus.org/trec). TREC teachers are required to transfer their experience of research and current science into their classroom through the development of relevant activities and resources. Teachers and researchers are encouraged to participate

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

    Science.gov (United States)

    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.

  17. ¹³⁷Cs in irrigation water and its effect on paddy fields in Japan after the Fukushima nuclear accident.

    Science.gov (United States)

    Yoshikawa, Natsuki; Obara, Hitomi; Ogasa, Marie; Miyazu, Susumu; Harada, Naoki; Nonaka, Masanori

    2014-05-15

    There is concern that radiocesium deposited in the environment after the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 will migrate to paddy fields through hydrological pathways and cause serious and long-lasting damage to the agricultural activities. This study was conducted in the Towa region of Nihonmatsu in the northern part of Fukushima Prefecture, Japan, (1) to quantify (137)Cs in stream water used to irrigate paddy fields by separating the dissolved and particulate components in water samples and then fractionating the particulate components bonded in different ways using a sequential extraction procedure, and (2) to determine the amounts of radiocesium newly added to paddy fields in irrigation water relative to the amounts of radiocesium already present in the fields from the deposition of atmospheric fallout immediately after the FDNPP accident. Three catchments were studied, and the (137)Cs activity concentrations in stream water samples were 79-198 mBq L(-1) under stable runoff conditions and 702-13,400 Bq L(-1) under storm runoff conditions. The residual fraction (F4, considered to be non-bioavailable) was dominant, accounting for 59.5-82.6% of the total (137)Cs activity under stable runoff conditions and 69.4-95.1% under storm runoff conditions. The (137)Cs newly added to paddy fields in irrigation water only contributed 0.03-0.05% of the amount already present in the soil (201-348 kBq m(-2)). This indicates that the (137)Cs inflow load in irrigation water is negligible compared with that already in the soil. However, the contribution from the potentially bioavailable fractions (F1+F2+F3) was one order of magnitude larger, accounting for 0.20-0.59%. The increase in the dissolved and soluble radiocesium fraction (F1) was especially large (3.0% to infinity), suggesting that radiocesium migration in irrigation water is increasing the accumulation of radiocesium in rice. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Irrigation water policy analysis using a business simulation game

    Science.gov (United States)

    Buchholz, M.; Holst, G.; Musshoff, O.

    2016-10-01

    Despite numerous studies on farmers' responses to changing irrigation water policies, uncertainties remain about the potential of water pricing schemes and water quotas to reduce irrigation. Thus far, policy impact analysis is predominantly based upon rational choice models that assume behavioral assumptions, such as a perfectly rational profit-maximizing decision maker. Also, econometric techniques are applied which could lack internal validity due to uncontrolled field data. Furthermore, such techniques are not capable of identifying ill-designed policies prior to their implementation. With this in mind, we apply a business simulation game for ex ante policy impact analysis of irrigation water policies at the farm level. Our approach has the potential to reveal the policy-induced behavioral change of the participants in a controlled environment. To do so, we investigate how real farmers from Germany, in an economic experiment, respond to a water pricing scheme and a water quota intending to reduce irrigation. In the business simulation game, the participants manage a "virtual" cash-crop farm for which they make crop allocation and irrigation decisions during several production periods, while facing uncertain product prices and weather conditions. The results reveal that a water quota is able to reduce mean irrigation applications, while a water pricing scheme does not have an impact, even though both policies exhibit equal income effects for the farmers. However, both policies appear to increase the variation of irrigation applications. Compared to a perfectly rational profit-maximizing decision maker, the participants apply less irrigation on average, both when irrigation is not restricted and when a water pricing scheme applies. Moreover, the participants' risk attitude affects the irrigation decisions.

  19. Organic fertilizer application increases the soil respiration and net ecosystem carbon dioxide absorption of paddy fields under water-saving irrigation.

    Science.gov (United States)

    Yang, Shihong; Xiao, Ya Nan; Xu, Junzeng

    2018-04-01

    Quantifying carbon sequestration in paddy soil is necessary to understand the effect of agricultural practices on carbon cycles. The objective of this study was to assess the effect of organic fertilizer addition (MF) on the soil respiration and net ecosystem carbon dioxide (CO 2 ) absorption of paddy fields under water-saving irrigation (CI) in the Taihu Lake Region of China during the 2014 and 2015 rice-growing seasons. Compared with the traditional fertilizer and water management (FC), the joint regulation of CI and MF (CM) significantly increased the rice yields and irrigation water use efficiencies of paddy fields by 4.02~5.08 and 83.54~109.97% (p < 0.05). The effects of organic fertilizer addition on soil respiration and net ecosystem CO 2 absorption rates showed inter-annual differences. CM paddy fields showed a higher soil respiration and net CO 2 absorption rates during some periods of the rice growth stage in the first year and during most periods of the rice growth stage in the second year. These fields also had significantly higher total CO 2 emission through soil respiration (total R soil ) and total net CO 2 absorption compared with FC paddy fields (p < 0.05). The total R soil and net ecosystem CO 2 absorption of CM paddy fields were 67.39~91.55 and 129.41~113.75 mol m -2 , which were 27.66~135.52 and 12.96~31.66% higher than those of FC paddy fields. The interaction between water and fertilizer management had significant effects on total net ecosystem CO 2 absorption. The frequent alternate wet-dry cycles of CI paddy fields increased the soil respiration and reduced the net CO 2 absorption. Organic fertilizer promoted the soil respiration of paddy soil but also increased its net CO 2 absorption and organic carbon content. Therefore, the joint regulation of water-saving irrigation and organic fertilizer is an effective measure for maintaining yield, increasing irrigation water use efficiency, mitigating CO 2 emission, and promoting paddy

  20. Improving efficiencies of irrigation and nitrogen uptake in wheat

    International Nuclear Information System (INIS)

    Bazza, M.

    2000-01-01

    Three years of field studies and lysimeter experiments on irrigated wheat had the objective of finding ways of managing irrigation and N fertilization to minimize losses and reduce contamination of groundwater. Applied N had significant positive effects on crop-water consumptive use. The highest N losses occurred during early growth. Irrigation had little effect on N loss when it was practiced efficiently. Under the prevailing conditions, it is recommended that no N be applied to wheat at planting, in order to limit N losses by leaching caused by the high precipitation that usually occurs during early development when crop-N requirements are small. No more than 120 kg N ha -1 should be applied in total to minimize groundwater pollution and maximize N-uptake efficiency and economic returns. Also, for economic and environmental reasons, irrigation should be limited to 80% of the total requirement and to depths of 40 to 60 mm. (author)

  1. Effects of different irrigation methods on pepper yield and soilborne diseases incidence

    Directory of Open Access Journals (Sweden)

    Seral YÜCEL

    2013-12-01

    Full Text Available In this study, the effect of different irrigation strategies and irrigation methods on yields and the incidence of wilt (Fusarium oxysporum and root rot (Fusarium solani and Macrophomina phaseolina diseases causing significant yield losses on field grown processing red pepper is determined. Experiments were carried out at Topçu Station of the Soil and Water Resources Research Institute of Tarsus in 2010 and 2011. Karaisalı processing pepper (Capsicum annuum L. was used in the experiments. Three furrows and five drip irrigation treatments were used in the study. The disease incidence rates were found 8.0-18.2% in furrow irrigation plots and 4.5-10.0% in drip irrigation plots in 2010, while it was 3.4-9.7% in furrow irrigation plots and 2.2-4.5% in drip irrigation plots in 2011. Pepper yields ranged from 3 416 to 4 417 kg da-1 and 3 376 to 4 779 kg da-1 in drip irrigated plots in 2010 and 2011, respectively. However, yields varied between 3 172-3 559 kg da-1 and 2 932-4 150 kg da-1 in furrow irrigated plots in 2010 and 2011 growing seasons.

  2. Content Of 2,4-D-14C Herbicide Residue In Water And Soil Of Irrigated Rice Field System

    International Nuclear Information System (INIS)

    Chairul, Sofnie M.; Djabir, Elida; Magdalena, Nelly

    2000-01-01

    The investigation of 2,4-D exp.-14C herbicide residue in water and soil of irrigated rice field system was carried out. Rice plant and weeds (Monochoria vaginalis Burn. F. Presl) were planted in 101 buckets using two kinds of soil condition, I.e. normal soil and 30 % above normal compact soil. After one week planting, the plants were sprayed with 1 u Ci of 2,4-D exp.-14C and 0,4 mg non labeled 2,4-D. The herbicide residue content was determined 0, 2, 4, 8 and 10 weeks after spraying with 2,4-D herbicide. The analysis was done using Combustion Biological Oxidizer merk Harvey ox-400, and counted with Liquid Scintillation Counter merk Beckman model LS-1801. The results indicates that the herbicide contents in water and soil decrease from the first spraying with herbicide until harvest herbicide Residue content in water after harvest was 0.87 x 10 exp.-6 ppm for soil normal condition, and 0.59 x 10 exp.-6 pm for the soil 30 % up normal condition, while herbicide content in soil was 1.54 x 10 exp.-6 ppm for soil normal condition and 1.48 x 10 exp.-6 ppm for soil 30 % up normal. 2,4-D herbicide residue content in rice after harvest was 0.27 x 10 exp.-6 ppm for normal soil condition and 0.25 x 10 exp.-6 ppm for the soil 30 % up normal. 2,4-D herbicide residue content in roots and leaves of weeds after harvest were respectively 0.29 x 10 exp.-6 ppm and 0.18 x 10 exp.-6 for normal soil condition, while for 30 % up normal soil were 0.25 x 10 exp.-5 ppm and 0.63 x 10 exp.-7 ppm. This result indicates that there is no effect pollution to surrounding area, because the herbicide content is still bellow the allowed detection limit, 0.05 ppm

  3. Effect of different drip irrigation regimes on yield and oil quality of sunflower

    Directory of Open Access Journals (Sweden)

    Semih Metin SEZEN

    2016-06-01

    Full Text Available This study examines the effects of different irrigation regimes on yield, yield components, oil yield and quality and water use of sunflower (Oleko variety irrigated with a drip system under field conditions in 2010 and 2011 growing seasons at the Alata Horticultural Research Institute, Tarsus Soil and Water Resources area in the Mediterranean region of Turkey. Irrigation regimes consisted of three irrigation intervals (A1:= 25 mm; A2:= 50 mm; A3: = 75 mm of cumulative pan evaporation and six irrigation levels (I1=0.50, I2=0.75, I3=1.00 and I4=1.25. In addition, I5=PRD75 and I6=PRD50 treatments were considered. They received 75 and 50% of the full irrigation (I3 treatment from alternative laterals, respectively. Also, rainfed treatment is a control plot in the experiment. Maximum and minimum yields were obtained from the A2I4 and rainfed treatments, respectively in all experimental years. As the irrigation level value decreased the total yields in each irrigation interval also decreased. Seasonal irrigation amounts in the treatments varied from 199 mm to 563 mm in the experimental years. Seasonal evapotranspiration values in the treatments varied from 243 mm to 611 mm in the experimental years. Both irrigation amounts and irrigation frequencies had significantly effects on oil content of sunflower. The saturated (palmitic and stearic acid and unsaturated (oleic and linoleic acid fatty acid contents were significantly affected by water stress. In conclusion, A2I4 irrigation regime is recommended for sunflower production in the Mediterranean region in order to attain higher yields with improved quality. In case of water shortage, A2I13 irrigation regime is recommended to increase sunflower yield and quality.

  4. Field evaluation of urea fertilizer and water use efficiency by tomato under trickle fertigation and furrow irrigation in the Islamic Republic of Iran

    International Nuclear Information System (INIS)

    Sagheb, N.; Hobbi, M.S.

    2002-01-01

    Urea fertilizer and water use efficiency by tomato (Early Urbana VF) were studied in a sandy loam soil, comparing trickle fertigation and conventional furrow irrigation -- band fertilization systems. During the period of 1995-1998, a conventional treatment, NS, with band application of 50, 150 and 100 kg N as urea, P as diammonium phosphate and K as potassium sulfate respectively was carried out. The average concentration of N in the total irrigation water was 0, 38, 76 and 114 mg/L for the N0, N1, N2 and N3 fertigation treatments, respectively. All fertigation treatments also received equally 24 and 16 mg/L P and K, respectively. An increase of K for the conventional treatment to 1200 kg/ha in 1998 coincided with the increase of the same element to 190 mg/L for the trickle irrigated treatments. To evaluate the urea-N use efficiency, the plants of isotope subplots received 2% 15 N a.e. urea. The soil moisture in all treatments was measured by the neutron moisture gauge. During the first 3 years of experimentation there was no significant difference between the yields of the treatments. For the years 1995 through 1997 the average tomato yield was low in comparison to the yield shown in most reports. The yield variance among treatments and years was negligible. The highest fruit yield, 27.3 t/ha for the N1 treatment was observed in 1997. In this experiment, the low yield and urea-N use efficiency can be primarily attributed to unbalanced applied fertilizers in the trickle irrigation system. The highest urea-N use efficiency was 12.3% for the fertigation N1 treatment in 1997. In the 1998, a repetition of the experiment with increasing K rates for all treatments at the same experimental site, led to a considerable increase in yield and urea-N use efficiency as compared to previous years. The tomato fresh fruit yield attained for N0, N1, N2, N3 and NS respectively 84, 76, 69, 36 and 26 t/ha. Based on the 14N/15N ratio analysis of the dry matter the urea-N use efficiency

  5. Magnetic field experiment on the SUNSAT satellite

    Science.gov (United States)

    Kotzé, P. B.; Langenhoven, B.; Risbo, T.

    2002-03-01

    On Tuesday 23 February 1999, at 10:29 UTC, SUNSAT was launched into an 857×655 km, 96.47° polar orbit on a Boeing-Delta II rocket from Vandenberg Air Force Base in California, USA. Both SUNSAT and Ørsted were NASA-sponsored secondary payloads accompanying the USA Air Force Argos satellite. In the process it became South Africa's (and Africa's) first satellite in space. Although sponsored by several private industrial organisations, it is essentially a student project with more than 96 graduate students in the Department of Electronic and Electrical Engineering at the University of Stellenbosch providing the majority of SUNSAT's engineering development and operation since 1992. This paper reports on the magnetic field experiment on board the Sunsat satellite, consisting of two fluxgate magnetometers, called Orimag and Scimag, both built and calibrated by the Hermanus Magnetic Observatory. Orimag is mainly used for orientation control purposes on SUNSAT, while Scimag, mounted on a boom of 2.2 m is designed to perform geomagnetic field observations, employing standard navigation fluxgate technology.

  6. Effect of Supplementary Irrigation on Yield, Yield Components and Protein Percentages of Chickpea Cultivars in Ilam, Iran

    Directory of Open Access Journals (Sweden)

    A. Maleki

    2012-01-01

    Full Text Available In order to study the effect of supplementary irrigation on yield, yield components and protein percentages of three cultivars of chickpea an experiment carried out as split plot, based on randomized complete blocks design, with three replications in Ilam, in 2009-2010 growing season. Irrigation treatments were: control, without irrigation (I0, irrigation at the stage of %50 blooming, irrigation at the stage of %50 flowering, irrigation at the stage of pods filling, which were allocated to main plots and genotypes, ILC482, Filip93-93 and local variety to sub plots. Irrigation treatments had significantly effect on seed and biological yields, harvest index, pod numbers per plant, seed numbers per pod and 100 seed weight. The Filip93-93 produced highest (1140.51 kg/ha and the local variety lowest seed yields (1056.98 kg/ha.Irrigation at the stage of pod filling and blooming increased by seed yield %41.3 and %29.3 respectively as  compared to control .Irrigation at the pod filling period produced the highest seed yield. The Filip93-93 produced highest yield (1263.31 kg/ha when the field irrigated at pod filling stage and the local variety at control treatment (without irrigation the lowest seed yield (893.26 kg/ha.

  7. Cultural adaptation in translational research: field experiences.

    Science.gov (United States)

    Dévieux, Jessy G; Malow, Robert M; Rosenberg, Rhonda; Jean-Gilles, Michèle; Samuels, Deanne; Ergon-Pérez, Emma; Jacobs, Robin

    2005-06-01

    The increase in the incidence of HIV/AIDS among minorities in the United States and in certain developing nations has prompted new intervention priorities, stressing the adaptation of efficacious interventions for diverse and marginalized groups. The experiences of Florida International University's AIDS Prevention Program in translating HIV primary and secondary prevention interventions among these multicultural populations provide insight into the process of cultural adaptations and address the new scientific emphasis on ecological validity. An iterative process involving forward and backward translation, a cultural linguistic committee, focus group discussions, documentation of project procedures, and consultations with other researchers in the field was used to modify interventions. This article presents strategies used to ensure fidelity in implementing the efficacious core components of evidence-based interventions for reducing HIV transmission and drug use behaviors and the challenges posed by making cultural adaptation for participants with low literacy. This experience demonstrates the importance of integrating culturally relevant material in the translation process with intense focus on language and nuance. The process must ensure that the level of intervention is appropriate for the educational level of participants. Furthermore, the rights of participants must be protected during consenting procedures by instituting policies that recognize the socioeconomic, educational, and systemic pressures to participate in research.

  8. [Influences of micro-irrigation and subsoiling before planting on enzyme activity in soil rhizosphere and summer maize yield.

    Science.gov (United States)

    Zhang, Ming Zhi; Niu, Wen Quan; Xu, Jian; Li, Yuan

    2016-06-01

    In order to explore the influences of micro-irrigation and subsoiling before planting on enzyme activity in soil rhizosphere and summer maize yield, an orthogonal experiment was carried out with three factors of micro-irrigation method, irrigation depth, and subsoiling depth. The factor of irrigation method included surface drip irrigation, subsurface drip irrigation, and moistube-irrigation; three levels of irrigation depth were obtained by controlling the lower limit of soil water content to 50%, 65%, and 80% of field holding capacity, respectively; and three depths of deep subsoiling were 20, 40, and 60 cm. The results showed that the activities of catalase and urease increased first and then decreased, while the activity of phosphatase followed an opposite trend in the growth season of summer maize. Compared with surface drip irrigation and moistube-irrigation, subsurface drip irrigation increased the average soil moisture of 0-80 cm layer by 6.3% and 1.8% in the growth season, respectively. Subsurface drip irrigation could significantly increase soil urease activity, roots volume, and yield of summer maize. With the increase of irrigation level, soil phosphatase activity decreased first and then increased, while urease activity and yield increased first and then decreased. The average soil moisture and root volume all increased in the growth season of summer maize. The increments of yield and root volume from subsoiling of 40 to 20 cm were greater than those from 60 to 40 cm. The highest enzyme activity was obtained with the treatment of subsoiling of 40 cm. In terms of improving water resource use efficiency, nitrogen use efficiency, and crop yield, the best management strategy of summer maize was the combination of subsurface drip irrigation, controlling the lower limit of soil water content to 65% of field holding capacity, and 40 cm subsoiling before planting.

  9. Influence of irrigation during the growth stage on yield and quality in mango (Mangifera indica L).

    Science.gov (United States)

    Wei, Junya; Liu, Guoyin; Liu, Debing; Chen, Yeyuan

    2017-01-01

    Although being one of the few drought-tolerant plants, mango trees are irrigated to ensure optimum and consistent productivity in China. In order to better understand the effects of soil water content on mango yield and fruit quality at fruit growth stage, irrigation experiments were investigated and the object was to determine the soil water content criteria at which growth and quality of mango would be optimal based on soil water measured by RHD-JS water-saving irrigation system through micro-sprinkling irrigation. Five soil water content treatments (relative to the percentage of field water capacity) for irrigation (T1:79%-82%, T2:75%-78%, T3:71%-74%, T4: 65%-70%, T5:63%-66%) were compared in 2013. Amount of applied irrigation water for different treatments varied from 2.93m3 to 1.08 m3. The results showed that mango fruit production and quality at fruit growth stage were significantly affected under different irrigation water amounts. Variation in soil water content not only had effects on fruit size, but also on fruit yield. The highest fruit yield and irrigation water use efficiency were obtained from the T4 treatment. Irrigation water amount also affected fruit quality parameters like fruit total soluble solids, soluble sugar, starch, titratable acid and vitamin C content. Comprehensive evaluation of the effect of indexs of correlation on irrigation treatment by subordinate function showed that when the soil moisture content were controlled at about 65-70% of the field water moisture capacity, water demand in the growth and development of mango could be ensured, and maximum production efficiency of irrigation and the best quality of fruit could be achieved. In conclusion, treatment T4 was the optimum irrigation schedule for growing mango, thus achieving efficient production of mango in consideration of the compromise among mango yield, fruit quality and water use efficiency.

  10. 1. Introduction. 2. Laboratory experiments. 3. Field experiments. 4. Integrated field-laboratory experiments. 5. Panel recommendations

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Some recommendations for the design of laboratory and field studies in marine radioecology are formulated. The difficulties concerning the comparability of various experimental methods used to measure the fluxes of radionuclides through marine organisms and ecosystems, and also the use of laboratory results to make predictions for the natural environment are discussed. Three working groups were established during the panel meeting, to consider laboratory experiments, field studies, and the design and execution of integrated laboratory and field studies respectively. A number of supporting papers dealing with marine radioecological experiments were presented

  11. Field-Based Estimates of Global Warming Potential in Bioenergy Systems of Hawaii: Crop Choice and Deficit Irrigation.

    Directory of Open Access Journals (Sweden)

    Meghan N Pawlowski

    Full Text Available Replacing fossil fuel with biofuel is environmentally viable from a climate change perspective only if the net greenhouse gas (GHG footprint of the system is reduced. The effects of replacing annual arable crops with perennial bioenergy feedstocks on net GHG production and soil carbon (C stock are critical to the system-level balance. Here, we compared GHG flux, crop yield, root biomass, and soil C stock under two potential tropical, perennial grass biofuel feedstocks: conventional sugarcane and ratoon-harvested, zero-tillage napiergrass. Evaluations were conducted at two irrigation levels, 100% of plantation application and at a 50% deficit. Peaks and troughs of GHG emission followed agronomic events such as ratoon harvest of napiergrass and fertilization. Yet, net GHG flux was dominated by carbon dioxide (CO2, as methane was oxidized and nitrous oxide (N2O emission was very low even following fertilization. High N2O fluxes that frequently negate other greenhouse gas benefits that come from replacing fossil fuels with agronomic forms of bioenergy were mitigated by efficient water and fertilizer management, including direct injection of fertilizer into buried irrigation lines. From soil intensively cultivated for a century in sugarcane, soil C stock and root biomass increased rapidly following cultivation in grasses selected for robust root systems and drought tolerance. The net soil C increase over the two-year crop cycle was three-fold greater than the annualized soil surface CO2 flux. Deficit irrigation reduced yield, but increased soil C accumulation as proportionately more photosynthetic resources were allocated belowground. In the first two years of cultivation napiergrass did not increase net greenhouse warming potential (GWP compared to sugarcane, and has the advantage of multiple ratoon harvests per year and less negative effects of deficit irrigation to yield.

  12. Field-Based Estimates of Global Warming Potential in Bioenergy Systems of Hawaii: Crop Choice and Deficit Irrigation.

    Science.gov (United States)

    Pawlowski, Meghan N; Crow, Susan E; Meki, Manyowa N; Kiniry, James R; Taylor, Andrew D; Ogoshi, Richard; Youkhana, Adel; Nakahata, Mae

    2017-01-01

    Replacing fossil fuel with biofuel is environmentally viable from a climate change perspective only if the net greenhouse gas (GHG) footprint of the system is reduced. The effects of replacing annual arable crops with perennial bioenergy feedstocks on net GHG production and soil carbon (C) stock are critical to the system-level balance. Here, we compared GHG flux, crop yield, root biomass, and soil C stock under two potential tropical, perennial grass biofuel feedstocks: conventional sugarcane and ratoon-harvested, zero-tillage napiergrass. Evaluations were conducted at two irrigation levels, 100% of plantation application and at a 50% deficit. Peaks and troughs of GHG emission followed agronomic events such as ratoon harvest of napiergrass and fertilization. Yet, net GHG flux was dominated by carbon dioxide (CO2), as methane was oxidized and nitrous oxide (N2O) emission was very low even following fertilization. High N2O fluxes that frequently negate other greenhouse gas benefits that come from replacing fossil fuels with agronomic forms of bioenergy were mitigated by efficient water and fertilizer management, including direct injection of fertilizer into buried irrigation lines. From soil intensively cultivated for a century in sugarcane, soil C stock and root biomass increased rapidly following cultivation in grasses selected for robust root systems and drought tolerance. The net soil C increase over the two-year crop cycle was three-fold greater than the annualized soil surface CO2 flux. Deficit irrigation reduced yield, but increased soil C accumulation as proportionately more photosynthetic resources were allocated belowground. In the first two years of cultivation napiergrass did not increase net greenhouse warming potential (GWP) compared to sugarcane, and has the advantage of multiple ratoon harvests per year and less negative effects of deficit irrigation to yield.

  13. Decontamination of soils by irrigation with solutions containing complexing agents

    International Nuclear Information System (INIS)

    Pimpl, M.; Schuettelkopf, H.

    1982-01-01

    Experiments in laboratory scale were performed to increase the mobility of Pu, Am, and Cm in soil. Soil columns of 30 cm in diameter and 40 cm of length were contaminated on the surface with 5 μCi of Pu, Am, and Cm, applied as nitrates. By irrigation with 0.1 M DTPA-solution the actinides were mobilized and migrated with the irrigation solution through the columns. The migration velocity was measured and compared to the calculated one. Conclusions for the application of this procedure in field experiments are drawn. (author)

  14. Effect of Irrigation Methods, Nitrogen and Phosphorus Fertilizer Rates on Sugar Beet Yield and Quality

    International Nuclear Information System (INIS)

    Janat, M.; Abudlkareem, J.

    2007-01-01

    The experiment was conducted at a research station near Adlib. Two irrigation methods, sprinkler irrigation and drip fertigation, two phosphorus rates and four nitrogen rates 0, 70, 140 and 210 kg N/ha were tested. All N fertilizers were injected for drip irrigation or broadcasted for the sprinkler-irrigated treatments in six equally split applications. Neutron probe Results revealed that the introduction of drip fertigation was not proved to be a water saving relative to sprinkler irrigation. Dry matter production was slightly increased for the drip-fertigated treatments relative to sprinkler irrigated treatments. Nitrogen use efficiency was not improved under drip fertigation relative to that of sprinkler irrigation. Application of phosphorus fertilizer improved sugar beet yield as well as N uptake. No significant differences in sugar beet yield were observed due to the application of N fertilizer under drip fertigation. On the other hand, there was a trend toward increasing sugar beet yield grown under sprinkler irrigation. Drip fertigation had no negative effects on sugar content and other related properties, furthermore some of those properties were enhanced due to the employment of drip fertigation. Field water-use efficiency followed a similar trend and was increased under sprinkler irrigation relative to drip-fertigation for sugar beet yield parameter.

  15. Crop yield response to deficit irrigation imposed at different plant growth stages

    International Nuclear Information System (INIS)

    Kovaks, T.; Kovaks, G.; Szito, J.

    1995-01-01

    A series of field experiments were conducted between 1991 - 1994 using 7 irrigation treatments at two fertilizer levels. Nitrogen fertilizers used were labelled with 15 N stable isotope to examine the effect of irrigation on the fertilizer N use efficiency by isotope technique. The irrigation were maintained at four different growth stages of maize, soybean and potato( vegetative, flowering, yield formation and ripening ) in 4 replicates. The aim of study was to compare deficit irrigation( i.e. the water stress imposed, during one growth stage ) with normal irrigation practice included the traditional one. Two watering regimes were established : (1) normal watering when available water was within the range of 60 - 90 %, and (2) deficit irrigation, when the AW was at 30 to 60 %. Neutron probe was used for measuring the soil water status and evaporation data were recorded to determine the amount of irrigation water demand. Reference evapotranspiration ( ETo) was calculated according to Penman - Monteith. Crop water requirement ( ETm) were determined in every year. Actual evapotranspiration ( ETa) was computed using CROPWAT: FAO computer program for irrigation planning and management (1992). Every irrigation treatment was equipped with neutron access tubes in two replicates at a depth from 10 to 130 cm. tensiometers were installed at depths of 30, 50, 60 and 80 cm in one replicate of treatments and were measured on a daily basis while neutron probe measurements were used to monitor the soil water table fluctuations. The irrigation method used was a special type of low pressure drop irrigation. There were measured the amount of rainfall with irrigation water supplied and the moisture distribution profiles were drown for the different treatments. Relationships between relative yield decrease and evapotranspiration and also between the crop yield and water use were determined. 9 tabs, 9 refs, ( Author )

  16. Irrigation management of muskmelon with tensiometry

    Directory of Open Access Journals (Sweden)

    Márcio José de Santana

    2017-11-01

    Full Text Available The production and consumption of muskmelon have been increasing (MELO et al., 2014, thus, information on techniques for higher field productions are necessary. The experiment described in the present work was conducted in the IFTM, Uberaba, State of Minas Gerais, Brazil, aiming to evaluate the muskmelon yield under different soil water tensions. A randomized block experimental design was used with five treatments (soil water tensions of 10, 20, 30, 40 and 50 kPa and four replications (plots of two rows of 14 plants. Two harvests were carried out and the fruit yield, stem diameter, number of fruits per plant and efficiency of water use were evaluated. Irrigation was performed with a drip irrigation system and managed with tensiometry. The cultivar Bonus n.2 was used with spacing of 1.0 x 0.6 m. The data of the variables were subjected to the F test and regression test. The treatments showed statistical differences in number of fruits per plant, fruit weight (fruit yield and stem diameter. The highest fruit yield found was 1.36 kg fruit-1 and the highest water use efficiency was 4.08 g mm-1 with irrigation for a soil water tension of 10 kPa. The lowest fruit yield was found with irrigation for a soil water tension of 50 kPa.

  17. Forms of trace arsenic, cesium, cadmium, and lead transported into river water for the irrigation of Japanese paddy rice fields

    Science.gov (United States)

    Nakaya, Shinji; Chi, Hai; Muroda, Kengo; Masuda, Harue

    2018-06-01

    In this study, we focus on the behavior of geogenic, toxic trace elements, particularly As, Cs, Cd, and Pb, during their transportation in two rivers for irrigation commonly used in monsoon Asia; one river originates from an active volcano, Mt. Asama, and the other originates from a currently inactive volcano, Yatsugatake Mountains in Nagano, Japan. These rivers were investigated to understand the role of river water as a pollutant of rice and other aquatic plants (via irrigation) and aquatic animals. The results indicated that the behavior of toxic trace elements in river water are likely controlled by their interactions with particulate Fe, Al, and Ti compounds. The majority of Pb and Cd is transported as particulate matter with Fe, Al, and Ti, while the majority of As is transported in the dissolved form, predominantly as arsenate, with low abundance of particulate matter. Cs is transported either as the dissolved form or as particulate matter in both rivers. The investigated elements are transported in the rivers as particulate and dissolved forms, and the ratio of these forms is controlled by the pH and presence of particulate Fe, Al, and Ti phases in the river water. With respect to Cs in both rivers, the parameter governing the concentration and transportation of Cs, in the bimodal form (i.e., particulate and dissolved forms), through the river possibly shifts from sorption to pH by particulate Fe-Al-Ti, according to the abrupt increase in the concentration of Cs in the river. The chemical attraction of particulate Fe-Al-Ti for Cs is weaker than that for Pb and Cd, indicating that the lower electronegativity of Cs weakens the chemical attraction on a colloid for the competitive sorption with the other trace elements. The different relationships between As and Fe in the river and in the irrigation water and soil water, as well as those in paddy rice, suggested that As in paddy rice is not directly derived from As in the irrigation water from the river under

  18. Modeling root length density of field grown potatoes under different irrigation strategies and soil textures using artificial neural networks

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Sepaskhah, Ali Reza; Andersen, Mathias Neumann

    2014-01-01

    ) of the eight input variables: soil layer intervals (D), percentages of sand (Sa), silt (Si), and clay (Cl), bulk density of soil layers (Bd), weighted soil moisture deficit during the irrigation strategies period (SMD), geometric mean particle size diameter (dg), and geometric standard deviation (σg......). The results of the study showed that all the nine ANN models predicted the target RLD values satisfactorily with a correlation coefficient R2>0.98. The simplest and most complex ANN architectures were 3:2:1 and 5:5:1 consisting of D, SMD, dg, and D, Bd, SMD, σg, dg as the input variables, respectively. Low...

  19. Study of the weekly irrigation cycle of a cultivated field in a semi-arid area (Marrakech region, Morocco) by using CR-39 and LR-115 II track detectors and radon as a natural tracer

    International Nuclear Information System (INIS)

    Misdaq, M.A.; Essaouif, Z.

    2007-01-01

    Uranium ( 238 U) and thorium ( 232 Th) concentrations were measured in the soil of a cultivated field situated in a semi-arid area (Marrakech, Morocco) by using CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs). The same track detectors were used for measuring alpha- and beta-activities due to radon and thoron gases emanating from the soil of the studied irrigated agricultural field. The influence of the humidity (soil water content), soil depth and climate conditions on the weekly irrigation cycle of the studied cultivated field was investigated by exploiting radon measurements

  20. Radiation interception and radiation use efficiency of potato affected by different N fertigation and irrigation regimes

    DEFF Research Database (Denmark)

    Zhenjiang, Zhou; Andersen, Mathias Neumann; Plauborg, Finn

    2016-01-01

    Three years of field experiments were carried out to explore the response of potato dry matter production, accumulated intercepted photosynthetic active radiation (Aipar) and radiation use efficiency (RUE) to five N levels providing 0, 60, 100, 140 and 180 kg N ha−1 and three drip irrigation...... strategies, which were full, deficit and none irrigation. Results showed that, irrespective of years, dry matter production and Aipar were increased by prolonged N fertigation, even though N fertigation was carried out from middle to late growing season. The highest total and tuber dry matter and accumulated...... fertilization occurred when most N was applied early in the growing season and the latest N fertilization should be applied no later than 41–50 days after emergence. Deficit irrigation, which received ca.70% of irrigation applied to full irrigation, did not reduce radiation interception and radiation use...

  1. Effect of strategic irrigation on infection of apple scab (Venturia inaequalis)

    DEFF Research Database (Denmark)

    Korsgaard, Maren

    2016-01-01

    Strategic irrigation is a method to prevent Apple scab (Venturia inaequalis). It is performed by irrigating the orchard floor in dry periods during spring, 24 hours before rain forecast. Irrigating the old leaves on the orchard floor will elicit the release of ascospores, but due to the dry trees...... and the dry weather, the ascospores dry out without causing infections. The method relies on the occurrence of dry periods during the period of primary infection from April to mid-June. Experiments were carried out at the University of Copenhagen and in an unsprayed Danish organic orchard in 2014 and 2015....... Apple scab on fruit and leaves was reduced by strategic irrigation in ‘Elshof’ at the University field in both years. In the organic orchard the strategic irrigation reduced the infection of leaves by apple scab and Elsinoe leaf and fruit spot in some cultivars and some years. Studies of the ejection...

  2. Simulation of rice yield under different irrigation and nitrogen application managements by CropSyst model

    Directory of Open Access Journals (Sweden)

    Narjes ZARE

    2015-12-01

    Full Text Available The aim of this study was the calibration and validation of CropSyst model for rice in the city of Rasht. The necessary data were extracted from a field experiment which was carried out during 2005-2007 in a split-plot design. The main plots were irrigation regimes including continuous flooding irrigation and 5-day irrigation intervals. The subplots consisted of four nitrogen levels: zero N application, 45, 60 and 75 kg N ha-1. Normalized Root Mean Squared Error (nRMSE and Residual Mass Coefficient (Crm in calibration years were 9.3 % and 0.06, respectively. In validation year, nRMSE and Crm were 9.7 % and 0.11, respectively. According to other indices to assess irrigation regimes and fertilizer levels, the most suitable treatments regarding environmental aspect were 5-day irrigation regime and 45 kg N ha-1.

  3. Per-field crop classification in irrigated agricultural regions in middle Asia using random forest and support vector machine ensemble

    Science.gov (United States)

    Löw, Fabian; Schorcht, Gunther; Michel, Ulrich; Dech, Stefan; Conrad, Christopher

    2012-10-01

    Accurate crop identification and crop area estimation are important for studies on irrigated agricultural systems, yield and water demand modeling, and agrarian policy development. In this study a novel combination of Random Forest (RF) and Support Vector Machine (SVM) classifiers is presented that (i) enhances crop classification accuracy and (ii) provides spatial information on map uncertainty. The methodology was implemented over four distinct irrigated sites in Middle Asia using RapidEye time series data. The RF feature importance statistics was used as feature-selection strategy for the SVM to assess possible negative effects on classification accuracy caused by an oversized feature space. The results of the individual RF and SVM classifications were combined with rules based on posterior classification probability and estimates of classification probability entropy. SVM classification performance was increased by feature selection through RF. Further experimental results indicate that the hybrid classifier improves overall classification accuracy in comparison to the single classifiers as well as useŕs and produceŕs accuracy.

  4. KOEFISIEN TANAMAN PADI SAWAH PADA SISTEM IRIGASI HEMAT AIR Crop Coefficient for Paddy Rice Field under Water Saving Irrigation Systems

    Directory of Open Access Journals (Sweden)

    Joko Sujono

    2012-05-01

    Full Text Available Traditional irrigation for paddy rice is the leading of consumer of water, about 80 % of the water resource availabilityused for irrigation purpose. This phenomenon is related to the way how to estimate the crop water requirement where crop coefficient for paddy rice (k (Prosida is always greater than one starting from planting up to nearly harvesting. In this research, a number of water saving irrigations (WSI systems for paddy rice cultivation using pots such asalternate wetting and drying (AWD, shallow water depth with wetting and drying (SWD, semi-dry cultivation (SDC, system of rice intensification (SRI, and  AWD with mulch (AWD-Mul were applied. The amount of irrigated water and when it should be irrigated depend on evapotranspiration rate, soil moisture condition and the WSI system used. For this purpose, daily measurement of the pot weight was carried out. Crop coefficient (k  is then caluculated as a cratio between crop and reference evapotranspiration computed using Penman-Montheit  method. Results show that up to 45 days after transplanting, the k of WSI treatments were around half of the k (Prosida values currently used for computing the water requirement, whereas at the productive stage the k of WSI systems were relatively equal (AWD, SDC to or greater (SRI, SWD than the k (Prosida. Based on the the k values, the AWD and the SDC systems could save much water compared to the SRI or the SWD. Water saving could be increased by applying the AWD with mulch. ABSTRAK Irigasi padi sawah dengan sistem tradisional merupakan sistem irigasi  yang boros air, hampir 80 % sumber air yang ada untuk irigasi. Hal ini tidak terlepas dari perhitungan kebutuhan air tanaman dengan nilai koefisien tanaman (k menurut Standar Perencanaan Irigasi (Prosida selalu lebih besar dari satu mulai dari tanam hingga menjelang panen.Dalam penelitian ini beberapa metoda budidaya padi hemat air seperti alternate wetting and drying (AWD, shallow water depth

  5. Sensing technologies for precision irrigation

    CERN Document Server

    Ćulibrk, Dubravko; Minic, Vladan; Alonso Fernandez, Marta; Alvarez Osuna, Javier; Crnojevic, Vladimir

    2014-01-01

    This brief provides an overview of state-of-the-art sensing technologies relevant to the problem of precision irrigation, an emerging field within the domain of precision agriculture. Applications of wireless sensor networks, satellite data and geographic information systems in the domain are covered. This brief presents the basic concepts of the technologies and emphasizes the practical aspects that enable the implementation of intelligent irrigation systems. The authors target a broad audience interested in this theme and organize the content in five chapters, each concerned with a specific technology needed to address the problem of optimal crop irrigation. Professionals and researchers will find the text a thorough survey with practical applications.

  6. Willingness to Pay Additional Water Rate and Irrigation Knowledge of Farmers in Dinar Karakuyu Irrigation Areas in Turkey

    Directory of Open Access Journals (Sweden)

    Mevlüt Gül

    2017-08-01

    Full Text Available Water which has become commodity product which is an important product today. Turkey is not a water rich country. In this study, agricultural enterprises in the field of Irrigation Project in Dinar Karakuyu which was implemented in 1992 by DSI. The study analysed which factors affect the willingness to pay additional irrigation water rate with the help of logit model and the irrigation knowledge of farmers was determined by Likert scale. Dinar Karakuyu irrigation network has begun to lose the function in the region. It was supposed 100% irrigation rate but decreased by approximately 9% today. In this context, DSI (General Directorate of State Hydraulic Works plans to rehabilitation work in the same area. The main material of this study was data obtained from 67 agricultural enterprises through a survey covered by the Irrigation Rehabilitation Project in the province of Afyonkarahisar Karakuyu Dinar. The data was gathered with the help of questionnaires which were answered by farmers in Karakuyu Dinar region. The results indicated that 74.6% of farmers were willingness to pay additional water charge. The data were statistically analysed with the use of the logit model. The model results show that agricultural income, farmers’ educational level, computer ownership, attendance of agricultural training activities, family size and agricultural experience were positive factors affect farmers’ willingness to pay additional water fee.

  7. Irrigation effects on soil attributes and grapevine performance in a 'Godello' vineyard of NW Spain

    Science.gov (United States)

    Fandiño, María; Trigo-Córdoba, Emiliano; Martínez, Emma M.; Bouzas-Cid, Yolanda; Rey, Benjamín J.; Cancela, Javier J.; Mirás-Avalos, Jose M.

    2014-05-01

    Irrigation systems are increasingly being used in Galician vineyards. However, a lack of information about irrigation management can cause a bad use of these systems and, consequently, reductions in berry quality and loss of water resources. In this context, experiences with Galician cultivars may provide useful information. A field experiment was carried out over two seasons (2012-2013) on Vitis vinifera (L.) cv. 'Godello' in order to assess the effects of irrigation on soil attributes, grapevine performance and berry composition. The field site was a commercial vineyard located in A Rúa (Ourense-NW Spain). Rain-fed vines (R) were compared with two irrigation systems: surface drip irrigation (DI) and subsurface drip irrigation (SDI). Physical and chemical characteristics of soil were analyzed after installing irrigation systems at the beginning of each season, in order to assess the effects that irrigation might have on soil attributes. Soil water content, leaf and stem water potentials and stomatal conductance were periodically measured over the two seasons. Yield components including number of clusters, yield per plant and cluster average weight were taken. Soluble solids, pH, total acidity and amino acids contents were measured on the grapes at harvest. Pruning weight was also recorded. Soil attributes did not significantly vary due to the irrigation treatments. Stem water potentials were significantly lower for R plants on certain dates through the season, whereas stomatal conductance was similar for the three treatments in 2013, while in 2012 SDI plants showed greater stomatal conductance values. SDI plants yielded more than those R due to both a greater number of clusters per plant and to heavier clusters. Pruning weight was significantly higher in SI plants. Berry composition was similar for the three treatments except for the amino acids content, which was higher under SDI conditions. These results may be helpful for a sustainable management of irrigation

  8. Water sensors with cellular system eliminate tail water drainage in alfalfa irrigation

    Directory of Open Access Journals (Sweden)

    Rajat Saha

    2011-10-01

    Full Text Available Alfalfa is the largest consumer of water among all crops in California. It is generally flood-irrigated, so any system that decreases runoff can improve irrigation efficiency and conserve water. To more accurately manage the water flow at the tail (bottom end of the field in surface-irrigated alfalfa crops, we developed a system that consists of wetting-front sensors, a cellular communication system and a water advance model. This system detects the wetting front, determines its advance rate and generates a cell-phone alert to the irrigator when the water supply needs to be cut off, so that tail water drainage is minimized. To test its feasibility, we conducted field tests during the 2008 and 2009 alfalfa growing seasons. The field experiments successfully validated the methodology, producing zero tail water drainage.

  9. Experiments of Accuracy Air Ion Field Measurement

    Czech Academy of Sciences Publication Activity Database

    Bartušek, Karel; Fiala, P.; Jirků, T.; Kadlecová, E.

    2007-01-01

    Roč. 3, č. 8 (2007), s. 1330-1333 ISSN 1931-7360 Institutional research plan: CEZ:AV0Z20650511 Keywords : air ion field * gerdien condenser * picoampermeter Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  10. Cockle Field Caging Experiment Data (2014)

    Data.gov (United States)

    U.S. Environmental Protection Agency — To determine whether differences in cockle density or qualitative burial depth observed during the 2014 field survey were affected by green macroalgal (GMA) mats, we...

  11. Field Trips as Valuable Learning Experiences in Geography Courses

    Science.gov (United States)

    Krakowka, Amy Richmond

    2012-01-01

    Field trips have been acknowledged as valuable learning experiences in geography. This article uses Kolb's (1984) experiential learning model to discuss how students learn and how field trips can help enhance learning. Using Kolb's experiential learning theory as a guide in the design of field trips helps ensure that field trips contribute to…

  12. Minimizing magnetic fields for precision experiments

    Energy Technology Data Exchange (ETDEWEB)

    Altarev, I.; Fierlinger, P.; Lins, T.; Marino, M. G.; Nießen, B.; Petzoldt, G.; Reisner, M.; Stuiber, S., E-mail: stefan.stuiber@ph.tum.de; Sturm, M.; Taggart Singh, J.; Taubenheim, B. [Physikdepartment, Technische Universität München, D-85748 Garching (Germany); Rohrer, H. K. [Rohrer GmbH, D-80667 München (Germany); Schläpfer, U. [IMEDCO AG, CH-4614 Hägendorf (Switzerland)

    2015-06-21

    An increasing number of measurements in fundamental and applied physics rely on magnetically shielded environments with sub nano-Tesla residual magnetic fields. State of the art magnetically shielded rooms (MSRs) consist of up to seven layers of high permeability materials in combination with highly conductive shields. Proper magnetic equilibration is crucial to obtain such low magnetic fields with small gradients in any MSR. Here, we report on a scheme to magnetically equilibrate MSRs with a 10 times reduced duration of the magnetic equilibration sequence and a significantly lower magnetic field with improved homogeneity. For the search of the neutron's electric dipole moment, our finding corresponds to a 40% improvement of the statistical reach of the measurement. However, this versatile procedure can improve the performance of any MSR for any application.

  13. Minimizing magnetic fields for precision experiments

    International Nuclear Information System (INIS)

    Altarev, I.; Fierlinger, P.; Lins, T.; Marino, M. G.; Nießen, B.; Petzoldt, G.; Reisner, M.; Stuiber, S.; Sturm, M.; Taggart Singh, J.; Taubenheim, B.; Rohrer, H. K.; Schläpfer, U.

    2015-01-01

    An increasing number of measurements in fundamental and applied physics rely on magnetically shielded environments with sub nano-Tesla residual magnetic fields. State of the art magnetically shielded rooms (MSRs) consist of up to seven layers of high permeability materials in combination with highly conductive shields. Proper magnetic equilibration is crucial to obtain such low magnetic fields with small gradients in any MSR. Here, we report on a scheme to magnetically equilibrate MSRs with a 10 times reduced duration of the magnetic equilibration sequence and a significantly lower magnetic field with improved homogeneity. For the search of the neutron's electric dipole moment, our finding corresponds to a 40% improvement of the statistical reach of the measurement. However, this versatile procedure can improve the performance of any MSR for any application

  14. Winter wheat grain yield and its components in the North China Plain: irrigation management, cultivation, and climate

    Directory of Open Access Journals (Sweden)

    Lihua Lv

    2013-09-01

    Full Text Available Irrigation has been identified as the main driving factor of groundwater drawdown in the North China Plain (NCP. In order to develop appropriate irrigation strategies for satisfactory yields of wheat (Triticum aestivum L., grain yield (GY, yield components, and water use efficiency (WUE were studied. A field experiment was conducted with two types of winter wheat, 'Shimai15' and 'Shixin733', and five irrigation treatments, including rainfed and four spring irrigation water applications, in four growing seasons (2005 to 2009. Results showed that maximum GY was achieved with three irrigation treatments in the 2005-2006 and 2008-2009 dry seasons and two irrigation treatments in the 2006-2007 normal season. However, in the 2007-2008 wet season, the four irrigation treatments, especially the additional irrigation event at the reviving stage (28, produced maximum GY. Grain yield was significantly related to seasonal full evapotranspiration (ET and 410 to 530 mm of seasonal full ET, including 143 mm rainfall and 214 mm irrigation water, which led to maximum GY. The two types of cultivars responded differently to irrigation management in different rainfall years. The yield of the water-saving cv. 'Shimai 15' was much higher in the dry seasons than in the other seasons. Variations of yield components were mainly caused by irrigation time and meteorological factors. The higher accumulated temperature during the sowing and tillering stages (24 and irrigation or precipitation at the reviving stage (28 significantly improved tiller growth. The lower average temperature in March and April greatly increased grain number per spike. Sunshine duration played a decisive role in improving grain weight. Our results provide very useful information about irrigation time and frequency of winter wheat in the NCP in order to obtain high yield but reduce the use of underground water.

  15. Monitoring and Evaluation of Cultivated Land Irrigation Guarantee Capability with Remote Sensing

    Science.gov (United States)

    Zhang, C., Sr.; Huang, J.; Li, L.; Wang, H.; Zhu, D.

    2015-12-01

    Abstract: Cultivated Land Quality Grade monitoring and evaluation is an important way to improve the land production capability and ensure the country food safety. Irrigation guarantee capability is one of important aspects in the cultivated land quality monitoring and evaluation. In the current cultivated land quality monitoring processing based on field survey, the irrigation rate need much human resources investment in long investigation process. This study choses Beijing-Tianjin-Hebei as study region, taking the 1 km × 1 km grid size of cultivated land unit with a winter wheat-summer maize double cropping system as study object. A new irrigation capacity evaluation index based on the ratio of the annual irrigation requirement retrieved from MODIS data and the actual quantity of irrigation was proposed. With the years of monitoring results the irrigation guarantee capability of study area was evaluated comprehensively. The change trend of the irrigation guarantee capability index (IGCI) with the agricultural drought disaster area in rural statistical yearbook of Beijing-Tianjin-Hebei area was generally consistent. The average of IGCI value, the probability of irrigation-guaranteed year and the weighted average which controlled by the irrigation demand index were used and compared in this paper. The experiment results indicate that the classification result from the present method was close to that from irrigation probability in the gradation on agriculture land quality in 2012, with overlap of 73% similar units. The method of monitoring and evaluation of cultivated land IGCI proposed in this paper has a potential in cultivated land quality level monitoring and evaluation in China. Key words: remote sensing, evapotranspiration, MODIS cultivated land quality, irrigation guarantee capability Authors: Chao Zhang, Jianxi Huang, Li Li, Hongshuo Wang, Dehai Zhu China Agricultural University zhangchaobj@gmail.com

  16. Microbial risk in wastewater irrigated lettuce: comparing Escherichia coli contamination from an experimental site with a laboratory approach.

    Science.gov (United States)

    Makkaew, P; Miller, M; Fallowfield, H J; Cromar, N J

    This study assessed the contamination of Escherichia coli, in lettuce grown with treated domestic wastewater in four different irrigation configurations: open spray, spray under plastic sheet cover, open drip and drip under plastic sheet cover. Samples of lettuce from each irrigation configuration and irrigating wastewater were collected during the growing season. No E. coli was detected in lettuce from drip irrigated beds. All lettuce samples from spray beds were positive for E. coli, however, no statistical difference (p > 0.05) was detected between lettuces grown in open spray or covered spray beds. The results from the field experiment were also compared to a laboratory experiment which used submersion of lettuce in wastewater of known E. coli concentration as a surrogate method to assess contamination following irrigation. The microbial quality of spray bed lettuces was not significantly different from submersed lettuce when irrigated with wastewater containing 1,299.7 E. coli MPN/100 mL (p > 0.05). This study is significant since it is the first to validate that the microbial contamination of lettuce irrigated with wastewater in the field is comparable with a laboratory technique frequently applied in the quantitative microbial risk assessment of the consumption of wastewater irrigated salad crops.

  17. Effect of cover crops on greenhouse gas emissions in an irrigated field under integrated soil fertility management

    Science.gov (United States)

    Guardia, Guillermo; Abalos, Diego; García-Marco, Sonia; Quemada, Miguel; Alonso-Ayuso, María; Cárdenas, Laura M.; Dixon, Elizabeth R.; Vallejo, Antonio

    2016-09-01

    Agronomical and environmental benefits are associated with replacing winter fallow by cover crops (CCs). Yet, the effect of this practice on nitrous oxide (N2O) emissions remains poorly understood. In this context, a field experiment was carried out under Mediterranean conditions to evaluate the effect of replacing the traditional winter fallow (F) by vetch (Vicia sativa L.; V) or barley (Hordeum vulgare L.; B) on greenhouse gas (GHG) emissions during the intercrop and the maize (Zea mays L.) cropping period. The maize was fertilized following integrated soil fertility management (ISFM) criteria. Maize nitrogen (N) uptake, soil mineral N concentrations, soil temperature and moisture, dissolved organic carbon (DOC) and GHG fluxes were measured during the experiment. Our management (adjusted N synthetic rates due to ISFM) and pedo-climatic conditions resulted in low cumulative N2O emissions (0.57 to 0.75 kg N2O-N ha-1 yr-1), yield-scaled N2O emissions (3-6 g N2O-N kg aboveground N uptake-1) and N surplus (31 to 56 kg N ha-1) for all treatments. Although CCs increased N2O emissions during the intercrop period compared to F (1.6 and 2.6 times in B and V, respectively), the ISFM resulted in similar cumulative emissions for the CCs and F at the end of the maize cropping period. The higher C : N ratio of the B residue led to a greater proportion of N2O losses from the synthetic fertilizer in these plots when compared to V. No significant differences were observed in CH4 and CO2 fluxes at the end of the experiment. This study shows that the use of both legume and nonlegume CCs combined with ISFM could provide, in addition to the advantages reported in previous studies, an opportunity to maximize agronomic efficiency (lowering synthetic N requirements for the subsequent cash crop) without increasing cumulative or yield-scaled N2O losses.

  18. Effect of drip irrigation on yield, evapotranspiration and water use efficiency of sweet basil (Ocimum basilicum L.

    Directory of Open Access Journals (Sweden)

    Pejić Borivoj

    2017-01-01

    Full Text Available The experiments showing the effect of drip irrigation on yield, evapotranspiration and water productivity of sweet basil (Ocimum basilicum L. were conducted at the experimental field of the Alternative Crops Department, Institute of Field and Vegetable Crops, Novi Sad. Irrigation was scheduled on the basis of the water balance method. Daily evapotranspiration (ETd was computed from the reference evapotranspiration (ETo and crop coefficient (kc in May, June, July and August of 0.5, 0.6, 1.1 and 1.0, respectively. ETo was calculated using Hargreaves equation. The irrigation depth was restricted to the soil depth of 0.3 m. In other words, irrigation started when readily available water in the soil layer of 0.3 m was completely depleted by plants. The irrigation rate was 30 mm (30 l m-2 while the amount of water added by irrigation during the season was 140 mm. Basil sensitivity to water stress was determined using a yield response factor (Ky. According to the results, the yield of fresh herb of basil under irrigation (32.015 t ha-1 was higher by 9% compared to non-irrigated, control variant (29.364 t ha-1. Worthy of note, basil essential oil yield was significantly affected by irrigation (35.329/28.766 kg ha-1. The content of essential oil was significantly higher in irrigated (6.45 g kg-1 than in non-irrigated variant (5.33 g kg-1 in the first harvest, while no significant difference between irrigated and non-irrigated variants was obtained in the second harvest (6.83 and 6.62 g kg-1 , respectively. Water used on evapotranspiration in irrigation conditions (ETm was 431 mm and 270 mm in non-irrigated, control variant (ETa. The values of irrigation water use efficiency (Iwue and evapotranspiration water use efficiency (ETwue were 1.89 kg m-3 and 1.65 kg m-3 respectively. Ky value (0.22 exhibits all essential characteristics of climate conditions of 2016 rainy year. These preliminary results could be used as a good platform for basil growers in the

  19. Local irrigation of the surgical field with antibiotics in the end of procedure reduces the infection rate in herniated lumbar disc surgery.

    Science.gov (United States)

    Kërveshi, Armend; Halili, Nehat; Kastrati, Bujar; Qosja, Faik; Kabashi, Serbeze; Muçaj, Sefedin

    2014-12-01

    Reported rate of infections after lumbar discectomy is 1%-15 %. This complication may result in disability or even the death. The aim of the study is to assess the rate of infection associated with lumbar discectomies when combined systemic and local antibiotic prophylaxis was employed. In this retrospective study we analyzed all patients operated for herniated lumbar disc from 2009 -2012 in our institute. Beside of receiving systemic prophylaxis with 2g of Cefazoline, all patients had their operative field irrigated at the end of operation with Amikacin sulfate injection. Wound was considered infected when local and systemic signs of infection were revealed and were associated with elevated ESR, leukocytosis and elevated CRP. Assessment of infection is done by neurosurgeon during the hospitalization and later at outpatient's clinic along postoperative course of three months. A total of 604 patients were operated, of those 285 patients (47.2 %) females and 319 males (52.8 %), 12 patients were operated on two levels (1.98 %). Average patient age was 32.5 years (range 20-65 years) Localization of herniated disc was: in L/2-L/3 20 patients or 3.3 %, the L/3-L/4 level 42 patients or 7 % , the L/4 -L /5 262 patients or 43.3 % at the level L/V- S/1 280 patients or 46.3 %. Three patients (0.49%) developed wound infection, two of them superficial infection only with local signs: local pain, redness and leakage. They were treated with oral antibiotics. One with deep wound infection. He presented with local and systemic signs and treated with i.v antibiotics. All the cultures from wound swab revealed staphylococcus aureus. Prophylaxis with systemic antibiotic (Cefazoline 2.0) intravenous administration 30 minutes before the incision and irrigation of operative field with local antibiotic Amikacine sulfate at the end of procedure reduces the infection rate in patients operated for herniated lumbar disc when compared with systemic antibiotic prophylaxis only.

  20. A monitoring of chemical contaminants in waters used for field irrigation and livestock watering in the Veneto region (Italy), using bioassays as a screening tool.

    Science.gov (United States)

    De Liguoro, Marco; Bona, Mirco Dalla; Gallina, Guglielmo; Capolongo, Francesca; Gallocchio, Federica; Binato, Giovanni; Di Leva, Vincenzo

    2014-03-01

    In this study, 50 livestock watering sources (ground water) and 50 field irrigation sources (surface water) from various industrialised areas of the Veneto region were monitored for chemical contaminants. From each site, four water samples (one in each season) were collected during the period from summer 2009 through to spring 2010. Surface water samples and ground water samples were first screened for toxicity using the growth inhibition test on Pseudokirchneriella subcapitata and the immobilisation test on Daphnia magna, respectively. Then, based on the results of these toxicity tests, 28 ground water samples and 26 surface water samples were submitted to chemical analysis for various contaminants (insecticides/acaricides, fungicides, herbicides, metals and anions) by means of UPLC-MS(n) HPLC-MS(n), AAS and IEC. With the exception of one surface water sample where the total pesticides concentration was greater than 4 μg L(-1), positive samples (51.9 %) showed only traces (nanograms per liter) of pesticides. Metals were generally under the detection limit. High concentrations of chlorines (up to 692 mg L(-1)) were found in some ground water samples while some surface water samples showed an excess of nitrites (up to 336 mg L(-1)). Detected levels of contamination were generally too low to justify the toxicity recorded in bioassays, especially in the case of surface water samples, and analytical results painted quite a reassuring picture, while tests on P. subcapitata showed a strong growth inhibition activity. It was concluded that, from an ecotoxicological point of view, surface waters used for field irrigation in the Veneto region cannot be considered safe.

  1. Entrepreneurship, teams and sustainability: A series of field experiments

    NARCIS (Netherlands)

    Rosendahl Huber, L.

    2015-01-01

    This dissertation reports the results from three field experiments that were conducted within the setting of one of the leading, internationally renowned entrepreneurship education programs for primary schools called BizWorld. The first field experiment evaluates the program’s effectiveness in terms

  2. Analysis of ARAC participation in the Idaho field experiment

    International Nuclear Information System (INIS)

    Rosen, L.C.; Hill, K.L.

    1986-02-01

    The 1981 Idaho Field Experiment to coordinate data sets and evaluate model and computer facilities is summarized herein. Participation of the Atmospheric Release Advisory Capability (ARAC) of the Lawrence Livermore National Laboratory in the field experiment is discussed. The computed ARAC results are compared with the observational data sets and analyzed. 12 refs., 44 figs., 3 tabs

  3. Airborne ground penetrating radar: practical field experiments

    CSIR Research Space (South Africa)

    Van Schoor, Michael

    2013-10-01

    Full Text Available 1. All the radargrams were processed by applying basic GPR processing steps, which included a time zero correction, a dewow filter and the application of an automatic gain control (AGC) function. No migration was applied so as to preserve.... Suitable automatic detection algorithm could potentially be employed if target responses with specific characteristics are being sought. The results from this experiment are likely to be frequency independent. If so, a low frequency GPR system – say...

  4. Overview of the Bushland Evapotranspiration and Agricultural Remote sensing EXperiment 2008 (BEAREX08): A field experiment evaluating methods for quantifying ET at multiple scales

    Science.gov (United States)

    Evett, Steven R.; Kustas, William P.; Gowda, Prasanna H.; Anderson, Martha C.; Prueger, John H.; Howell, Terry A.

    2012-12-01

    In 2008, scientists from seven federal and state institutions worked together to investigate temporal and spatial variations of evapotranspiration (ET) and surface energy balance in a semi-arid irrigated and dryland agricultural region of the Southern High Plains in the Texas Panhandle. This Bushland Evapotranspiration and Agricultural Remote sensing EXperiment 2008 (BEAREX08) involved determination of micrometeorological fluxes (surface energy balance) in four weighing lysimeter fields (each 4.7 ha) containing irrigated and dryland cotton and in nearby bare soil, wheat stubble and rangeland fields using nine eddy covariance stations, three large aperture scintillometers, and three Bowen ratio systems. In coordination with satellite overpasses, flux and remote sensing aircraft flew transects over the surrounding fields and region encompassing an area contributing fluxes from 10 to 30 km upwind of the USDA-ARS lysimeter site. Tethered balloon soundings were conducted over the irrigated fields to investigate the effect of advection on local boundary layer development. Local ET was measured using four large weighing lysimeters, while field scale estimates were made by soil water balance with a network of neutron probe profile water sites and from the stationary flux systems. Aircraft and satellite imagery were obtained at different spatial and temporal resolutions. Plot-scale experiments dealt with row orientation and crop height effects on spatial and temporal patterns of soil surface temperature, soil water content, soil heat flux, evaporation from soil in the interrow, plant transpiration and canopy and soil radiation fluxes. The BEAREX08 field experiment was unique in its assessment of ET fluxes over a broad range in spatial scales; comparing direct and indirect methods at local scales with remote sensing based methods and models using aircraft and satellite imagery at local to regional scales, and comparing mass balance-based ET ground truth with eddy covariance

  5. Local land-atmosphere feedbacks limit irrigation demand

    Science.gov (United States)

    Decker, Mark; Ma, Shaoxiu; Pitman, Andy

    2017-05-01

    Irrigation is known to influence regional climate but most studies forecast and simulate irrigation with offline (i.e. land only) models. Using south eastern Australia as a test bed, we demonstrate that irrigation demand is fundamentally different between land only and land-atmosphere simulations. While irrigation only has a small impact on maximum temperature, the semi-arid environment experiences near surface moistening in coupled simulations over the irrigated regions, a feedback that is prevented in offline simulations. In land only simulations that neglect the local feedbacks, the simulated irrigation demand is 25% higher and the standard deviation of the mean irrigation rate is 60% smaller. These local-scale irrigation-driven feedbacks are not resolved in coarse-resolution climate models implying that use of these tools will overestimate irrigation demand. Future studies of irrigation demand must therefore account for the local land-atmosphere interactions by using coupled frameworks, at a spatial resolution that captures the key feedbacks.

  6. Tandem mirror and field-reversed mirror experiments

    Energy Technology Data Exchange (ETDEWEB)

    Coensgen, F.H.; Simonen, T.C.; Turner, W.C.

    1979-08-21

    This paper is largely devoted to tandem mirror and field-reversed mirror experiments at the Lawrence Livermore Laboratory (LLL), and briefly summarizes results of experiments in which field-reversal has been achieved. In the tandem experiment, high-energy, high-density plasmas (nearly identical to 2XIIB plasmas) are located at each end of a solenoid where plasma ions are electrostatically confined by the high positive poentials arising in the end plug plasma. End plug ions are magnetically confined, and electrons are electrostatically confined by the overall positive potential of the system. The field-reversed mirror reactor consists of several small field-reversed mirror plasmas linked together for economic reasons. In the LLL Beta II experiment, generation of a field-reversed plasma ring will be investigated using a high-energy plasma gun with a transverse radial magnetic field. This plasma will be further heated and sustained by injection of intense, high-energy neutral beams.

  7. Preliminary experiments with a cusp-field ion source

    International Nuclear Information System (INIS)

    Bickes, R.W. Jr.; O'Hagan, J.B.

    1980-12-01

    Preliminary experiments with a cusp field ion source have been completed. Measurements were made of the total ion current and mass and energy distributions as a function of source operating conditions and cusp field geometry. These experiments have indicated that a cusp field source may be used in the Sandia Neutron Generator for Cancer Therapy and may permit the incorporation of a simplified unpumped accelerator design. Suggestions for future work are briefly outlined

  8. Short-rotation Willow Biomass Plantations Irrigated and Fertilised with Wastewaters. Results from a 4-year multidisciplinary field project in Sweden, France, Northern Ireland and Greece

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Stig [Svaloef Weibull AB, Svaloef (Sweden); Cuingnet, Christian; Clause, Pierre [Association pour le Developpement des Culture Energetiques, Lille (France); Jakobsson, Ingvar [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden); Dawson, Malcolm [Queens Univ., Northern Ireland (United Kingdom); Backlund, Arne [A and B Backlund ApS, Charlottenlund (Denmark); Mavrogianopoulus, George [Agricultural Univ. of Athens (Greece)

    2003-01-01

    This report summarises results and experiences gathered from field trials with recycling of pre-treated wastewater, diverted human urine mixed with water, and municipal sludge, within plantations of willow species specifically selected for biomass production. Experimental sites were established in Sweden (Roma), France (Orchies), Northern Ireland (Culmore) and Greece (Larissa). The project was carried out during a 4-year period with financial support from the EU FAIR Programme. The experimental sites were supplied with primary effluent from municipal treatment plants (Culmore and Larissa), stored industrial effluent from a chicory processing plant (Orchies), biologically treated and stored municipal wastewater (Roma) and human urine mixture from diverting low-flush toilets mixed with water (Roma). Application rates of the wastewaters or the urine mixture were equivalent to the calculated evapotranspiration rate at each site. Wastewaters were also applied up to three times this value to evaluate any possible negative effects. Estimations and evaluations were carried out mainly concerning: biomass growth, potential biological attacks of the plantations, plant water requirements, fertilisation effects of the wastewater, plant uptake of nutrients and heavy metals from applied wastewater, possible soil or groundwater impact, sanitary aspects, and potentials for removal in the soil-plant filter of nutrients and biodegradable organic material from applied wastewater. The results clearly indicated that biomass production in young willow plantations could be enhanced substantially after recycling of wastewater resources. The impact on soil and groundwater of nutrients (nitrogen and phosphorus) and heavy metals (copper, zinc, lead and cadmium) was limited, even when the application of water and nutrients exceeded the plant requirements. Also, the soil-plant system seemed to function as a natural treatment filter for pre-treated (primary settled) wastewater, with a treatment

  9. Quantification of hydrological fluxes in irrigated lands using isotopes for improved water use efficiency

    International Nuclear Information System (INIS)

    Iqbal, N.; Rafiq, M.; Iqbal, T.; Fazal, M.

    2012-01-01

    For the study of water percolation using stable and radioactive isotopes, two experimental plots each measuring 5m X 5m were prepared at NIAB Agriculture Farm, Faisalabad. One plot was given normal irrigation and the other was irrigated with almost double quantity of water than the first one. Study was carried out on wheat and maize crops during 2007-2010. Infiltration rates were calculated from the solute transport by advection. The infiltration rates were also calculated by the water balance approach using moisture content data obtained by neutron moisture probe and flow simulation approach using software 'HYDRUS 1D'. The moisture in the field with normal irrigation percolated up to 90 cm depth. It percolated up to 160 cm in the field with excess irrigation. Infiltration rates determined by different techniques are given. The infiltration rates varied during whole of the experiment period. The rates were highest right after irrigation and then decreased with increase in time. The maximum and minimum infiltration rates determined by different techniques are given, which shows that average infiltration rates calculated by the four methods in case of excess irrigation range between 0.4 and 0.51 cm/day and are in good agreement. Infiltration rates in case of normal irrigation were determined only by tritium and water balance approach and range between 0.21 and 0.34 cm/day. (orig./A.B.)

  10. Decentralising Zimbabwe’s water management: The case of Guyu-Chelesa irrigation scheme

    Science.gov (United States)

    Tambudzai, Rashirayi; Everisto, Mapedza; Gideon, Zhou

    Smallholder irrigation schemes are largely supply driven such that they exclude the beneficiaries on the management decisions and the choice of the irrigation schemes that would best suit their local needs. It is against this background that the decentralisation framework and the Dublin Principles on Integrated Water Resource Management (IWRM) emphasise the need for a participatory approach to water management. The Zimbabwean government has gone a step further in decentralising the management of irrigation schemes, that is promoting farmer managed irrigation schemes so as to ensure effective management of scarce community based land and water resources. The study set to investigate the way in which the Guyu-Chelesa irrigation scheme is managed with specific emphasis on the role of the Irrigation Management Committee (IMC), the level of accountability and the powers devolved to the IMC. Merrey’s 2008 critique of IWRM also informs this study which views irrigation as going beyond infrastructure by looking at how institutions and decision making processes play out at various levels including at the irrigation scheme level. The study was positioned on the hypothesis that ‘decentralised or autonomous irrigation management enhances the sustainability and effectiveness of irrigation schemes’. To validate or falsify the stated hypothesis, data was gathered using desk research in the form of reviewing articles, documents from within the scheme and field research in the form of questionnaire surveys, key informant interviews and field observation. The Statistical Package for Social Sciences was used to analyse data quantitatively, whilst content analysis was utilised to analyse qualitative data whereby data was analysed thematically. Comparative analysis was carried out as Guyu-Chelesa irrigation scheme was compared with other smallholder irrigation scheme’s experiences within Zimbabwe and the Sub Saharan African region at large. The findings were that whilst the

  11. Multitracing Experiment With Solved and Particulate Tracers In An Unsaturated Field Soil

    Science.gov (United States)

    Burkhardt, M.; Kasteel, R.; Vereecken, H.

    Solute movement and colloid migration follow preferential flow paths in structured soils at the field scale. The use of microsphreres is a possible option to mimic colloid transport through the vadose zone into the groundwater. We present results of multi- tracing experiments conducted in an Orthic Luvisol using bromide (Br-), the reactive dye tracer Brilliant Blue (BB) and microspheres. The fluorescent microspheres (1 and 10 µm in diameter) were functionalized with a negative surface charge. Eight field plots (about 2 m2) were irrigated with 10 mm and 40 mm during 6 h. Four field plots were sampled directly after the irrgation, the others were exposed for 90 days to natural wheather conditions. Photographs of horizontal cross-sections and disturbed soil sam- ples were taken every 5 to 10 cm down to a depth of 160 cm. Image analysis was used to derive concentration distributions of BB using a calibration relationship between concentration and color spectra. The microspheres were quantified after desorption of the soil samples by fluorescent microscopy and image analysis. We used moment analysis to characterize transport phenomena. We found that transport through the soil matrix was affected by sorption, but all of the applied compounds were transported through preferential flow paths (earthworm burrows) down to a depth of 160 cm irre- spective of their chemical properties. Furthermore, this study shows that microspheres can be used to mimic colloid facilitated transport under unsaturated conditions in a field soil.

  12. Deficit irrigation based on drought tolerance and root signalling in potatoes and tomatoes

    DEFF Research Database (Denmark)

    Jensen, Christian Richardt; Battilano, Adriano; Plauborg, Finn

    2010-01-01

    Agriculture is a big consumer of fresh water in competition with other sectors of the society. Within the EU-project SAFIR new water-saving irrigation strategies were developed based on pot, semi-field and field experiments with potatoes (Solanum tuberosum L.), fresh tomatoes (Lycopersicon escule...

  13. Classroom and Field Experiments for Florida's Environmental Resources.

    Science.gov (United States)

    Lewis, Jim

    This booklet is intended to help teachers in Florida manage the growing interest in environmental education. Fourteen experiments are grouped into the environmental areas of the water cycle, groundwater, water pollution, waste and water treatment, air pollution, and field experiments. Experiments include demonstrations of the water cycle, the…

  14. Yield and water use efficiency of irrigated soybean in Vojvodina, Serbia

    Directory of Open Access Journals (Sweden)

    Pejić Borivoj

    2012-01-01

    Full Text Available Research was carried out at Rimski Šančevi experiment field of Institute of Field and Vegetable Crops in Novi Sad in the period 1993-2004. The experiment included an irrigated and non-irrigated control treatment. Irrigation water use efficiency (Iwue and evapotranspiration water use efficiency (ETwue were determined in order to assess the effectiveness of irrigation on soybean yield. The average yield increases of soybean due to irrigation practice was 0.82 t ha-1, ranging from 2.465 t ha-1 in years with limited precipitation and higher than average seasonal temperatures (2000 to 0 t ha-1 in rainy years (1996, 1997, 1999. Evapotranspiration water use efficiency (ETwue of soybean ranged from 0.11 kg m-3 to 1.36 kg m-3 with an average value of 0.66 kg m-3, while irrigation water use efficiency (Iwue varied from 0.11 kg m-3 to 1.04 kg m-3 with an average value of 0.56 kg m-3. Effect of irrigation on yield of soybean and results of both ETwue and Iwue which were similar to those obtained from the literature indicate that irrigation schedule of soybean in the study period was properly adapted to plant water requirements and water-physical soil properties. Determined values of ETwue and Iwue could be used for the planning, design and operation of irrigation systems, as well as for improving the production technology of soybean in the region.

  15. Radiation use efficiency and yield of winter wheat under deficit irrigation in North China

    International Nuclear Information System (INIS)

    Han, H.; Li, Z.; Ning, T.; Bai, M.; Zhang, X.; Shan, Y.

    2008-01-01

    An experiment was conducted in North China to investigate the effects of deficit irrigation and winter wheat varieties on the photosynthetic active radiation (PAR) capture ration, PAR utilization and grain yield. Field experiments involved Jimai 20 (J; high yield variety) and Lainong 0153 (L; dryland variety) with non-irrigation and irrigated at the jointing stage. The results showed that whether irrigated at jointing stage or not, there was no significant difference between J and L with respect to the amount of PAR intercepted by the winter wheat canopies. However, significant differences were observed between the varieties with respect to the amount of PAR intercepted by plants that were 60-80 cm above the ground surface. This result was mainly caused by the changes in the vertical distributions of leaf area index. As a result, the effects of the varieties and deficit irrigation on the radiation use efficiency (RUE) and grain yield of winter wheat were due to the vertical distribution of PAR in the winter wheat canopies. During the late growing season of winter wheat, irrespective of the irrigation regime, the RUE and grain yield of J were significantly higher than those of L. These results suggest that a combination of deficit irrigation and a suitable winter wheat variety should be applied in North China

  16. Effect of irrigation, intercrop and cultivar on agronomic and nutritional characteristics of quinoa

    Science.gov (United States)

    A field experiment was conducted to determine the effect of three irrigation regimes and three intercrop treatments on emergence, plant height, seed yield, protein and mineral concentration of two quinoa (Chenopodium quinoa) varieties. The experiment was carried out using a strip plot, randomized co...

  17. Utilizing on-farm best management practices: Managing Nitrate Leaching Using Evapotranspiration Based Irrigation Methods

    Science.gov (United States)

    Zaragosa, I.; Melton, F. S.; Dexter, J.; Post, K.; Haffa, A.; Kortman, S.; Spellenberg, R.; Cahn, M.

    2017-12-01

    In efforts to provide tools to allow farmers to optimize and quantify water usage and fertilizer applications, University of California Cooperative Extension (UCCE) developed the CropManage irrigation and nitrogen scheduling tool that provides real time evapotranspiration (ETc) based irrigation recommendations and fertilizer recommendations on a per field basis. CropManage incorporates satellite based estimates of fractional cover from web data services from the Satellite Irrigation Management Information Support (SIMS) system developed by NASA Ames Research Center in collaboration with California State University Monterey Bay (CSUMB). In this study, we conducted field trials to quantify the benefits of using these tools to support best management practices (BMPs) for irrigation and nutrient management in strawberries and lettuce in the Salinas Valley, California. We applied two different irrigation treatments based on full replacement (100%) of crop evapotranspiration (ETc), and irrigation at 130% of ETc replacement to approximate irrigation under business as usual irrigation management. Both field studies used a randomized block design with four replicates each. We used CropManage to calculate the 100% and 130% ETc replacement requirements prior to each irrigation event. We collected drainage volume and samples and analyzed them for 8500 to nitrate as (NO3-) concentrations. Experimental results for both strawberries and lettuce showed a significant decrease in the percentage of applied nitrogen leached for the 100% ETc replacement treatment against the 130% ETc replacement treatment. For strawberries, we observed that 24% of applied nitrogen was leached under the 100% ETc replacement treatment, versus 51% of applied nitrogen that was leached under the 130% ETc replacement treatment. For lettuce, we observe that 2% of the applied nitrogen leached bellow the soil profile, versus 6% of the applied nitrogen for the 130%ETc replacement treatment. In both experiments

  18. Arctic Observing Experiment (AOX) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Rigor, Ignatius [Applied Physics Lab, University of Washington; Johnson, Jim [Applied Physics Lab, University of Washington; Motz, Emily [National Ice Center; Bisic, Aaron [National Ice Center

    2017-06-30

    Our ability to understand and predict weather and climate requires an accurate observing network. One of the pillars of this network is the observation of the fundamental meteorological parameters: temperature, air pressure, and wind. We plan to assess our ability to measure these parameters for the polar regions during the Arctic Observing Experiment (AOX, Figure 1) to support the International Arctic Buoy Programme (IABP), Arctic Observing Network (AON), International Program for Antarctic Buoys (IPAB), and Southern Ocean Observing System (SOOS). Accurate temperature measurements are also necessary to validate and improve satellite measurements of surface temperature across the Arctic. Support for research associated with the campaign is provided by the National Science Foundation, and by other US agencies contributing to the US Interagency Arctic Buoy Program. In addition to the support provided by the U.S Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s North Slope of Alaska (NSA) site at Barrow and the National Science Foundation (NSF), the U.S. IABP is supported by the U.S. Coast Guard (USCG), the National Aeronautics and Space Administration (NASA), the National Ice Center (NIC), the National Oceanic and Atmospheric Administration (NOAA), and the Office of Naval Research (ONR).

  19. Effect of tillage on water advance and distribution under surge and continuous furrow irrigation methods for cotton in Egypt

    NARCIS (Netherlands)

    Ismail, S.M.

    2006-01-01

    A field experiment was carried out to assess the effect of tillage on water advance and water distribution in the root zone area (0.5 m) under continuous and surge flow irrigation in a cotton field. The experiment was conducted at the Agriculture Experimental Station, Assiut University, Assiut,

  20. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    We show that societies with a history of irrigation-based agriculture have been less likely to adopt democracy than societies with a history of rainfed agriculture. Rather than actual irrigation, the empirical analysis is based on how much irrigation potentially can increase yields.Irrigation pot...

  1. Mapping daily evapotranspiration at field scales over rainfed and irrigated agricultural areas using remote sensing data fusion

    Science.gov (United States)

    A continuous monitoring of daily evapotranspiration (ET) at field scale can be achieved by combining thermal infrared remote sensing data information from multiple satellite platforms. Here, an integrated approach to field scale ET mapping is described, combining multi-scale surface energy balance e...

  2. Magnetic field saturation in the Riga dynamo experiment.

    Science.gov (United States)

    Gailitis, A; Lielausis, O; Platacis, E; Dement'ev, S; Cifersons, A; Gerbeth, G; Gundrum, T; Stefani, F; Christen, M; Will, G

    2001-04-02

    After the dynamo experiment in November 1999 [A. Gailitis et al., Phys. Rev. Lett. 84, 4365 (2000)] had shown magnetic field self-excitation in a spiraling liquid metal flow, in a second series of experiments emphasis was placed on the magnetic field saturation regime as the next principal step in the dynamo process. The dependence of the strength of the magnetic field on the rotation rate is studied. Various features of the saturated magnetic field are outlined and possible saturation mechanisms are discussed.

  3. Effect of different irrigation systems on root growth of maize and cowpea plants in sandy soil

    Directory of Open Access Journals (Sweden)

    Noha A. Mahgoub

    2017-10-01

    Full Text Available A field experiment was conducted at the Experimental Farm, Faculty of Agriculture, Suez Canal University to study the influence of different irrigation systems on root length density and specific root length of maize and cowpea plants cultivated in sandy soil. Three irrigation systems (Surface, drip and sprinkler irrigation were used in this study. The NPK fertilizers were applied as recommended doses for maize and cowpea. Root samples were collected from the soil profile below one plant (maize and cowpea which was irrigated by the three irrigation systems by using an iron box (30 cm× 20 cm which is divided into 24 small boxes each box is (5× 5 × 5 cm. At surface irrigation, root length density of cowpea reached to soil depth 30-40cm with lateral distances 5-10 cm and 15-20 cm. Vertical distribution of root length density of maize was increased with soil depth till 20-25 cm, and then it decreased till soil depth 35-40cm. Under drip irrigation, root length density of cowpea increased horizontally from 0-5cm to 10-15cm then it decreased till soil depth 25-30 cm and below this depth root length density disappeared. For the root length density and specific root length of maize under drip irrigation, the data showed that root length density and specific root length decreased with increasing in soil depth. The root length density of cowpea under sprinkler irrigation at 0-5cm disappeared from horizontal distance at 25-30 cm. The data showed that root length density of maize under sprinkler irrigation was higher at the soil top layers 0-5 cm and 5-10 cm than other layers from 10-40 cm.

  4. Proton and deuterium NMR experiments in zero field

    International Nuclear Information System (INIS)

    Millar, J.M.

    1986-02-01

    High field solid-state NMR lineshapes suffer from inhomogeneous broadening since resonance frequencies are a function of molecular orientation. Time domain zero field NMR is a two-dimensional field-cycling technique which removes this broadening by probing the evolution of the spin system under zero applied field. The simplest version, the sudden transition experiment, induces zero field evolution by the sudden removal of the applied magnetic field. Theory and experimental results of this experiment and several variations using pulsed dc magnetic fuelds to initiate zero field evolution are presented. In particular, the pulsed indirect detection method allows detection of the zero field spectrum of one nuclear spin species via another (usually protons) by utilizing the level crossings which occur upon adiabatic demagnetization to zero field. Experimental examples of proton/deuteron systems are presented which demonstrate the method results in enhanced sensitivity relative to that obtained in sudden transition experiments performed directly on deuterium. High resolution 2 H NQR spectra of a series of benzoic acid derivatives are obtained using the sudden transition and indirect detection methods. Librational oscillations in the water molecules of barium chlorate monohydrate are studied using proton and deuterium ZF experiments. 177 refs., 88 figs., 2 tabs

  5. Syringe irrigation: blending endodontics and fluid dynamics

    NARCIS (Netherlands)

    Boutsioukis, C.; van der Sluis, L.W.M.; Basrani, B.

    2015-01-01

    Syringe irrigation remains a widely used irrigant delivery method during root canal treatment. An interdisciplinary approach involving well-established methods from the field of fluid dynamics can provide new insights into the mechanisms involved in cleaning and disinfection of the root canal system

  6. Attention discrimination: theory and field experiments with monitoring information acquisition

    Czech Academy of Sciences Publication Activity Database

    Bartoš, Vojtěch; Bauer, Michal; Chytilová, Julie; Matějka, Filip

    2016-01-01

    Roč. 106, č. 6 (2016), s. 1437-1475 ISSN 0002-8282 Institutional support: RVO:67985998 Keywords : inattention * discrimination * field experiment Subject RIV: AH - Economics Impact factor: 4.026, year: 2016

  7. Diversity and population dynamics of pests and predators in irrigated rice fields with treated and untreated pesticide.

    Science.gov (United States)

    Rattanapun, W

    2012-01-01

    The monitoring of rice pests and their predators in pesticide untreated and treated rice fields was conducted at the southern of Thailand. Twenty-two species in 15 families and 6 orders of rice pests were sampled from untreated rice field. For treated rice field, 22 species in 14 families and 5 orders of rice pest were collected. Regardless of treatment type, dominant species and individual number of rice pest varied to physiological stage of rice. Lepidopteran pests had highest infestation during the vegetative stage of rice growth, while hemipteran pests composed of hopper species (Hemipetra: Auchenorrhyncha) and heteropteran species (Hemiptera: Heteroptera) were dominant groups during the reproductive stage and grain formation and ripening stage of rice growth. In contrast, dominant species of predator did not change throughout rice growing season. There were 35 species in 25 families and seven orders and 40 species in 29 families and seven orders of predators collected from untreated and treated rice field, respectively. Major predators of both rice fields were Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae), Tetragnatha sp. (Araneae: Tetragnathidae) and Agriocnemis pygmaea Rambur (Odonata: Agrionidae). The population dynamic of predators were not related with rice pest population in both treatments. However, the fluctuation of population pattern of rice pests in the untreated treatment were more distinctly synchronized with their predators than that of the treated treatment. There were no significant differences in the total number of rice pest and predator between two treatments at vegetative and reproductive stages of rice growth. Untreated rice field had a higher population number of predator and a lower population number of rice pest than that of treated rice field during grain formation and ripening stages. These results indicated the ago-ecosystem balance in rice fields could be produced through minimal pesticide application, in order to allow

  8. Incentives versus sorting in tournaments: evidence from a field experiment

    NARCIS (Netherlands)

    Leuven, E.; Oosterbeek, H.; Sonnemans, J.; van der Klaauw, B.

    2011-01-01

    Existing field evidence on rank-order tournaments typically does not allow disentangling incentive and sorting effects. We conduct a field experiment illustrating the confounding effect. Students in an introductory microeconomics course selected themselves into tournaments with low, medium, or high

  9. Superparamagnetic beads in rotating magnetic fields: microfluidic experiments

    NARCIS (Netherlands)

    Den Toonder, J.M.J.; Bokdam, M.

    2008-01-01

    The effect of the Mason number, ratio of viscous and magnetic force, on suspended superparamagnetic micro sized beads was investigated experimentally. Microfluidic experiments were performed in a set-up that generates a rotating homogeneous magnetic field. In the presence of a magnetic field, the

  10. [Effect of mineral N fertilizer reduction and organic fertilizer substitution on soil biological properties and aggregate characteristics in drip-irrigated cotton field.

    Science.gov (United States)

    Li, Rui; Tai, Rui; Wang, Dan; Chu, Gui-Xin

    2017-10-01

    A four year field study was conducted to determine how soil biological properties and soil aggregate stability changed when organic fertilizer and biofertilizer were used to reduce chemical fertilizer application to a drip irrigated cotton field. The study consisted of six fertilization treatments: unfertilized (CK); chemical fertilizer (CF, 300 kg N·hm -2 ; 90 kg P2O5 · hm -2 , 60 kg K2 O·hm -2 ); 80% CF plus 3000 kg·hm -2 organic fertilizer (80%CF+OF); 60% CF plus 6000 kg·hm -2 organic fertilizer (60%CF+OF); 80% CF plus 3000 kg·hm -2 biofertilizer (80%CF+BF); and 60% CF plus 6000 kg·hm -2 biofertilizer (60%CF+BF). The relationships among soil organic C, soil biological properties, and soil aggregate size distribution were determined. The results showed that organic fertilizer and biofertilizer both significantly increased soil enzyme activities. Compared with CF, the biofertilizer treatments increased urease activity by 55.6%-84.0%, alkaline phosphatise activity by 53.1%-74.0%, invertase activity by 15.1%-38.0%, β-glucosidase activity by 38.2%-68.0%, polyphenoloxidase activity by 29.6%-52.0%, and arylsulfatase activity by 35.4%-58.9%. Soil enzyme activity increased as the amount of organic fertilizer and biofertilizer increased (i.e., 60%CF+OF > 80%CF+OF, 60%CF+BF > 80%CF+BF). Soil basal respiration decreased significantly in the order BF > OF > CF > CK. Soil microbial biomass C and N were 22.3% and 43.5% greater, respectively, in 60%CF+BF than in CF. The microbial biomass C:N was significantly lower in 60%CF+BF than in CF. The organic fertilizer and the biofertilizer both improved soil aggregate structure. Soil mass in the >0.25 mm fraction was 7.1% greater in 80%CF+OF and 8.0% greater in (60%CF+OF) than in CF. The geometric mean diameter was 9.2% greater in 80%CF+BF than in 80%CF+OF. Redundancy analysis and cluster analysis both demonstrated that soil aggregate structure and biological activities increased when organic fertilizer and biofertilizer were

  11. Willingness to pay for more efficient irrigation techniques in the Lake Karla basin, Greece.

    Science.gov (United States)

    Mylopoulos, Nikitas; Fafoutis, Chrysostomos

    2014-05-01

    Thessaly, the second largest plain of Greece, is an intensively cultivated agricultural region. The intense and widespread agriculture of hydrophilic crops, such as cotton, has led to a remarkable water demand increase, which is usually covered by the overexploitation of groundwater resources. The Lake Karla basin is a prominent example of this unsustainable practice. Competition for the limited available freshwater resources in the Lake Karla basin is expected to increase in the near future as demand for irrigation water increases and drought years are expected to increase due to climate change. Together with the Unions of Agricultural Cooperatives, the Local Organizations of Land Reclamation is planning to introduce more efficient, water saving automated drip irrigation in the area among farmers who currently use non-automated drip irrigation, in order to ensure that these farmers can better cope with drought years and that water will be used more efficiently in crop production. Saving water use in irrigated agriculture is expected to be beneficial to both farmers and the restoration of Lake Karla and its wildlife like plants and birds. The aim of this study is to understand and record the farmers' opinions regarding the use of irrigation water and the restoration of Lake Karla, and to extract valuable conclusions and perform detailed analysis of the criteria for a new irrigation method. A general choice experiment with face-to-face interviews was conducted, using a random sample of 150 open field farmers from the study area. The farmers, who use the non-automated drip irrigation method and their farms are located within the watershed of Lake Karla, were interviewed regarding their willingness to switch to more efficient irrigation techniques, such as automated and controlled drip irrigation.The most important benefits of automated drip irrigation are an increase in crop yield, as plants are given water in a more precise way (based on their needs during the

  12. Using Automation to Improve Surface Irrigation Management

    Science.gov (United States)

    In the Lower Mississippi Water Resource Area (WRA 08), also called the Mid-South, 2 million ha of cropland (80% of the irrigated farmland) employ surface irrigation, almost equally divided between furrow (52%) and controlled flooding (48%). Because Mid-South farmers experience less-than-optimal surf...

  13. Evaluation of the Effect of Different Irrigation Levels of Drip Irrigation (Tape on Yield and Yield Components of Corn

    Directory of Open Access Journals (Sweden)

    mohammad karimi

    2016-02-01

    Full Text Available Introduction: One of the serious problems in the further development of maize cultivation is increasing irrigation efficiency. Using conventional irrigation causes a shortage of water resources to increase the acreage of the crop. With regard to the development of maize cultivation, agronomic and executable methods must be studied to reduce water consumption. Using drip irrigation system is most suitable for row crops. Hamedi et al. (2005 compared drip (tape and surface irrigation systems on yield of maize in different levels of water requirement and indicated that drip irrigation increases the amount of yield to 2015 kg/ha and water use efficiency to 3 time. Kohi et al. (2005 investigated the effects of deficit irrigation use of drip (tape irrigation on water use efficiency on maize in planting of one and two rows. The results showed that maximum water use efficiency related to crop density, water requirement and planting pattern 85000, 125% and two rows, respectively with 1.46 kg/m3. Jafari and Ashrafi (2011 studied the effects of irrigation levels, plant density and planting pattern in drip irrigation (tape on corn. The results showed that the amount of irrigation water and crop density on the level of 1% and their interactions and method of planting were significant at the 5 and 10% on water use efficiency, respectively. The yield was measured under different levels of irrigation, crop density and method of planting and the difference was significant on the level of 1%. Lamm et al. (1995 studied water requirement of maize in field with silt loam texture under sub drip irrigation and reported that water use reduced to 75%; but yield of maize remained at maximum amount of 12.5 t/ha. The objective of this study was to evaluate the drip (tape irrigation method for corn production practices in the Qazvin province in Iran. Materials and Methods: In this study, yield and yield components of corn (SC 704 were investigated under different levels of

  14. Strategies to evaluate goodness of reference strips for in-season, field scale, irrigated corn nitrogen sufficiency

    Science.gov (United States)

    The nitrogen (N) sufficiency approach to assess plant N status for in-season N management requires a non-N-limiting reference to make N recommendations. Use of reference strips in fields with spatially variable soils and the impact this variability has within N enriched reference strips are not we...

  15. Evaluation of potential water conservation using site-specific irrigation

    Science.gov (United States)

    With the advent of site-specific variable-rate irrigation (VRI) systems, irrigation can be spatially managed within sub-field-sized zones. Spatial irrigation management can optimize spatial water use efficiency and may conserve water. Spatial VRI systems are currently being managed by consultants ...

  16. Tracking antibiotic resistance genes in soil irrigated with dairy wastewater

    Science.gov (United States)

    In southern Idaho, the application of dairy wastewater to agricultural soils is a widely used practice to irrigate crops and recycle nutrients. In this study, small-scale field plots were irrigated monthly (6 times) with dairy wastewater (100%), wastewater diluted to 50% with irrigation (canal) wate...

  17. Weed Control with Cover Crops in Irrigated Potatoes

    OpenAIRE

    G.H. Mehring; J.E. Stenger; H.M. Hatterman-Valenti

    2016-01-01

    Field experiments at Oakes, ND, USA in 2010 and Carrington, ND, USA in 2011 were conducted to evaluate the potential for cover crops grown in the Northern Great Plains, USA in order to reduce weed emergence and density in irrigated potatoes. Treatments included five cover crop treatments and three cover crop termination treatments. Termination of cover crops was done with glyphosate, disk-till, and roto-till. Cover crop biomass accumulation was greatest for rye/canola and triticale at Oakes, ...

  18. Operational experience gained from the Central Brae subsea field

    International Nuclear Information System (INIS)

    Sapp, S.J.; Gomersall, S.D.

    1994-01-01

    The size of the field discoveries made in the North Sea in recent years has declined dramatically. With the low oil price many small fields are not viable stand alone developments. The North Sea has a large, well developed infrastructure of production facilities and pipelines. With many platforms now operating below optimum production rate, subsea tieback of these small fields utilizing the available processing capacity is the most economically attractive means of development. This paper presents a history of such a field development. The Central Brae field is located within the Brae complex of fields, 155 miles north east of Aberdeen, and has been developed by means of a subsea facility tied back to the Brae Alpha platform. A great deal of experience has been gained through the field development, not only in subsea operations but also in completion and template design and operating philosophy

  19. Sediment Transport Model for a Surface Irrigation System

    Directory of Open Access Journals (Sweden)

    Damodhara R. Mailapalli

    2013-01-01

    Full Text Available Controlling irrigation-induced soil erosion is one of the important issues of irrigation management and surface water impairment. Irrigation models are useful in managing the irrigation and the associated ill effects on agricultural environment. In this paper, a physically based surface irrigation model was developed to predict sediment transport in irrigated furrows by integrating an irrigation hydraulic model with a quasi-steady state sediment transport model to predict sediment load in furrow irrigation. The irrigation hydraulic model simulates flow in a furrow irrigation system using the analytically solved zero-inertial overland flow equations and 1D-Green-Ampt, 2D-Fok, and Kostiakov-Lewis infiltration equations. Performance of the sediment transport model was evaluated for bare and cropped furrow fields. The results indicated that the sediment transport model can predict the initial sediment rate adequately, but the simulated sediment rate was less accurate for the later part of the irrigation event. Sensitivity analysis of the parameters of the sediment module showed that the soil erodibility coefficient was the most influential parameter for determining sediment load in furrow irrigation. The developed modeling tool can be used as a water management tool for mitigating sediment loss from the surface irrigated fields.

  20. Speed control variable rate irrigation

    Science.gov (United States)

    Speed control variable rate irrigation (VRI) is used to address within field variability by controlling a moving sprinkler’s travel speed to vary the application depth. Changes in speed are commonly practiced over areas that slope, pond or where soil texture is predominantly different. Dynamic presc...

  1. Ring Irrigation System (RIS) design through customer preference representation

    OpenAIRE

    Ridwan Infandra I.Z.; Rianmora Suchada; Werawatganon Siwat

    2018-01-01

    In agricultural field, irrigation is one of the most interesting considerations affecting the rate of plant growth and development. Micro-irrigation as the dripping or sprinkle method is one of the irrigation types that applies the small amount of water for fulfilling the humidity requirement. The most important factors affecting the demand of water for plants are soil conditions and effect of climatic factors. With less human labour required, to improve the irrigation method from the recent ...

  2. South American Field Experience: An Initiative in International Education. The Implementation Journal for the South American Field Experience.

    Science.gov (United States)

    Martin, William J.

    A description is provided of Williamsport Area Community College's (WACC's) South American Field Experience program, a travel/study program for faculty and staff designed to provide a variety of learning experiences through a three week trip to Peru, Chile, Argentina, and Brazil. Chapter I presents an overview of the development of the project,…

  3. Limited irrigation research and infrared thermometry for detecting water stress

    Science.gov (United States)

    The USDA-ARS Limited Irrigation Research Farm, located outside of Greeley Colorado, is an experiment evaluating management perspectives of limited irrigation water. An overview of the farm systems is shown, including drip irrigation systems, water budgeting, and experimental design, as well as preli...

  4. Ecophysiological Evaluation of Three Maize (Zea mays L. Cultivars under Irrigation Regimes and Use of Super Absorbent

    Directory of Open Access Journals (Sweden)

    Allahyar Hassanzadeh

    2016-03-01

    Full Text Available To evaluate the effects of using super absorbent and irrigation regimes on seed yield and yield components of maize cultivars a split plot experiment based on randomized complete block design with three replications was performed at the Research Field of Malekan Islamic Azad University. Main factor consisted of three irrigation regimes (irrigation after 70, 110 and 150 mm evaporation from pan and subfactor of two levels of super absorbent applications (application and without application and three maize cultivars (704, Iranian maxima and overseas maxima. Based on the results obtained it was revealed that highest seed yield (985 g/m2 belonged to the plants irrigated after 70 mm evaporation from the pan without using super absorbent. Irrigation after evaporation of 150 mm from the pan decreased both seed numbers per plant and 100 seed weight, and seed yield loss amounted to be 46.1% as compared with irrigation after 70 mm evaporation from the pan. Without using super absorbent and irrigation after 150 mm evaporation from the pan decreased seed number per ear by 38.8% and 100 seed weight by 13.8%. However, application of super absorbent and irrigation of plants after 150 mm evaporation from the pan increased by grain yield 38% as compared with out using super absorbent. There were not significant difference between cultivars for seed yield and yield components. It could be concluded that application of super absorbent under water shortage conditions may reduce crop yield losses.

  5. Effects of Sowing Date and Limited Irrigation on Yield and Yield Components of Five Rainfed Wheat Varieties in Maragheh Region

    Directory of Open Access Journals (Sweden)

    A. R. Tavakkoli

    2013-03-01

    Full Text Available In order to investigate the effects of sowing date (SD and single irrigation (SI amounts on yield and yield components of rainfed wheat varieties, a field experiment was conducted as split-split plots arranged in a randomized complete blocks design with three replications during 2002-2004 at main station of Dryland Agricultural Research Institute in Maragheh, Iran. Treatments included three sowing dates (early, normal and late, three levels of single irrigation (rainfed, 50 mm and 100 mm only at planting time and five wheat varieties (three numbered lines, Azar2 and double-cross Shahi. Results revealed that interactions of SD, SI and wheat varieties were significant for grain yield, number of kernels per spike and water productivity (P≤0.01. Single irrigation at normal planting time increased grain yield, straw, biomass, harvest index, and water productivity. Grain yield and water productivity were increased by 131% and 84.8%, respectively. Single irrigation at late planting time was not significant on agronomic traits and produced low water productivity. Regarding the reaction of wheat to planting date and single irrigation, results showed that normal single irrigation can improve yield, yield components and water productivity index. The effectiveness of single irrigation under dryland conditions can be observed in all wheat cultivars. Although this effectiveness on yield and yield components is observable, but it is necessary to select the time of irrigation properly.

  6. Influencing attitudes toward science through field experiences in biology

    Science.gov (United States)

    Carpenter, Deborah Mcintyre

    The purpose of this study was to determine how student attitudes toward science are influenced by field experiences in undergraduate biology courses. The study was conducted using two institutions of higher education including a 2-year lower-level and a 2-year upper-level institution. Data were collected through interviews with student participants, focus group discussions, students' journal entries, and field notes recorded by the researcher during the field activities. Photographs and video recordings were also used as documentation sources. Data were collected over a period of 34 weeks. Themes that emerged from the qualitative data included students' beliefs that field experiences (a) positively influence student motivation to learn, (b) increase student ability to learn the concepts being taught, and (c) provide opportunities for building relationships and for personal growth. The findings of the study reinforce the importance of offering field-study programs at the undergraduate level to allow undergraduate students the opportunity to experience science activities in a field setting. The research study was framed by the behavioral and developmental theories of attitude and experience including the Theory of Planned Behavior (Ajzen, 1991) and the Theory of Experiential Learning (Kolb, 1984).

  7. Grimsel Test Site: modelling radionuclide migration field experiments

    International Nuclear Information System (INIS)

    Heer, W.; Hadermann, J.

    1994-09-01

    In the migration field experiments at Nagra's Grimsel Test Site, the processes of nuclide transport through a well defined fractured shear-zone in crystalline rock are being investigated. For these experiments, model calculations have been performed to obtain indications on validity and limitation of the model applied and the data deduced under field conditions. The model consists of a hydrological part, where the dipole flow fields of the experiments are determined, and a nuclide transport part, where the flow field driven nuclide propagation through the shear-zone is calculated. In addition to the description of the model, analytical expressions are given to guide the interpretation of experimental results. From the analysis of experimental breakthrough curves for conservative uranine, weakly sorbing sodium and more stronger sorbing strontium tracers, the following main results can be derived: i) The model is able to represent the breakthrough curves of the migration field experiments to a high degree of accuracy, ii) The process of matrix diffusion is manifest through the tails of the breakthrough curves decreasing with time as t -3/2 and through the special shape of the tail ends, both confirmed by the experiments, iii) For nuclide sorbing rapidly, not too strongly, linearly, and exhibiting a reversible cation exchange process on fault gouge, the laboratory sorption coefficient can reasonably well be extrapolated to field conditions. Adequate care in selecting and preparing the rock samples is, of course, a necessary requirement. Using the parameters determined in the previous analysis, predictions are made for experiments in a smaller an faster flow field. For conservative uranine and weakly sorbing sodium, the agreement of predicted and measured breakthrough curves is good, for the more stronger sorbing strontium reasonable, confirming that the model describes the main nuclide transport processes adequately. (author) figs., tabs., 29 refs

  8. Irrigation as an Historical Climate Forcing

    Science.gov (United States)

    Cook, Benjamin I.; Shukla, Sonali P.; Puma, Michael J.; Nazarenko, Larissa S.

    2014-01-01

    Irrigation is the single largest anthropogenic water use, a modification of the land surface that significantly affects surface energy budgets, the water cycle, and climate. Irrigation, however, is typically not included in standard historical general circulation model (GCM) simulations along with other anthropogenic and natural forcings. To investigate the importance of irrigation as an anthropogenic climate forcing, we conduct two 5-member ensemble GCM experiments. Both are setup identical to the historical forced (anthropogenic plus natural) scenario used in version 5 of the Coupled Model Intercomparison Project, but in one experiment we also add water to the land surface using a dataset of historically estimated irrigation rates. Irrigation has a negligible effect on the global average radiative balance at the top of the atmosphere, but causes significant cooling of global average surface air temperatures over land and dampens regional warming trends. This cooling is regionally focused and is especially strong in Western North America, the Mediterranean, the Middle East, and Asia. Irrigation enhances cloud cover and precipitation in these same regions, except for summer in parts of Monsoon Asia, where irrigation causes a reduction in monsoon season precipitation. Irrigation cools the surface, reducing upward fluxes of longwave radiation (increasing net longwave), and increases cloud cover, enhancing shortwave reflection (reducing net shortwave). The relative magnitude of these two processes causes regional increases (northern India) or decreases (Central Asia, China) in energy availability at the surface and top of the atmosphere. Despite these changes in net radiation, however, climate responses are due primarily to larger magnitude shifts in the Bowen ratio from sensible to latent heating. Irrigation impacts on temperature, precipitation, and other climate variables are regionally significant, even while other anthropogenic forcings (anthropogenic aerosols

  9. Irrigation of steppe soils in the south of Russia: Problems and solutions (Analysis of Irrigation Practices in 1950-1990)

    Science.gov (United States)

    Minashina, N. G.

    2009-07-01

    Experience in irrigation of chernozems in the steppe zone of Russia for a period from 1950 to 1990 is analyzed. By the end of this period and in the subsequent years, the areas under irrigation reduced considerably, and the soil productivity worsened. This was caused by the improper design of irrigation systems, on the one hand, and by the low tolerance of chernozems toward increased moistening upon irrigation, on the other hand. The analysis of the factors and regimes of soil formation under irrigation conditions shows that irrigation-induced changes in the soil hydrology also lead to changes in the soil physicochemical, biochemical, and other properties. In particular, changes in the composition of exchangeable cations lead to the development of solonetzic process. In many areas, irrigation of chernozems was accompanied by the appearance of solonetzic, vertic, saline, and eroded soils. The development of soil degradation processes is described. In general, the deterioration of irrigated chernozems was related to the absence of adequate experience in irrigation of steppe soils, unskilled personnel, improper regime of irrigation, and excessively high rates of watering. In some cases, the poor quality of irrigation water resulted in the development of soil salinization and alkalization. To improve the situation, the training of personnel is necessary; the strategy of continuous irrigation should be replaced by the strategy of supplementary irrigation in the critical periods of crop development.

  10. Spatiotemporal monitoring of soil water content profiles in an irrigated field using probabilistic inversion of time-lapse EMI data

    KAUST Repository

    Moghadas, Davood

    2017-10-17

    Monitoring spatiotemporal variations of soil water content (θ) is important across a range of research fields, including agricultural engineering, hydrology, meteorology and climatology. Low frequency electromagnetic induction (EMI) systems have proven to be useful tools in mapping soil apparent electrical conductivity (σa) and soil moisture. However, obtaining depth profile water content is an area that has not been fully explored using EMI. To examine this, we performed time-lapse EMI measurements using a CMD mini-Explorer sensor along a 10 m transect of a maize field over a 6 day period. Reference data were measured at the end of the profile via an excavated pit using 5TE capacitance sensors. In order to derive a time-lapse, depth-specific subsurface image of electrical conductivity (σ), we applied a probabilistic sampling approach, DREAM(ZS), on the measured EMI data. The inversely estimated σ values were subsequently converted to θ using the Rhoades et al. (1976) petrophysical relationship. The uncertainties in measured σa, as well as inaccuracies in the inverted data, introduced some discrepancies between estimated σ and reference values in time and space. Moreover, the disparity between the measurement footprints of the 5TE and CMD Mini-Explorer sensors also led to differences. The obtained θ permitted an accurate monitoring of the spatiotemporal distribution and variation of soil water content due to root water uptake and evaporation. The proposed EMI measurement and modeling technique also allowed for detecting temporal root zone soil moisture variations. The time-lapse θ monitoring approach developed using DREAM(ZS) thus appears to be a useful technique to understand spatiotemporal patterns of soil water content and provide insights into linked soil moisture vegetation processes and the dynamics of soil moisture/infiltration processes.

  11. Spatiotemporal monitoring of soil water content profiles in an irrigated field using probabilistic inversion of time-lapse EMI data

    Science.gov (United States)

    Moghadas, Davood; Jadoon, Khan Zaib; McCabe, Matthew F.

    2017-12-01

    Monitoring spatiotemporal variations of soil water content (θ) is important across a range of research fields, including agricultural engineering, hydrology, meteorology and climatology. Low frequency electromagnetic induction (EMI) systems have proven to be useful tools in mapping soil apparent electrical conductivity (σa) and soil moisture. However, obtaining depth profile water content is an area that has not been fully explored using EMI. To examine this, we performed time-lapse EMI measurements using a CMD mini-Explorer sensor along a 10 m transect of a maize field over a 6 day period. Reference data were measured at the end of the profile via an excavated pit using 5TE capacitance sensors. In order to derive a time-lapse, depth-specific subsurface image of electrical conductivity (σ), we applied a probabilistic sampling approach, DREAM(ZS) , on the measured EMI data. The inversely estimated σ values were subsequently converted to θ using the Rhoades et al. (1976) petrophysical relationship. The uncertainties in measured σa, as well as inaccuracies in the inverted data, introduced some discrepancies between estimated σ and reference values in time and space. Moreover, the disparity between the measurement footprints of the 5TE and CMD Mini-Explorer sensors also led to differences. The obtained θ permitted an accurate monitoring of the spatiotemporal distribution and variation of soil water content due to root water uptake and evaporation. The proposed EMI measurement and modeling technique also allowed for detecting temporal root zone soil moisture variations. The time-lapse θ monitoring approach developed using DREAM(ZS) thus appears to be a useful technique to understand spatiotemporal patterns of soil water content and provide insights into linked soil moisture vegetation processes and the dynamics of soil moisture/infiltration processes.

  12. Spatiotemporal monitoring of soil water content profiles in an irrigated field using probabilistic inversion of time-lapse EMI data

    KAUST Repository

    Moghadas, Davood; Jadoon, Khan Zaib; McCabe, Matthew

    2017-01-01

    Monitoring spatiotemporal variations of soil water content (θ) is important across a range of research fields, including agricultural engineering, hydrology, meteorology and climatology. Low frequency electromagnetic induction (EMI) systems have proven to be useful tools in mapping soil apparent electrical conductivity (σa) and soil moisture. However, obtaining depth profile water content is an area that has not been fully explored using EMI. To examine this, we performed time-lapse EMI measurements using a CMD mini-Explorer sensor along a 10 m transect of a maize field over a 6 day period. Reference data were measured at the end of the profile via an excavated pit using 5TE capacitance sensors. In order to derive a time-lapse, depth-specific subsurface image of electrical conductivity (σ), we applied a probabilistic sampling approach, DREAM(ZS), on the measured EMI data. The inversely estimated σ values were subsequently converted to θ using the Rhoades et al. (1976) petrophysical relationship. The uncertainties in measured σa, as well as inaccuracies in the inverted data, introduced some discrepancies between estimated σ and reference values in time and space. Moreover, the disparity between the measurement footprints of the 5TE and CMD Mini-Explorer sensors also led to differences. The obtained θ permitted an accurate monitoring of the spatiotemporal distribution and variation of soil water content due to root water uptake and evaporation. The proposed EMI measurement and modeling technique also allowed for detecting temporal root zone soil moisture variations. The time-lapse θ monitoring approach developed using DREAM(ZS) thus appears to be a useful technique to understand spatiotemporal patterns of soil water content and provide insights into linked soil moisture vegetation processes and the dynamics of soil moisture/infiltration processes.

  13. Ghana - Agriculture - Irrigation

    Data.gov (United States)

    Millennium Challenge Corporation — The Millennium Development Authority (MiDA) financed the construction of a new irrigation scheme in Kpong and the renovation of two irrigation schemes in Botanga and...

  14. The Temporal Variation of Leaf Water Potential in Pistachio under Irrigated and Non-Irrigated Conditions

    Directory of Open Access Journals (Sweden)

    Yusuf AYDIN

    2014-09-01

    Full Text Available The present study was carried out in the experimental field of Pistachio Research Institute on pistachio trees which has uzun variety that was 30 years old. The aim of this research was to determine the Leaf Water Potential (LWP of Pistacia vera L. under irrigated and non-irrigated conditions. In the study, the leaf water potential of pistachio was investigated under fully irrigated and non irrigated conditions. The leaf water potential values were measured one day before and after irrigation by using pressure chamber technique at the beginning, mid and end of irrigation season. According to the results obtained from measurements, the LWP value at the beginning of the irrigation season was -3.7 MPa at noon time due to relatively high temperature for both treatments. At the time of pre-dawn and sunset, this value increased and reached to - 1.6 MPa due to relatively low temperature. In general, the LWP values during the mid of irrigation season, in the irrigated treatments, reached to almost -2.5 MPa in the non-irrigated treatment and the value was measured as -3.68 MPa.

  15. Enhancing Adoption of Irrigation Scheduling to Sustain the Viability of Fruit and Nut Crops in California

    Science.gov (United States)

    Fulton, A.; Snyder, R.; Hillyer, C.; English, M.; Sanden, B.; Munk, D.

    2012-04-01

    stress in order to manage it in heterogeneous fields; and (iii) predicting crop responses to water stress. The capacities of this IMO include: 1. Modeling of the disposition of applied water in spatially variable fields; 2. Conjunctive scheduling for multiple fields, rather than scheduling each field independently; 3. Long range forecasting of crop water requirements to better utilize limited water or limited delivery system capacity: and 4. Explicit modeling of the uncertainties of water use and crop yield. This was one of the first efforts to employ a "Next Generation" type computer irrigation scheduling advisory model or IMO in orchard crops. This paper discusses experiences with introducing this model to fruit and nut growers of various size and scale in the northern Sacramento Valley of California and the accuracy of its forecasts of irrigation needs in fruit and nut crops. Strengths and opportunities to forge ahead in the development of a "Next Generation" irrigation scheduler were identified from this on-farm evaluation.

  16. Root canal irrigants

    OpenAIRE

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-01-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are...

  17. IRRIGATION USING SOLAR PUMP

    OpenAIRE

    Prof. Nitin P.Choudhary*1 & Ms. Komal Singne2

    2017-01-01

    In this report the described design of a PV and soil moisture sensor based automated irrigation system is introduced. This project aims to provide a human friendly, economical and automated water pumping system which eliminates the problems of over irrigation and helps in irrigation water optimization and manage it in accordance with the availability of water. Our project not only tries to modernize the irrigation practices and ensure the optimum yield by carefully fulfilling the requirements...

  18. Translocations of 2,4-D-14C Herbicides In Weed And Rice Plant On Irrigated Rice Field System

    International Nuclear Information System (INIS)

    Chairul, Sofnie M.; Idawati; Mulyadi

    2000-01-01

    The investigation of translocation 2,4-D herbicides using 14 C as tracer on irradiated rice plant system. Condition of the soil was two kinds, that is normal soil and soil 30% up normal. The soil of rice field was spray with 1μCi of 2,4-D non labelled, one week after planting. A part of rice plant and weed was determined the radioactivity after 0, 2, 4, 8, and 10 weeks after spraying. The result showed that radioactivity maximum after zero week was in root and leaf of weeds, the second weeks in root of rice, the forth weeks in rice stick, and eighth weeks in leaf of rice. This result occur at normal condition soil of solid 30 % up normal soil. The residues of 2.4-D in rice was 4,24x10 -3 ppb at normal soil and 3.16x10 -3 ppb at solid 30% up normal soil. This result still lower than rate of WHO/FAO, that is 0,05 ppm

  19. Experiments on plasma turbulence induced by strong, steady electric fields

    International Nuclear Information System (INIS)

    Hamberger, S.M.

    1975-01-01

    The author discusses the effect of applying a strong electric field to collisionless plasma. In particular are compared what some ideas and prejudices lead one to expect to happen, what computer simulation experiments tell one ought to happen, and what actually does happen in two laboratory experiments which have been designed to allow the relevant instability and turbulent processes to occur unobstructed and which have been studied in sufficient detail. (Auth.)

  20. Irrigation in endodontic treatment.

    Science.gov (United States)

    Basrani, Bettina

    2011-01-01

    The primary endodontic treatment goal is to optimize root canal disinfection and to prevent reinfection. Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal system. In this review of the literature, various irrigants and the interactions between irrigants are discussed and new delivery systems are introduced.

  1. Severe Weather Field Experience: An Undergraduate Field Course on Career Enhancement and Severe Convective Storms

    Science.gov (United States)

    Godfrey, Christopher M.; Barrett, Bradford S.; Godfrey, Elaine S.

    2011-01-01

    Undergraduate students acquire a deeper understanding of scientific principles through first-hand experience. To enhance the learning environment for atmospheric science majors, the University of North Carolina at Asheville has developed the severe weather field experience. Participants travel to Tornado Alley in the Great Plains to forecast and…

  2. Effects of limited irrigation on yield and water use efficiency of two ...

    African Journals Online (AJOL)

    The effects of irrigation on grain yield and water use efficiency was studied on two sequence replaced dryland winter wheat (Triticum aestivum L.) cultivars, Changwu 135 (CW, a new cultivar) and Pingliang 40 (PL, an old cultivar). Field experiments were carried out on Changwu country on Loess Plateau, China. Whereas ...

  3. Rice production with less irrigation water is possible in a Sahelian environment

    NARCIS (Netherlands)

    Vries, de M.E.; Rodenburg, J.; Bado, B.V.; Sow, A.; Leffelaar, P.A.; Giller, K.E.

    2010-01-01

    We investigated the possibility of saving irrigation water in rice production in a Sahelian environment with different nitrogen rates and weed control treatments. A series of field experiments was conducted at Ndiaye (shallow water table, dry and wet season) and at Fanaye (deep water table, wet

  4. Alternate furrow irrigation of four fresh-market tomato cultivars under semi-arid condition of Ethiopia – Part II: Physiological response

    Directory of Open Access Journals (Sweden)

    Ashinie Bogale

    2016-11-01

    Full Text Available Understanding the variation in physiological response to deficit irrigation together with better knowledge on physiological characteristics of different genotypes that contribute to drought adaptation mechanisms would be helpful in transferring different irrigation technologies to farmers. A field experiment was carried to investigate the physiological response of four tomato cultivars (Fetan, Chali, Cochoro and ARP Tomato d2 to moderate water deficit induced by alternate furrow irrigation (AFI and deficit irrigation (DI under semi-arid condition of Ethiopia during 2013 and 2014. The study also aimed at identifying physiological attributes to the fruit yield of tomato under different deficit irrigation techniques. A factorial combination of irrigation treatments and cultivar were arranged in a complete randomized design with three replicates. Results showed that stomatal conductance (g_s was significantly reduced while photosynthetic performance measured as chlorophyll fluorescence (Fv’/Fm’, relative water content (RWC and leaf ash content remained unaffected under deficit irrigations. Significant differences among cultivars were found for water use efficiency (WUE, g_s, chlorophyll content (Chl_SPAD, normal difference vegetation index (NDVI, leaf ash content and fruit growth rate. However, cultivar differences in WUE were more accounted for by the regulation of g_s, therefore, g_s could be useful for breeders for screening large numbers of genotypes with higher WUE under deficit irrigation condition. The study result also demonstrated that cultivar with traits that contribute to achieve higher yields under deficit irrigation strategies has the potential to increase WUE.

  5. Distributed ecohydrological modelling to evaluate irrigation system performance in Sirsa district, India II: Impact of viable water management scenarios

    NARCIS (Netherlands)

    Singh, R.; Jhorar, R.K.; Dam, van J.C.; Feddes, R.A.

    2006-01-01

    This study focuses on the identification of appropriate strategies to improve water management and productivity in an irrigated area of 4270 km2 in India (Sirsa district). The field scale ecohydrological model SWAP in combination with field experiments, remote sensing and GIS has been applied in a

  6. Evaluation some Forage Legumes in Limited Irrigation Condition

    Directory of Open Access Journals (Sweden)

    Hassan Moniri Far

    2015-11-01

    Full Text Available Forage legumes respond differently to limited irrigation regimes. Their evaluation may, thus, help to select drought tolerant types for limited irrigation conditions. In this study four type of forage legume were studied for two years in Tikma-Dash Research Station of East Azarbaijan Agricultural and Natural Research Center, Tabriz, Iran, in a randomized complete block design using split-plot experiment in 2011-2013 years. Irrigation regimes (without irrigation, one irrigation and two irrigations were assigned to main plots and four forage types (hairy vetch, grass pea, Pannonica sativa and lathyrus were assigned to subplots. The results of analysis of variance showed that the effect of irrigation on plant height, number of shoots, leaf area and plant fresh and dry weights were not significant. Howere, legume types affected these traits significantly (P≤0.01. The effect of irrigation levels and legume types on protein content of hay were significant (P

  7. Effect of Irrigation Method on Yield and Quality of Soybean%灌溉方式对大豆产量及品质的影响

    Institute of Scientific and Technical Information of China (English)

    张丽华; 谭国波; 赵洪祥; 闫伟平; 孟祥盟; 方向前; 边少锋

    2011-01-01

    Soybean are sensitive to soil moisture,in order to study the effect of irrigation methods on yield,quality of soybean and water use efficiency( WUE) ,a field experiment was carried out in 2009 and 2010. Three irrigation methods including conventional furrow irrigation,fixed furrow irrigation and alternative furrow irrigation,and three irrigation amount including 15, 22.5 and 30 mm were used in the test. The results showed that appropriate irrigation could obviously improve WUE and yield of soybean. The soybean yield increased obviously with increase of irrigation amount in 2009 which the rainfall was infrequent. The yield,pods per plant,seeds weights and WUE of alternative furrow irrigation 22. 5 mm were higher than other irrigation combinations. Rainfall mainly focused in July and August in 2010,so irrigation was carried out in September. The yield of irrigation 22.5 and 15 mm was higher than 30 mm and control obviously. The yield of irrigation 22.5 mm was higher than 15 mm obviously. The difference of yield wasn't significant between irrigation 30 mm and control. The difference of yield of different irrigation methods wasn't significant with the same irrigation amount. Pods and seeds per plant and WUE of irrigation 22. 5 mm was extremely significant higher than other irrigation amount. The number of pods and seeds and WUE of alternative furrow irrigation 22. 5 mm was extremely significant higher than other irrigation methods. Irrigation could increase soybean protein content to a certain extent. However,oil content was reduced,but the difference of quality wasn' t significant between irrigation and control. The results of two years experiments showed that alternative furrow irrigation with irrigation amount of 22. 5 mm was the best irrigation combination.%于2009和2010年采取常规灌溉、固定隔沟灌溉和交替隔沟灌溉3种灌溉方式,设置15、22.5和30 mm3个灌水量,考察灌溉方式及灌溉量对大豆产量、植株性状、品质及土壤

  8. Attention discrimination: theory and field experiments with monitoring information acquisition

    Czech Academy of Sciences Publication Activity Database

    Bartoš, Vojtěch; Bauer, M.; Chytilová, J.; Matějka, Filip

    2016-01-01

    Roč. 106, č. 6 (2016), s. 1437-1475 ISSN 0002-8282 R&D Projects: GA ČR(CZ) GA14-30724S Institutional support: PRVOUK-P23 Keywords : inattention * discrimination * field experiment Subject RIV: AH - Economics Impact factor: 4.026, year: 2016

  9. Exploring International Multicultural Field Experiences in Educational Technology

    Science.gov (United States)

    Wilder, Hilary; Ferris, Sharmila Pixy; An, Heejung

    2010-01-01

    Purpose: The purpose of this paper is to explore an online field experience between technology facilitator candidates in the USA and K-12 teachers in Namibia, to improve candidates' understanding of diversity and equity issues in the successful incorporation of information and communication technologies (ICT) in teaching and learning.…

  10. British Isles Field Experience: An Initiative in International Education.

    Science.gov (United States)

    Martin, William J.

    The British Isles Field Experience (BIFE) program was initiated at Williamsport Area Community College (WACC) to provide a group of WACC faculty and staff members with individual and group activities of a personal, professional, and cultural nature in order to promote an international perspective that can be infused into student, collegiate, and…

  11. Overview of quasi single helicity experiments in reversed field pinches

    International Nuclear Information System (INIS)

    Martin, P.; Marrelli, L.; Spizzo, G.

    2003-01-01

    We report the results of an experimental and theoretical project dedicated to the study of Quasi Single Helicity Reversed Field Pinch plasmas. The project has involved several RFP devices and numerical codes. It appears that QSH spectra are a feature common to all the experiments. (author)

  12. Psychology as Field Experience: Impact on Attitudes Toward Social Interventions.

    Science.gov (United States)

    Snellman, Lynn A.; And Others

    An innovation in the teaching of undergraduate psychology courses is the implementation of a field experience that gives students the opportunity to apply newly learned skills and knowledge in a community setting. Changes in undergraduates' attitudes toward various delinquency interventions were examined as a result of participation in a…

  13. Dynamic Incentive Effects of Relative Performance Pay: A Field Experiment

    NARCIS (Netherlands)

    J. Delfgaauw (Josse); A.J. Dur (Robert); J.A. Non (Arjan); W.J.M.I. Verbeke (Willem)

    2010-01-01

    textabstractWe conduct a field experiment among 189 stores of a retail chain to study dynamic incentive effects of relative performance pay. Employees in the randomly selected treatment stores could win a bonus by outperforming three comparable stores from the control group over the course of four

  14. Infusing Outdoor Field Experiences into the Secondary Biology Curriculum.

    Science.gov (United States)

    Owens, Ginny

    1984-01-01

    To offer students biological field experiences, teachers should use their own basic skills, be enthusiastic motivators, participate in community programs/courses/workshops to acquire additional skills/knowledge for outdoor biological education, plan outdoor excursions with safety considerations in mind, and use available resources for classroom…

  15. Rational Ignorance in Education: A Field Experiment in Student Plagiarism

    Science.gov (United States)

    Dee, Thomas S.; Jacob, Brian A.

    2012-01-01

    Plagiarism appears to be a common problem among college students, yet there is little evidence on the effectiveness of interventions designed to minimize plagiarism. This study presents the results of a field experiment that evaluated the effects of a web-based educational tutorial in reducing plagiarism. We found that assignment to the treatment…

  16. Managing neurogenic bowel dysfunction: what do patients prefer? A discrete choice experiment of patient preferences for transanal irrigation and standard bowel management

    Directory of Open Access Journals (Sweden)

    Nafees B

    2016-02-01

    Full Text Available Beenish Nafees,1 Andrew J Lloyd,2 Rachel S Ballinger,2 Anton Emmanuel3 1Health Outcomes Research, Nafees Consulting Limited, London, 2Patient-Reported Outcomes Research, ICON plc, Oxford, 3Department of Gastroenterology and Nutrition, University College Hospital, London, UK Background: Most patients with bowel dysfunction secondary to neurological illness are managed by a range of nonsurgical methods, including dietary changes, laxatives, and suppository use to transanal irrigation (TAI. The aim of the present study was to explore individuals’ preferences regarding TAI devices and furthermore investigate willingness to pay (WTP for attributes in devices in the UK. Methods: A discrete choice experiment survey was conducted to evaluate the patients’ perceived value of TAI devices. Attributes were selected based upon a literature review and input from clinicians. Interviews were conducted with three clinicians and the survey was developed and finalized with the input from both patients and professionals. The final attributes were “risk of urinary tract infections” (UTIs, “risk of fecal incontinence” (FI, “frequency of use”, “time spent on toilet”, “ease of use”, “level of control/independence”, and “cost”. Participants were recruited by a patient panel of TAI device users in the UK. Data were analyzed using the conditional logit model whereby the coefficients obtained from the model provided an estimate of the (log odds ratios (ORs of preference for attributes. WTP was also estimated for each attribute. Results: A total of 129 participants were included in the final analyses. Sixty two percent of the participants had suffered from three UTIs in the preceding year and 58% of patients reported currently experiencing FI using their current device. All attributes were significant predictors of choice. The most important attributes for participants were the “risk of FI”, “frequency of use”, and “risk of UTIs

  17. Morphophysiology of guava under saline water irrigation and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Idelfonso L. Bezerra

    Full Text Available ABSTRACT The aim of this study was to evaluate the growth of grafted guava cv. ‘Paluma’ subjected to different concentrations of salts in irrigation water and nitrogen (N fertilization. The plants were transplanted to 150 L lysimeters and under field conditions at the Science and Agri-food Technology Center of the Federal University of Campina Grande, in the municipality of Pombal - PB. The experiment was conducted in randomized block design in a 5 x 4 factorial scheme, with three replicates, and the treatments corresponded to five levels of electrical conductivity of irrigation water - ECw (0.3; 1.1; 1.9; 2.7 and 3.5 dS m-1 and four N doses (70, 100, 130 and 160% of the N dose recommended for the crop. The doses equivalent to 100% corresponded to 541.1 mg of N dm-3 of soil. Irrigation water salinity above 0.3 dS m-1 negatively affects the number of leaves, leaf area, stem diameter, dry phytomass of leaves, branches and shoots . A significant interaction between irrigation water salinity and N fertilization was observed only for the number of leaves and leaf area at 120 days after transplanting. N dose above 70% of the recommendation (378.7 mg N dm-3 soil did not mitigate the deleterious effects caused by salt stress on plant growth.

  18. Bacterial Transport in Heterogeneous Porous Media: Laboratory and Field Experiments

    Science.gov (United States)

    Fuller, M. E.

    2001-12-01

    A fully instrumented research site for examining field-scale bacterial transport has been established on the eastern shore of Virginia. Studies employing intact sediment cores from the South Oyster site have been performed to examine the effects of physical and chemical heterogeneity, to derive transport parameters, and to aid in the selection of bacterial strains for use in field experiments. A variety of innovative methods for tracking bacteria were developed and evaluated under both laboratory and field conditions, providing the tools to detect target cell concentrations in groundwater down to effects of physical and chemical heterogeneity on field-scale bacterial transport. The results of this research not only contribute to the development of more effective bioremediation strategies, but also have implications for a better understanding of bacterial movement in the subsurface as it relates to public health microbiology and general microbial ecology.

  19. Effects of surface and subsurface drip irrigation regimes with saline water on yield and water use efficiency of potato in arid conditions of Tunisia

    Directory of Open Access Journals (Sweden)

    Fathia El Mokh

    2014-12-01

    Full Text Available Field experiments were conducted on a sandy soil during spring of 2009 and autumn of 2010 in southern Tunisia for evaluating the effects of two drip irrigation methods and three irrigation regimes on soil moisture and salinity, yield and water use efficiency of potato (Solanum tuberosum L.. The surface drip (SDI and subsurface drip (SSDI irrigation methods were used. Irrigation regimes consisted in replacement of cumulated ETc when readily available water is depleted with levels of 100% (FI100, 60% (DI60 and 30% (DI30. FI100 was considered as full irrigation while DI60 and DI30 were considered as deficit irrigation regimes. Well water with an ECi of 7.0 dS/m was used for irrigation. Findings are globally consistent between the two experiments. Results show that soil moisture content and salinity were significantly affected by irrigation treatments and methods. Higher soil moisture content and lower soil salinity were maintained with SSDI than SDI for all irrigation treatments. For both irrigation methods, higher salinity and lower moisture content in the root zone are observed under DI60 and DI30 treatments compared to FI100. Potato yields were highest over two cropping periods for the SSDI method although no significant differences were observed with the SDI. Irrigation regimes resulted in significant difference in both irrigation methods on yield and its components. Yields were highest under FI100. Compared to FI100, considerable reductions in potato yields were observed under DI60 and DI30 deficit treatments resulting from a reduction in tubers number/m² and average tuber weight and size. Water use efficiency (WUE was found to vary significantly among irrigation methods and treatments and varied between 5.9 and 20.5 kg/m3. WUE of SSDI method had generally higher values than SDI. The lowest WUE values were observed for the FI100 treatment, while the highest values were obtained under DI30 treatment for both methods. SSDI method provides

  20. Microrelief-Controlled Overland Flow Generation: Laboratory and Field Experiments

    Directory of Open Access Journals (Sweden)

    Xuefeng Chu

    2015-01-01

    Full Text Available Surface microrelief affects overland flow generation and the related hydrologic processes. However, such influences vary depending on other factors such as rainfall characteristics, soil properties, and initial soil moisture conditions. Thus, in-depth research is needed to better understand and evaluate the combined effects of these factors on overland flow dynamics. The objective of this experimental study was to examine how surface microrelief, in conjunction with the factors of rainfall, soil, and initial moisture conditions, impacts overland flow generation and runoff processes in both laboratory and field settings. A series of overland flow experiments were conducted for rough and smooth surfaces that represented distinct microtopographic characteristics and the experimental data were analyzed and compared. Across different soil types and initial moisture conditions, both laboratory and field experiments demonstrated that a rough soil surface experienced a delayed initiation of runoff and featured a stepwise threshold flow pattern due to the microrelief-controlled puddle filling-spilling-merging dynamics. It was found from the field experiments that a smooth plot surface was more responsive to rainfall variations especially during an initial rainfall event. However, enhanced capability of overland flow generation and faster puddle connectivity of a rough field plot occurred during the subsequent rain events.

  1. Water Use and Crop Coefficients in Sprinkler Irrigated Rice

    Directory of Open Access Journals (Sweden)

    Antonino Spanu

    Full Text Available Field experiments were carried out during the years 2002, 2004, 2005 and 2006 to analyze water-soil-atmosphere interactions in sprinkler irrigated rice. The research was carried out in Sardinia (39º 59’ N; 8º 40’ E, at altitude 15 m. The cultivars used in the experiments, respectively in 2002 and in 2004-2005-2006, were Irat 212 and Eurosis. In each year cultivars were subjected to the same crop management. Irrigation was applied since the emergence with the sprinkler method, taking into account the loss of water from ‘Class A’ pan evaporation. Soil water content was monitored at 0.10 m intervals until 1.00-m depth using a ‘Diviner 2000’ (Sentek. In 2002 seven irrigation scheduling treatments were compared. In 2004, 2005, 2006 irrigation treatments provided for optimal soil water conditions during the growing season. In 2002 the results highlighted: 1 0-0.20 m depth was the most important layer for crop water uptake and the best correlated layer with rice rough yield; 2 the positive relationship between yield and water supply was significant until 6500 m3 ha-1 of water applied. Further seasonal irrigation volumes did not increase significantly yield. In 2004, 2005 and 2006 the analysis of the soil water balance at different crop phenological stages allowed to estimate crop coefficients (Kc using the Penman-Monteith equation and the ‘Class A’ pan evaporation (Kcev. Kc varied over the three-year period on average from 0.90 to 1.07 and 0.97, respectively for the emergence-end of tillering, end of tillering-heading and heading-maturing periods, while crop coefficients as a ratio between maximum crop evapotranspiration (ETc and Epan, Kcev ranged from 0.78 to 0.92 and 0.81 for the same time periods.

  2. Turfgrass water consumption on green and fairway as a function of turfgrass species and day number after irrigation to field capacity

    DEFF Research Database (Denmark)

    Aamlid, T S; Kvalbein, A; Kusliene, Gedrime

    Worldwide, lack of irrigation water is a serious threat to the turfgrass sector. The objective of this research was to determine crop coefficients (Kc), i.e. the ratio between actual and reference evapotranspiration, for cool season turfgrasses on greens and fairways.......Worldwide, lack of irrigation water is a serious threat to the turfgrass sector. The objective of this research was to determine crop coefficients (Kc), i.e. the ratio between actual and reference evapotranspiration, for cool season turfgrasses on greens and fairways....

  3. The electromagnetic bio-field: clinical experiments and interferences.

    Science.gov (United States)

    Burnei, G; Hodorogea, D; Georgescu, I; Gavriliu, Ş; Drăghici, I; Dan, D; Vlad, C; Drăghici, L

    2012-06-12

    One of the most important factors is the technical and scientifically rapid development that is continually modifying the world we live in and polluting it with electromagnetic radiations. A functional and structural influence of magnetic and electromagnetic field on living organisms is presented in the literature by many performed experiments. The notion of bio-field represents the electromagnetic field generated by the bio-structures, not only in their normal physiological activities but also in their pathological states. There is a tight interdependency between the bio-field and the bio-structure, which respects the primary notion of an electromagnetic field given by the Maxwell-Faraday laws, in which, the electromagnetic phenomena are simplified to the field variations. These variations can be expressed in a coherent differential equation system that bounds the field vectors to different space points at different time moments. The living organisms cannot contain electrostatic and magneto-static fields due to the intense activity of the bio-structures. The biochemical reactions that have high rhythms and speeds always impose the electrodynamics character of the biologic field that also corresponds to the stability of the protein molecule that can be explained only through a dynamic way. The existent energy is not considered an exciting agent, and it does not lead to any effects. The parameters of these elementary bio-fields cannot yet be fully known due to technical reasons. The biological structures are very complex ones and undergo continuous dynamical activity. That is why the calculus model should be related to the constant dynamics, nowadays being very difficult to express.

  4. A ``Cyber Wind Facility'' for HPC Wind Turbine Field Experiments

    Science.gov (United States)

    Brasseur, James; Paterson, Eric; Schmitz, Sven; Campbell, Robert; Vijayakumar, Ganesh; Lavely, Adam; Jayaraman, Balaji; Nandi, Tarak; Jha, Pankaj; Dunbar, Alex; Motta-Mena, Javier; Craven, Brent; Haupt, Sue

    2013-03-01

    The Penn State ``Cyber Wind Facility'' (CWF) is a high-fidelity multi-scale high performance computing (HPC) environment in which ``cyber field experiments'' are designed and ``cyber data'' collected from wind turbines operating within the atmospheric boundary layer (ABL) environment. Conceptually the ``facility'' is akin to a high-tech wind tunnel with controlled physical environment, but unlike a wind tunnel it replicates commercial-scale wind turbines operating in the field and forced by true atmospheric turbulence with controlled stability state. The CWF is created from state-of-the-art high-accuracy technology geometry and grid design and numerical methods, and with high-resolution simulation strategies that blend unsteady RANS near the surface with high fidelity large-eddy simulation (LES) in separated boundary layer, blade and rotor wake regions, embedded within high-resolution LES of the ABL. CWF experiments complement physical field facility experiments that can capture wider ranges of meteorological events, but with minimal control over the environment and with very small numbers of sensors at low spatial resolution. I shall report on the first CWF experiments aimed at dynamical interactions between ABL turbulence and space-time wind turbine loadings. Supported by DOE and NSF.

  5. Water deficit imposed by deficit irrigation at different plant growth stages of maize

    International Nuclear Information System (INIS)

    Calvache, M.; Reichardt, C.

    1995-01-01

    The purpose of this study was to identify specific growth stages of maize Crop, at which the plant is less sensitive to water stress so that irrigation can be omitted withhout significant decrease yield. The field experiment was conducted at a University experiment station, Tumbaco, Pichincha, Ecuador, during may - october 1993, on a sandy loam soil ( typic durustoll). Soil moisture was monitored with a neutron probe down to 0.70 m depth, before and 24 h after each irrigation. The actual evapotranspiration of the crop was estimated by the water - balance technique. Field water efficiency and crop water use efficiency were calculated by dividing actual grain yield by irrigation and by ETa, respectively. Nitrogen fertilizer use efficiency was calculated using N - 15 methodology in the 75 kg N/ ha treatment. From the yield data, it can be concluded that treatments which had irrigation deficit had lower yield than those that had suplementary irrigation. The flowering and yield formation stages were the most sensitive to moisture stress. Nitrogen fertilization significantly increased the grain yield. The crop water use effeciency was the lowest at the flowering and yield formation of the region, the treatments I1 and I7 had the same crop water use efficiency. The results of N - 15 labelled plots ( F1) showed that soil water deficiency significantly affects nitrogen was derived from fertilizer in treatments I3 and I7 and only 11 - 9% in the treatments I2 and I5 respectively. ( Author)

  6. Heavy-metal contamination of agricultural soils irrigated with industrial effluents

    International Nuclear Information System (INIS)

    Nabi, G.; Ashraf, M.; Aslam, M. R.

    2001-01-01

    Pakistan is facing a thread of degradation of water and land-resources by industrial effluents. To evaluated the suitability of these effluents as a source of irrigation for agriculture and the study their effects on soil chemical properties, experiments were conducted in the industrial area of Sheikhupura, where effluent from Paper and Board Mill (PBM), Leather Industry (LI) and Fertilizer Industry (FI) were being used for irrigation. At each site, two fields were selected, one irrigated with industrial effluents and the other with tube-well/canal water. The soil samples were collected and analyzed for pH, ECe, SAR and for heavy metals, such as Cu, Cd, Cr, Zn, Pb, Mn, Fe, Al and Ni. Soil receiving effluent from LI showed higher ECe and SAR values, as compared to the soils receiving other effluents. The concentration of Al was high in the soil irrigated with LI effluent. The Mn and Fe contents were higher in soils irrigated with PBM effluent. Effluent from LI is not fit for irrigation, since its recipient soil showed high concentration of Cr and also high sodicity values. Except Cr, the heavy metals were not of environmental concern. (author)

  7. Field-scale colloid migration experiments in a granite fracture

    International Nuclear Information System (INIS)

    Vilks, P.; Frost, L.H.; Bachinski, D.B.

    1997-01-01

    An understanding of particle migration in fractured rock, required to assess the potential for colloid-facilitated transport of radionuclides, can best be evaluated when the results of laboratory experiments are demonstrated in the field. Field-scale migration experiments with silica colloids were carried out at AECL's Underground Research Laboratory (URL), located in southern Manitoba, to develop the methodology for large-scale migration experiments and to determine whether colloid transport is possible over distances up to 17 m. In addition, these experiments were designed to evaluate the effects of flow rate and flow path geometry, and to determine whether colloid tracers could be used to provide additional information on subsurface transport to that provided by conservative tracers alone. The colloid migration studies were carried out as part of AECL's Transport Properties in Highly Fractured Rock Experiment, the objective of which was to develop and demonstrate methods for evaluating the solute transport characteristics of zones of highly fractured rock. The experiments were carried out within fracture zone 2 as two-well recirculating, two-well non-recirculating, and convergent flow tests, using injection rates of 5 and 101 min -1 . Silica colloids with a 20 nm size were used because they are potentially mobile due to their stability, small size and negative surface charge. The shapes of elution profiles for colloids and conservative tracers were similar, demonstrating that colloids can migrate over distances of 17 m. The local region of drawdown towards the URL shaft affected colloid migration and, to a lesser extent, conservative tracer migration within the flow field established by the two-well tracer tests. These results indicate that stable colloids, with sizes as small as 20 nm, have different migration properties from dissolved conservative tracers. (author)

  8. Biocide leaching during field experiments on treated articles.

    Science.gov (United States)

    Schoknecht, Ute; Mathies, Helena; Wegner, Robby

    2016-01-01

    Biocidal products can be sources of active substances in surface waters caused by weathering of treated articles. Marketing and use of biocidal products can be limited according to the European Biocidal Products Regulation if unacceptable risks to the environment are expected. Leaching of active substances from treated articles was observed in field experiments to obtain information on leaching processes and investigate the suitability of a proposed test method. Leaching under weathering conditions proceeds discontinuously and tends to decrease with duration of exposure. It does not only mainly depend on the availability of water but is also controlled by transport processes within the materials and stability of the observed substances. Runoff amount proved to be a suitable basis to compare results from different experiments. Concentrations of substances are higher in runoff collected from vertical surfaces compared to horizontal ones, whereas the leached amounts per surface area are higher from horizontal surfaces. Gaps in mass balances indicate that additional processes such as degradation and evaporation may be relevant to the fate of active substances in treated articles. Leached amounts of substances were considerably higher when the materials were exposed to intermittent water contact under laboratory conditions as compared to weathering of vertically exposed surfaces. Experiences from the field experiments were used to define parameters of a procedure that is now provided to fulfil the requirements of the Biocidal Products Regulation. The experiments confirmed that the amount of water which is in contact with exposed surfaces is the crucial parameter determining leaching of substances.

  9. From Perceptual Apparatus to Immersive Field of Experience

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2014-01-01

    Peter Sloterdijk ascribes to architecture the “the design of immersions” and hence the “production of embedding situations” or atmosphere (2011 (2006): 108-109), which as devised by Gernot Böhme becomes a fundamental concept of a new aesthetics (1993). Atmosphere implies affective immersion...... the immersive experiences relocate the vision within a “carnal density” (1992: 150), regaining all sensory modalities. Diverse perceptual apparatuses also defined a larger disciplinary expansion in the field of architecture and design. Conceived as sensorial activators, intensifiers of phenomena......, constitute a framework for a re-invention of perceptual worlds, providing a basis for tracing the conceptual contours of atmospheric perception, as well as for discerning the means of the production of space understood as an immersive field of experience. References: Böhme, G. (1993). "Atmosphere...

  10. Importance of rainfall and sprinkler irrigation in supporting sporulation, spread of inoculum in runoff-water, and new infections of Phytophthora ramorum under field conditions

    Science.gov (United States)

    Steve Tjosvold; David Chambers; Elizabeth. Fichtner

    2010-01-01

    If a nursery plant infected with Phytophthora ramorum is introduced in a non-infested area, then it is important to understand what environmental conditions could lead spread and infection of new hosts. Once an infected nursery plant is introduced in a nursery or landscape, moving water sources, such as from rain and irrigation events, could...

  11. Tuning the Mass of Chameleon Fields in Casimir Force Experiments

    CERN Document Server

    Brax, Ph; Davis, A C; Shaw, D J; Iannuzzi, D

    2010-01-01

    We have calculated the chameleon pressure between two parallel plates in the presence of an intervening medium that affects the mass of the chameleon field. As intuitively expected, the gas in the gap weakens the chameleon interaction mechanism with a screening effect that increases with the plate separation and with the density of the intervening medium. This phenomenon might open up new directions in the search of chameleon particles with future long range Casimir force experiments.

  12. Targets with thin ferromagnetic layers for transient field experiments

    International Nuclear Information System (INIS)

    Gallant, J.L.; Dmytrenko, P.

    1982-01-01

    Multilayer targets containing a central layer sufficiently thin so that all recoil nuclei can traverse it and subsequently stop in a suitable cubic environment have been prepared. Such targets are required in experiments making use of a magnetic field acting on an ion moving through a ferromagnetic material. The preparation and annealing of the ferromagnetic foils (iron and gadolinium) and the fabrication of the multilayer targets are described. (orig.)

  13. Prosocial Behavior and Subjective Insecurity in Violent Contexts: Field Experiments

    OpenAIRE

    V?lez, Mar?a Alejandra; Trujillo, Carlos Andres; Moros, Lina; Forero, Clemente

    2016-01-01

    Subjective insecurity is a key determinant of different forms of prosocial behavior. In Study 1, we used field experiments with farmers in Colombian villages exposed to different levels of violence to investigate how individual perceptions of insecurity affect cooperation, trust, reciprocity and altruism. To do so, we developed a cognitive-affective measure of subjective insecurity. We found that subjective insecurity has a negative effect on cooperation but influences trust and altruism posi...

  14. OVERCONFIDENCE, OMENS AND EMOTIONS: RESULTS FROM A FIELD EXPERIMENT

    OpenAIRE

    Maria De Paola; Francesca Gioia; Vincenzo Scoppa

    2013-01-01

    We analyze how overconfidence is affected by superstitious beliefs and emotions induced by positive and negative stimuli in a field experiment involving about 700 Italian students who were randomly assigned to numbered seats in their written examination sessions. According to widespread superstitions, some numbers are considered lucky, while others are considered unlucky. At the end of the examination, we asked students the grade they expected to get. We find that students tend to be systemat...

  15. An Integral, Multidisciplinary and Global Geophysical Field Experience for Undergraduates

    Science.gov (United States)

    Vázquez, O.; Carrillo, D. J.; Pérez-Campos, X.

    2007-05-01

    The udergraduate program of Geophysical Engineering at the School of Engineering, of the Univesidad Nacional Autónoma de México (UNAM), went through an update process that concluded in 2006. As part of the program, the student takes three geophysical prospecting courses (gravity and magnetics, electric, electromagnetics, and seismic methods). The older program required a three-week field experience for each course in order to gradute. The new program considers only one extended field experience. This work stresses the importance of international academic exchange, where undergraduate students could participate, such as the Summer of Applied Geophysical Experience (SAGE), and interaction with research programs, such as the MesoAmerican Subduction Experiment (MASE). Also, we propose a scheeme for this activity based on those examples; both of them have in common real geophysical problems, from which students could benefit. Our proposal covers academic and logistic aspects to be taken into account, enhancing the relevance of interaction between other academic institutions, industry, and UNAM, in order to obtain a broader view of geophysics.

  16. Dark matter effective field theory scattering in direct detection experiments

    Energy Technology Data Exchange (ETDEWEB)

    Schneck, K.; Cabrera, B.; Cerdeño, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, P.; Daal, M.; Di Stefano, P. C. F.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, J.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, P.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.

    2015-05-18

    We examine the consequences of the effective field theory (EFT) of dark matter–nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  17. [Effects of different fertilization measures on N2O emission in oil sunflower field in irrigation area of upper Yellow River].

    Science.gov (United States)

    Chen, Zhe; Chen, Yuan-yuan; Gao, Ji; Liu, Ru-liang; Yang, Zheng-li; Zhang, Ai-ping

    2015-01-01

    Agricultural soil has become the largest anthropogenic source of atmospheric nitrous oxide (N20). To estimate the impacts of long-term combined application of organic and inorganic fertilizers on N20 emission in a typical winter wheat-oil sunflower cropping system in the Ningxia irrigation area, we measured N20 fluxes using the static opaque chamber-gas chromatograph method and monitored the seasonal dynamics of related factors. Our results showed that nitrogen addition in the previous crop field significantly stimulated N2O emissions during the following oil-sunflower cultivation, and the mean fluxes of N300-OM, N240-OM1/2, N300 and N240 were (34.16 ± 9.72), (39.69 ±10.70), (27.75 ±9.57) and (26.30 ± 8.52) µg . m-2 . h-1, respectively, which were 4.09, 4.75, 3.32 and 3.15 times of the control groups. The total cumulative N2O emissions of fertilizer treatments in growing season was as high as 796.7 to 1242.5 g . hm-2, which was 2.99 to 4.67 times of the control groups. During the growing season, the rates of N2O emission in each month organic and inorganic fertlizers combined treatments were similar at high levels. N2O emission in chemical fertilizer treatments gradually decreased, and the main period of N2O emission occurred at the beginning of growing season. Taking July for example, N2O emission accounted for 41.3% to 41. 8% of total cumulative amount. The amounts of N20 emission under organic and inorganic fertilizers combined treatments were significantly higher than under chemical fertilizer treatments. The N2O emissions were not significantly different between conventional and optimized applications of nitrogen fertilizer under the same fertilizing method, either between N300-OM and N240-OM1/2, or between N300 and N240. On account of the drought, N2O emission in each treatment was mainly affected by soil moisture. N2O emission had a significant positive correlation with soil ammonium nitrogen content under combined applications of organic and inorganic

  18. Effects of deficit drip-irrigation scheduling regimes with saline water on pepper yield, water productivity and soil salinity under arid conditions of Tunisia

    Directory of Open Access Journals (Sweden)

    Kamel Nagaz

    2012-12-01

    Full Text Available A two-year study was carried out in order to assess the effects of different irrigation scheduling regimes with saline water on soil salinity, yield and water productivity of pepper under actual commercial-farming conditions in the arid region of Tunisia. Pepper was grown on a sandy soil and drip-irrigated with water having an ECi of 3.6 dS/m. Irrigation treatments consisted in water replacements of accumulated ETc at levels of 100% (FI, full irrigation, 80% (DI-80, 60% (DI-60, when the readily available water in the control treatment (FI is depleted, deficit irrigation during ripening stage (FI-MDI60 and farmer method corresponding to irrigation practices implemented by the local farmers (FM. Results on pepper yield and soil salinity are globally consistent between the two-year experiments and shows significant difference between irrigation regimes. Higher soil salinity was maintained over the two seasons, 2008 and 2009, with DI-60 and FM treatments than FI. FI-MDI60 and DI-80 treatments resulted also in low ECe values. Highest yields for both years were obtained under FI (22.3 and 24.4 t/ha although we didn’t find significant differences with the regulated deficit irrigation treatment (FI-DI60. However, the DI-80 and DI-60 treatments caused significant reductions in pepper yields through a reduction in fruits number/m² and average fruit weight in comparison with FI treatment. The FM increased soil salinity and caused significant reductions in yield with 14 to 43%, 12 to 39% more irrigation water use than FI, FI-MDI60 and DI-80 treatments, respectively, in 2008 and 2009. Yields for all irrigation treatments were higher in the second year compared to the first year. Water productivity (WP values reflected this difference and varied between 2.31 and 5.49 kg/m3. The WP was found to vary significantly among treatments, where the highest and the lowest values were observed for DI-60 treatment and FM, respectively. FI treatment provides

  19. Effects of Different Irrigation Programs on Fruit, Trunk Growth Rates, Quality and Yield of Grapefruit Trees

    OpenAIRE

    KANBER, Rıza; KÖKSAL, Harun; YAZAR, Attila; ÖZEKİCİ, Bülent; ÖNDER, Sermet

    1999-01-01

    Long-term field experiments were carried out between 1985 and 1988 to determine the effect of different irrigation intervals and pan coefficients on the fruit and trunk growth rates and yield of mature grapefruit trees grown in the Eastern Mediterranean Region of Turkey in a medium-light textured soil. Two different irrigation intervals (I 1 =15 and I 2 =25 days), and pan coefficients (k 1 =0.60 and k 2 =1.00) were used. Higher evapotranspiration values were obtained from the treatments with ...

  20. Armenia - Irrigation Infrastructure

    Data.gov (United States)

    Millennium Challenge Corporation — This study evaluates irrigation infrastructure rehabilitation in Armenia. The study separately examines the impacts of tertiary canals and other large infrastructure...

  1. The side effects of nitrification inhibitors on leaching water and soil salinization in a field experiment

    Energy Technology Data Exchange (ETDEWEB)

    Diez, J. A.; Arauzo, M.; Hernaiz, P.; Sanz, A.

    2010-07-01

    In experiments carried out in greenhouses, some authors have shown that ammonium sulphate induces greater soil acidity and salinity than other sources of N. Moreover, nitrification inhibitors (NI) tend to cause ammonium to accumulate in soil by retarding its oxidation to nitrate. This accumulated ammonium would also have an effect on soil salinity. Consequently, the aim of this paper was to evaluate the soil and leaching water salinization effects associated with adding NI, dicyandiamide (DCD) and dimethylpyrazole-phosphate (DMPP) to ammonium sulphate nitrate (ASN) fertilizer. This experiment was carried out in the field with an irrigated maize crop. Drainage and Na concentration were measured during both seasons (2006 and 2007) and leached Na was determined. The treatments with NI (DCD and DMPP) were associated with greater Na concentrations in soil solutions and consequently higher rates of Na leaching (in 2007, ASN-DCD 1,292 kg Na ha{sup -}1, ASN-DMPP 1,019 kg Na ha{sup -}1). A treatment involving only ASN also increased the Na concentration in soil and the amount of Na leached in relation to the Control (in 2007, ASN 928 kg Na ha{sup -}1 and Control 587 kg Na ha{sup -}1). The increase in the ammonium concentration in the soil due to the NI treatments could have been the result of the displacement of Na ions from the soil exchange complex through a process which finally led to an increase in soil salinity. Treatments including ammonium fertilizer formulated with NI produced a greater degree of soil salinization due to the presence of ammonium from the fertilizer and accumulated ammonium from the nitrification inhibition. (Author) 31 refs.

  2. Irrigation management strategies to improve Water Use Efficiency of potatoes crop in Central Tunisia

    Science.gov (United States)

    Ghazouani, Hiba; Provenzano, Giuseppe; Rallo, Giovanni; Mguidiche, Amel; Douh, Boutheina; Boujelben, Abdelhamid

    2015-04-01

    In Tunisia, the expansion of irrigated area and the semiarid climate make it compulsory to adopt strategies of water management to increase water use efficiency. Subsurface drip irrigation (SDI), providing the application of high frequency small irrigation volumes below the soil surface have been increasingly used to enhance irrigation efficiency. At the same time, deficit irrigation (DI) has shown successful results with a large number of crop in various countries. However, for some crops like potatoes, DI is difficult to manage due to the rapid effect of water stress on tuber yield. Irrigation frequency is a key factor to schedule subsurface drip irrigation because, even maintaining the total seasonal volume, soil wetting patterns can result different during the growth period, with consequence on crop yield. Despite the need to enhance water use efficiency, only a few studies related to deficit irrigation of horticultural crops have been made in Tunisia. Objective of the paper was to assess the effects of different on-farm irrigation strategies on water use efficiency of potatoes crop irrigated with subsurface drip irrigation in a semiarid area of central Tunisia. After validation, Hydrus-2D model was used to simulate soil water status in the root zone, to evaluate actual crop evapotranspiration and then to estimate indirectly water use efficiency (IWUE), defined as the ratio between crop yield and total amount of water supplied with irrigation. Field experiments, were carried out in Central Tunisia (10° 33' 47.0" E, 35° 58' 8.1° N, 19 m a.s.l) on a potatoes crop planted in a sandy loam soil, during the growing season 2014, from January 15 (plantation of tubers) to May 6 (harvesting). Soil water status was monitored in two plots (T1 and T2) maintained under the same management, but different irrigation volumes, provided by a SDI system. In particular, irrigation was scheduled according to the average water content measured in the root zone, with a total of 8

  3. Scheduling of Irrigation and Leaching Requirements

    Directory of Open Access Journals (Sweden)

    Amer Hassan Al-haddad

    2015-03-01

    Full Text Available Iraq depends mainly on Tigris and Euphrates Rivers to provide high percentage of agricultural water use for thousands years. At last years, Iraq is suffering from shortage in water resources due to global climate changes and unfair water politics of the neighboring countries, which affected the future of agriculture plans for irrigation, added to that the lack of developed systems of water management in the irrigation projects and improper allocation of irrigation water, which reduces water use efficiency and lead to losing irrigation water and decreasing in agricultural yield. This study aims at studying the usability of irrigation and leaching scheduling within the irrigating projects and putting a complete annual or seasonal irrigation program as a solution for the scarcity of irrigation water, the increase of irrigation efficiency, lessening the salinity in the projects and preparing an integral irrigation calendar through field measurements of soil physical properties and chemical for project selected and compared to the results of the irrigation scheduling and leaching with what is proposed by the designers. The process is accomplished by using a computer program which was designed by Water Resources Department at the University of Baghdad, with some modification to generalize it and made it applicable to various climatic zone and different soil types. Study area represented by large project located at the Tigris River, and this project was (Al-Amara irrigation project. Sufficient samples of project's soil were collected so as to identify soil physical and chemical properties and the salinity of soil and water as well as identifying the agrarian cycles virtually applied to this project. Finally, a comparison was conducted between the calculated water quantities and the suggested ones by the designers. The research results showed that using this kind of scheduling (previously prepared irrigation and leaching scheduling with its properties

  4. Soil salinity under deficit drip irrigation of potato and millet in in an arid environment

    Directory of Open Access Journals (Sweden)

    Kamel Nagaz

    2017-06-01

    Full Text Available The influence of deficit irrigation (DI with saline water on soil salinity in a drip-irrigated potato and millet fields was investigated. We had compared proportional soil salinity developed under Full and DI under drip irrigation. For both experiments, the treatments were (1 Full, control treatment where rooting zone soil water content was increased to field capacity at each irrigation; (2 DI80; (3 DI60 and DI40; 20, 40 and 60% deficit irrigation compared to Full treatment were applied, respectively. Soil salinity was assessed using the isosalinity maps constructed with grid soil sampling of plant root zone at harvest. Results show that high spatial variability was observed in salinity along soil profiles when applying saline water with drip irrigation for potato. For the DI40 and DI60 treatments, high soil salinity was recorded in the upper soil layer close to the emitter. Increase of soil salinity within soil depths of 30 cm or below was also observed under DI60 and DI40 treatments. The lowest increase was noted under the full treatment. Surface soil salinity was somewhat higher under DI60 and DI40 compared with that of full and DI80 irrigation treatments. The distribution of salts around the dripper changes during the crop season according to applied irrigation treatments, with overall higher concentrations between the drippers and towards the margin of wetted band. Iso-salinity maps at harvest of potato showed that the surface layer of 30 cm depth had the lowest salinity which gradually increased at deeper zones irrespective of the treatment. Salt accumulation essentially occurred at wetting front between the drippers and the plant row. Although salt accumulation was relatively highest along the row under DI treatments, the area of accumulation was relatively shifted toward the center between the rows and the drip line. The results also show the importance of the potato cropping season to benefit from the leaching of soluble salts with the

  5. Optimization of modern irrigation for biosaline agriculture

    International Nuclear Information System (INIS)

    Shahid, S.A.; Hasbini, B.

    2007-01-01

    significantly reduced by decreasing emitter spacing i.e. an ECe of 26, are more effective in terms of leaching capability as compared to impact sprinklers. Overlapping in sprinkler irrigation reduced the evaporation compared with single jet where no overlapping was made. This has a direct effect on soil sanity development. Wind has a significant effect on the water distribution (sprinkler experiment) and subsequent salinity development and can cause long term salinity problems. Windbreak can offer solutions to this effect. (author)

  6. Field experiment on multicomponent ion exchange in a sandy aquifer

    International Nuclear Information System (INIS)

    Bjerg, P.L.; Christensen, T.H.

    1990-01-01

    A field experiment is performed in a sandy aquifer in order to study ion exchange processes and multicomponent solute transport modeling. An injection of groundwater spiked with sodium and potassium chloride was performed over a continuous period of 37 days. The plume is monitored by sampling 350 filters in a spatial grid. The sampling aims at establishing compound (calcium, magnesium, potassium, sodium, chloride) breakthrough curves at various filters 15 to 100 m from the point of injection and areal distribution maps at various cross sections from 0 to 200 m from the point of injection. A three-dimensional multicomponent solute transport model will be used to model the field experiments. The chemical model includes cation exchange, precipitation, dissolution, complexation, ionic strength and the carbonate system. Preliminary results from plume monitoring show that the plume migration is relatively well controlled considering the scale and conditions of the experiment. The transverse dispersion is small causing less dilution than expected. The ion exchange processes have an important influence on the plume composition. Retardation of the injected ions is substantial, especially for potassium. Calcium exhibits a substantial peak following chloride due to release from the ion exchange sites on the sediment. (Author) (8 refs., 5 figs., tab.)

  7. Modelling Water Flow through Paddy Soils under Alternate Wetting and Drying Irrigation Practice

    Science.gov (United States)

    Shekhar, S.; Mailapalli, D. R.; Das, B. S.; Raghuwanshi, N. S.

    2017-12-01

    Alternate wetting and drying (AWD) irrigation practice in paddy cultivation requires an optimum soil moisture stress (OSMS) level at which irrigation water savings can be maximized without compromising the yield reduction. Determining OSMS experimentally is challenging and only possible with appropriate modeling tools. In this study, field experiments on paddy were conducted in thirty non-weighing type lysimeters during dry seasons of 2016 and 2017. Ten plots were irrigated using continuous flooding (CF) and the rest were irrigated with AWD practice at 40mb and 75mb soil moisture stress levels. Depth of ponding and soil suction at 10, 40 and 70 cm from the soil surface were measured daily from all lysimeter plots. The measured field data were used in calibration and validation of Hydrus-1D model and simulated the water flow for both AWD and CF plots. The Hydrus-1D is being used to estimate OSMS for AWD practice and compared the seasonal irrigation water input and deep percolation losses with CF practice.

  8. Effect of irrigation techniques and strategies on water footprint of growing crops

    Science.gov (United States)

    Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y. Y.

    2014-12-01

    Reducing the water footprint (WF) of growing crops, the largest water user and a significant contributor to the WF of many consumer products, plays a significant role in integrated and sustainable water management. The water footprint for growing crop is accounted by relating the crop yield with the corresponding consumptive water use (CWU), which both can be adjusted by measures that affect the crop growth and root-zone soil water balance. This study explored the scope for reducing the water footprint of irrigated crops by experimenting set of field level technical and managerial measures: (i) irrigation technologies (Furrow, sprinkler, drip and sub-surface drip), (ii) irrigation strategies (full and a range of sustained and controlled deficit) and (iii) field management options (zero, organic and synthetic mulching). Ranges of cases were also considered: (a) Arid and semi-arid environment (b) Loam and Sandy-loam soil types and (c) for Potato, Wheat and Maize crops; under (c) wet, normal and dry years. AquaCrop, the water driven crop growth and soil water balance model, offered the opportunity to systematically experiment these measures on water consumption and yield. Further, the green and blue water footprints of growing crop corresponding to each measure were computed by separating the root zone fluxes of the AquaCrop output into the green and blue soil water stocks and their corresponding fluxes. Results showed that in arid environment reduction in irrigation supply, CWU and WF up to 300 mm, 80 mm and 75 m3/tonne respectively can be achieved for Maize by a combination of organic mulching and drip technology with controlled deficit irrigation strategies (10-20-30-40% deficit with reference to the full irrigation requirement). These reductions come with a yield drop of 0.54 tonne/ha. In the same environment under the absence of mulching practice, the sub-surface drip perform better in reducing CWU and WF of irrigated crops followed by drip and furrow irrigation

  9. Field screening of water quality, bottom sediment, and biota associated with irrigation drainage in and near Walker River Indian Reservation, Nevada 1994-95

    Science.gov (United States)

    Thodal, Carl E.; Tuttle, Peter L.

    1996-01-01

    A study was begun in 1994 to determine whether the quality of irrigation drainage from the Walker River Indian Reservation, Nevada, has caused or has potential to cause harmful effects on human health or on fish and wildlife, or may adversely affect the suitability of the Walker River for other beneficial uses. Samples of water, bottom sediment, and biota were collected during June-August 1994 (during a drought year) from sites upstream from and on the Walker River Indian Reservation for analyses of trace elements. Other analyses included physical characteristics, major dissolved constituents, selected species of water-soluble nitrogen and phosphorus, and selected pesticides in bottom sediment. Water samples were collected again from four sites on the Reservation in August 1995 (during a wetterthan- average year) to provide data for comparing extreme climatic conditions. Water samples collected from the Walker River Indian Reservation in 1994 equaled or exceeded the Nevada water-quality standard or level of concern for at least one of the following: water temperature, pH, dissolved solids, unionized ammonia, phosphate, arsenic, boron, chromium, lead, and molybdenum; in 1995, only a single sample from one site exceeded a Nevada water-quality standard for molybdenum. Levels of concern for trace elements in bottom sediment collected in 1994 were equaled or exceeded for arsenic, iron, manganese, and zinc. Concentrations of organochiorine pesticide residues in bottom sediment were below analytical reporting limits. Levels of concern for trace-elements in samples of biota were equaled or exceeded for arsenic, boron, copper, and mercury. Results of toxicity testing indicate that only water samples from Walker Lake caused a toxic response in test bacteria. Arsenic and boron concentrations in water, bottom sediment, and biological tissue exceeded levels of concern throughout the Walker River Basin, but most commonly in the lower Walker River Basin. Mercury also was elevated

  10. Water deficit imposed by partial irrigation at different plant growth stages of common bean

    International Nuclear Information System (INIS)

    Calvache, M.; Reichardt, K.

    1995-01-01

    The purpose of this study was to identify specific growth stages of common bean crop, at which the plant is less sensitive to water stress so that irrigation can be omitted without significant decrease in biological nitrogen fixation and yield. Two field experiments were conducted at a University experiments station, Tumbaco, Pichincha, Ecuador, on a sandy loam soil ( Typic durustoll ). The climate is warm and dry ( mean air temperature 16 degree Celcius and mean relative humidity 74% ) during the cropping season and rainfall of 123 mm was recorded during the cropping period. The treatments consisted of combinations of 7 irrigation regimes ( I1 = all normal watering; I2 = all stres; I3 = traditional practice; I4 = single stress at vegetation; I5 flowering; I6 = yield formation and I7 = ripening stages ) and 2 levels of applied N ( 20 and 80 kg/ ha ). Differential irrigation was started after 3 uniform irrigations for germination and crop establishment. Soil moisture was monitored with a neutron probe down to 0.60 m depth, before and 24 h after each irrigation. Biological Nitrogen Fixation was calculated using the N- 15 metodology in the 20 kg N/ ha treatment. From the yield data, it can be concluded that treatments which had irrigation deficit had lower yield than those that had suplementary irrigation. The flowering stage was the most sensitive to number of pods and grain yield. Biological Nitrogen Fixation was significantly affected by water stress at flowering and formation stages. The crop water use efficiency ( kg/ m 3 ) was the lowest at flowering period and the yield response factor ( Ky ) was higher in treatments I2 ( all stress ) and I5 (stress at flowering ). Comparing with traditional practice by farmers of the region, only treatments I1 and I7 had 13 and 10 % higher crop water use effeciency. 15 tabs., 7 refs. ( Author )

  11. Magnetic Field Design for the LANL nEDM Experiment

    Science.gov (United States)

    Dadisman, Ryan

    2017-09-01

    A recent UCN source upgrade at LANSCE makes possible an order of magnitude advancement in the measurement of the neutron electric dipole moment by use of the familiar Ramsey method of separated oscillatory fields. A highly uniform B0 magnetic field is required to achieve sufficiently long spin-relaxation times and to suppress the false EDM caused by the geometric phase effect. We identified a multi-gap solenoid as an ideal candidate to simultaneously achieve the uniformity requirements, via optimization of the gap lengths between and current within different sections, and provide plentiful access to the fiducial region. Results from initial tests of the coil when installed in the magnetic shield house enclosing the experiment will be presented. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Award Number DE-SC-0014622.

  12. Brine Migration in Heated Salt: Lessons Learned from Field Experiments

    Science.gov (United States)

    Kuhlman, K. L.; Matteo, E. N.; Mills, M.

    2017-12-01

    We summarize several interesting brine migration related phenomena hinted at in field experiments from field testing related to salt radioactive waste repositories in Germany and the US. Past heater tests in salt have shown 1) thermal-hydrological-mechanical coupling is quite strong during both heating and cooling; 2) chemical composition of brine evolves during heating, and comprises a mix of several water sources; and 3) acid gas (HCl) generation has been observed during past heater tests and may have multiple mechanisms for formation. We present a heated brine migration test design, formulated with these complexities in mind. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

  13. Incineration in the nuclear field. The SGN experience

    International Nuclear Information System (INIS)

    Carpentier, S.

    1993-01-01

    The operation of power reactors, like that of fuel fabrication and nuclear fuel reprocessing plants, generated substantial quantities of waste. A large share of this waste is low- and medium-level waste, which is also combustible. Similarly, a number of institutes, laboratories, and hospitals, in the course of their activities, generated waste which a portion is radioactive and combustible. The chief advantage of incineration is to minimize the volume of burnable waste treated, and to produce a residue termed 'ash'. SGN has built up 25 years of experience in this field. The incinerators have been designed and the incineration processes are specially studied by SGN

  14. French developments and experience in the field of inservice inspection

    International Nuclear Information System (INIS)

    Saglio, Robert; Destribats, M.-T.; Pigeon, Michel; Roule, Maurice; Touffait, A.-M.

    1979-01-01

    The French PWR nuclear plant program was at the origin of a large amount of R and D work in the field of inservice inspection. The actions which were undertaken may be split up into different levels: - the regulatory level, the R and D level, the design level, the flaw evaluation level. The first results of pre and inservice inspections are presented. The experience gained by French Atomic Energy Commission with new techniques like focussed ultrasonics transducers and multi frequencies Eddy current apparatus are discussed

  15. EFEDA - European field experiment in a desertification-threatened area

    Science.gov (United States)

    Bolle, H.-J.; Andre, J.-C.; Arrue, J. L.; Barth, H. K.; Bessemoulin, P.; Brasa, A.; De Bruin, H. A. R.; Cruces, J.; Dugdale, G.; Engman, E. T.

    1993-01-01

    During June 1991 more than 30 scientific teams worked in Castilla-La Mancha, Spain, studying the energy and water transfer processes between soil, vegetation, and the atmosphere in semiarid conditions within the coordinated European research project EFEDA (European Field Experiment in Desertification-threatened Areas). Measurements were made from the microscale (e.g., measurements on single plants) up to a scale compatible with the grid size of global models. For this purpose three sites were selected 70 km apart and heavily instrumented at a scale in the order of 30 sq km. Aircraft missions, satellite data, and movable equipment were deployed to provide a bridge to the larger scale. This paper gives a description of the experimental design along with some of the preliminary results of this successful experiment.

  16. User experiences with editorial control in online newspaper comment fields

    DEFF Research Database (Denmark)

    Løvlie, Anders Sundnes; Ihlebæk, Karoline Andrea; Larsson, Anders Olof

    2017-01-01

    This article investigates user experiences with editorial control in online newspaper comment fields following the public backlash against online comments after the 2011 terror attacks in Norway. We analyze data from a survey of online news consumers focusing on experiences and attitudes towards...... editorial control set against a spectrum between “interventionist” and “noninterventionist” positions. Results indicate that interventionist respondents rate the quality of online comments as poor, whereas noninterventionist respondents have most often experienced being the target of editorial control...... measures and feel that editorial control has intensified after the terror attacks. We conclude that newspapers should pay attention to the different needs of participants when devising strategies for editorial control. Media professionals should also consider changes to increase the transparency...

  17. A field experiment on power line stabilization by SMES system

    International Nuclear Information System (INIS)

    Irie, F.; Takeo, M.; Sato, S.; Katahira, O.; Fukui, F.; Takamatsu, M.

    1992-01-01

    In this paper field experiments on stabilization of a hydro power plant by a SMES system are reported, where a generator having a rating of 60 kW at 3.3kV is connected to a 6.6kV power distribution line. The SMES system is composed of two 30kVA GTO convertors and a superconducting magnet system with an energy of 30kJ at 100A. Experiments of stabilization for the generator fluctuation caused by a sudden insertion of inductors in the line are successfully performed for some control modes. The value of the SMES system to compensate for a short period voltage dip is also confirmed

  18. On Storks and Babies: Correlation, Causality and Field Experiments

    Directory of Open Access Journals (Sweden)

    Lambrecht Anja

    2016-11-01

    Full Text Available The explosion of available data has created much excitement among marketing practitioners about their ability to better understand the impact of marketing investments. Big data allows for detecting patterns and often it seems plausible to interpret them as causal. While it is quite obvious that storks do not bring babies, marketing relationships are usually less clear. Apparent “causalities” often fail to hold up under examination. If marketers want to be sure not to walk into a causality trap, they need to conduct field experiments to detect true causal relationships. In the present digital environment, experiments are easier than ever to execute. However, they need to be prepared and interpreted with great care in order to deliver meaningful and genuinely causal results that help improve marketing decisions.

  19. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    2017-01-01

    . We argue that the effect has historical origins: irrigation allowed landed elites in arid areas to monopolize water and arable land. This made elites more powerful and better able to oppose democratization. Consistent with this conjecture, we show that irrigation dependence predicts land inequality...

  20. Effective colostomy irrigation.

    Science.gov (United States)

    Mazier, W P; Dignan, R D; Capehart, R J; Smith, B G

    1976-06-01

    The ultimate goal of the cone method of colostomy irrigation is to return patients with colostomies to their former role in society with confidence in themselves to the extent that having a colostomy is not considered a handicap. The results have generally been excellent. We believe all patients with stomas should be afforded the opportunity to attempt colostomy irrigation.

  1. Comparative study of irrigation water use and groundwater recharge under various irrigation schemes in an agricultural region, central Taiwan

    Science.gov (United States)

    Chen, Shih-Kai; Jang, Cheng-Shin; Tsai, Cheng-Bin

    2016-04-01

    The risk of rice production has increased notably due to climate change in Taiwan. To respond to growing agricultural water shortage without affecting normal food production in the future, the application of water-saving irrigation will be a substantial resolution. However, the adoption of water-saving irrigation may result in the reducing of groundwater recharge because continuous flooding in the paddy fields could be regarded as an important source for groundwater recharge. The aim of this study was to evaluate the irrigation water-saving benefit and groundwater recharge deficit when adopting the System of Rice Intensification, known as SRI methodology, in the Choushui River alluvial fan (the largest groundwater pumping and the most important rice-cropping region in central Taiwan). The three-dimensional finite element groundwater model, FEMWATER, was applied to simulate the infiltration process and groundwater recharge under SRI methodology and traditional irrigation schemes including continuous irrigation, and rotational irrigation in two rice-crop periods with hydro-climatic data of 2013. The irrigation water use was then calculated by water balance. The results showed that groundwater recharge amount of SRI methodology was slightly lower than those of traditional irrigation schemes, reduced 3.6% and 1.6% in the first crop period, and reduced 3.2% and 1.6% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. However, the SRI methodology achieved notably water-saving benefit compared to the disadvantage of reducing the groundwater recharge amount. The field irrigation requirement amount of SRI methodology was significantly lower than those of traditional irrigation schemes, saving 37% and 20% of irrigation water in the first crop period, and saving 53% and 35% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. Therefore, the amount of groundwater pumping for

  2. Alkali Rydberg states in electromagnetic fields: computational physics meets experiment

    International Nuclear Information System (INIS)

    Krug, A.

    2001-11-01

    We study highly excited hydrogen and alkali atoms ('Rydberg states') under the influence of a strong microwave field. As the external frequency is comparable to the highly excited electron's classical Kepler frequency, the external field induces a strong coupling of many different quantum mechanical energy levels and finally leads to the ionization of the outer electron. While periodically driven atomic hydrogen can be seen as a paradigm of quantum chaotic motion in an open (decaying) quantum system, the presence of the non-hydrogenic atomic core - which unavoidably has to be treated quantum mechanically - entails some complications. Indeed, laboratory experiments show clear differences in the ionization dynamics of microwave driven hydrogen and non-hydrogenic Rydberg states. In the first part of this thesis, a machinery is developed that allows for numerical experiments on alkali and hydrogen atoms under precisely identical laboratory conditions. Due to the high density of states in the parameter regime typically explored in laboratory experiments, such simulations are only possible with the most advanced parallel computing facilities, in combination with an efficient parallel implementation of the numerical approach. The second part of the thesis is devoted to the results of the numerical experiment. We identify and describe significant differences and surprising similarities in the ionization dynamics of atomic hydrogen as compared to alkali atoms, and give account of the relevant frequency scales that distinguish hydrogenic from non-hydrogenic ionization behavior. Our results necessitate a reinterpretation of the experimental results so far available, and solve the puzzle of a distinct ionization behavior of periodically driven hydrogen and non-hydrogenic Rydberg atoms - an unresolved question for about one decade. Finally, microwave-driven Rydberg states will be considered as prototypes of open, complex quantum systems that exhibit a complicated temporal decay

  3. Radio frequency wave experiments on the MST reversed field pinch

    International Nuclear Information System (INIS)

    Forest, C.B.; Chattopadhyay, P.K.; Nornberg, M.D.; Prager, S.C.; Thomas, M.A.; Harvey, R.W.; Ram, A.K.

    1999-04-01

    Experiments, simulations, and theory all indicate that the magnetic fluctuations responsible for the poor confinement in the reversed field pinch (RFP) can be controlled by altering the radial profile of the current density. The magnetic fluctuations in the RFP are due to resistive MHD instabilities caused by current profile peaking; thus confinement in the RFP is ultimately the result of a misalignment between inductively driven current profiles and the stable current profiles characteristic of the Taylor state. If a technique such as rf current drive can be developed to non-inductively sustain a Taylor state (a current profile linearly stable to all tearing modes), the confinement of the RFP and its potential as a reactor concept are likely to increase. Whether there is a self-consistent path from poor confinement to greatly improved confinement through current profile modification is an issue for future experiments to address if and only if near term experiments can demonstrate: (1) coupling to and the propagation of rf waves in RFP plasmas, (2) efficient current drive, and (3) control of the power deposition which will make it possible to control the current profile. In this paper, modeling results and experimental plans are presented for two rf experiments which have the potential of satisfying these three goals: high-n parallel lower hybrid (LH) waves and electron Bernstein waves (EBWs)

  4. Effects of dripper discharge and irrigation frequency on growth and yield of maize in loess plateau of northwest china

    International Nuclear Information System (INIS)

    Xiukang, W.; Zhanbin, L.; Yingying, X.

    2014-01-01

    A field experiment was conducted at the Changwu Experimental Station in Changwu County, Shaanxi Province, in northwestern China from 2010 to 2011 with four treatments and six replicates in a randomized complete block design to determine appropriate dripper discharge and irrigation frequency for maize (Zea mays, L.) irrigated by drip irrigated system. Dripper discharge was applied to maize 1L/h of dripper discharge, 2 days irrigation frequency and 100% of evaporation from a class a pan (T1), 2, 3 and 4 L/h corresponding to 4, 6 and 8 days irrigation frequency, and deficit irrigation water levels was 90%, 80% and 70% of evaporation (T2, T3 and T4), respectively. The results indicated that longest root, root activity, plant height, leaf area, biomass and grain yields values were highest in T1 in both years. The highest grain yield was obtained of 8.78 and 8.84 t ha-1 under T1 in both years, and the minimum yield was obtained with 8.15 and 7.78 t ha-1 under T4 in 2010 and 2011, respectively. The maximum irrigation water use efficiency (IWUE) was 3.247 and 3.283 kg m-3 in both years under T4. Despite the reduction of growth and grain yield in T3, the dripper discharge was 3L/h, 6 days irrigation frequency and 80% of evaporation was still high and acceptable for maize production and irrigation water use efficiency in Loess Plateau of Northwest China. (author)

  5. Estimating Leaching Requirements for Barley Growth under Saline Irrigation

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Busaidi

    2012-01-01

    Full Text Available The utilization of marginal water resources for agriculture is receiving considerable attention. The lands irrigated with saline water are required to reduce salt accumulations through leaching and/or drainage practices. A field experiment was carried out to investigate the effect of saline irrigation and leaching fraction on barley (Hordeum vulgare L. growth. For this purpose highly saline water was diluted to the salinity levels of 3, 6 and 9 dS m-1 and applied by drip irrigation at 0.0, 0.15, 0.20 and 0.25 leaching fractions (LF. The results of the experiment showed that both quantity and quality of water regulated salts distribution within the soil in the following manner: a the salts were found higher near or immediate below the soil surface; b an enhanced LF carried more salts down the soil horizon but there was no significant difference in plant yield between different treatments of leaching fractions. Salinity of water significantly impaired barley growth. The good drainage of sandy soil enhanced the leaching process and minimized the differences between leaching fractions. The increment in saline treatments (3, 6 and 9 dS m-1 added more salts and stressed plant growth. However, the conjunctive use of marginal water at proportional LF could be effective in enhancing the yield potential of crops in water-scarce areas.

  6. Best Practice Irrigation Management and Extension in Peri-Urban Landscapes--Experiences and Insights from the Hawkesbury-Nepean Catchment, Australia

    Science.gov (United States)

    Maheshwari, B. L.; Plunkett, M.

    2015-01-01

    Purpose: The aim of this article to examine key irrigation management issues and their implications for future research and extension developments. Design/Methodology/Approach: Peri-urban landscapes are important as they supply fresh fruit, vegetables, turf, ornamental plants and other farm products to the cities. In this study, the…

  7. Dynamics of soil organic carbon and microbial activity in treated wastewater irrigated agricultural soils along soil profiles

    Science.gov (United States)

    Jüschke, Elisabeth; Marschner, Bernd; Chen, Yona; Tarchitzky, Jorge

    2010-05-01

    Treated wastewater (TWW) is an important source for irrigation water in arid and semiarid regions and already serves as an important water source in Jordan, the Palestinian Territories and Israel. Reclaimed water still contains organic matter (OM) and various compounds that may effect microbial activity and soil quality (Feigin et al. 1991). Natural soil organic carbon (SOC) may be altered by interactions between these compounds and the soil microorganisms. This study evaluates the effects of TWW irrigation on the quality, dynamics and microbial transformations of natural SOC. Priming effects (PE) and SOC mineralization were determined to estimate the influence of TWW irrigation on SOC along soil profiles of agricultural soils in Israel and the Westbank. The used soil material derived from three different sampling sites allocated in Israel and The Palestinian Authority. Soil samples were taken always from TWW irrigated sites and control fields from 6 different depths (0-10, 10-20, 20-30, 30-50, 50-70, 70-100 cm). Soil carbon content and microbiological parameters (microbial biomass, microbial activities and enzyme activities) were investigated. In several sites, subsoils (50-160 cm) from TWW irrigated plots were depleted in soil organic matter with the largest differences occurring in sites with the longest TWW irrigation history. Laboratory incubation experiments with additions of 14C-labelled compounds to the soils showed that microbial activity in freshwater irrigated soils was much more stimulated by sugars or amino acids than in TWW irrigated soils. The lack of such "priming effects" (Hamer & Marschner 2005) in the TWW irrigated soils indicates that here the microorganisms are already operating at their optimal metabolic activity due to the continuous substrate inputs with soluble organic compounds from the TWW. The fact that PE are triggered continuously due to TWW irrigation may result in a decrease of SOC over long term irrigation. Already now this could be

  8. Identifying Discrimination at Work: The Use of Field Experiments.

    Science.gov (United States)

    Pager, Devah; Western, Bruce

    2012-06-01

    Antidiscrimination law offers protection to workers who have been treated unfairly on the basis of their race, gender, religion, or national origin. In order for these protections to be invoked, however, potential plaintiffs must be aware of and able to document discriminatory treatment. Given the subtlety of contemporary forms of discrimination, it is often difficult to identify discrimination when it has taken place. The methodology of field experiments offers one approach to measuring and detecting hiring discrimination, providing direct observation of discrimination in real-world settings. In this article, we discuss the findings of two recent field experiments measuring racial discrimination in low wage labor markets. This research provides several relevant findings for researchers and those interested in civil rights enforcement: (1) it produces estimates of the rate of discrimination at the point of hire; (2) it yields evidence about the interactions associated with discrimination (many of which reveal the subtlety with which contemporary discrimination is practiced); and (3) it provides a vehicle for both research on and enforcement of antidiscrimination law.

  9. Effects of No-tillage Combined with Reused Plastic Film Mulching on Maize Yield and Irrigation Water Productivity

    OpenAIRE

    SU Yong-zhong; ZHANG Ke; LIU Ting-na; WANG Ting

    2016-01-01

    A field experiment was conducted to determine the effects of reused plastic film mulching and no-tillage on maize yield and irriga-tion water productivity(IWP) in the marginal oasis in the middle of Hexi Corridor region of northwestern China. The aim is to provide an alternative tillage and cultivation pattern for reducing plastic film pollution, saving cost and increasing income, and improving resource use efficiency. The field experiment was carried out in three soils with different texture...

  10. Crystal field parameters in UCl4: Experiment versus theory

    International Nuclear Information System (INIS)

    Zolnierek, Z.; Gajek, Z.; Khan Malek, C.

    1984-01-01

    Crystal field effect on U 4+ ion with the 3 H 4 ground term in tetragonal ligand field of UCl 4 has been studied in detail. Crystal field parameters determined experimentally from optical spectroscopy and magnetic susceptibility are in good agreement with CEP sets derived from the modified point charge model and the ab initio method. Theoretical calculations lead to overestimating the A 4 4 4 > and lowering the A 2 0 2 > values in comparison to those found in the experiments. The discrepancies are, however, within an accuracy of calculations. A large reduction of expectation values of the magnetic moment operator for the eigenvectors of lowest CF levels (17.8%), determined from magnetic susceptibility, cannot be attributed to the overlap and covalency effects only. The detailed calculations have shown that the latter effects provide about 4.6% reduction of respective matrix elements, and the applied J-J mixing procedure increases this factor up to 6.5%. Since similar, as in UCl 4 , reduction factor (proportional15%) has already been observed in a number of different uranium compounds, it seems to be likely that this feature is involved in the intrinsic properties of the U 4+ ion. We endeavor to explain this effect in terms of configuration interaction mechanisms. (orig.)

  11. Crystal field parameters in UCI 4: Experiment versus theory

    Science.gov (United States)

    Zolnierek, Z.; Gajek, Z.; Malek, Ch. Khan

    1984-08-01

    Crystal field effect on U 4+ ion with the 3H 4 ground term in tetragonal ligand field of UCl 4 has been studied in detail. Crystal field parameters determined experimentally from optical spectroscopy and magnetic susceptibility are in good agreement with CFP sets derived from the modified point charge model and the ab initio method. Theoretical calculations lead to overestimating the A44 and lowering the A02 values in comparison to those found in the experiments. The discrepancies are, however, within an accuracy of calculations. A large reduction of expectation values of the magnetic moment operator for the eigenvectors of lowest CF levels (17.8%), determined from magnetic susceptibility, cannot be attributed to the overlap and covalency effects only. The detailed calculations have shown that the latter effects provide about 4.6% reduction of respective matrix elements, and the applied J-J mixing procedure increases this factor up to 6.5%. Since similar, as in UCl 4, reduction factor(≈15%) has already been observed in a number of different uranium compounds, it seems likely that this feature is involved in the intrinsic properties of the U 4+ ion. We endeavor to explain this effect in terms of configuration interaction mechanisms.

  12. Field experiment with liquid manure and enhanced biochar

    Science.gov (United States)

    Dunst, Gerald

    2017-04-01

    Field experiments with low amounts of various liquid manure enhanced biochars. In 2016 a new machine was developed to inject liquid biochar based fertilizer directly into the crop root zone. A large-scale field experiment with corn and oil seed pumpkin was set-up on 42 hectares on 15 different fields in the south East of Austria. Three treatments were compared: (1) surface spreading of liquid manure as control (common practice), (2) 20 cm deep root zone injection with same amount of liquid manure, and (3) 20 cm deep root zone injection with same amount of liquid manure mixed with 1 to 2 tons of various nutrient enhanced biochars. The biochar were quenched with the liquid phase from a separated digestate from a biogas plant (feedstock: cow manure). From May to October nitrate and ammonium content was analyzed monthly from 0-30cm and 30-60cm soil horizons. At the end of the growing season the yield was determined. The root zone injection of the liquid manure reduced the nitrate content during the first two months at 13-16% compared to the control. When the liquid manure was blended with biochar, Nitrate soil content was lowest (reduction 40-47%). On average the root zone injection of manure-biochar increased the yield by 7% compared to the surface applied control and 3% compared to the root zone injected manure without biochar. The results shows, that biochar is able to reduce the Nitrate load in soils and increase the yield of corn at the same time. The nutrient efficiency of organic liquid fertilizers can be increased.

  13. Multi-Disciplinary Research Experiences Integrated with Industry –Field Experiences

    Directory of Open Access Journals (Sweden)

    Suzanne Lunsford

    2015-10-01

    Full Text Available The purpose of this environmentally inquiry-based lab was to allow the students to engage into real-world concepts that integrate industry setting (Ohio Aggregate Industrial Mineral Association with the academia setting. Our students are engaged into a field trip where mining occurs to start the problem based learning of how the heavy metals leak in the mining process. These heavy metals such as lead and indium in the groundwater are a serious concern for the environment (Environmental Protection Agency from the mining process. The field experiences at the mining process assist in building our students interest in developing sensors to detect heavy metals of concern such as lead and indium simultaneously by a unique electrochemistry technique called Square Wave Anodic Stripping Voltammetry (SWASV. The field experience assists building the students interest in real –world application and what qualities do they want the electrochemical sensor to possess to be successful for real world usage. During the field trip the students are engaged into learning novel instrumentation such as an SEM (Scanning Electron Microscope to study the working electrode sensor developed to understand the sensor surface morphology properties better as well. The integration of industry setting with academia has been a positive experience for our students that has allowed their understanding of real-world science research needs to succeed in an industrial setting of research.

  14. Field Experiments on SAR Detection of Film Slicks

    Science.gov (United States)

    Ermakov, S.; da Silva, J. C. B.; Kapustin, I.; Sergievskaya, I.

    2013-03-01

    Field experiments on radar detection of film slicks using satellite synthetic aperture radar TerraSAR-X and X-band scatterometer on board a research vessel are described. The experiments were carried out with surfactant films with known physical parameters, the surface tension and the film elasticity, at low to moderate wind conditions and at different radar incidence angles. It is shown that the depression of radar backscatter (contrast) in films slicks for X-band SAR weakly depends on wind velocity/direction, film elasticity and incidence angles within the range of 200-400. Scatterometer contrasts obtained at incidence angles of about 600 are larger than SAR contrasts. Theoretical analysis of radar contrasts for low-to-moderate incidence angles has been carried out based on a hydrodynamic model of wind wave damping due to films and on a composite radar imaging model. The hydrodynamic model takes into account wave damping due to viscoelastic films, wind wave generation and a phenomenological term describing nonlinear limitation of the wind wave spectrum. The radar model takes into account Bragg scattering and specular scattering mechanisms, the latter is usually negligible compared to the Bragg mechanism at moderate incidence angles (larger than 30-35 degrees), but gives noticeable contribution to radar backscattering at smaller incidence angles particularly for slick areas when cm-scale ripples are strongly depressed by films. Calculated radar contrasts in slicks are compared with experiments and it is concluded that development of the model is needed to predict quantitatively observations.

  15. Data management for interdisciplinary field experiments: OTTER project support

    Science.gov (United States)

    Angelici, Gary; Popovici, Lidia; Skiles, J. W.

    1993-01-01

    The ability of investigators of an interdisciplinary science project to properly manage the data that are collected during the experiment is critical to the effective conduct of science. When the project becomes large, possibly including several scenes of large-format remotely sensed imagery shared by many investigators requiring several services, the data management effort can involve extensive staff and computerized data inventories. The OTTER (Oregon Transect Ecosystem Research) project was supported by the PLDS (Pilot Land Data System) with several data management services, such as data inventory, certification, and publication. After a brief description of these services, experiences in providing them are compared with earlier data management efforts and some conclusions regarding data management in support of interdisciplinary science are discussed. In addition to providing these services, a major goal of this data management capability was to adopt characteristics of a pro-active attitude, such as flexibility and responsiveness, believed to be crucial for the effective conduct of active, interdisciplinary science. These are also itemized and compared with previous data management support activities. Identifying and improving these services and characteristics can lead to the design and implementation of optimal data management support capabilities, which can result in higher quality science and data products from future interdisciplinary field experiments.

  16. Trash-polluted irrigation: characteristics and impact on agriculture

    Science.gov (United States)

    Sulaeman, D.; Arif, SS; Sudarmadji

    2018-04-01

    Trash pollution has been a problem in sustainable water resources management. Trash pollutes not only rivers, lakes and seas, but also irrigation canals and rice fields. This study aimed to identify the characteristics of solid waste (type, time of occurrence and sources of trash) and its impact on agriculture. The study was conducted in four irrigation areas, namely Gamping, Merdiko, Nglaren and Karangploso in Bantul District, Yogyakarta Special Region. We applied the Irrigation Rapid Trash Assessment (IRTA) as our field survey instrument. The results showed that trash was found throughout irrigation canals and rice fields, and the occurrence was influenced by water flow, time and farmer activities. The irrigation was dominantly polluted by plastic trash (52.2%), biodegradable waste (17.91%) and miscellaneous trash (12.3%). The IRTA score showed that Gamping Irrigation Area was at marginal condition, bearing a high risk of disturbing the operation and maintenance of the irrigation canals as well as farmers’ health. Trash in irrigation also generated technical impact of the irrigation operation and maintenance, environmental quality, and social life. This research also offered environmental policy integration approach and water-garbage governance approach as an alternative solution to manage water resources and agriculture in a sustainable manner, under the pressure of increasing amount of trash.

  17. Toroidal magnetic field system for a 2-MA reversed-field pinch experiment

    International Nuclear Information System (INIS)

    Melton, J.G.; Linton, T.W.

    1983-01-01

    The engineering design of the toroidal magnetic field (TF) system for a 2-MA Reversed-Field Pinch experiment (ZT-H) is described. ZT-H is designed with major radius 2.15 meters, minor radius 0.40 meters, and a peak toroidal magnetic field of 0.85 Tesla. The requirement for highly uniform fields, with spatial ripple <0.2% leads to a design with 72 equally spaced circular TF coils, located at minor radius 0.6 meters, carrying a maximum current of 9.0 MA. The coils are driven by a 12-MJ capacitor bank which is allowed to ring in order to aid the reversal of magnetic field. A stress analysis is presented, based upon calculated hoop tension, centering force, and overturning moment, treating these as a combination of static loads and considering that the periodic nature of the loading causes little amplification. The load transfer of forces and moments is considered as a stress distribution resisted by the coils, support structures, wedges, and the structural shell

  18. Predicting deep percolation with eddy covariance under mulch drip irrigation

    Science.gov (United States)

    Ming, Guanghui; Tian, Fuqiang; Hu, Hongchang

    2016-04-01

    Water is essential for the agricultural development and ecological sustainability of the arid and semi-arid oasis with rare precipitation input and high evaporation demand. Deep percolation (DP) defined as excess irrigation water percolating below the plant root zone will reduce irrigation water use efficiency (WUE). But the DP was often ignored in mulch drip irrigation (MDI) which has reached the area of 1.6 million hectares in Xinjiang, the northwest of China. In this study DP experiments were conducted at an agricultural experiment station located within an irrigation district in the Tarim River Basin for four cotton growing periods. First it was detected the irrigation water infiltrated into the soil layers below 100cm and the groundwater level responded to the irrigation events well. Then DP below 100cm soil layers was calculated using the soil water balance method with the aid of eddy covariance (with the energy balance closure of 0.72). The negative DP (groundwater contribution to the crop-water use through capillary rising) at the seedling and harvesting stages can reach 77mm and has a good negative correlation with the groundwater level and positive correlation with potential evaporation. During the drip irrigation stage approximately 45% of the irrigation became DP and resulted in the low irrigation WUE of 0.6. The DP can be 164mm to 270mm per year which was positive linearly correlated to irrigation depth and negative linear correlated to irrigation interval. It is better to establish the irrigation schedule with small irrigation depth and given frequently to reduce deep percolation and meet crop needs.

  19. Fate of diuron and linuron in a field lysimeter experiment.

    Science.gov (United States)

    Guzzella, L; Capri, E; Di Corcia, A; Barra Caracciolo, A; Giuliano, G

    2006-01-01

    The environmental fate of herbicides can be studied at different levels: in the lab with disturbed or undisturbed soil columns or in the field with suction cup lysimeters or soil enclosure lysimeters. A field lysimeter experiment with 10 soil enclosures was performed to evaluate the mass balance in different environmental compartments of the phenylurea herbicides diuron [3-(3,4-diclorophenyl)-1,1-dimethyl-urea] and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea]. After application on the agricultural soil, the herbicides were searched for in soil, pore water, and air samples. Soil and water samples were collected at different depths of the soil profile and analyzed to determine residual concentrations of both the parent compounds and of their main transformation products, to verify their persistence and their leaching capacity. Air volatilization was calculated using the theoretical profile shape method. The herbicides were detected only in the surface layer (0-10 cm) of soil. In this layer, diuron was reduced to 50% of its initial concentration at the end of the experiment, while linuron was still 70% present after 245 d. The main metabolites detected were DCPMU [3-(3,4-dichlorophenyl)-1-methylurea] and DCA (3,4-dichloroaniline). In soil pore water, diuron and linuron were detected at depths of 20 and 40 cm, although in very low concentrations. Therefore the leaching of these herbicides was quite low in this experiment. Moreover, volatilization losses were inconsequential. The calculated total mass balance showed a high persistence of linuron and diuron in the soil, a low mobility in soil pore water (less than 0.5% in leachate water), and a negligible volatilization effect. The application of the Pesticide Leaching Model (PELMO) showed similar low mobility of the chemicals in soil and water, but overestimated their volatilization and their degradation to the metabolite DCPMU. In conclusion, the use of soil enclosure lysimeters proved to be a good

  20. Sugar cane yield response to deficit irrigation at two growth stages

    International Nuclear Information System (INIS)

    Pene, C.B.G.

    1995-01-01

    A field study on sugar cane (Saccharum officinarum L.) yield response to deficit irrigation during both tillering and stem elongation stages, in order to increase crop water use efficiency, was carried out at Institut des Savanes (IDESSA) experimental station of Ferkessedougou, in Northern Ivory Coast. This cane crop tested was Co 449, an early - maturing genotype of indian origin. This experiment has been conducted for three consecutive years as virgin crop ( from November, 1991 to December 1992 ), first ratoon crop ( from December 1992 to January 1994 ) and as second ratoon crop ( from January 1994 to January 1995 ). The experimental design was a randomized complete block with 10 irrigation treatments in 4 replicates of 54 m sup2 sized plots. Water was applied through an improved furrow irrigation system. Crop water consumption was estimated using the water balance approach based on neutron probe and tensiometer measurements. This field water balance method required the determination of soil hydraulic conductivity as a function of water content and the neutron calibration curve. Data presented are related to the two ratoon crops for which field water balance measurements were investigated. It has been shown in the study that sugar cane growth and yield decline due to water deficit is significantly high during stem elongation as compared to tillering. As a result, the sugar cane tested was much more sensitive to water stress at stem elongation than at tillering. Therefore, deficit irrigation practice as to increase crop water use efficiency might be recommended at tillering rather than stem elongation. The water management strategy to be suggested here may consist of omitting irrigation during tillering ( assuming that the crop is successfully established ), for the benefit of stem elongation. As far as stem elongation is concerned, a moderate water deficit of about 25% with respect to the full irrigation regime appears to increase crop water use efficiency.6 figs

  1. Assessing the Efficacy of the SWAT Auto-Irrigation Function to Simulate Irrigation, Evapotranspiration, and Crop Response to Management Strategies of the Texas High Plains

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2017-07-01

    Full Text Available In the semi-arid Texas High Plains, the underlying Ogallala Aquifer is experiencing continuing decline due to long-term pumping for irrigation with limited recharge. Accurate simulation of irrigation and other associated water balance components are critical for meaningful evaluation of the effects of irrigation management strategies. Modelers often employ auto-irrigation functions within models such as the Soil and Water Assessment Tool (SWAT. However, some studies have raised concerns as to whether the function is able to adequately simulate representative irrigation practices. In this study, observations of climate, irrigation, evapotranspiration (ET, leaf area index (LAI, and crop yield derived from an irrigated lysimeter field at the USDA-ARS Conservation and Production Research Laboratory at Bushland, Texas were used to evaluate the efficacy of the SWAT auto-irrigation functions. Results indicated good agreement between simulated and observed daily ET during both model calibration (2001–2005 and validation (2006–2010 periods for the baseline scenario (Nash-Sutcliffe efficiency; NSE ≥ 0.80. The auto-irrigation scenarios resulted in reasonable ET simulations under all the thresholds of soil water deficit (SWD triggers as indicated by NSE values > 0.5. However, the auto-irrigation function did not adequately represent field practices, due to the continuation of irrigation after crop maturity and excessive irrigation when SWD triggers were less than the static irrigation amount.

  2. Prosocial Behavior and Subjective Insecurity in Violent Contexts: Field Experiments

    Science.gov (United States)

    Vélez, María Alejandra; Trujillo, Carlos Andres; Moros, Lina; Forero, Clemente

    2016-01-01

    Subjective insecurity is a key determinant of different forms of prosocial behavior. In Study 1, we used field experiments with farmers in Colombian villages exposed to different levels of violence to investigate how individual perceptions of insecurity affect cooperation, trust, reciprocity and altruism. To do so, we developed a cognitive-affective measure of subjective insecurity. We found that subjective insecurity has a negative effect on cooperation but influences trust and altruism positively. In Study 2, carried out three years after Study 1, we repeated the initial design with additional measures of victimization. Our goal was to relate subjective insecurity with actual victimization. The findings of Study 2 support the initial results, and are robust and consistent for cooperative behavior and trust when including victimization as a mediator. Different indicators of victimization are positively correlated with subjective insecurity and an aggregate index of victimization has a negative effect on cooperation but exerts a positive influence on trust. PMID:27472437

  3. Field experience with KWU SG chemical cleaning process

    International Nuclear Information System (INIS)

    Odar, S.

    1989-01-01

    The ingress of corrosion products into PWR steam generators (SG's) their deposition and the subsequent concentration of salt impurities can induce a variety of mechanisms for corrosion attack on SG tubing. Already, some plants have had to replace their steam generators due to severe corrosion damage and others are seriously considering the same costly action in the near future. One of the most effective ways to counteract corrosion mechanisms and thus to reduce the likelihood of SG replacement becoming necessary is to clean the SG's and to keep them clean. For many years, the industry has been involved in developing different types of cleaning techniques. Among these, chemical cleaning has been shown to be especially effective. In this article, the KWU chemical cleaning process, for which there is considerable application experience, is described. The results of field applications will be presented together with material compatibility data and information on cleaning effectiveness. (author)

  4. Prosocial Behavior and Subjective Insecurity in Violent Contexts: Field Experiments.

    Directory of Open Access Journals (Sweden)

    María Alejandra Vélez

    Full Text Available Subjective insecurity is a key determinant of different forms of prosocial behavior. In Study 1, we used field experiments with farmers in Colombian villages exposed to different levels of violence to investigate how individual perceptions of insecurity affect cooperation, trust, reciprocity and altruism. To do so, we developed a cognitive-affective measure of subjective insecurity. We found that subjective insecurity has a negative effect on cooperation but influences trust and altruism positively. In Study 2, carried out three years after Study 1, we repeated the initial design with additional measures of victimization. Our goal was to relate subjective insecurity with actual victimization. The findings of Study 2 support the initial results, and are robust and consistent for cooperative behavior and trust when including victimization as a mediator. Different indicators of victimization are positively correlated with subjective insecurity and an aggregate index of victimization has a negative effect on cooperation but exerts a positive influence on trust.

  5. Prosocial Behavior and Subjective Insecurity in Violent Contexts: Field Experiments.

    Science.gov (United States)

    Vélez, María Alejandra; Trujillo, Carlos Andres; Moros, Lina; Forero, Clemente

    2016-01-01

    Subjective insecurity is a key determinant of different forms of prosocial behavior. In Study 1, we used field experiments with farmers in Colombian villages exposed to different levels of violence to investigate how individual perceptions of insecurity affect cooperation, trust, reciprocity and altruism. To do so, we developed a cognitive-affective measure of subjective insecurity. We found that subjective insecurity has a negative effect on cooperation but influences trust and altruism positively. In Study 2, carried out three years after Study 1, we repeated the initial design with additional measures of victimization. Our goal was to relate subjective insecurity with actual victimization. The findings of Study 2 support the initial results, and are robust and consistent for cooperative behavior and trust when including victimization as a mediator. Different indicators of victimization are positively correlated with subjective insecurity and an aggregate index of victimization has a negative effect on cooperation but exerts a positive influence on trust.

  6. Anomalous cross-field velocities in a CIV laboratory experiment

    International Nuclear Information System (INIS)

    Axnaes, I.

    1988-10-01

    The axial and radial ion velocities and the electron radial velocity are determined in coaxial plasma gun operated under critical velocity conditions. The particle celocities are determined from probe measurement together with He I 3889 AA absolute intensity measurements and the consideration of the total momentum balance of the current sheet. The ions are found move axially and the electrons radially much faster than predicted by the E/B drift in the macroscopic fields. These results agree with what can be expected from the instability processes, which has earlier been proposed to operate in these experiments. It is therefore a direct experimental demonstration that instability processes have to be invoked not only for the electron heating, but also to explain the macroscopic velocities and currents. (author)

  7. Experiments on a Toroidal Screw Pinch with Various Field Programming

    Energy Technology Data Exchange (ETDEWEB)

    Zwicker, H.; Wilhelm, R.; Krause, H. [Max-Planck-Institut Fuer Plasmaphysik, EURATOM-Association, Garching, Munich, Federal Republic of Germany (Germany)

    1971-10-15

    In the toroidal screw pinch ISAR-IV (large diameter 60 cm, aspect ratio 5, maximum storage, energy 140 kj) attempts were made to get an improved stability of the plasma by different kinds of field programming. The best results were obtained with positive trapped B{sub z}-fields and simultaneous switching of main B{sub z}-field and I{sub z}-current. In this case the dense plasma column (n{sub e} Almost-Equal-To 2-3 x 10{sup 16} , kT Almost-Equal-To 50-100 eV, {beta} Almost-Equal-To 15-20%) is surrounded by a force-free plasma ({beta} = 1%) with weak shear and it behaves stably for, at least, 25 {mu}s. The resulting containment time nr of near 10{sup 12} s cm{sup -3} remains a factor of 2-3 below the upper limit given by the classical diffusion. The following loss of the equilibrium position near the coil axis ({Delta} Almost-Equal-To 1-2 cm) is connected to a strong damping of the axial plasma current which starts near the end of the containment. It may be assumed that the increase of the effective plasma resistance mainly results from a contact of the force-free regions with the tube wall. Attempts were made to improve the containment by suitable programming of a plasma z-current. The results are presented. Experiments with one quartz limiter inside the torus improved the equilibrium but introduced instabilities at the new surface of the dilute plasma. To obtain more information about the outer region, the dilute plasma was produced without a dense core and separated from the tube walls by weak adiabatic compression. Under these Tokamak-like conditions the q-value was varied. In the region of q Almost-Equal-To 1 there appeared instabilities which seem to haver higher m-modes and rather short wavelengths. In a different kind of field programming the field distribution of the ''diffuse pinch'' was realized within an accuracy of 5-10% (kT Almost-Equal-To 100 eV, {beta} Almost-Equal-To 30%). In contrast to the predictions of MHD-theory, stability was observed only for

  8. Contributions of meaningful experiences gatherings to artistic education field

    Directory of Open Access Journals (Sweden)

    Bernardo Bustamante Cardona

    2012-06-01

    Full Text Available This article shows a theoretical approach to and a description of some contributions of a work of transformation of educational and sociocultural reality carried out by a group of people and institutions, among which are San Buenaventura University, Antioquia Museum, Ediarte Inc. and Antioquia University. Such intervention aims at contributing to the improvement of Artistic Education quality in Antioquia and the nation. In order to understand the significance of these Gatherings, a short historical framework is explained in which global and regional processes of academic activities having an impact on the structure of the Artistic Education field are pointed out. Likewise, some perspectives in the definition of artistic education are tackled and then a definition of Pierre Bourdieu´s concept of fieldis presented. Therefore, Meaningful Experiences Gatherings in Artistic Education (MEGAE are presented and the three first gatherings are described. Finally, it is shown the panorama of the contributions of the gatherings both in the theoretical formulation and relational structure of the field.

  9. Design experiences for medical irradiation field at the musashi reactor

    International Nuclear Information System (INIS)

    Aizawa, Otohiko

    1994-01-01

    The design of the medical irradiation field at the Musashi reactor was carried out from 1974 to 1975, about 20 years ago. Various numerical analyses have been carried out recently, and it is astonishing to find out that the performance close to the optimum as a 100 kW reactor has been obtained. The reason for this is that the design was carried out by dividing into the stationary part and the moving part, and as for the moving part, the structure was determined by repeating trial and error and experiments. In this paper, the comparison of the analysis carried out later with the experimental data and the change of the absorbed dose at the time of medical irradiation accompanying the change of neutron energy spectra are reported. As the characteristics of the medical irradiation field at the Musashi reactor, the neutron energy spectra and the absorbed dose and mean medical irradiation time are shown. As the problems in boron neutron capture therapy, the neutron fluence required for the therapy, the way of thinking on background dose, and the problem of determining the irradiation time are discussed. The features of epithermal neutron beam are explained. (K.I.)

  10. ARM Cloud-Aerosol-Precipitation Experiment (ACAPEX) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Leung, L Ruby [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    The U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility’s ARM Cloud-Aerosol-Precipitation Experiment (ACAPEX) field campaign contributes to CalWater 2015, a multi-agency field campaign that aims to improve understanding of atmospheric rivers and aerosol sources and transport that influence cloud and precipitation processes. The ultimate goal is to reduce uncertainties in weather predictions and climate projections of droughts and floods in California. With the DOE G-1 aircraft and ARM Mobile Facility 2 (AMF2) well equipped for making aerosol and cloud measurements, ACAPEX focuses specifically on understanding how aerosols from local pollution and long-range transport affect the amount and phase of precipitation associated with atmospheric rivers. ACAPEX took place between January 12, 2015 and March 8, 2015 as part of CalWater 2015, which included four aircraft (DOE G-1, National Oceanic and Atmospheric Administration [NOAA] G-IV and P-3, and National Aeronautics and Space Administration [NASA] ER-2), the NOAA research ship Ron Brown, carrying onboard the AMF2, National Science Foundation (NSF)-sponsored aerosol and precipitation measurements at Bodega Bay, and the California Department of Water Resources extreme precipitation network.

  11. IRRIGATION OF ORNAMENTAL PLANT NURSERY

    Directory of Open Access Journals (Sweden)

    Eduardo de Aguiar do Couto

    2013-01-01

    Full Text Available Airports consume significant amounts of water which can be compared to the volume consumed by mid-size cities, thus practices aimed at reducing water consumption are important and necessar y. The objective of this study was to assess the reuse potential of sewage effluent produced at a mid-size international airport for nursery irri gation. The sewage treatment system consisted of a facultative pond followed by a constructed wetland, which were monitored during one hydrological year a nd the parameters COD, pH, solids, nitrogen, phosphorus and Escherichia coli we re analyzed. Removal efficiencies of 85% and 91% were achieved for C OD and solids, respectively. Removal efficiencies for ammonia nitrogen a nd total phosphorus were 77% and 59%, respectively. In terms of E. coli concen tration, the treated effluent met the recommendations by the World Health Organization for reuse in irrigation with the advantage of providing high levels of residual nutrient. The ornamental species Impatiens walleriana was irrigated with treated sewage effluent and plant growth characteristics were evalua ted. The experiment showed that reuse can enhance plant growth without signi ficantly affecting leaf tissue and soil characteristics. This study highlighted th e importance of simple technologies for sewage treatment especially in count ries which still do not present great investment in sanitation and proved that effluent reuse for landscape irrigation can provide great savings of water and financial resources for airport environments.

  12. Root Zone Sensors for Irrigation Management in Intensive Agriculture

    Directory of Open Access Journals (Sweden)

    Jochen Hemming

    2009-04-01

    Full Text Available Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of efficient irrigation systems, which includes the implementation of a suitable method for precise scheduling. At the farm level, irrigation is generally scheduled based on the grower’s experience or on the determination of soil water balance (weather-based method. An alternative approach entails the measurement of soil water status. Expensive and sophisticated root zone sensors (RZS, such as neutron probes, are available for the use of soil and plant scientists, while cheap and practical devices are needed for irrigation management in commercial crops. The paper illustrates the main features of RZS’ (for both soil moisture and salinity marketed for the irrigation industry and discusses how such sensors may be integrated in a wireless network for computer-controlled irrigation and used for innovative irrigation strategies, such as deficit or dual-water irrigation. The paper also consider the main results of recent or current research works conducted by the authors in Tuscany (Italy on the irrigation management of container-grown ornamental plants, which is an important agricultural sector in Italy.

  13. Rice production with minimal irrigation and no nitrogen fertilizer by intensive use of treated municipal wastewater.

    Science.gov (United States)

    Muramatsu, Ayumi; Watanabe, Toru; Sasaki, Atsushi; Ito, Hiroaki; Kajihara, Akihiko

    2014-01-01

    We designed a new cultivation system of rice with circulated irrigation to remove nitrogen from treated municipal wastewater effectively and assessed the possibility of nitrogen removal in the new system without any adverse effects on rice production through bench-scale experiments through two seasons. Overgrowth of the rice plant, which can lead to lodging and tasteless rice, was found in the first season probably because nitrogen supply based on standard practice in normal paddy fields was too much in the closed irrigation system. In the second season, therefore, the amount of treated wastewater initially applied to the system was reduced but this resulted in a considerably decreased yield. On the other hand, the taste of the rice was significantly improved. The two-season experiments revealed that the new system enabled rice production with minimal irrigation (approximately 50% on the yield base compared to normal paddy fields) and no nitrogen fertilizer. The system also achieved >95% removal of nitrogen from the treated wastewater used for circulated irrigation. The accumulation of harmful metals in the rice was not observed after one season of cultivation in the new system. The accumulation after cultivation using the same soil repeatedly for a longer time should be examined by further studies.

  14. Development and experiences of photovoltaic water pumping for a drip irrigation in agriculture; Desarrollo y experiencias de sistemas de bombeo fotovoltaico para aplicaciones de riego tecnificado en la agricultura

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Reinhold; Sapiain, Raul; Torres, Ariel; Loose, Dirk [Centro de Energias Renovables, Arica (Chile); Hahn, Andreas [Eschborn (Germany)

    2000-07-01

    The following paper shows results and experiences from a pilot project of photovoltaic water pumping for drip irrigation in agriculture of rural areas. The project participants are local farmers in direct co-operation with the Renewable Energy Centre of the University of Tarapaca and the German Agency for Technical Co-operation, GTZ. Activities focus on the planification, design, implementation and evaluation of four different pilot installations for the small and medium scale agriculture in different locations of the desert area of northern Chile. In the first phase, photovoltaic pumping systems were installed with water storage tanks and a drip irrigation systems were installed with water storage tanks and a drip irrigation system working only by gravity at very low operating pressures. In the second phase, a new system configuration was developed with a direct driven photovoltaic pumping system without water storage tank, the drip irrigation system here is directly connected to the pump with variable water flow and system pressure conditions. Part of the pilot project is a monitoring system, which allows a complete short term and long term evaluation under technical, agricultural and economical aspects. The measured data and obtained experiences shown so far interesting result as for example the high system's reliability, a good performance of the low pressure irrigation, an adequate matching between the solar pump and the drip irrigation in the direct driven system and a simple irrigation management and operation, compared with conventional pumping systems. The project's results could offer a new alternative for photovoltaic pumping systems in the productive agricultural sector of desert rural areas. [Spanish] El presente trabajo muestra los resultados y experiencias obtenidas en un programa piloto de bombeo fotovoltaico para nuevas aplicaciones de riego tecnificado en la agricultura de zonas rurales. En este programa el Centro de Energias Renovables

  15. Movement of Irrigation Water in Soil from a Surface Emitter

    Directory of Open Access Journals (Sweden)

    Ibrahim Abbas Dawood

    2016-09-01

    Full Text Available rickle irrigation is one of the most conservative irrigation techniques since it implies supplying water directly on the soil through emitters. Emitters dissipate energy of water at the end of the trickle irrigation system and provide water at emission points. The area wetted by an emitter depends upon the discharge of emitter, soil texture, initial soil water content, and soil permeability. The objectives of this research were to predict water distribution profiles through different soils for different conditions and quantify the distribution profiles in terms of main characteristics of soil and emitter. The wetting patterns were simulated at the end of each hour for a total time of application of 12 hrs, emitter discharges of 0.5, 0.75, 1, 2, 3, 4, and 5 lph, and five initial volumetric soil water contents. Simulation of water flow from a single surface emitter was carried out by using the numerically-based software Hydrus-2D/3D, Version 2.04. Two approaches were used in developing formulas to predict the domains of the wetted pattern. In order to verify the results obtained by implementing the software Hydrus-2D/3D a field experiment was conducted to measure the wetted diameter and compare measured values with simulated ones. The results of the research showed that the developed formulas to express the wetted diameter and depth in terms of emitter discharge, time of application, and initial soil water content are very general and can be used with very good accuracy.

  16. Yield response and economics of shallow subsurface drip irrigation systems

    Science.gov (United States)

    Field tests were conducted using shallow subsurface drip irrigation (S3DI) on cotton (Gossypium hirsutum, L.), corn (Zea mays, L.), and peanut (Arachis hypogeae, L.) in rotation to investigate yield potential and economic sustainability of this irrigation system technique over a six year period. Dri...

  17. Thermal infrared sensors for postharvest deficit irrigation of peach

    Science.gov (United States)

    California has been in a historic drought and the lack of water has been a major problem for agriculture especially for crops that depend on irrigation. A multi-year field study was carried out to demonstrate the feasibility of applying thermal infrared sensors for managing deficit irrigation in an ...

  18. Irrigation methods for efficient water application: 40 years of South ...

    African Journals Online (AJOL)

    The purpose of an irrigation system is to apply the desired amount of water, at the correct application rate and uniformly to the whole field, at the right time, with the least amount of non-beneficial water consumption (losses), and as economically as possible. We know that irrigated agriculture plays a major role in the ...

  19. Alfalfa response to irrigation from limited water supplies

    Science.gov (United States)

    A five-year field study (2007-2011) of irrigated alfalfa production with a limited water supply was conducted in southwest Kansas with two years of above-average precipitation, one year of average precipitation, and two years of below-average precipitation. The irrigation treatments were designed to...

  20. SEBAL Model Using to Estimate Irrigation Water Efficiency & Water Requirement of Alfalfa Crop

    Science.gov (United States)

    Zeyliger, Anatoly; Ermolaeva, Olga

    2013-04-01

    The sustainability of irrigation is a complex and comprehensive undertaking, requiring an attention to much more than hydraulics, chemistry, and agronomy. A special combination of human, environmental, and economic factors exists in each irrigated region and must be recognized and evaluated. A way to evaluate the efficiency of irrigation water use for crop production is to consider the so-called crop-water production functions, which express the relation between the yield of a crop and the quantity of water applied to it or consumed by it. The term has been used in a somewhat ambiguous way. Some authors have defined the Crop-Water Production Functions between yield and the total amount of water applied, whereas others have defined it as a relation between yield and seasonal evapotranspiration (ET). In case of high efficiency of irrigation water use the volume of water applied is less than the potential evapotranspiration (PET), then - assuming no significant change of soil moisture storage from beginning of the growing season to its end-the volume of water may be roughly equal to ET. In other case of low efficiency of irrigation water use the volume of water applied exceeds PET, then the excess of volume of water applied over PET must go to either augmenting soil moisture storage (end-of-season moisture being greater than start-of-season soil moisture) or to runoff or/and deep percolation beyond the root zone. In presented contribution some results of a case study of estimation of biomass and leaf area index (LAI) for irrigated alfalfa by SEBAL algorithm will be discussed. The field study was conducted with aim to compare ground biomass of alfalfa at some irrigated fields (provided by agricultural farm) at Saratov and Volgograd Regions of Russia. The study was conducted during vegetation period of 2012 from April till September. All the operations from importing the data to calculation of the output data were carried by eLEAF company and uploaded in Fieldlook web

  1. Assessing the changes of groundwater recharge / irrigation water use between SRI and traditional irrigation schemes in Central Taiwan

    Science.gov (United States)

    Chen, Shih-Kai; Jang, Cheng-Shin; Tsai, Cheng-Bin

    2015-04-01

    To respond to agricultural water shortage impacted by climate change without affecting rice yield in the future, the application of water-saving irrigation, such as SRI methodology, is considered to be adopted in rice-cultivation in Taiwan. However, the flooded paddy fields could be considered as an important source of groundwater recharge in Central Taiwan. The water-saving benefit of this new methodology and its impact on the reducing of groundwater recharge should be integrally assessed in this area. The objective of this study was to evaluate the changes of groundwater recharge/ irrigation water use between the SRI and traditional irrigation schemes (continuous irrigation, rotational irrigation). An experimental paddy field located in the proximal area of the Choushui River alluvial fan (the largest groundwater pumping region in Taiwan) was chosen as the study area. The 3-D finite element groundwater model (FEMWATER) with the variable boundary condition analog functions, was applied in simulating groundwater recharge process and amount under traditional irrigation schemes and SRI methodology. The use of effective rainfall was taken into account or not in different simulation scenarios for each irrigation scheme. The simulation results showed that there were no significant variations of infiltration rate in the use of effective rainfall or not, but the low soil moisture setting in deep soil layers resulted in higher infiltration rate. Taking the use of effective rainfall into account, the average infiltration rate for continuous irrigation, rotational irrigation, and SRI methodology in the first crop season of 2013 were 4.04 mm/day, 4.00 mm/day and 3.92 mm/day, respectively. The groundwater recharge amount of SRI methodology was slightly lower than those of traditional irrigation schemes, reducing 4% and 2% compared with continuous irrigation and rotational irrigation, respectively. The field irrigation requirement amount of SRI methodology was significantly

  2. Approaches and challenges of soil water monitoring in an irrigated vineyard

    Science.gov (United States)

    Nolz, Reinhard; Loiskandl, Willibald

    2016-04-01

    Monitoring of water content is an approved method to quantify certain components of the soil water balance, for example as basis for hydrological studies and soil water management. Temporal soil water data also allow controlling water status by means of demand-oriented irrigation. Regarding spatial variability of water content due to soil characteristics, plant water uptake and other non-uniformities, it is a great challenge to select a location that is most likely representing soil water status of a larger area (e.g. an irrigated field). Although such an approach might not satisfy the requirements of precision farming - which becomes more and more related to industrial agriculture - it can help improving water use efficiency of small-scale farming. In this regard, specific conditions can be found in typical vineyards in the eastern part of Austria, where grapes are grown for high quality wine production. Generally, the local dry-subhumid climate supports grape development. However, irrigation is temporarily essential in order to guarantee stable yields and high quality. As the local winegrowers traditionally control irrigation based on their experience, there is a potential to improve irrigation management by means of soil water data. In order to gain experience with regard to irrigation management, soil water status was determined in a small vineyard in Austria (47°48'16'' N, 17°01'57'' E, 118 m elevation). The vineyard was equipped with a subsurface drip irrigation system and access tubes for measuring water content in soil profiles. The latter was measured using a portable device as well as permanently installed multi-sensor capacitance probes. Soil samples were taken at chosen dates and gravimetrically analyzed in the laboratory. Water content data were analyzed using simple statistical procedures and the temporal stability concept. Soil water content was interpreted considering different environmental conditions, including rainfall and irrigation periods

  3. An Oceanographic Decision Support System for Scientific Field Experiments

    Science.gov (United States)

    Maughan, T.; Das, J.; McCann, M. P.; Rajan, K.

    2011-12-01

    Thom Maughan, Jnaneshwar Das, Mike McCann, Danelle Cline, Mike Godin, Fred Bahr, Kevin Gomes, Tom O'Reilly, Frederic Py, Monique Messie, John Ryan, Francisco Chavez, Jim Bellingham, Maria Fox, Kanna Rajan Monterey Bay Aquarium Research Institute Moss Lading, California, United States Many of the coastal ocean processes we wish to observe in order to characterize marine ecosystems have large spatial extant (tens of square km) and are dynamic moving kilometers in a day with biological processes spanning anywhere from minutes to days. Some like harmful algal blooms generate toxins which can significantly impact human health and coastal economies. In order to obtain a viable understanding of the biogeochemical processes which define their dynamics and ecology, it is necessary to persistently observe, track and sample within and near the dynamic fields using augmented methods of observation such as autonomous platforms like AUVs, gliders and surface craft. Field experiments to plan, execute and manage such multitude of assets are challenging. To alleviate this problem the autonomous systems group with its collaborators at MBARI and USC designed, built and fielded a prototype Oceanographic Decision Support System (ODSS) that provides situational awareness and a single portal to visualize and plan deployments for the large scale October 2010 CANON field program as well as a series of 2 week field programs in 2011. The field programs were conducted in Monterey Bay, a known 'red tide' incubator, and varied from as many as twenty autonomous platforms, four ships and 2 manned airplanes to coordinated AUV operations, drifters and a single ship. The ODSS web-based portal was used to assimilate information from a collection of sources at sea, including AUVs, moorings, radar data as well as remote sensing products generated by partner organizations to provide a synthesis of views useful to predict the movement of a chlorophyll patch in the confines of the northern Monterey Bay

  4. Stable isotopic composition of perchlorate and nitrate accumulated in plants: Hydroponic experiments and field data.

    Science.gov (United States)

    Estrada, Nubia Luz; Böhlke, J K; Sturchio, Neil C; Gu, Baohua; Harvey, Greg; Burkey, Kent O; Grantz, David A; McGrath, Margaret T; Anderson, Todd A; Rao, Balaji; Sevanthi, Ritesh; Hatzinger, Paul B; Jackson, W Andrew

    2017-10-01

    Natural perchlorate (ClO 4 - ) in soil and groundwater exhibits a wide range in stable isotopic compositions (δ 37 Cl, δ 18 O, and Δ 17 O), indicating that ClO 4 - may be formed through more than one pathway and/or undergoes post-depositional isotopic alteration. Plants are known to accumulate ClO 4 - , but little is known about their ability to alter its isotopic composition. We examined the potential for plants to alter the isotopic composition of ClO 4 - in hydroponic and field experiments conducted with snap beans (Phaseolus vulgaris L.). In hydroponic studies, anion ratios indicated that ClO 4 - was transported from solutions into plants similarly to NO 3 - but preferentially to Cl - (4-fold). The ClO 4 - isotopic compositions of initial ClO 4 - reagents, final growth solutions, and aqueous extracts from plant tissues were essentially indistinguishable, indicating no significant isotope effects during ClO 4 - uptake or accumulation. The ClO 4 - isotopic composition of field-grown snap beans was also consistent with that of ClO 4 - in varying proportions from irrigation water and precipitation. NO 3 - uptake had little or no effect on NO 3 - isotopic compositions in hydroponic solutions. However, a large fractionation effect with an apparent ε ( 15 N/ 18 O) ratio of 1.05 was observed between NO 3 - in hydroponic solutions and leaf extracts, consistent with partial NO 3 - reduction during assimilation within plant tissue. We also explored the feasibility of evaluating sources of ClO 4 - in commercial produce, as illustrated by spinach, for which the ClO 4 - isotopic composition was similar to that of indigenous natural ClO 4 - . Our results indicate that some types of plants can accumulate and (presumably) release ClO 4 - to soil and groundwater without altering its isotopic characteristics. Concentrations and isotopic compositions of ClO 4 - and NO 3 - in plants may be useful for determining sources of fertilizers and sources of ClO 4 - in their growth

  5. The large-s field-reversed configuration experiment

    International Nuclear Information System (INIS)

    Hoffman, A.L.; Carey, L.N.; Crawford, E.A.; Harding, D.G.; DeHart, T.E.; McDonald, K.F.; McNeil, J.L.; Milroy, R.D.; Slough, J.T.; Maqueda, R.; Wurden, G.A.

    1993-01-01

    The Large-s Experiment (LSX) was built to study the formation and equilibrium properties of field-reversed configurations (FRCs) as the scale size increases. The dynamic, field-reversed theta-pinch method of FRC creation produces axial and azimuthal deformations and makes formation difficult, especially in large devices with large s (number of internal gyroradii) where it is difficult to achieve initial plasma uniformity. However, with the proper technique, these formation distortions can be minimized and are then observed to decay with time. This suggests that the basic stability and robustness of FRCs formed, and in some cases translated, in smaller devices may also characterize larger FRCs. Elaborate formation controls were included on LSX to provide the initial uniformity and symmetry necessary to minimize formation disturbances, and stable FRCs could be formed up to the design goal of s = 8. For x ≤ 4, the formation distortions decayed away completely, resulting in symmetric equilibrium FRCs with record confinement times up to 0.5 ms, agreeing with previous empirical scaling laws (τ∝sR). Above s = 4, reasonably long-lived (up to 0.3 ms) configurations could still be formed, but the initial formation distortions were so large that they never completely decayed away, and the equilibrium confinement was degraded from the empirical expectations. The LSX was only operational for 1 yr, and it is not known whether s = 4 represents a fundamental limit for good confinement in simple (no ion beam stabilization) FRCs or whether it simply reflects a limit of present formation technology. Ideally, s could be increased through flux buildup from neutral beams. Since the addition of kinetic or beam ions will probably be desirable for heating, sustainment, and further stabilization of magnetohydrodynamic modes at reactor-level s values, neutral beam injection is the next logical step in FRC development. 24 refs., 21 figs., 2 tabs

  6. Field-reversed experiments (FRX) on compact toroids

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, W.T.; Linford, R.K.; Lipson, J.; Platts, D.A.; Sherwood, E.G.

    1981-11-01

    Equilibrium, stability, and confinement properties of compact toroids produced in field-reversed theta-pinch experiments (FRX) are reported. Two experimental facilities, FRX-A and FRX-B, have been used to study highly elongated compact toroid plasmas confined in a purely poloidal field geometry. Spatial scans and fill pressure scaling of the equilibrium plasma parameters are presented. Plasma conditions range from T/sub e/approx.150 eV, T/sub i/approx.800 eV, n/sub m/approx.1 x 10/sup 15/ cm/sup -3/ to T/sub e/approx.100 eV, T/sub i/approx.150 eV, n/sub m/approx.4 x 10/sup 15/ cm/sup -3/. Typical confined plasma dimensions are: major radius Rapprox.4 cm, minor radius aapprox.2 cm, and total length 35--50 cm. The plasma configuration remains in a stable equilibrium for up to 50 ..mu..sec followed by the destructive n = 2 rotational instability. The stable period prior to the onset of the rotational mode is up to one hundred times greater than characteristic Alfven transit times of the plasma. This stable period increases and the mode growth rate decreases with increased a/rho/sub i/ (where rho/sub i/ is the ion gyroradius). Agreement of experimental and theoretical mode frequencies for the instability is observed. Preferential particle loss has been proposed as a likely cause of rotation. The particle inventory at the onset of the instability is consistent with this hypothesis. The particle loss rate is also consistent with the predicted anomalous transport near the separatrix. Contributions to rotational instability from diffusion, end-shorting, equipartition, and compression are also discussed.

  7. Field-reversed experiments (FRX) on compact toroids

    International Nuclear Information System (INIS)

    Armstrong, W.T.; Linford, R.K.; Lipson, J.; Platts, D.A.; Sherwood, E.G.

    1981-01-01

    Equilibrium, stability, and confinement properties of compact toroids produced in field-reversed theta-pinch experiments (FRX) are reported. Two experimental facilities, FRX-A and FRX-B, have been used to study highly elongated compact toroid plasmas confined in a purely poloidal field geometry. Spatial scans and fill pressure scaling of the equilibrium plasma parameters are presented. Plasma conditions range from T/sub e/approx.150 eV, T/sub i/approx.800 eV, n/sub m/approx.1 x 10 15 cm -3 to T/sub e/approx.100 eV, T/sub i/approx.150 eV, n/sub m/approx.4 x 10 15 cm -3 . Typical confined plasma dimensions are: major radius Rapprox.4 cm, minor radius aapprox.2 cm, and total length 35--50 cm. The plasma configuration remains in a stable equilibrium for up to 50 μsec followed by the destructive n = 2 rotational instability. The stable period prior to the onset of the rotational mode is up to one hundred times greater than characteristic Alfven transit times of the plasma. This stable period increases and the mode growth rate decreases with increased a/rho/sub i/ (where rho/sub i/ is the ion gyroradius). Agreement of experimental and theoretical mode frequencies for the instability is observed. Preferential particle loss has been proposed as a likely cause of rotation. The particle inventory at the onset of the instability is consistent with this hypothesis. The particle loss rate is also consistent with the predicted anomalous transport near the separatrix. Contributions to rotational instability from diffusion, end-shorting, equipartition, and compression are also discussed

  8. Which Order? Whose Order? Balinese Irrigation Management in Sulawesi, Indonesia

    NARCIS (Netherlands)

    Roth, D.

    2006-01-01

    This paper deals with irrigation management among Balinese migrant settlers in Sulawesi, Indonesia. As settlers in the command area of a state-built irrigation system, they have become part of its blueprinted managerial structure. However, many settlers derived their experience from subak, the

  9. Automated cycled sprinkler irrigation for spring frost protection of cranberries

    Science.gov (United States)

    Sprinkler irrigation is essential for preventing spring frost bud damage in cranberry (Vaccinium macrocarpon Ait). Risk-averse growers have been reluctant to adopt the intermittent cycling of irrigation pumps as a standard management practice. In the spring of 2013 and 2014, an experiment was conduc...

  10. Modeling the effects of different irrigation water salinity on soil water movement, uptake and multicomponent solute transport

    Science.gov (United States)

    Lekakis, E. H.; Antonopoulos, V. Z.

    2015-11-01

    Simulation models can be important tools for analyzing and managing irrigation, soil salinization or crop production problems. In this study a mathematical model that describes the water movement and mass transport of individual ions (Ca2+, Mg2+ and Na+) and overall soil salinity by means of the soil solution electrical conductivity, is used. The mass transport equations of Ca2+, Mg2+ and Na+ have been incorporated as part of the integrated model WANISIM and the soil salinity was computed as the sum of individual ions. The model was calibrated and validated against field data, collected during a three year experiment in plots of maize, irrigated with three different irrigation water qualities, at Thessaloniki area in Northern Greece. The model was also used to evaluate salinization and sodification hazards by the use of irrigation water with increasing electrical conductivity of 0.8, 3.2 and 6.4 dS m-1, while maintaining a ratio of Ca2+:Mg2+:Na+ equal to 3:3:2. The qualitative and quantitative procedures for results evaluation showed that there was good agreement between the simulated and measured values of the water content, overall salinity and the concentration of individual soluble cations, at two soil layers (0-35 and 35-75 cm). Nutrient uptake was also taken into account. Locally available irrigation water (ECiw = 0.8 dS m-1) did not cause soil salinization or sodification. On the other hand, irrigation water with ECiw equal to 3.2 and 6.4 dS m-1 caused severe soil salinization, but not sodification. The rainfall water during the winter seasons was not sufficient to leach salts below the soil profile of 110 cm. The modified version of model WANISIM is able to predict the effects of irrigation with saline waters on soil and plant growth and it is suitable for irrigation management in areas with scarce and low quality water resources.

  11. Toxigenic Vibrio cholerae O1 in vegetables and fish raised in wastewater irrigated fields and stabilization ponds during a non-cholera outbreak period in Morogoro, Tanzania

    DEFF Research Database (Denmark)

    Hounmanou, Yaovi M G; Mdegela, Robinson H; Dougnon, Tamègnon V

    2016-01-01

    gene (tcpA) and the haemolysin gene (hlyA). RESULTS: The prevalence of V. cholerae in wastewater, vegetables and fish was 36.7, 21.7 and 23.3 %, respectively. Two isolates from fish gills were V. cholerae O1 and tested positive for ctx and tcpA. One of these contained in addition the hlyA gene while......BACKGROUND: Cholera, one of the world's deadliest infectious diseases, remains rampant and frequent in Tanzania and thus hinders existing control measures. The present study was undertaken to evaluate the occurrence of toxigenic Vibrio cholerae O1 in wastewater, fish and vegetables during a non......-outbreak period in Morogoro, Tanzania. METHODS: From October 2014 to February 2015, 60 wastewater samples, 60 fish samples from sewage stabilization ponds and 60 wastewater irrigated vegetable samples were collected. Samples were cultured for identification of V. cholerae using conventional bacteriological...

  12. Status of SRNL radiological field lysimeter experiment-Year 1

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Roberts, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Bagwell, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2013-10-01

    The Savannah River National Laboratory (SRNL) Radiological Field Lysimeter Experiment is a one-of-a-kind field facility designed to study radionuclide geochemical processes at a larger spatial scale (from grams to tens of kilograms sediment) and temporal scale (from months to 10 years) than is readily afforded through laboratory studies. The lysimeter facility is intended to capture the natural heterogeneity of moisture and temperature regimes in the vadose zone, the unsaturated subsurface region between the surface soil and the underlying aquifer. The 48 lysimeter columns, which contain various radionuclides (and stable iodine), were opened to rainfall infiltration on July 5, 2012. The objective of this report is to provide a status of the lysimeter facility operations and to compile data collected during FY13, including leachate volume, rainfall, and soil moisture and temperature in situ probe data. Radiological leachate data are not presented in this document but will be the subject of a separate document.1 Leachate samples were collected quarterly and shipped to Clemson University for radiological analyses. Rainfall, leachate volume, moisture and temperature probe data were collected continuously. During operations of the facility this year, there were four safety or technical concerns that required additional maintenance: 1) radioactivity was detected in one of the overflow bottles (captured water collected from the secondary containment that does not come in contact with the radiological source material); 2) rainwater accumulated within the sample-bottle storage sheds; 3) overflow containers collected more liquid than anticipated; and 4) significant spider infestation occurred in the sample-bottle storage sheds. To address the first three concerns, each of the lysimeter columns was re-plumbed to improve and to minimize the number of joint unions. To address the fourth concern regarding spiders, new sample-bottle water sheds were purchased and a pest control

  13. Field Experiment on Soaking Characteristics of Collapsible Loess

    Directory of Open Access Journals (Sweden)

    Zhichao Wang

    2017-01-01

    Full Text Available In collapsible loess area, migration of soil moisture often causes the temporal discontinuity and spatial nonuniformity of collapsibility, which leads to great damage for infrastructures. Therefore, the research on water infiltration is the key to solving the problem of collapsibility. The aim of this paper is to investigate the spatiotemporal evolution of infiltration characteristics of collapsible loess. A field soaking experiment was conducted on collapsible loess in western China, in which a soaking pool with diameter of 15 m was built. Time-Domain-Reflectometry (TDR system and soil sampling were employed to measure the water content within the depth of 12 m. Then the saturation isograms were drawn for visualization of the process of infiltration. Also, a pilot tunnel was excavated to investigate how the free face can affect the infiltration behaviors. The experimental results revealed the characteristics of infiltration in both horizontal and vertical directions. Moreover, the response of free face on infiltration behaviors was also found. These findings of research could provide the data for the infiltration laws of unsaturated loess and thereby provide the basis for integrated treatment of collapsible loess.

  14. Natural selection on immune defense: A field experiment.

    Science.gov (United States)

    Langeloh, Laura; Behrmann-Godel, Jasminca; Seppälä, Otto

    2017-02-01

    Predicting the evolution of phenotypic traits requires an understanding of natural selection on them. Despite its indispensability in the fight against parasites, selection on host immune defense has remained understudied. Theory predicts immune traits to be under stabilizing selection due to associated trade-offs with other fitness-related traits. Empirical studies, however, report mainly positive directional selection. This discrepancy could be caused by low phenotypic variation in the examined individuals and/or variation in host resource level that confounds trade-offs in empirical studies. In a field experiment where we maintained Lymnaea stagnalis snails individually in cages in a lake, we investigated phenotypic selection on two immune defense traits, phenoloxidase (PO)-like activity and antibacterial activity, in hemolymph. We used a diverse laboratory population and manipulated snail resource level by limiting their food supply. For six weeks, we followed immune activity, growth, and two fitness components, survival and fecundity of snails. We found that PO-like activity and growth were under stabilizing selection, while antibacterial activity was under positive directional selection. Selection on immune traits was mainly driven by variation in survival. The form of selection on immune defense apparently depends on the particular trait, possibly due to its importance for countering the present parasite community. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  15. Chaos in reversed-field-pinch plasma simulation and experiment

    International Nuclear Information System (INIS)

    Watts, C.; Newman, D.E.; Sprott, J.C.

    1994-01-01

    We investigate the possibility that chaos and simple determinism are governing the dynamics of reversed-field-pinch (RFP) plasmas using data from both numerical simulations and experiment. A large repertoire of nonlinear-analysis techniques is used to identify low-dimensional chaos. These tools include phase portraits and Poincare sections, correlation dimension, the spectrum of Lyapunov exponents, and short-term predictability. In addition, nonlinear-noise-reduction techniques are applied to the experimental data in an attempt to extract any underlying deterministic dynamics. Two model systems are used to simulate the plasma dynamics. These are the DEBS computer code, which models global RFP dynamics, and the dissipative trapped-electron-mode model, which models drift-wave turbulence. Data from both simulations show strong indications of low-dimensional chaos and simple determinism. Experimental data were obtained from the Madison Symmetric Torus RFP and consist of a wide array of both global and local diagnostic signals. None of the signals shows any indication of low-dimensional chaos or other simple determinism. Moreover, most of the analysis tools indicate that the experimental system is very high dimensional with properties similar to noise. Nonlinear noise reduction is unsuccessful at extracting an underlying deterministic system

  16. Bio-mechanical removing of contaminated soils: a field experiment

    International Nuclear Information System (INIS)

    Jouve, A.; Maubert, H.; Schulte, E.

    1992-01-01

    If, in spite of safety precautions, a major nuclear accident would occur, countermeasures should be taken to attenuate the impact of radioactive deposits. The European RESSAC program (REhabilitation of Soils and Surfaces after an ACcident) aims at studying actions for normal life return in contaminated zones. One of them, called the Decontaminating Vegetal Network (D.V.N.) associates the biological action of turfing plants, producing a dense root-network capable to trap the top contaminated soil particles, and the mechanical efficiency of a turf harvester which can remove only 1 cm of soil. This performance, not associated with other techniques of soil removal such as scrapers or bulldozers, leads to minimize the waste production. The D.V.N is a vegetal cover spread over the contaminated soil, using the hydro-seeding technique. The growing plants are forming a pleasant lawn which may have a positive impact on the public opinion compared to techniques using bitumen mixtures to cover the soil. Field experiments involving labelling solutions of stable molybdenum salts simulating the contamination of the soil have shown that this technique can be applied as well on homogeneous cultivated soil surfaces as on roughly ploughed soils. 4 refs., 3 figs., 2 tabs

  17. Mismo field experiment in the equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Masumoto, Y.; Kuroda, Y.; Katsumata, M.; Mizuno, K.; Takayabu, Y.N.; Yoshizaki, M.; Shareef, A.; Fujiyoshi, Y.; McPhaden, M.J.; Murty, V.S.N.; Shirooka, R; Yasunaga, K.; Yamada, H.; Sato, N.; Ushiyama, T.; Moteki, Q.; Seiki, A.; Fujita, M.; Ando, K.; Hase, H.; Ueki, I; Horii, T.; Yokoyama, C.; Miyakawa, T.

    MISMO FIELD EXPERIMENT IN THE EQUATORIAL INDIAN OCEAN * b y Ku n i o yo n e y a m a , yu K i o ma s u m o t o , yo s h i f u m i Ku r o d a , ma s a K i Ka t s u m a t a , Ke i s u K e mi z u n o , yu K a r i n. ta K a y a b u , ma s a n o r i... yo s h i z a K i , al i sh a r e e f, ya s u s h i fu j i y o s h i , mi c h a e l j. mcPh a d e n , V. s. n. mu r t y , ry u i c h i sh i r o o K a , Ka z u a K i ya s u n a g a , hi r o y u K i ya m a d a , na o K i sa t o , to m o K i us...

  18. ARM West Antarctic Radiation Experiment (AWARE) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Lubin, Daniel [Univ. of California, San Diego, CA (United States). Scripps Inst. of Oceanography; Bromwich, David H [Ohio State University; Vogelmann, Andrew M [Brookhaven National Lab. (BNL), Upton, NY (United States); Verlinde, Johannes [Pennsylvania State Univ., University Park, PA (United States); Russell, Lynn M [Univ. of California, San Diego, CA (United States). Scripps Inst. of Oceanography

    2017-09-15

    The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) West Antarctic Radiation Experiment (AWARE) is the most technologically advanced atmospheric and climate science campaign yet fielded in Antarctica. AWARE was motivated be recent concern about the impact of cryospheric mass loss on global sea level rise. Specifically, the West Antarctic Ice Sheet (WAIS) is now the second largest contributor to rising sea level, after the Greenland Ice Sheet. As steadily warming ocean water erodes the grounding lines of WAIS components where they meet the Amundsen and Bellingshausen Seas, the retreating grounding lines moving inland and downslope on the underlying terrain imply mechanical instability of the entire WAIS. There is evidence that this point of instability may have already been reached, perhaps signifying more rapid loss of WAIS ice mass. At the same time, the mechanical support provided by adjacent ice shelves, and also the fundamental stability of exposed ice cliffs at the ice sheet grounding lines, will be adversely impacted by a warming atmosphere that causes more frequent episodes of surface melting. The surface meltwater damages the ice shelves and ice cliffs through hydrofracturing. With the increasing concern regarding these rapid cryospheric changes, AWARE was motivated by the need to (a) diagnose the surface energy balance in West Antarctica as related to both summer season climatology and potential surface melting, and (b) improve global climate model (GCM) performance over Antarctica, such that future cryospheric projections can be more reliable.

  19. Idaho field experiment 1981. Volume 2: measurement data

    Energy Technology Data Exchange (ETDEWEB)

    Start, G E; Sagendorf, J F; Ackermann, G R; Cate, J H; Hukari, N F; Dickson, C R

    1984-04-01

    The 1981 Idaho Field Experiment was conducted in southeastern Idaho over the upper Snake River Plain. Nine test-day case studies were conducted between July 15 and 30, 1981. Releases of SF/sub 6/ gaseous tracer were made for 8-hour periods from 46m above ground. Tracer was sampled hourly, for 12 sequential hours, at about 100 locations within an area 24km square. Also, a single total integrated sample of about 30 hours duration was collected at approximately 100 sites within an area 48 by 72km square (using 6km spacings). Extensive tower profiles of meteorology at the release point were collected. RAWINSONDES, RABALS and PIBALS were collected at 3 to 5 sites. Horizontal, low-altitude winds were monitored using the INEL MESONET. SF/sub 6/ tracer plume releases were marked with co-located oil fog releases and bi-hourly sequential launches of tetroon pairs. Aerial LIDAR observations of the oil fog plume and airborne samples of SF/sub 6/ were collected. High altitude aerial photographs of daytime plumes were collected. Volume II lists the data in tabular form or cites the special supplemental reports by other participating contractors. While the primary user file and the data archive are maintained on 9 track/1600 cpi magnetic tapes, listings of the individual values are provided for the user who either cannot utilize the tapes or wishes to preview the data. The accuracies and quality of these data are described.

  20. Perspectives on global nursing leadership: international experiences from the field.

    Science.gov (United States)

    Buckner, E B; Anderson, D J; Garzon, N; Hafsteinsdóttir, T B; Lai, C K Y; Roshan, R

    2014-12-01

    Nursing leaders from six countries engaged in a year-long discussion on global leadership development. The purpose of these dialogues was to strengthen individual and collective capacity as nursing leaders in a global society. Field experiences in practice and education were shared. Perspectives on global leadership can strengthen nurses' contributions to practice, workplace and policy issues worldwide. Transformational leadership empowers nurses' increasing confidence. Mentoring is needed to stimulate leadership development but this is lacking in many settings where nurses practice, teach and influence policy. Organizations with global mission provide opportunity for nurses' professional growth in leadership through international dialogues. Dialogues among participants were held monthly by conference calls or videoconferences. Example stories from each participant illustrated nursing leadership in action. From these exemplars, concepts were chosen to create a framework. Emerging perspectives and leadership themes represented all contexts of practice, education, research and policy. The cultural context of each country was reflected in the examples. Themes emerged that crossed global regions and countries. Themes were creativity, change, collaboration, community, context and courage. Relationships initially formed in professional organizations can be extended to intentionally facilitate global nursing leadership development. Exemplars from the dialogues demonstrated nursing leadership in health policy development within each cultural context. Recommendations are given for infrastructure development in organizations to enhance future collaborations. © 2014 International Council of Nurses.

  1. Test plan for FY-94 digface characterization field experiments

    International Nuclear Information System (INIS)

    Josten, N.E.; Roybal, L.G.

    1994-08-01

    The digface characterization concept has been under development at the Idaho National Engineering Laboratory (INEL) since fiscal year (FY) 1992 through the support of the Buried Waste Integrated Demonstration Program. A digface characterization system conducts continuous subsurface characterization simultaneously with retrieval of hazardous and radioactive waste from buried waste sites. The system deploys multiple sensors at the retrieval operation digface and collects data that provide a basis for detecting, locating, and classifying buried materials and hazardous conditions before they are disturbed by the retrieval equipment. This test plan describes ongoing efforts to test the digface characterization concept at the INEL's Cold Test Pit using a simplified prototype deployment apparatus and off-the-shelf sensors. FY-94 field experiments will explore problems in object detection and classification. Detection and classification of objects are fundamental to three of the four primary functions of digface characterization during overburden removal. This test plan establishes procedures for collecting and validating the digface characterization data sets. Analysis of these data will focus on testing and further developing analysis methods for object detection and classification during overburden removal

  2. Micro-scale hydrological field experiments in Romania

    Directory of Open Access Journals (Sweden)

    Minea Gabriel

    2016-02-01

    Full Text Available The paper (communication presents an overview of hydrologic field experiments at micro-scale in Romania. In order to experimentally investigate micro (plot-scale hydrological impact of soil erosion, the National Institute of Hydrology and Water Management founded Voineşti Experimental Basin (VES in 1964 and the Aldeni Experimental Basins (AEB in 1984. AEB and VES are located in the Curvature Subcarpathians. Experimental plots are organized in a double systems and have an area of 80 m2 (runoff plots at AEB and 300 m2 (water balance plots at VES. Land use of plot: first plot ”grass-land” is covered with perennial grass and second plot (control consists in ”bare soil”. Over the latter one, the soil is hoeing, which results in a greater development of infiltration than in the first plot. Experimental investigations at micro-scale are aimed towards determining the parameters of the water balance equation, during natural and artificial rainfalls, researching of flows and soil erosion processes on experimental plots, extrapolating relations involving runoff coefficients from a small scale to medium scale. Nowadays, the latest evolutions in data acquisition and transmission equipment are represented by sensors (such as: sensors to determinate the soil moisture content. Exploitation and dissemination of hydrologic data is accomplished by research themes/projects, year-books of basic data and papers.

  3. Field experience in use of radiation instruments in Cirus reactor

    International Nuclear Information System (INIS)

    Ramesh, N.; Sharma, R.C.; Agarwal, S.K.; Sawant, D.K.; Yadav, R.K.B.; Prasad, S.K.

    2005-01-01

    Cirus, located at Bhabha Atomic Research Centre, is a 40 MW (Th) research reactor fuelled by natural uranium, moderated by heavy water and cooled by de-mineralized light water. Graphite is used as reflector in this reactor. The reactor, commissioned in the year 1960, was in operation with availability factor of about 70% till early nineties. There after signs of ageing started surfacing up. After ageing studies, refurbishment plan was finalized and executed during the period from 1997-2002. after successful refurbishment, the reactor is in operation at full power. A wide range of radiation instruments have been used at Cirus for online monitoring of the radiological status of various process systems and environmental releases. Also, variety of survey meters, counting systems and monitors have been used by the health physics unit of the reactor for radiation hazard control. Many of these instruments, which were originally of Canadian design, have undergone changes due to obsolescence or as part of upgradation. This paper describes the experience with the radiation instruments of Cirus, bringing out their effectiveness in meeting the design intent, difficulties faced in their field use, and modifications carried out based on the performance feed back. Also, this paper highlights the areas where further efforts are needed to develop nuclear instrumentation to further strengthen monitoring and surveillance. (author)

  4. Romanian Radiation Protection Training Experience in Medical Field

    International Nuclear Information System (INIS)

    Steliana Popescu, F.; Milu, C.; Naghi, E.; Calugareanu, L.; Stroe, F. M.

    2003-01-01

    Studies conducted by the Institute of Public Health Bucharest during the last years emphasised the need of appropriate radioprotection training in the medical field. With the assistance of the International Atomic Energy Agency in Vienna, the Pilot Centre on Clinical Radio pathology in the Institute of Public Health-Bucharest, provided, from 2000 a 7 modular courses (40 hours each), covering the basic topics of ionizing radiation, biological and physical dosimetry, effects of exposure to ionising radiation, radioprotection concepts, planning and medical response in case of a nuclear accident or radiological emergency. The courses are opened for all health specialists, especially for occupational health physicians, focusing on health surveillance of radiation workers and medical management of overexposed workers. Each module is followed up by an examination and credits. The multidisciplinary team of instructors was trained within several train-the-trainers courses, organised by IAEA. The paper discusses the evaluation of these 3 years experience in training and its feedback impact, the aim of the program being to develop a knowledge in the spirit of the new patterns of radiological protection, both for safety and communication with the public. (Author)

  5. Effective media models for unsaturated fractured rock: A field experiment

    International Nuclear Information System (INIS)

    Nicholl, M.J.; Glass, R.J.

    1995-01-01

    A thick unsaturated rock mass at Yucca Mountain is currently under consideration as a potential repository site for disposal of high level radioactive waste. In accordance with standard industry and scientific practices, abstract numerical models will be used to evaluate the potential for radionuclide release through the groundwater system. At this time, currently available conceptual models used to develop effective media properties are based primarily on simplistic considerations. The work presented here is part of an integrated effort to develop effective media models at the intermediate block scale (approximately 8-125m) through a combination of physical observations, numerical simulations and theoretical considerations. A multi-purpose field experiment designed and conducted as part of this integrated effort is described. Specific goals of this experimental investigation were to: (1) obtain fracture network data from Topopah Spring Tuff for use in block scale simulations; (2) identity positions of the network conducting flow under three different boundary conditions; (3) visualize preferential flow paths and small-scale flow structures; (4) collect samples for subsequent hydraulic testing and use in block-scale simulations; and (5) demonstrate the ability of Electrical Resistance Tomography (ERT) to delineate fluid distribution within fractured rock

  6. A review of mechanical move sprinkler irrigation control and automation technologies

    Science.gov (United States)

    Electronic sensors, equipment controls, and communication protocols have been developed to meet the growing interest in site-specific irrigation using center pivot and lateral move irrigation systems. Onboard and field-distributed sensors can collect data necessary for real-time irrigation manageme...

  7. Irrigation initiation timing in soybean grown on sandy soils in Northeast Arkansas

    Science.gov (United States)

    Irrigation initiation timing was evaluated in furrow-irrigated soybean field with sandy soils in Mississippi County, AR. A major objective of this 2015 study was to validate and expand irrigation timing recommendations that pair plant growth measures with weather cues including use of local weather ...

  8. EPIC Calibration/Validation Experiment Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Steven E [National Severe Storm Laboratory/NOAA; Chilson, Phillip [University of Oklahoma; Argrow, Brian [University of Colorado

    2017-03-15

    A field exercise involving several different kinds of Unmanned Aerial Systems (UAS) and supporting instrumentation systems provided by DOE/ARM and NOAA/NSSL was conducted at the ARM SGP site in Lamont, Oklahoma on 29-30 October 2016. This campaign was part of a larger National Oceanic and Atmospheric Administration (NOAA) UAS Program Office program awarded to the National Severe Storms Laboratory (NSSL). named Environmental Profiling and Initiation of Convection (EPIC). The EPIC Field Campaign (Test and Calibration/Validation) proposed to ARM was a test or “dry-run” for a follow-up campaign to be requested for spring/summer 2017. The EPIC project addresses NOAA’s objective to “evaluate options for UAS profiling of the lower atmosphere with applications for severe weather.” The project goal is to demonstrate that fixed-wing and rotary-wing small UAS have the combined potential to provide a unique observing system capable of providing detailed profiles of temperature, moisture, and winds within the atmospheric boundary layer (ABL) to help determine the potential for severe weather development. Specific project objectives are: 1) to develop small UAS capable of acquiring needed wind and thermodynamic profiles and transects of the ABL using one fixed-wing UAS operating in tandem with two different fixed rotary-wing UAS pairs; 2) adapt and test miniaturized, high-precision, and fast-response atmospheric sensors with high accuracy in strong winds characteristic of the pre-convective ABL in Oklahoma; 3) conduct targeted short-duration experiments at the ARM Southern Great Plains site in northern Oklahoma concurrently with a second site to be chosen in “real-time” from the Oklahoma Mesonet in coordination with the (National Weather Service (NWS)-Norman Forecast Office; and 4) gain valuable experience in pursuit of NOAA’s goals for determining the value of airborne, mobile observing systems for monitoring rapidly evolving high-impact severe weather

  9. Performance of cotton crop grown under surface irrigation and drip fertigation. I. seed cotton yield, dry matter production, and lint properties

    International Nuclear Information System (INIS)

    Janat, M.; Somi, G.

    2002-01-01

    Drip fertigation is a key factor in modern irrigated agriculture, where water and fertilizers are the most expensive inputs for this irrigation method. Drip fertigation experiments were carried out a Hama, north of Syria (Tezeen's Irrigation Research Station), for four consecutive years 1995 - 1998. Cotton (Gossypium hirsutim L.) variety Aleppo 33/1 was planted after unfertilized maize in order to deplete as much as possible the available N and reduce the field variability on the corresponding experimental units and irrigated thereafter. Treatments consisted of two irrigation methods (Surface irrigation and drip fertigation) and five N rates within drip fertigated cotton, including the control (N 0 = 0, N 1 = 60, N 2 = 120, N 3 = 180, N 4 240 kg N ha -1 ). The N fertilizer treatment for surface irrigated cotton was 180 kg N ha -1 in accordance with the recommended rate of ministry of Agriculture and Agrarian Reform. The experimental design was randomized block design with six replicates. Fertigation resulted in large water saving, and highly improved field water-use efficiency. Further, increasing N application rates under drip fertigation increased dry matter yield. The principal benefit of drip fertigation was the achievement of higher field water-use efficiencies, which were increased more than three-fold for both dry matter and seed cotton yield, relative to surface irrigation. The highest water-use efficiencies were obtained with the addition of 180 and 240 kg N ha -1 in 1995 and 1996 and 120 kg N ha -1 in 1997 and 1998. Dry matter production and partitioning among different plant parts at physiological maturity stage varied due to N input and irrigation methods. The overall dry matter distribution among different plant structures for drip fertigated-treatments was: Stems, 20.3 - 21.3%; leaves 26.3 - 28.7%; and fruiting forms, 50 - 53.2%. For the surface-irrigated treatment, the partitioning was stems, 23.1%; leaves, 28.3%; and fruiting form, 48.6%. The

  10. Irrigation and fertigation frequencies with nitrogen in the watermelon culture

    Directory of Open Access Journals (Sweden)

    Carlos Newdmar Vieira Fernandes

    2014-06-01

    Full Text Available This study evaluates the influence of different irrigation frequencies and different nitrogen fertigation frequencies on the growth performance of the watermelon (Citrullus lanatus culture. Two experiments were conducted at the Paraguay farm in the Cruz municipality, Ceará, Brazil. They was randomized blocks design with six treatments and four replications. The irrigation frequency experiment consisted of the application of different irrigation frequencies. The treatments were: DM - daily irrigation in the morning with 100% daily dosage; DT - daily irrigation in the afternoon, with 100% daily dosage; DMT - twice daily irrigation, with 50% daily dosage in the morning and 50% daily dosage in the afternoon; 2D - irrigation every two days; 3D - irrigation every three days and 4D - irrigation every four days. To the experiment with different nitrogen fertigation frequencies, the treatments used were: 2F - 2 fertigations in a cycle; 4F - 4 fertigations in a cycle; 8F - 8 fertigations in a cycle; 16F - 16 fertigations in a cycle; 32F - 32 fertigations in a cycle and 64F - 64 fertigations in a cycle. We evaluated the marketable yield (PC, fruit weight (M, polar diameter (DP, equatorial diameter (DE, shell thickness (EC and soluble solids (SS. The irrigation frequency treatments influenced all variables significantly, with twice daily irrigation (DMT, 50% in the morning and the 50% in the afternoon promoting the highest productivity (69.79 t ha-1. The different frequencies of fertigation also significantly influenced all variables, except for the shell thickness, the highest yield (80.69 t ha-1 being obtained with treatment 64 fertigations in a cycle.

  11. A Fuzzy analytical hierarchy process approach in irrigation networks maintenance

    Science.gov (United States)

    Riza Permana, Angga; Rintis Hadiani, Rr.; Syafi'i

    2017-11-01

    Ponorogo Regency has 440 Irrigation Area with a total area of 17,950 Ha. Due to the limited budget and lack of maintenance cause decreased function on the irrigation. The aim of this study is to make an appropriate system to determine the indices weighted of the rank prioritization criteria for irrigation network maintenance using a fuzzy-based methodology. The criteria that are used such as the physical condition of irrigation networks, area of service, estimated maintenance cost, and efficiency of irrigation water distribution. 26 experts in the field of water resources in the Dinas Pekerjaan Umum were asked to fill out the questionnaire, and the result will be used as a benchmark to determine the rank of irrigation network maintenance priority. The results demonstrate that the physical condition of irrigation networks criterion (W1) = 0,279 has the greatest impact on the assessment process. The area of service (W2) = 0,270, efficiency of irrigation water distribution (W4) = 0,249, and estimated maintenance cost (W3) = 0,202 criteria rank next in effectiveness, respectively. The proposed methodology deals with uncertainty and vague data using triangular fuzzy numbers, and, moreover, it provides a comprehensive decision-making technique to assess maintenance priority on irrigation network.

  12. Memory of irrigation effects on hydroclimate and its modeling challenge

    Science.gov (United States)

    Chen, Fei; Xu, Xiaoyu; Barlage, Michael; Rasmussen, Roy; Shen, Shuanghe; Miao, Shiguang; Zhou, Guangsheng

    2018-06-01

    Irrigation modifies land-surface water and energy budgets, and also influences weather and climate. However, current earth-system models, used for weather prediction and climate projection, are still in their infancy stage to consider irrigation effects. This study used long-term data collected from two contrasting (irrigated and rainfed) nearby maize-soybean rotation fields, to study the effects of irrigation memory on local hydroclimate. For a 12 year average, irrigation decreases summer surface-air temperature by less than 1 °C and increases surface humidity by 0.52 g kg‑1. The irrigation cooling effect is more pronounced and longer lasting for maize than for soybean. Irrigation reduces maximum, minimum, and averaged temperature over maize by more than 0.5 °C for the first six days after irrigation, but its temperature effect over soybean is mixed and negligible two or three days after irrigation. Irrigation increases near-surface humidity over maize by about 1 g kg‑1 up to ten days and increases surface humidity over soybean (~ 0.8 g kg‑1) with a similar memory. These differing effects of irrigation memory on temperature and humidity are associated with respective changes in the surface sensible and latent heat fluxes for maize and soybean. These findings highlight great need and challenges for earth-system models to realistically simulate how irrigation effects vary with crop species and with crop growth stages, and to capture complex interactions between agricultural management and water-system components (crop transpiration, precipitation, river, reservoirs, lakes, groundwater, etc.) at various spatial and temporal scales.

  13. The Influence of Legitimacy Perceptions on Cooperation – A Framed Field Experiment

    NARCIS (Netherlands)

    Bouma, J.A.; Joy, K.J.; Paranjape, S.; Ansink, E.

    2014-01-01

    Decentralization of irrigation management is claimed to improve performance by enhancing legitimacy and, thus, increasing cooperation. We test this hypothesis by collecting information about water users' legitimacy perceptions and assessing the impact of these perceptions on irrigation charge

  14. Zone edge effects with variable rate irrigation

    Science.gov (United States)

    Variable rate irrigation (VRI) systems may offer solutions to enhance water use efficiency by addressing variability within a field. However, the design of VRI systems should be considered to maximize application uniformity within sprinkler zones, while minimizing edge effects between such zones alo...

  15. Uncertainties in modelling the climate impact of irrigation

    Science.gov (United States)

    de Vrese, Philipp; Hagemann, Stefan

    2017-11-01

    Irrigation-based agriculture constitutes an essential factor for food security as well as fresh water resources and has a distinct impact on regional and global climate. Many issues related to irrigation's climate impact are addressed in studies that apply a wide range of models. These involve substantial uncertainties related to differences in the model's structure and its parametrizations on the one hand and the need for simplifying assumptions for the representation of irrigation on the other hand. To address these uncertainties, we used the Max Planck Institute for Meteorology's Earth System model into which a simple irrigation scheme was implemented. In order to estimate possible uncertainties with regard to the model's more general structure, we compared the climate impact of irrigation between three simulations that use different schemes for the land-surface-atmosphere coupling. Here, it can be shown that the choice of coupling scheme does not only affect the magnitude of possible impacts but even their direction. For example, when using a scheme that does not explicitly resolve spatial subgrid scale heterogeneity at the surface, irrigation reduces the atmospheric water content, even in heavily irrigated regions. Contrarily, in simulations that use a coupling scheme that resolves heterogeneity at the surface or even within the lowest layers of the atmosphere, irrigation increases the average atmospheric specific humidity. A second experiment targeted possible uncertainties related to the representation of irrigation characteristics. Here, in four simulations the irrigation effectiveness (controlled by the target soil moisture and the non-vegetated fraction of the grid box that receives irrigation) and the timing of delivery were varied. The second experiment shows that uncertainties related to the modelled irrigation characteristics, especially the irrigation effectiveness, are also substantial. In general the impact of irrigation on the state of the land

  16. Calculations of transient fields in the Felix experiments at Argonne using null field integrated techniques

    International Nuclear Information System (INIS)

    Han, H.C.; Davey, K.R.; Turner, L.

    1985-08-01

    The transient eddy current problem is characteristically computationally intensive. The motivation for this research was to realize an efficient, accurate, solution technique involving small matrices via an eigenvalue approach. Such a technique is indeed realized and tested using the null field integral technique. Using smart (i.e., efficient, global) basis functions to represent unknowns in terms of a minimum number of unknowns, homogeneous eigenvectors and eigenvalues are first determined. The general excitatory response is then represented in terms of these eigenvalues/eigenvectors. Excellent results are obtained for the Argonne Felix cylinder experiments using a 4 x 4 matrix. Extension to the 3-D problem (short cylinder) is set up in terms of an 8 x 8 matrix

  17. Effects of irrigation on the seasonal abundance of Empoasca vitis in north-Italian vineyards.

    Science.gov (United States)

    Fornasiero, D; Duso, C; Pozzebon, A; Tomasi, D; Gaiotti, F; Pavan, F

    2012-02-01

    The effect of irrigation on the abundance of Empoasca vitis (Göthe) populations was investigated in four vineyards located in northeastern Italy. In two experiments, we compared leafhopper population densities in plots irrigated (micro-spray irrigation system) or nonirrigated. In another experiment, we studied the effect of various irrigation systems on E. vitis populations over two successive seasons. In particular, five treatments were compared: control (not irrigated), traditional drip system, three types of subirrigation varying in distance from the row (40, 135, and 95 cm). In this vineyard, stem water potential was monitored with a pressure chamber. E. vitis population densities were affected by irrigation, with higher densities of this pest recorded on irrigated vines. Highest E. vitis densities were detected in drip irrigation plots compared with nonirrigated plots where water stress was highest. Moderate water stress (subirrigation plots) was associated with intermediate leafhopper densities. Implications for integrated pest management are discussed.

  18. High magnetic field generation for laser-plasma experiments

    International Nuclear Information System (INIS)

    Pollock, B. B.; Froula, D. H.; Davis, P. F.; Ross, J. S.; Fulkerson, S.; Bower, J.; Satariano, J.; Price, D.; Krushelnick, K.; Glenzer, S. H.

    2006-01-01

    An electromagnetic solenoid was developed to study the effect of magnetic fields on electron thermal transport in laser plasmas. The solenoid, which is driven by a pulsed power system supplying 30 kJ, achieves magnetic fields of 13 T. The field strength was measured on the solenoid axis with a magnetic probe and optical Zeeman splitting. The measurements agree well with analytical estimates. A method for optimizing the solenoid design to achieve magnetic fields exceeding 20 T is presented

  19. Chernobyl Experience in the Field of Retrospective Dosimetry

    International Nuclear Information System (INIS)

    Chumak, V.; Bakhanova, E.

    2011-01-01

    Chernobyl accident, which occurred on April 26, 1986 at NPP located less than 150 km north of Kiev, is the largest nuclear accident ever. Unprecedented scale of the accident was determined not only by the amount of released activity, but also by a number of population and workers involved and, therefore, exposed to enhanced doses of ionizing radiation. Population of the 30-km exclusion zone numbering about 116,000 persons of all ages and both genders was evacuated within days and weeks after the accident, emergency workers called ''liquidators of the accident'' (males age 20-50) were involved into clean-up and recovery for 5 years and their number is estimated as 600,000, about 300,000 are Ukrainian citizens. Due to unexpected and excessively large scale accident, none of residents had personal dosimeters, personal dosimetry of liquidators was not total, dosimetry techniques and practices were far from the optimum. As a result, an acute need for retrospective dose assessment was dictated by radiation protection and research considerations. This need was responded by implementation of wide scale dose reconstruction efforts, which covered main exposed cohorts and encompassed broad variety of newly developed methods: analytical (time-and-motion), modeling, biological and physical (EPR spectroscopy of teeth, TL of quartz). The presentation summarizes vast experience accumulated by RCRM in the field of retrospective dosimetry of large cohorts of exposed population and professionals. These dose reconstruction projects were implemented, in particular, in the framework of epidemiological studies, designed to follow-up medical consequences of Chernobyl accident and study health effects of ionizing radiation, in particular, Ukrainian-American studies of cataracts and leukemia among liquidators. Over 25 years passed after Chernobyl accident a broad variety of retrospective dosimetry problems was addressed by the team of Research Center for Radiation Medicine AMS Ukraine. In

  20. Chemical colostomy irrigation with glyceryl trinitrate solution.

    Science.gov (United States)

    O'Bichere, A; Bossom, C; Gangoli, S; Green, C; Phillips, R K

    2001-09-01

    Colostomy irrigation may improve patient quality of life, but is time consuming. This study tests the hypothesis that irrigation with glyceryl trinitrate solution, by inducing gastrointestinal smooth muscle relaxation, may accelerate expulsion of stool by passive emptying, thereby reducing irrigation time. Fifteen colostomy irrigators(with more than 3 years' experience) performed washout with tap water compared with water containing 0.025 mg/kg glyceryl trinitrate. Fluid inflow time, total washout time, and hemodynamic changes occurring during glyceryl trinitrate irrigation were documented by an independent observer. Subjects recorded episodes of fecal leakage and overall satisfaction on a visual analog scale. Cramps, headaches, and whether or not a stoma bag was used were expressed as a percentage of number of irrigations. Comparison of fluid inflow time, total washout time, leakage, and satisfaction was by Wilcoxon's signed-rank test and headaches, cramps, and stoma bag use was by McNemar's test. Pulse rate (paired t-test), systolic and diastolic blood pressures (Wilcoxon's test) at 20 and 240 minutes after washout with glyceryl trinitrate solution were compared with baseline. Fifteen patients (9 female), with a mean age of 53 (31-73) years, provided 30 sessions (15 with water and 15 with glyceryl trinitrate). Medians (interquartile ranges) for water vs. glyceryl trinitrate were fluid inflow time 7 (4-10) vs. 4, (3-5; P = 0.001); total washout time 40 (30-55) vs. 21, (15-24; P colostomy irrigation time compared with the generally recommended tap water. Patients suffer fewer leakages and are highly satisfied, but side effects are potential drawbacks. Other colonoplegic agent solutions should now be evaluated.

  1. Vegetative growth and yield of strawberry under irrigation and soil mulches for different cultivation environments

    Directory of Open Access Journals (Sweden)

    Pires Regina Célia de Matos

    2006-01-01

    Full Text Available The vegetative growth and yield of strawberry in relation to irrigation levels and soil mulches are still not well known, mainly for different environmental conditions. Two experiments were carried out in Atibaia, SP, Brazil, during 1995, one in a protected environment and the other in an open field, to evaluate the cultivar Campinas IAC-2712, under different irrigation levels and soil mulches (black and clear polyethylene. Three water potential levels in the soil were used in order to define irrigation time, corresponding to -0.010 (N1, -0.035 (N2, and -0.070 (N3 MPa, measured through tensiometers installed at the 10 cm depth. A 2 x 3 factorial arrangement was adopted, as randomized complete block, with 5 replicates. In the protected cultivation, the irrigation levels of -0.010 and -0.035 MPa and the clear plastic mulch favored the vegetative growth, evaluated through plant height, maximum horizontal dimension of the plant, leaf area index, as well as by total marketable fruit yield and its components (mean number and weight of fruits per plant. In the open field cultivation, no effect of treatments due to rainfall were observed.

  2. Drip irrigation using a PLC based adaptive irrigation system

    OpenAIRE

    Shahidian, S.; Serralheiro, R. P.; Teixeira, J. L.; Santos, F. L.; Oliveira, M. R. G.; Costa, J. L.; Toureiro, C.; Haie, Naim; Machado, R. M.

    2009-01-01

    Most of the water used by man goes to irrigation. A major part of this water is used to irrigate small plots where it is not feasible to implement full-scale Evapotranspiration based irrigation controllers. During the growth season crop water needs do not remain constant and varies depending on the canopy, growth stage and climate conditions such as temperature, wind, relative humidity and solar radiation. Thus, it is necessary to find an economic irrigation controller that can adapt the dail...

  3. Effectiveness of urease inhibition on the abatement of ammonia, nitrous oxide and nitric oxide emissions in a non-irrigated Mediterranean barley field.

    Science.gov (United States)

    Abalos, Diego; Sanz-Cobena, Alberto; Misselbrook, Thomas; Vallejo, Antonio

    2012-09-01

    Urea is considered the cheapest and most commonly used form of inorganic N fertilizer worldwide. However, its use is associated with emissions of ammonia (NH(3)), nitrous oxide (N(2)O) and nitric oxide (NO), which have both economic and environmental impact. Urease activity inhibitors have been proposed as a means to reduce NH(3) emissions, although limited information exists about their effect on N(2)O and NO emissions. In this context, a field experiment was carried out with a barley crop (Hordeum vulgare L.) under Mediterranean conditions to test the effectiveness of the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) on reducing these gaseous N losses from surface applied urea. Crop yield, soil mineral N concentrations, dissolved organic carbon (DOC), denitrification potential, NH(3), N(2)O and NO fluxes were measured during the growing season. The inclusion of the inhibitor reduced NH(3) emissions in the 30 d following urea application by 58% and net N(2)O and NO emissions in the 95 d following urea application by 86% and 88%, respectively. NBPT addition also increased grain yield by 5% and N uptake by 6%, although neither increase was statistically significant. Under the experimental conditions presented here, these results demonstrate the potential of the urease inhibitor NBPT in abating NH(3), N(2)O and NO emissions from arable soils fertilized with urea, slowing urea hydrolysis and releasing lower concentrations of NH(4)(+) to the upper soil layer. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Effect of different levels of nitrogen fertilizer on yield and quality of sugar beet Beta vulgaris irrigated with saline groundwater (fertigation and surface irrigation) and grown under saline conditions

    International Nuclear Information System (INIS)

    Janat, M.

    2009-07-01

    In a field experiment Sugar beet Beta vulgaris was grown as a spring crop during the growing seasons of 2004 and 2006, in salt affected soil, previously planted with sesbania and barley (2005 and 2003) to evaluate the response of sugar beet to two irrigation methods, (drip fertigation and surface irrigation), different levels of nitrogen fertilizer and its effect on yield and quality. Different rates of nitrogen fertilizers (0, 50, 100, 150 and 200 kg N/ ha) as urea (46% N) were injected for drip irrigation or broadcasted for the surface-irrigated treatments in four equally split applications. The 15 N labelled urea was applied to sub-plots of 1.0 m 2 in each experimental unit in a manner similar to that of unlabeled urea. Irrigation scheduling was carried out using the direct method of neutron scattering technique. Sugar beet was irrigated when soil moisture in the upper 25 cm was 80% of the field capacity (FC) and such practice continued until the six leaf stage. From the latter stage until harvest, sugar beet was irrigated when soil moisture in the upper 50 cm reached 80% of the FC. The amount of irrigation water applied, electrical conductivity of the soil paste, dry matter and fresh roots yield, total nitrogen uptake and N derived from fertilizer were also determined. Furthermore, Nitrogen use as well as water use-efficiencies for dry matter and roots yield were also calculated. Results revealed that sugar beets and dry matter yield increased with increasing N input up to 100-150 kg N/ha which was indicated by the higher dry matter yield, and sugar beet yield. Sugar percentage was also increased relative to the average percentage recorded in Syria. Crop water use efficiencies, for both the drip-fertigated and surface-irrigated treatments were increased in most cases with increasing rate of nitrogen fertilizer. During the course of this study, small increases in soil salinity under both irrigation methods were observed. Higher increases in soil salinity was

  5. Municipal Treated Wastewater Irrigation: Microbiological Risk Evaluation

    Directory of Open Access Journals (Sweden)

    Antonio Lonigro

    2008-06-01

    Full Text Available Municipal wastewater for irrigation, though treated, can contain substances and pathogens toxic for humans and animals. Pathogens, although not harmful from an agronomical aspect, undoubtedly represent a major concern with regards to sanitary and hygienic profile. In fact, vegetable crops irrigated with treated wastewater exalt the risk of infection since these products can also be eaten raw, as well as transformed or cooked. Practically, the evaluation of the microbiological risk is important to verify if the microbial limits imposed by law for treated municipal wastewater for irrigation, are valid, thus justifying the treatments costs, or if they are too low and, therefore, they don’ t justify them. Different probabilistic models have been studied to assess the microbiological risk; among these, the Beta-Poisson model resulted the most reliable. Thus, the Dipartimento di Scienze delle Produzioni Vegetali of the University of Bari, which has been carrying out researches on irrigation with municipal filtered wastewater for several years, considered interesting to verify if the microbial limits imposed by the italian law n.185/03 are too severe, estimating the biological risk by the probabilistic Beta-Poisson model. Results of field trials on vegetable crops irrigated by municipal filtered wastewater, processed by the Beta-Poisson model, show that the probability to get infection and/or illness is extremely low, and that the actual italian microbial limits are excessively restrictive.

  6. Automated Irrigation System for Greenhouse Monitoring

    Science.gov (United States)

    Sivagami, A.; Hareeshvare, U.; Maheshwar, S.; Venkatachalapathy, V. S. K.

    2018-06-01

    The continuous requirement for the food needs the rapid improvement in food production technology. The economy of food production is mainly dependent on agriculture and the weather conditions, which are isotropic and thus we are not able to utilize the whole agricultural resources. The main reason is the deficiency of rainfall and paucity in land reservoir water. The continuous withdrawal water from the ground reduces the water level resulting in most of the land to come under the arid. In the field of cultivation, use of appropriate method of irrigation plays a vital role. Drip irrigation is a renowned methodology which is very economical and proficient. When the conventional drip irrigation system is followed, the farmer has to tag along the irrigation timetable, which is different for diverse crops. The current work makes the drip irrigation system an automated one, thereby the farmer doesn't want to follow any timetable since the sensor senses the soil moisture content and based on it supplies the water. Moreover the practice of economical sensors and the simple circuitry makes this project as an inexpensive product, which can be bought even by an underprivileged farmer. The current project is best suited for places where water is limited and has to be used in limited quantity.

  7. Automated Irrigation System for Greenhouse Monitoring

    Science.gov (United States)

    Sivagami, A.; Hareeshvare, U.; Maheshwar, S.; Venkatachalapathy, V. S. K.

    2018-03-01

    The continuous requirement for the food needs the rapid improvement in food production technology. The economy of food production is mainly dependent on agriculture and the weather conditions, which are isotropic and thus we are not able to utilize the whole agricultural resources. The main reason is the deficiency of rainfall and paucity in land reservoir water. The continuous withdrawal water from the ground reduces the water level resulting in most of the land to come under the arid. In the field of cultivation, use of appropriate method of irrigation plays a vital role. Drip irrigation is a renowned methodology which is very economical and proficient. When the conventional drip irrigation system is followed, the farmer has to tag along the irrigation timetable, which is different for diverse crops. The current work makes the drip irrigation system an automated one, thereby the farmer doesn't want to follow any timetable since the sensor senses the soil moisture content and based on it supplies the water. Moreover the practice of economical sensors and the simple circuitry makes this project as an inexpensive product, which can be bought even by an underprivileged farmer. The current project is best suited for places where water is limited and has to be used in limited quantity.

  8. Effect of irrigation and nitrogen fertilizer levels on yield and yield components of dill (Anethum graveolens L.

    Directory of Open Access Journals (Sweden)

    S. Madadi Bonab

    2016-05-01

    Full Text Available In order to investigate the effect of irrigation and nitrogen fertilizer on yield and yield components of (Anethum graveolens L., a field experiment was performed in Agricultural Research Farm of the University of Tabriz, Iran, during growing season of 2009-2010. The experiment was carried out as split plot based on randomized complete block design with three replications. Irrigation treatments (irrigation after 70, 100, 130 mm evaporation from class A pan and nitrogen levels (0, 40, 80, 120 kg.ha-1 were allocated to main and sub-plots, respectively. The results showed that nitrogen fertilizer had significant (p≤0.05 effect on minor diameter umbrella, 1000-seed weight, seed yield and harvest index. However, irrigation and effect between irrigation and nitrogen were not affected any of the traits. The greatest minor diameter umbrella was obtained with control nitrogen treatment and maximum 1000-seed weight, harvest index and seed yield were obtained from 40 kg.ha-1 nitrogen. There was no any significant difference between 40 and 80 kg.ha-1 nitrogen levels. Therefore, it seems that for producing the highest yield application of 40 kg.ha-1 nitrogen is suitable. As water deficit no significant effects on this traits, of dill, it can be concluded that dill is a tolerant plant to drought stress.

  9. Soil-pit Method for Distribution and Leaching Loss of Nitrogen in Winter Wheat’s Soil, Weishan Irrigation District

    Science.gov (United States)

    Zhao, Erni; Xu, Lirong; Wang, Rongzhen

    2018-01-01

    Unreasonable application of irrigation and fertilizer will cause the waste of water and nitrogen and environmental pollution. In this paper, a series of soil-pit experiments were carried out to study the distribution and leaching loss of nitrogen in winter wheat’s soil. The results showed that NO3 - concentration at 20-80cm depth mainly responded to fertilizer application at the beginning of field experiment, but the amount of irrigation became the dominant factor with the growth of winter wheat. It is noteworthy that the distribution of NO3 - was mainly affected by the amount of fertilizer applied at the depth of 120-160cm in the whole period of growth of winter wheat. The accumulation position of NH4 + was deepened as the amount of irrigation increased, however, the maximum aggregation depth of ammonium nitrogen was no more than 80cm owing to its poor migration. It can be concluded that the influence of irrigation amount on the concentration of NH4 + in soil solution was more obvious than that of fertilizer. Compared with fertilizer, the amount of irrigation played a leading role in the utilization ratio of nitrogen and the yield of winter wheat. In summary, the best water and fertilizer treatment occurred in No.3 soil-pit, which meant that the middle amount of water and fertilizer could get higher wheat yield and less nitrogen leaching losses in the study area.

  10. Effect of Irrigation Intervalsand Plantingdate on Agronomic Characteristics of Degen and Drfi (Securiger securidaca L. in Birjand Region

    Directory of Open Access Journals (Sweden)

    h Tabiei

    2014-07-01

    Full Text Available Degen & Drfiis a plant that has medicinal and nutritional importance. Degen&Drfi and countless of plants in this genus had application for medicinal uses such as weight loss and diabetes control. Its seeds also contain protein and lipids as well as some starchy foods are consumed. In order to investigate the effect of irrigation regime and planting date on agronomic characteristics of Degen&Drfi a field experiment carried out in region of kahi, Birjand, south khorasan, Iran, 2010. The experiment was conducted in split plot design in a randomized complete block with four replications. Irrigation regime, including: six, twelve and eighteen days' intervals as main factors and planting Date at four levels (20, 25, 30 April, and5 May were devoted to sub-plots. Analysis of variance showed that irrigation regime for all treatment, had more significant influence on trait including plant height, number of pods per plant, seeds per pod, biomass, grain yield and harvest index, and had significant influence the yield of flowers per plant and weight seed. The highest amounts of each trait were gained from 12 days interval irrigation. The effect of planting date was significant all treatment for all traits except 1000-seed weight. Planting in 20 April had highest values of characteristics. Interaction between irrigation and planting date were significant for number of stems, flowers and pods per plant, biomass, harvest index and grain yield at 1% and plant height at 5% level. The highest seed yield was obtained from irrigation in 12 days interval and planting in the 20 April. Results showed that irrigation in 12 days interval and planting especially in late April are the best treatment forDegen&Drfi production.

  11. Saline water irrigation of quinoa and chickpea

    DEFF Research Database (Denmark)

    Hirich, A.; Jelloul, A.; Choukr-Allah, R.

    2014-01-01

    A pot experiment was conducted in the south of Morocco to evaluate the response of chickpea and quinoa to different irrigation water salinity treatments (1, 4, 7 and 10 dS m-1 for chickpea and 1, 10, 20 and 30 dS m-1 for quinoa). Increasing salinity affected significantly (P

  12. Contamination of rice (Oryza sativa L) with Cadmium and Arsenic by irrigation with the Bogota River water in rice soils of the Lower Basin

    International Nuclear Information System (INIS)

    Montenegro, Omar; Mejia L

    2001-01-01

    In this study, field and greenhouse experiments were simultaneously carried out with rice (oryza sativa l., variedad oryzica-1) in soils of the Bogota River lower basin (Los Manueles Series, a member of the clayed, mixed, isohipertermic family of the Fluventic Vertic Haplustepts) to evaluate the effect of Cd and As content of the irrigation waters (of the Bogota River and greenhouse) on soils and: 1) rice growth physiological parameters; 2) Cd and As accumulated in different parts of rice plants; 3) yields and other aspects and properties of rice crop. The results lead to the following conclusions: 1) The Cd and As content of the Bogota River water, increased during the driest months and was minimum in those with the highest precipitation; Cd and As concentrations in both seasons surpassed the maximum permissible limits. 2) Rice height was highest when irrigation water does have neither Cd nor As. Effects of both elements showed an inverse lineal tendency. 3) The gradual increase of Cd in irrigation water reduced in 12.5% the number of grains per panicle; the increase of As induced a 10% reduction. 4) The highest concentration of Cd and As in irrigation waters significantly reduced yields; maximum yields l were obtained when Cd and As were absent from irrigation waters. 5) For any concentration of As in irrigation water the highest concentration of Cd was accumulated in rice leafs when concentration of Cd 2 was 2mg/l; above this value Cd accumulation in leafs el decreased with the gradual increase of As concentration. 6) Cd and As accumulated in rice grains increased with the gradual increment of both elements in the irrigation waters; Cd and As accumulated were respectively 50 and 15 times higher than the maximum critical levels proposed for rice grains. 7) Cd and As accumulated progressively on soils with gradual increase of both elements in irrigation waters 8) Cd and As concentration in irrigation waters apparently does not affect the rice mill behavior

  13. Yield, Quality and Water Consumption of Stevia rebaudiana Bertoni Grown under Different Irrigation Regimes in Southern Italy

    Directory of Open Access Journals (Sweden)

    Antonella Lavini

    2008-06-01

    Full Text Available Stevia rebaudiana Bertoni is a herbaceous perennial plant originating in the north-east of Paraguay. Its leaves contain low-calorie sweetening agents that can be used as a natural alternative to artificial sweeteners. The leaves are consumed in special human diets and for the treatment of various diseases. The aim of the present work is to study water consumption, yield potential and quality characteristics of this species under different irrigation levels in southern Italy. The field work was carried out in 2006-2007. Irrigation treatments consisted of a control (T100, irrigated with 100% restitution of water consumption and two treatments that received a water depth of 33% (T33 and 66% (T66 of treatment T100. Watering volume was estimated to replenish the soil profile to field capacity for a depth of 0.40 m. The crop was harvested twice a year, and agronomic performance as well as the major cation and glycoside contents (stevioside and rebaudioside A were evaluated. Overall, the crop coefficients were similar between the two years, although in each year the second growing period showed higher values due to the higher evaporative demand of this period. Interactions of years with irrigation treatments and harvest time were not significant either for yield or yield components. In both cuts the T100 treatments achieved 40% higher leaf dry yield than T33, while T66 showed intermediate values. The harvest index and water use efficiency showed no differences between the two cuts for the same treatments, while the values of both indices decreased with the increase in irrigation regime. Stevioside, rebaudioside A and cation content in the leaves were unaffected by irrigation regime. In order to develop the field cultivation of this species, field experiments are required to prepare a cultivation protocol as well as a genetic improvement program to develop varieties that better respond to the local environment.

  14. Yield, Quality and Water Consumption of Stevia rebaudiana Bertoni Grown under Different Irrigation Regimes in Southern Italy

    Directory of Open Access Journals (Sweden)

    Riccardo d’Andria

    2011-02-01

    Full Text Available Stevia rebaudiana Bertoni is a herbaceous perennial plant originating in the north-east of Paraguay. Its leaves contain low-calorie sweetening agents that can be used as a natural alternative to artificial sweeteners. The leaves are consumed in special human diets and for the treatment of various diseases. The aim of the present work is to study water consumption, yield potential and quality characteristics of this species under different irrigation levels in southern Italy. The field work was carried out in 2006-2007. Irrigation treatments consisted of a control (T100, irrigated with 100% restitution of water consumption and two treatments that received a water depth of 33% (T33 and 66% (T66 of treatment T100. Watering volume was estimated to replenish the soil profile to field capacity for a depth of 0.40 m. The crop was harvested twice a year, and agronomic performance as well as the major cation and glycoside contents (stevioside and rebaudioside A were evaluated. Overall, the crop coefficients were similar between the two years, although in each year the second growing period showed higher values due to the higher evaporative demand of this period. Interactions of years with irrigation treatments and harvest time were not significant either for yield or yield components. In both cuts the T100 treatments achieved 40% higher leaf dry yield than T33, while T66 showed intermediate values. The harvest index and water use efficiency showed no differences between the two cuts for the same treatments, while the values of both indices decreased with the increase in irrigation regime. Stevioside, rebaudioside A and cation content in the leaves were unaffected by irrigation regime. In order to develop the field cultivation of this species, field experiments are required to prepare a cultivation protocol as well as a genetic improvement program to develop varieties that better respond to the local environment.

  15. Solar-thermal jet pumping for irrigation

    Science.gov (United States)

    Clements, L. D.; Dellenback, P. A.; Bell, C. A.

    1980-01-01

    This paper describes a novel concept in solar powered irrigation pumping, gives measured performance data for the pump unit, and projected system performance. The solar-thermal jet pumping concept is centered around a conventional jet eductor pump which is commercially available at low cost. The jet eductor pump is powered by moderate temperature, moderate pressure Refrigerant-113 vapor supplied by a concentrating solar collector field. The R-113 vapor is direct condensed by the produced water and the two fluids are separated at the surface. The water goes on to use and the R-113 is repressurized and returned to the solar field. The key issue in the solar-thermal jet eductor concept is the efficiency of pump operation. Performance data from a small scale experimental unit which utilizes an electrically heated boiler in place of the solar field is presented. The solar-thermal jet eductor concept is compared with other solar irrigation concepts and optimal application situations are identified. Though having lower efficiencies than existing Rankine cycle solar-thermal irrigation systems, the mechanical and operational simplicity of this concept make it competitive with other solar powered irrigation schemes.

  16. Effect of Different Methods of Chemical Weed Control Irrigation Regimes on Weed Biomass and Safflower Yield

    Directory of Open Access Journals (Sweden)

    M. Matinfar

    2011-06-01

    Full Text Available In order to investigate the effects of different weed control methods and moisture regimes on safflower (Carthamus tinctorius, a field split plot experiment based on randomized complete block design with 4 replications was conducted in Takestan Iran, during growing seasons of 2007-8. Three irrigations regimes (normal irrigation, restricted irrigation at stem elongation and restricted irrigation at  flowering stage were assigned to the main plots and nine chemical weed control method (complete hand weeding, treflan with 2 L/ha as pre plant herbicide, sonalan with 3 L/ha ad pre plant herbicide, estomp with 3 L/ha as pre plant herbicide, gallant super with 0/75 L/ha as post emergence herbicide, treflan with 2 L/ha as pre plant herbicide+ gallant super with 0/75 L/ha as post emergence herbicide, sonalan with 3 L/ha as pre plant herbicide + gallant super with 0/75 L/ha as post emergence herbicide estomp with 3 L/ha as pre plant herbicide + gallant super with 0/75 L/ha as post emergence herbicide and without hand weeding to sub- plots. At the end of growing period traits like number of head   per plant, number of seed per head, 1000 grain weight, percent of seed oil, yield of seed oil and grain yield were measured. Results indicated that treflan + gallant super treatment in restricted irrigation at stem elongation stage had the lowest dry weight of weeds. In this study maximum grain yield (2927 Kg/ha was achieved from hand weeding + usual irrigation treatments. In general treflan + gallant super treatment was the most effective treatment on safflower yield and weed control.

  17. An assessment of colostomy irrigation.

    Science.gov (United States)

    Laucks, S S; Mazier, W P; Milsom, J W; Buffin, S E; Anderson, J M; Warwick, M K; Surrell, J A

    1988-04-01

    One hundred patients with permanent sigmoid colostomies were surveyed to determine their satisfaction and success with the "irrigation" technique of colostomy management. Most patients who irrigate their colostomies achieve continence. Odors and skin irritation are minimized. The irrigation method is economical, time efficient, and allows a reasonably liberal diet. It avoids bulky appliances and is safe. In appropriately selected patients, the irrigation technique is the method of choice for management of an end-sigmoid colostomy.

  18. Field Experiments Aimed To The Analysis of Flood Generation Processes

    Science.gov (United States)

    Carriero, D.; Iacobellis, V.; Oliveto, G.; Romano, N.; Telesca, V.; Fiorentino, M.

    The study of the soil moisture dynamics and of the climate-soil-vegetation interac- tion is essential for the comprehension of possible climatic change phenomena, as well as for the analysis of occurrence of extreme hydrological events. In this trend the theoretically-based distribution of floods recently derived by Fiorentino and Ia- cobellis, [ŞNew insights about the climatic and geologic control on the probability distribution of floodsT, Water Resources Research, 2001, 37: 721-730] demonstrated, by an application in some Southern Italy basins, that processes at the hillslope scale strongly influence the basin response by means of the different mechanisms of runoff generation produced by various distributions of partial area contributing. This area is considered as a stochastic variable whose pdf position parameter showed strong de- pendence on the climate as it can seen in the studied basins behavior: in dry zones, where there is the prevalence of the infiltration excess (Horton) mechanism, the basin water loss parameter decreases as basin area increases and the flood peak source area depends on the permeability of soils; in humid zones, with the prevalence of satu- ration excess (Dunne) process, the loss parameter seems independent from the basin area and very sensitive to simple climatic index while only small portion of the area invested by the storm contributes to floods. The purpose of this work is to investigate the consistency of those interpretations by means of field experiments at the hillslope scale to establish a parameterization accounting for soil physical and hydraulic prop- erties, vegetation characteristics and land-use. The research site is the catchment of River Fiumarella di Corleto, which is located in Basilicata Region, Italy, and has a drainage area of approximately 32 km2. The environment has a rather dynamic geo- morphology and very interesting features from the soil-landscape modeling viewpoint [Santini A., A. Coppola, N. Romano, and

  19. Effects of Furrow Irrigation on the Growth, Production, and Water Use Efficiency of Direct Sowing Rice

    Directory of Open Access Journals (Sweden)

    Chunlin He

    2010-01-01

    Full Text Available Rice farming is the major crop production in Asia and is predicted to increase significantly in the near future in order to meet the demands for the increasing human population. Traditional irrigation methods used in rice farming often result in great water loss. New water-saving methods are urgently needed to reduce water consumption. Three field and pot experiments were conducted to evaluate the furrow irrigation (FI system to improve water use efficiency (WUE and production of direct sowing rice in southern China. Compared to the conventional irrigation (CI system (continuous flooding irrigation, for every square hectometer of rice field, the FI system reduced water use by 3130 m3, or 48.1%, and increased grain production by 13.9% for an early cultivar. For a late cultivar, the FI system reduced water use by 2655 m3, or 40.6%, and an increase of grain production by 12.1%. The improved WUE in the FI system is attributed to (1 a significant reduction of irrigation rate, seepage, evaporation, and evapotranspiration; (2 a significant reduction in the reduced materials, such as ferrous ion (Fe2+, and therefore an increase in the vitality of the root system, evident by the increases in the number of white roots by 32.62%, and decreases in the number of black roots by 20.04% and yellow roots by 12.58%; the use of the FI system may also reduce humidity of the rice field and enhance gas transport in the soil and light penetration, which led to reduced rice diseases and increased leaf vitality; and (3 increases in tiller and effective spikes by 11.53% and the weight per thousand grains by 1.0 g. These findings suggest that the shallow FI system is a promising means for rice farming in areas with increasing water shortages.

  20. Effects of furrow irrigation on the growth, production, and water use efficiency of direct sowing rice.

    Science.gov (United States)

    He, Chunlin

    2010-08-03

    Rice farming is the major crop production in Asia and is predicted to increase significantly in the near future in order to meet the demands for the increasing human population. Traditional irrigation methods used in rice farming often result in great water loss. New water-saving methods are urgently needed to reduce water consumption. Three field and pot experiments were conducted to evaluate the furrow irrigation (FI) system to improve water use efficiency (WUE) and production of direct sowing rice in southern China. Compared to the conventional irrigation (CI) system (continuous flooding irrigation), for every square hectometer of rice field, the FI system reduced water use by 3130 m3, or 48.1%, and increased grain production by 13.9% for an early cultivar. For a late cultivar, the FI system reduced water use by 2655 m3, or 40.6%, and an increase of grain production by 12.1%. The improved WUE in the FI system is attributed to (1) a significant reduction of irrigation rate, seepage, evaporation, and evapotranspiration; (2) a significant reduction in the reduced materials, such as ferrous ion (Fe2+), and therefore an increase in the vitality of the root system, evident by the increases in the number of white roots by 32.62%, and decreases in the number of black roots by 20.04% and yellow roots by 12.58%; the use of the FI system may also reduce humidity of the rice field and enhance gas transport in the soil and light penetration, which led to reduced rice diseases and increased leaf vitality; and (3) increases in tiller and effective spikes by 11.53% and the weight per thousand grains by 1.0 g. These findings suggest that the shallow FI system is a promising means for rice farming in areas with increasing water shortages.

  1. Drip irrigation and fertigation of potato under light-textured soils of cappadocia region

    International Nuclear Information System (INIS)

    Halitgil, M. B.; Onaran, H.; Munsuz, N.; Kislal, H.; Akin, A.; Unlenen, A. L.; Cayci, G.; Kutuk, C.

    2002-01-01

    In order to evaluate potato response to drip irrigation and N fertigation; and also to improve nitrogen and water use efficiencies of potato and eventually to obtain less nitrogen polluted surface and water, 10 field experiments were carried out at three different locations in Cappadocia Region of Turkey in 1997, 1998, 1999 and 2000 growing seasons. Nitrogen as ammonium sulphate ((NH 4 ) 2 So 4 ), was supplied by drip irrigation water (fertigation) at rates of 0, 30, 60 and 90 kg N/da. Also, soil N application treatment equivalent to the fertigation treatment of 60kg N/da was included. These five treatments were investigated in a completely randomized block design with four replicants. Agria potato variety was used in all experiments and potato was planted in mid May and harvested at the end of October.''1''5N-labelled ammonium sulphate fertilizer were applied in isotope-sub plots within the macroplots for each treatment, in order to determine the amount of nitrogen taken up by the plant, nitrogen use efficiency and the distribution of residual nitrogen at different depths in the soil profile. Each year, during the growth period, total 12 irrigations were done and 50 mm of water was applied at each irrigation. At harvest, plant samples (tuber and leaf+vein) and soil samples were taken from each plot and N%, ''1''5N% atom excess (''1''5N% a.e.) and Ndff% determinations were done. Soil water contents at differrent soil depths were determined by soil moisture neutron probe at plantingand at harvest period so that water contents at different soil layers and water use efficiencies were calculated for each treatment. The results obtained showed that 3350 kg/da mean total marketable tuber yield was obtained with application of 600 mm irrigation water. Also,it was found that water did not move below 90 cm of soil layer in drip irrigation-fertigation system, which showed clearly that no nitrogen movement occured beyond 90 cm soil depth. Tuber yields and %Ndff increased when

  2. Using Field Experiments to Evaluate the Impact of Financial Planning and Counseling Interventions

    Science.gov (United States)

    Collins, J. Michael

    2017-01-01

    Field experiments, which are a powerful research technique, are common in some fields, but they have not been widely used in studying the effect of financial and counseling planning interventions. Financial services can benefit from the expanded use of field experiments to explore potential causal mechanisms for the effects of financial planning…

  3. Accounting for user expectations in the valuation of reliable irrigation water access in the Ethiopian highlands

    DEFF Research Database (Denmark)

    Kassahun, Habtamu Tilahun; Nicholson, Charles F.; Jacobsen, Jette Bredahl

    2016-01-01

    We estimate the willingness-to-pay (WTP) for reliable access to irrigation water for a sample of farmers in a watershed of the Ethiopian highlands who do not have prior experience with irrigation. To address the lack of previous irrigation experience, we account for underlying expectations...... of future irrigation productivity using an Integrated Choice and Latent Variable (ICLV) econometric model. We then compare the ICLV estimates with alternative models that do not account for expectations regarding productivity increases with irrigation. Our results indicate that both the ICLV and alternative...

  4. Rotating magnetic field current drive-theory and experiment

    International Nuclear Information System (INIS)

    Donnelly, I.J.

    1989-01-01

    Rotating magnetic fields have been used to drive plasma current and establish a range of compact torus configurations, named rotamaks. The current drive mechanism involves a ponderomotive force acting on the electron fluid. Recent extensions of the theory indicate that this method is most suitable for driving currents in directions perpendicular to the steady magnetic fields

  5. On the control of irrigation through soil moisture measurement using a neutron depth probe in horizontal subsurface measuring circuits

    International Nuclear Information System (INIS)

    Schaecke, B.; Schaecke, E.

    1977-01-01

    An outline is given of the advantages inherent in soil moisture measurement by means of a neutron probe in horizontal subsurface measuring circuits for irrigation control. Preliminary experience for the setting up of a field calibration curve and for practical measurement are submitted. This technique includes the following advantages: almost complete covering of the upper soil range which is of interest to irrigation control; good measuring density; suitable distribution of measuring points per unit area; possibility of continuous probe passage; optimal repeatability of measurements; exploration of a unit area with but few measuring circuits; no obstacles to tillage, drilling, intercultivation and harvest operations; and complete conservation of crop and plot which is not reached with any other soil moisture measurement technique so far available. Making use of the above advantages, the new technique allows automatic irrigation control with only one neutron depth probe. (author)

  6. Effect of nitrate addition on the efficient use of ammonium sulfate fertilizer on corn under saline conditions . II. field experiment

    International Nuclear Information System (INIS)

    Khalifa, Kh.; Zidan, A

    2003-01-01

    two field experiments during two consecutive seasons, were conducted on corn (Zea mays L. var. Ghota-82), grown on a saline soil under flood irrigation system at ACSAD research station located at the Euphrates valley, Deir-Ez-zor district, east of Syria. The objective was to study the effect of applying different ratios of mixed NO 3 -N and NH 4 -N fertilizers on the biomass yield of corn. Five rates of nitrogen (0, 50, 100, 150 and 200 kg N/ha) were applied either in a single or in combination of two forms of 15 N labelled nitrogen fertilizers ( 15 NH 4 ) 2 SO 4 and Ca( 15 NO 3 ) 2 . Total N, 15 N, nitrogen use efficiency (N recovery) and dry matter yield were the parameters investigated. The results showed that: (1) The high concentrations of NH 4 -N reduced dry matter yield; (2) NO 3 -N was more effective in increasing total N content of plant tissues than the same concentration of NH 4 -N; (3) Combination treatments always induced both higher yields and N content of plant tissues than single treatments of NH 4 -N; (4) NH 4 -N form increased the NO 3 -N uptake, and the NO 3 -N form had an effect on the absorption of NH 4 -N; (5) the recovery of NO 3 -N form was much higher than NH 4 -N form under saline soil conditions. (author)

  7. Communication, Community, and Disconnection: Pre-Service Teachers in Virtual School Field Experiences

    Science.gov (United States)

    Wilkens, Christian; Eckdahl, Kelli; Morone, Mike; Cook, Vicki; Giblin, Thomas; Coon, Joshua

    2014-01-01

    This study examined the experiences of 11 graduate-level pre-service teachers completing Virtual School Field Experiences (VSFEs) with cooperating teachers in fully online, asynchronous high school courses in New York State. The VSFEs included a 7-week online teacher training course, and a 7-week online field experience. Pre-service teachers…

  8. Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

    International Nuclear Information System (INIS)

    Al-Ghobari, H.M.; Mohammad, F.S.; El Marazky, M.S.A.

    2016-01-01

    Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema) in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

  9. Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghobari, H.M.; Mohammad, F.S.; El Marazky, M.S.A.

    2016-07-01

    Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema) in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

  10. Sensor-Based Model Driven Control Strategy for Precision Irrigation

    Directory of Open Access Journals (Sweden)

    Camilo Lozoya

    2016-01-01

    Full Text Available Improving the efficiency of the agricultural irrigation systems substantially contributes to sustainable water management. This improvement can be achieved through an automated irrigation system that includes a real-time control strategy based on the water, soil, and crop relationship. This paper presents a model driven control strategy applied to an irrigation system, in order to make an efficient use of water for large crop fields, that is, applying the correct amount of water in the correct place at the right moment. The proposed model uses a predictive algorithm that senses soil moisture and weather variables, to determine optimal amount of water required by the crop. This proposed approach is evaluated against a traditional irrigation system based on the empirical definition of time periods and against a basic soil moisture control system. Results indicate that the use of a model predictive control in an irrigation system achieves a higher efficiency and significantly reduce the water consumption.

  11. Sorption of pathogens during sub-surface drip irrigation with wastewater

    Science.gov (United States)

    Levi, Laillach; Gillerman Gillerman, Leonid; Kalavrouziotis, Ioannis; Oron, Gideon

    2017-04-01

    Water scarcity continues to be one of the major threats to human survival in many regions worldwide, such as Africa, the Mediterranean Basin, the State of California in the US. Due to a mixture of factors such as population growth, reduction in water resources availability and higher demand for high quality waters in these regions these countries face water shortage issues that stem from overuse, extensive extraction of groundwater, and frequent drought events. In addition, there are increases in environmental and health awareness that have led to intensive efforts in the treatment and reuse of nonconventional water sources, mainly wastewater and greywater. One approach to water shortages issues is to use wastewater as means to close the gap between supply and demand. However, the need to treat wastewater and to disinfect it forces additional economic burden on the users, primarily for agricultural irrigation. A possible solution might be to use the soil as a sorbent for the contained pathogens. Under sub-surface drip irrigation, not allowing the wastewater to reach the soil surface, the pathogens will remain in the soil. It was as well shown in field experiments that the opening size of roots will not allow pathogens to penetrate into the plants. Additional advantages such as water saving, protection of the pipe systems and others are also important. Field experiments in commercial fields just emphasize the main advantages of sub-surface drip irrigation.

  12. Effects of soil moisture conservation practice, irrigation and fertilization on Jatropha curcas

    Directory of Open Access Journals (Sweden)

    Aran Phiwngam

    2016-11-01

    Full Text Available A field experiment was conducted on an Ultic Haplustalf at the Kanchanaburi Research Station, Muang district, Kanchanaburi province, western Thailand between July 2011 and June 2012. Split plots in a randomized complete block design with four replications were employed, having eight main plots (soil moisture conservation practice and irrigation, W1–W8 and 2 sub plots (fertilization, F1 and F2. Jatropha curcas (KUBP 78-9 Var., having been planted at 2 × 2 m spacing, was aged 2 yr when the experiment was commenced. The highly significantly heaviest 100-seed weight of 42 g was obtained 1 mth after water irrigation which had been applied at the rate of 16 L/plant, particularly in the treatment with crop residue mulching (W8 but there were no significant differences among the other treatments where irrigation had been applied (W5–W7. Fertilization and a combination between different fertilizers and soil moisture conservation schemes plus irrigation showed no different effect on the weight of 100 seeds throughout the year of measurement. Growing J. curcas with drip-irrigated water at the rate of 16 L/plant applied every 2 d and crop residue mulching (W8 significantly gave the highest seed yield of 1301.3 kg/ha at 15% moisture content. There were no significant differences among the seed yields from the plots applied with the same amount of irrigated water but with no mulching (W7 and half that amount of irrigated water with crop residue mulching (W6, producing yields of 1112.0 kg/ha and 1236.3 kg/ha, respectively. Three-year-old J. curcas gave inferior seed yield when grown with no irrigated water supply (W1–W4. The application of 50–150–150 kg/ha of N–P2O5–K2O significantly induced a higher amount of seed yield (933.9 kg/ha than did the addition of 93.75–93.75–93.75 kg/ha of N–P2O5–K2O (786.3 kg/ha. The interaction between soil moisture conservation plus irrigation and fertilizer was clear. Applying 50–150

  13. NMR magnetic field controller for pulsed nuclear magnetic resonance experiments

    International Nuclear Information System (INIS)

    Scheler, G.; Anacker, M.

    1975-01-01

    A nuclear magnetic resonance controller for magnetic fields, which can also be used for pulsed NMR investigations, is described. A longtime stability of 10 -7 is achieved. The control signal is generated by a modified time sharing circuit with resonance at the first side band of the 2 H signal. An exact calibration of the magnetic field is achieved by the variation of the H 1 - or of the time-sharing frequency. (author)

  14. Field reversal experiments (FRX). [Equilibrium, confinement, and stability

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1978-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centers the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFC's with a major radius R = 2-6 cm, minor radius a approximately 2 cm, and a total length l approximately 35 cm. The observed temperatures are T/sub e/ approximately 100 eV and T/sub i/ = 150-350 eV with a peak density n approximately 2 x 10/sup 15/ cm/sup -3/. After the plasma reaches equilibrium, the RFC remains stable for up to 30 ..mu..s followed by the rapid growth of the rotational m = 2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behavior of the m = 2 mode qualitatively agrees with the theoretically predicted instability for rotational velocities exceeding some critical value.

  15. Calculations of self-generated magnetic fields in parylene disc experiments

    International Nuclear Information System (INIS)

    Dahlbacka, G.H.; Mead, W.C.; Max, C.E.; Thomson, J.J.

    1975-01-01

    Experiments have been planned at Livermore to measure self-generated magnetic fields using the Faraday Rotation of frequency quadrupled 1.1 μm laser light. The LASNEX code was used during the planning of these experiments and has provided valuable information in establishing the conditions under which the thermoelectric fields expected can be measured. Suspected thermoelectric fields have been inferred from experiments that have been carried out at NRL

  16. Effects of Supplemental Irrigation on Yield and Growth Indices of Three

    Directory of Open Access Journals (Sweden)

    M. Parsa

    2012-04-01

    Full Text Available In order to investigate the effects of different irrigation regimes on yield and growth indices of three chickpea cultivars, an experiment was conducted during the 2007 growing season at Mashhad (Iran. Six irrigation regimes including I1; full irrigation, I2; irrigation at branching, I3; irrigation at flowering, I4; irrigation at pod formation, I5; irrigation at seed filling stage and I6; dry farming without irrigation (main factors. Three Kabuli chickpea cultivars ILC482, Jam, Karaj 12-60-31 (sub factors in a spilt block experiment based on randomized block design with three replications. There were significant differences between supplemental irrigation levels on grain yield. The results showed that grain yield in supplemental irrigation at flowering stage was more than to supplemental irrigation at branching, podding and seed filling stages (respectively 3.3, 3.1 and 23%. Within the three cultivars, grain yield, biological yield and harvest index were highest and lowest in ILC482 and Karaj 12-60-31 cultivars respectively. The results showed that supplemental irrigation at flowering stage increased dry matter, leaf area index, crop growth rate, relative growth rate and net assimilation rate. The results showed that flowering stage in chickpea cultivars was sensitive to drought stress so, ILC482 cultivar also showed more tolerance to water stress condition.

  17. On the design and implementation of environmental conservation mechanisms : Evidence from field experiments

    NARCIS (Netherlands)

    Kitesa, Rahel

    2018-01-01

    This doctoral dissertation consists of three chapters on the design and implementation of environmental conservation mechanisms using economic experiments. The first chapter examines how variations in information and context affect the outcomes of valuation using field experiment. The chapter shows

  18. Dwarf cashew growth irrigated with saline waters

    Directory of Open Access Journals (Sweden)

    Hugo Orlando Carvallo Guerra

    2009-12-01

    Full Text Available The cashew production is one of the most important agricultural activities from the social-economical viewpoint for the North East of Brazil; besides to produce a great deal of hand labor, it is very important as an exporting commodity. The inadequate use of irrigation in the semi arid regions of the North East of Brazil has induced soil salinization and consequently problems for the irrigated agriculture. In spite of this, few works have been conducted to study the effect of saline stress on the growth and development of the cashew. Because of the lack of information for this crop, an experiment was conducted to study the effect of salinity stress on the phytomass production and nutrient accumulation on the different organs of the precocious dwarf cashew (Anacardium occidentale L. clone CCP76. The study was conducted under controlled conditions using as statistical scheme a randomized block design factorial with six replicates. Five salinity treatments were considered for the irrigation water (electrical conductivities of 0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1 at 25oC. The increasing in salinity of the irrigation water reduced the phytomass at different organs of the studied plant. The nitrogen, phosphorus, potassium, chloride and sodium in the plant varied with the salinity of the irrigation water according with the part of the plant analyzed; in some parts increased, in others decreased, in others increased initially and decreased afterwards, and finally, in other part of the plant the salinity of the irrigation water did not affect the nutrient concentration.

  19. Irrigation method does not affect wild bee pollinators of hybrid sunflower

    Directory of Open Access Journals (Sweden)

    Hillary Sardiñas

    2016-09-01

    Full Text Available Irrigation method has the potential to directly or indirectly influence populations of wild bee crop pollinators nesting and foraging in irrigated crop fields. The majority of wild bee species nest in the ground, and their nests may be susceptible to flooding. In addition, their pollination of crops can be influenced by nectar quality and quantity, which are related to water availability. To determine whether different irrigation methods affect crop pollinators, we compared the number of ground-nesting bees nesting and foraging in drip- and furrow-irrigated hybrid sunflower fields in the Sacramento Valley. We found that irrigation method did not impact wild bee nesting rates or foraging bee abundance or bee species richness. These findings suggest that changing from furrow irrigation to drip irrigation to conserve water likely will not alter hybrid sunflower crop pollination.

  20. [Ecological risks of reclaimed water irrigation: a review].

    Science.gov (United States)

    Chen, Wei-Ping; Zhang, Wei-Ling; Pan, Neng; Jiao, Wen-Tao

    2012-12-01

    Wastewater reclamation and reuse have become an important approach to alleviate the water crisis in China because of its social, economic and ecological benefits. The irrigation on urban green space and farmland is the primary utilization of reclaimed water, which has been practiced world widely. To understand the risk of reclaimed water irrigation, we summarized and reviewed the publications associated with typical pollutants in reclaimed water including salts, nitrogen, heavy metals, emerging pollutants and pathogens, systematically analyzed the ecological risk posed by reclaimed water irrigation regarding plant growth, groundwater quality and public health. Studies showed that salt and salt ions were the major risk sources of reclaimed water irrigation, spreading disease was another potential risk of using reclaimed water, and emerging pollutants was the hot topic in researches of ecological risk. Based on overseas experiences, risk control measures on reclaimed water irrigation in urban green space and farmland were proposed. Five recommendations were given to promote the safe use of reclaimed water irrigation including (1) strengthen long-term in situ monitoring, (2) promote the modeling studies, (3) build up the connections of reclaimed water quality, irrigation management and ecological risk, (4) evaluate the soil bearing capacity of reclaimed water irrigation, (5) and establish risk management system of reclaimed water reuse.

  1. Simulation experiment on magnetic field reconnection processes in tokamak

    International Nuclear Information System (INIS)

    Kiwamoto, Y.

    1982-01-01

    Two experimental studies on magnetic field line reconnection processes relevant to tokamak physics are going on in Japan. In Yokohama National University, reconnection of poloidal magnetic field lines is studied by the author when reversing the toroidal current of a small toroidal plasma in a short period (typically less than 4 μsec). Interaction of two current carrying plasma (linear) columns is being studied by Kawashima and his coleagues in Institute of Space and Aeronautical Sciences. Mutual attraction and merging of the plasma columns and resulting plasma heating are reported. (author)

  2. Modeling nitrate leaching and optimizing water and nitrogen management under irrigated maize in desert oases in Northwestern China.

    Science.gov (United States)

    Hu, Kelin; Li, Yong; Chen, Weiping; Chen, Deli; Wei, Yongping; Edis, Robert; Li, Baoguo; Huang, Yuanfang; Zhang, Yuanpei

    2010-01-01

    Understanding water and N transport through the soil profile is important for efficient irrigation and nutrient management to minimize nitrate leaching to the groundwater, and to promote agricultural sustainable development in desert oases. In this study, a process-based water and nitrogen management model (WNMM) was used to simulate soil water movement, nitrate transport, and crop growth (maize [Zea mays L.]) under desert oasis conditions in northwestern China. The model was calibrated and validated with a field experiment. The model simulation results showed that about 35% of total water input and 58% of the total N input were leached to <1.8 m depth under traditional management practice. Excessive irrigation and N fertilizer application, high nitrate concentration in the irrigation water, together with the sandy soil texture, resulted in large nitrate leaching. Nitrate leaching was significantly reduced under the improved management practice suggested by farm extension personnel; however, the water and nitrate inputs still far exceeded the crop requirements. More than 1700 scenarios combining various types of irrigation and fertilizer practices were simulated. Quantitative analysis was conducted to obtain the best management practices (BMPs) with simultaneous consideration of crop yield, water use efficiency, fertilizer N use efficiency, and nitrate leaching. The results indicated that the BMPs under the specific desert oasis conditions are to irrigate the maize with 600 mm of water in eight times with a single fertilizer application at a rate of 75 kg N ha(-1).

  3. Optimizing nitrogen fertilizer application to irrigated wheat. Results of a co-ordinated research project. 1994-1998

    International Nuclear Information System (INIS)

    2000-07-01

    This TECDOC summarizes the results of a Co-ordinated Research Project (CRP) on the Use of Nuclear Techniques for Optimizing Fertilizer Application under Irrigated Wheat to Increase the Efficient Use of Nitrogen Fertilizer and Consequently Reduce Environmental Pollution. The project was carried out between 1994 and 1998 through the technical co-ordination of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. Fourteen Member States of the IAEA and FAO carried out a series of field experiments aimed at improving irrigation water and fertilizer-N uptake efficiencies through integrated management of the complex Interactions involving inputs, soils, climate, and wheat cultivars. Its goals were: to investigate various aspects of fertilizer N uptake efficiency of wheat crops under irrigation through an interregional research network involving countries growing large areas of irrigated wheat; to use 15 N and the soil-moisture neutron probe to determine the fate of applied N, to follow water and nitrate movement in the soil, and to determine water balance and water-use efficiency in irrigated wheat cropping systems; to use the data generated to further develop and refine various relationships in the Ceres-Wheat computer simulation model; to use the knowledge generated to produce a N-rate-recommendation package to refine specific management strategies with respect to fertilizer applications and expected yields

  4. Characterizing the Effects of Irrigation in the Middle East and North Africa Using Remotely Sensed Vegetation and Water Cycle Observations

    Science.gov (United States)

    Bolten, John; Ozdogan, Mutlu; Beaudoing, Hiroko; Rodell, Matthew

    2012-01-01

    A majority of the countries in the Middle East and North Africa (MENA) region suffer from water scarcity due in part to widespread rainfall deficits, unprecedented levels of water demand, and the inefficient use of renewable freshwater resources. Since a majority of the water withdrawal in the MENA is used for irrigation, there is a desperate need for improved understanding of irrigation practices and agricultural water use in the region. Here, satellite-derived irrigation maps and crop-type agricultural data are applied to the Land Data Assimilation System for the MENA region (MENA LDAS), designed to provide regional, gridded fields of hydrological states and fluxes relevant for water resources assessments. Within MENA-LDAS, the Catchment Land Surface Model (CLSM) simulates the location, timing, and amount of water applied through agricultural irrigation practices over the region from 2002-2012. In addition to simulating the irrigation impact on evapotranspiration, soil moisture, and runoff, we also investigate regional changes in terrestrial water storage (TWS) observed from the Gravity Recovery and Climate Experiment (GRACE) and simulated by CLSM.

  5. Can nitrate contaminated groundwater be remediated by optimizing flood irrigation rate with high nitrate water in a desert oasis using the WHCNS model?

    Science.gov (United States)

    Liang, Hao; Qi, Zhiming; Hu, Kelin; Prasher, Shiv O; Zhang, Yuanpei

    2016-10-01

    Nitrate contamination of groundwater is an environmental concern in intensively cultivated desert oases where this polluted groundwater is in turn used as a major irrigation water resource. However, nitrate fluxes from root zone to groundwater are difficult to monitor in this complex system. The objectives of this study were to validate and apply the WHCNS (soil Water Heat Carbon Nitrogen Simulator) model to simulate water drainage and nitrate leaching under different irrigation and nitrogen (N) management practices, and to assess the utilization of groundwater nitrate as an approach to remediate nitrate contaminated groundwater while maintain crop yield. A two-year field experiment was conducted in a corn field irrigated with high nitrate groundwater (20 mg N L(-1)) in Alxa, Inner Mongolia, China. The experiment consisted of two irrigation treatments (Istd, standard, 750 mm per season; Icsv, conservation, 570 mm per season) factorially combined with two N fertilization treatments (Nstd, standard, 138 kg ha(-1); Ncsv, conservation, 92 kg ha(-1)). The validated results showed that the WHCNS model simulated values of crop dry matter, yield, soil water content and soil N concentration in soil profile all agreed well with the observed values. Compared to the standard water management (Istd), the simulated drainage and nitrate leaching decreased about 65% and 59%, respectively, under the conservation water management (Icsv). Nearly 55% of input N was lost by leaching under the IstdNstd and IstdNcsv treatments, compared to only 26% under the IcsvNstd and IcsvNcsv treatments. Simulations with more than 240 scenarios combing different levels of irrigation and fertilization indicated that irrigation was the main reason leading to the high risk of nitrate leaching, and the nitrate in irrigation groundwater can be best utilized without corn yield loss when the total irrigation was reduced from the current 750 mm to 491 mm. This reduced irrigation rate facilitated

  6. Root Development of Transplanted Cotton and Simulation of Soil Water Movement under Different Irrigation Methods

    Directory of Open Access Journals (Sweden)

    Hao Zhang

    2017-07-01

    Full Text Available Winter wheat and cotton are the main crops grown on the North China Plain (NCP. Cotton is often transplanted after the winter wheat harvest to solve the competition for cultivated land between winter wheat and cotton, and to ensure that both crops can be harvested on the NCP. However, the root system of transplanted cotton is distorted due to the restrictions of the seedling aperture disk before transplanting. Therefore, the investigation of the deformed root distribution and water uptake in transplanted cotton is essential for simulating soil water movement under different irrigation methods. Thus, a field experiment and a simulation study were conducted during 2013–2015 to explore the deformed roots of transplanted cotton and soil water movement using border irrigation (BI and surface drip irrigation (SDI. The results showed that SDI was conducive to root growth in the shallow root zone (0–30 cm, and that BI was conducive to root growth in the deeper root zone (below 30 cm. SDI is well suited for producing the optimal soil water distribution pattern for the deformed root system of transplanted cotton, and the root system was more developed under SDI than under BI. Comparisons between experimental data and model simulations showed that the HYDRUS-2D model described the soil water content (SWC under different irrigation methods well, with root mean square errors (RMSEs of 0.023 and 0.029 cm3 cm−3 and model efficiencies (EFs of 0.68 and 0.59 for BI and SDI, respectively. Our findings will be very useful for designing an optimal irrigation plan for BI and SDI in transplanted cotton fields, and for promoting the wider use of this planting pattern for cotton transplantation.

  7. Representing Farmer Irrigation Decisions in Northern India: Model Development from the Bottom Up.

    Science.gov (United States)

    O'Keeffe, J.; Buytaert, W.; Brozovic, N.; Mijic, A.

    2017-12-01

    The plains of northern India are among the most intensely populated and irrigated regions of the world. Sustaining water demand has been made possible by exploiting the vast and hugely productive aquifers underlying the Indo-Gangetic basin. However, an increasing demand from a growing population and highly variable socio-economic and environmental variables mean present resources may not be sustainable, resulting in water security becoming one of India's biggest challenges. Unless solutions which take into consideration the regions evolving anthropogenic and environmental conditions are found, the sustainability of India's water resources looks bleak. Understanding water user decisions and their potential outcome is important for development of suitable water resource management options. Computational models are commonly used to assist water use decision making, typically representing natural processes well. The inclusion of human decision making however, one of the dominant drivers of change, has lagged behind. Improved representation of irrigation water user behaviour within models provides more accurate, relevant information for irrigation management. This research conceptualizes and proceduralizes observed farmer irrigation practices, highlighting feedbacks between the environment and livelihood. It is developed using a bottom up approach, informed through field experience and stakeholder interaction in Uttar Pradesh, northern India. Real world insights are incorporated through collected information creating a realistic representation of field conditions, providing a useful tool for policy analysis and water management. The modelling framework is applied to four districts. Results suggest predicted future climate will have little direct impact on water resources, crop yields or farmer income. In addition, increased abstraction may be sustainable in some areas under carefully managed conditions. By simulating dynamic decision making, feedbacks and interactions

  8. The Field Trip Book: Study Travel Experiences in Social Studies

    Science.gov (United States)

    Morris, Ronald V.

    2010-01-01

    Looking for social studies adventures to help students find connections to democratic citizenship? Look no further! This book provides just the answer teachers need for engaging students in field trips as researching learners with emphasis on interdisciplinary social studies plus skills in collecting and reporting data gathered from field…

  9. Tropospheric ozone lidar intercomparison experiment, TROLIX '91, field phase report

    International Nuclear Information System (INIS)

    Boesenberg, J.; Ancellet, G.; Bergwerff, H.; Cossart, G. v.; Fiedler, J.; Jonge, C. de; Mellqvist, J.; Mitev, V.; Sonnemann, G.; Swart, D.; Wallinder, E.

    1993-01-01

    The Tropospheric Ozone Lidar Intercomparison Experiment TROLIX '91 has been initiated as part of the TESLAS subproject of the cooperative programme EUROTRAC. It has been performed in June 1991 at the Rijksinstitut voor Volksgezondheid en Milieuhygiene (RIVM) in Bilthoven, The Netherlands. The experiment was based on the simultaneous operation of different types of differential absorption lidars (DIAL), a special version of a Differential Optical Absorption Spectroscopy Instrument (DOAS), helicopter borne in situ instruments, and many other supporting measurements. After a short introduction to the general methodology the instruments are described, the experimental operations are explained, and a selection of data are presented. Some examples are given for the results of the intercomparison, as far as they have been available at the present stage of evaluation. The main purpose of this report, however, is to provide an overview over the material collected during the experiment, on order to facilitate further detailed studies in cooperation between the different groups which have participated. (orig.)

  10. Effect of different rates of irrigation on nitrogen use efficiency and sugarbeet yield

    International Nuclear Information System (INIS)

    Khalifa, Kh.; Sharanek, A.; Ashawwa, F.

    1994-11-01

    Field experiments were conducted separately during three seasons, autumn 1986/1987, spring 1988, and spring 1989, at ACSAD research station in Deir-Ezzor, under flood irrigation system, using two different variets of Sugarbeet, kawipoly in the first season and Kawi-Interpoly in the second and third season. All experiments recieved sililar rate of irrigation to keep the soil moisture contents at three levels offield capacity (85, 75 and 65%). Fertilizer treatment were in the first season 3 rates (0, 120, 240 Kg N/Ha) of ammonium nitrate fertilizer sup 1 sup 5 NH sub 4 sup 1 sup 5 NO sub 3 (double labeled), in the second season two single labeled sup 1 sup 5 NH sub 4 NO sub 3 and NU sub 4 sup 1 sup 5 NO sub 3 were used at two rates (0, 120 Kg N/ha), in the third season labeld urea CO(sup 1 sup 5 NH sub 2) sub 2 and ammonium sulfate (sup 1 sup 5 NH sub 4) sub 4 SO sub 4 fertilizers were used separatly at two rates (0, 120 Kg N/ha). The results showed that nitrogen use efficincy (NUE) varied with type, from, rate of N fertilizer, and rate of irrigation at different growth stages of crop and was in the range (4.5-81.83%). The yield of roots at harvest were segnificantly increased by irrigation and nitrogen fertilization in the first and second season , also I x N had significant interaction effect on yield. Yield of roots in the third season were only increased by nitrogen application with no effect irrigation. 21 refs., 18 tabs

  11. Contrasting agronomic response of biochar amendment to a Mediterranean Cambisol: Incubation vs. field experiment

    Science.gov (United States)

    De la Rosa, José M.; Paneque, Marina; De Celis, Reyes; Miller, Ana Z.; Knicker, Heike

    2015-04-01

    The application of biochar to soil is being proposed as a novel approach to establish a significant long-term sink for atmospheric carbon dioxide in terrestrial ecosystems. In addition, biochars offer a simple, sustainable tool for managing organic wastes and to produce added value products. Numerous research studies pointed out that biochar can act as a soil conditioner enhancing plant growth by supplying and, more importantly, retaining nutrients and by providing other services such as improving soil physical and biological properties [1]. However, the effectiveness of biochar in enhancing plant fertility is a function of soil type, climate, and type of crop [2] but also of the biochar properties. The inherent variability of biochars due to different feedstock and production conditions implies a high variability of their effect on soil properties and productivity. Furthermore, due to the irreversibility of biochar application, it is necessary to perform detailed studies to achieve a high level of certainty that adding biochar to agricultural soils, for whatever reason, will not negatively affect soil health and productivity. The major goals of this research were: i) understanding how the properties of 5 different biochars produced by using different feedstock and pyrolysis conditions are related to their agronomic response, and ii) assessing the agronomic effect of biochar amendment under field conditions of a typical Mediterranean non-irrigated plantation. Four of the used biochars were produced by pyrolysis from wood (2), paper sludge (1) and sewage sludge (1), at temperatures up to 620 °C. The fifth biochar was produced from old grapevine wood by applying the traditional kiln method. Biochars were analysed for elemental composition (C, H, N), pH, WHC and ash contents. The H/C and O/C atomic ratios suggested high aromaticity of all biochars, which was confirmed by 13C solid-state NMR spectroscopy. The FT-IR spectra indicated the presence of lignin residues in

  12. The Mistra experiment for field containment code validation first results

    International Nuclear Information System (INIS)

    Caron-Charles, M.; Blumenfeld, L.

    2001-01-01

    The MISTRA facility is a large scale experiment, designed for the purpose of thermal-hydraulics multi-D codes validation. A short description of the facility, the set up of the instrumentation and the test program are presented. Then, the first experimental results, studying helium injection in the containment and their calculations are detailed. (author)

  13. International Field Experiences Promote Professional Development for Sustainability Leaders

    Science.gov (United States)

    Hull, R. Bruce; Kimmel, Courtney; Robertson, David P.; Mortimer, Michael

    2016-01-01

    Purpose: This paper aims to describe, explain and evaluate a graduate education program that provides international project experiences and builds competencies related to collaborative problem-solving, cultural capacity to work globally and sustainable development. Design/methodology/approach: Qualitative analysis of survey data from 28 students…

  14. Luck or cheating? A field experiment on honesty with children

    NARCIS (Netherlands)

    Bucciol, A.; Piovesan, M.

    2011-01-01

    We run an experiment to study the relationship between honesty, age and self-control. We focus on children aged between 5 and 15 as the literature suggests that self-control develops within such age range. We ask each child to toss a fair coin in private and to record the outcome (white or black) on

  15. Luck or cheating? A field experiment on honesty with children

    NARCIS (Netherlands)

    Bucciol, A.; Piovesan, M.

    2008-01-01

    We ran an experiment with children to study the development of honesty with age. We asked each child to toss a fair coin in private and to record the outcome (white or black) in a paper sheet. We rewarded only those who reported white. We found a fraction of reported whites signifi cantly larger

  16. Thermal and Field Enhanced Photoemission Comparison of Theory to Experiment

    CERN Document Server

    Lynn-Jensen, Kevin

    2004-01-01

    Photocathodes are a critical component of high-gain FEL’s and the analysis of their emission is complex. Relating their performance under laboratory conditions to conditions of an rf photoinjector is difficult. Useful models must account for cathode surface conditions and material properties, as well as drive laser parameters. We have developed a time-dependent model accounting for the effects of laser heating and thermal propagation on photoemission. It accounts for surface conditions (coating, field enhancement, reflectivity), laser parameters (duration, intensity, wavelength), and material characteristics (reflectivity, laser penetration depth, scattering rates) to predict current distribution and quantum efficiency. The applicatIon will focus on photoemission from metals and, in particular, dispenser photocathodes: the later introduces complications such as coverage non-uniformity and field enhancement. The performance of experimentally characterized photocathodes will be extrapolated to 0.1 - 1 nC bunch...

  17. Field error reduction experiment on the REPUTE-1 RFP device

    International Nuclear Information System (INIS)

    Toyama, H.; Shinohara, S.; Yamagishi, K.

    1989-01-01

    The vacuum chamber of the RFP device REPUTE-1 is a welded structure using 18 sets of 1 mm thick Inconel bellows (inner minor radius 22 cm) and 2.4 mm thick port segments arranged in toroidal geometry as shown in Fig. 1. The vacuum chamber is surrounded by 5 mm thick stainless steel shells. The time constant of the shell is 1 ms for vertical field penetration. The pulse length in REPUTE-1 is so far 3.2 ms (about 3 times longer than shell skin time). The port bypass plates have been attached as shown in Fig. 2 to reduce field errors so that the pulse length becomes longer and the loop voltage becomes lower. (author) 5 refs., 4 figs

  18. Laboratory and field experience with rim ditch dewatering of MFT

    Energy Technology Data Exchange (ETDEWEB)

    Demoz, A.; Mikula, R. [Natural Resources Canada, Devon, AB (Canada). CANMET Western Research Centre; Lahaie, R. [Syncrude Canada Ltd., Edmonton, AB (Canada)

    2010-07-01

    This PowerPoint presentation described a rim ditch method of dewatering mature fine tailings (MFT). Polymer additions were used to strengthen the MFT and to decrease the capillary suction time (CST). Laboratory and field-scale studies were conducted to demonstrate the dewatering method. The flocculants were added in a Komax inline mixer. Polymers were then injected into the tailings. The mixing processes were optimized in a series of laboratory studies and then demonstrated in the field tests. The tests showed that CST and high dewatering rates were consistently maintained using the method. MFT feeds were also consistent. Release water quality was improved using the method. The large-scale test site is now being monitored for compliance with Directive 74. tabs., figs.

  19. 4D experience on Girassol Field block 17, Angola

    Energy Technology Data Exchange (ETDEWEB)

    Lefeuvre, F.; Brechet, E.; Bertini, F.; Jourdan, J.M.; Cassou, G. [TOTAL S.A., Luanda (Angola); Dubucq, D. [TOTAL Angola, Luanda (Angola)

    2004-07-01

    The Girassol field is located in Angolan deep water of Block 17 and consists of large vertically stacked turbidities complexes. The reservoir extends over approximately 200 km{sup 2} and water depth ranges between 1300 and 1400 meters. In that context High Resolution 3D seismic became the most valuable tool to describe and monitor the reservoir. The field development plan took into account, through re-injection of the gas into the reservoir, Total environmental policy imposing the recycling of production gas. Monitoring of this injection was the main reason to shoot the first High Resolution 4D extremely early in the life of field. Despite the complexity of interpretation due to complex fluid situation and pressure effect, the results went way beyond expectations as the 4D images are of very high quality. Data has also been used to update and refine the reservoir flow model as well as to help deciding on the location of latest development wells. Other repeat surveys are scheduled, the next one before the end of 2004. The ultimate goal which we hope to reach in the very near future will be to use seismic-derived saturation and pressure changes to constrain the reservoir model during the history matching process. (author)

  20. [Irrigation in colostomies].

    Science.gov (United States)

    Campo, Juana; Lecona, Ana; Caparrós, M Rosario; Barbero, M Antonia; Javier Cerdán, F

    2002-01-01

    The degree of acceptation of irrigation from a colostomy varies ostensibly from some cases to others, therefore, we study what occurs in our medium, separating those patients which have previously undergone other procedures (Group A) from those patients who have been informed and trained about the immediate postoperative period (Group B). 48 patients, 22 or 46% of these patients were considered not apt for irrigation. Of the 26 to whom this procedure was proposed, 14 or 54% accepted. Of these, 5 or 36% abandoned its use while 9 continued its use; this is 64% of those who accepted this procedure, 35% of those to whom it was proposed and 19% of the total study group. 189 patients. This procedure was not recommended to 95 patients, 50%. Of the 94 patients to whom this procedure was proposed, 65 or 69% accepted. Of these, 22 or 34% abandoned its use while 43 continued its use; this is 66% of those; who accepted this procedure, 46% of those to whom it was proposed and 23% of the total study group. In our medium, the practice of irrigation oscillates between 19 and 23% of patients who have undergone a colostomy, without any significant difference referring to the moment when a patient started this procedure. A first report on this study was submitted in the III National Congress for Nursing in Colostomies.

  1. High throughput field plant phenotyping facility at University of Nebraska-Lincoln and the first year experience

    Science.gov (United States)

    Ge, Y.; Bai, G.; Irmak, S.; Awada, T.; Stoerger, V.; Graef, G.; Scoby, D.; Schnable, J.

    2017-12-01

    University of Nebraska - Lincoln's high throughput field plant phenotyping facility is a cable robot based system built on a 1-ac field. The sensor platform is tethered with eight cables via four poles at the corners of the field for its precise control and positioning. The sensor modules on the platform include a 4-band RGB-NIR camera, a thermal infrared camera, a 3D LiDAR, VNIR spectrometers, and environmental sensors. These sensors are used to collect multifaceted physiological, structural and chemical properties of plants from the field plots. A subsurface drip irrigation system is established in this field which allows a controlled amount of water and fertilizers to be delivered to individual plots. An extensive soil moisture sensor network is also established to monitor soil water status, and serve as a feedback loop for irrigation scheduling. In the first year of operation, the field is planted maize and soybean. Weekly ground truth data were collected from the plots to validate image and sensor data from the phenotyping system. This presentation will provide an overview of this state-of-the-art field plant phenotyping facility, and present preliminary data from the first year operation of the system.

  2. Nitrogen-use efficiency of irrigated wheat

    International Nuclear Information System (INIS)

    Uvalle-Bueno, X.; Osorio-Alatorre, R.; Ortiz-Monasterio, I.

    2000-01-01

    Field experiments with irrigated wheat were conducted from 1994 to 1998, using 15 N, with the objective of identifying appropriate ways of managing applied N to maximize economic profit, minimize N losses and avoid environmental pollution. Fertilizer application was partitioned with one third applied at sowing and two thirds added at Zadoks growth-stage 30 (Z-30), or two thirds at sowing and one third at Z-30, at total rates of 84, 167 and 250 kg N ha -1 . Urea and ammonium sulphate were compared as N-sources at sowing, whereas ammonium nitrate was used at Z-30. The optimum agronomic rate based on the average of the first two years was 178 kg N ha -1 . The economic optimum was 118 kg N ha -1 . The uptake of N from ammonium fertilizer was 20% higher than that from nitrate. Soil mineral N was relatively high at sowing and subsequent mineralization resulted in uptake of 90 kg N ha -1 from the zero-applied-N control plots. Soil-supplied N is, however, not considered when farmers decide on the rate of fertilizer to be applied, potentially resulting in high losses. Nitrogen-15 constituted a useful tool for understanding the relative contributions of soil and fertilizer to the N-nutrition of wheat. (author)

  3. Safe and High Quality Food Production using Low Quality Waters and Improved Irrigation Systems and Management (SAFIR)

    Science.gov (United States)

    Cary, L.; Kloppmann, W.; Battilani, A.; Bertaki, M.; Blagojevic, S.; Chartzoulakis, K.; Dalsgaard, A.; Forslund, A.; Jovanovic, Z.; Kasapakis, I.

    2009-04-01

    The safe use of treated domestic wastewater for irrigation needs to address the risks for humans (workers, exposed via contact with irrigation water, soil, crops and food, consumers, exposed via ingestion of fresh and processed food), for animals (via ingestion of crops an soil), for the crops and agricultural productivity (via salinity and trace element uptake), for soil (via accumulation or release of pollutants) as well as for surface, groundwaters and the associated ecosystems (via runoff and infiltration, Kass et al., 2005, Bouwer, 2000). A work package in the EU FP5 project SAFIR is dedicated to study the impact of wastewater irrigation on the soil-water-plant-product system. Its monitoring program comprises pathogens and inorganic pollutants, including both geogenic and potentially anthropogenic trace elements in the aim to better understand soil-irrigation water interactions. The SAFIR field study sites are found in China, Italy, Crete, and Serbia. A performance evaluation of SAFIR-specific treatment technology through the monitoring of waste water and irrigation water quality was made through waste water chemical and microbiological qualities, which were investigated upstream and downstream of the SAFIR specific treatment three times per season. Irrigation water transits through the uppermost soil decimetres to the crop roots. The latter will become, in the course of the irrigation season, the major sink of percolating water, together with evaporation. The water saving irrigation techniques used in SAFIR are surface and subsurface drip irrigation. The investigation of the solid soil phase concentrates on the root zone as main transit and storage compartment for pollutants and, eventually, pathogens. The initial soil quality was assessed through a sampling campaign before the onset of the first year irrigation; the soil quality has been monitored throughout three years under cultivation of tomatoes or potatoes. The plot layout for each of the study sites

  4. Modelling the Grimsel migration field experiments at PSI

    International Nuclear Information System (INIS)

    Heer, W.

    1997-01-01

    For several years tracer migration experiments have been performed at Nagra's Grimsel Test Site as a joint undertaking of Nagra, PNC and PSI. The aims of modelling the migration experiments are (1) to better understand the nuclide transport through crystalline rock; (2) to gain information on validity of methods and correlating parameters; (3) to improve models for safety assessments. The PSI modelling results, presented here, show a consistent picture for the investigated tracers (the non-sorbing uranine, the weakly sorbing sodium, the moderately sorbing strontium and the more strongly sorbing cesium). They represent an important step in building up confidence in safety assessments for radioactive waste repositories. (author) 5 figs., 1 tab., 12 refs

  5. Using Field Experiments to Change the Template of How We Teach Economics

    Science.gov (United States)

    List, John A.

    2014-01-01

    In this article, the author explains why field experiments can improve what we teach and how we teach economics. Economists no longer operate as passive observers of economic phenomena. Instead, they participate actively in the research process by collecting data from field experiments to investigate the economics of everyday life. This change can…

  6. 160 Gb/s all-optical packet switching field experiment

    DEFF Research Database (Denmark)

    Dorren, H.J.S.; Herrera, J.; Raz, O.

    2007-01-01

    We discus an all-optical packet switching experiment over 110 km of field installed optical fiber. The switching node is controlled by solely photonic control circuits.......We discus an all-optical packet switching experiment over 110 km of field installed optical fiber. The switching node is controlled by solely photonic control circuits....

  7. Community-Based Field Experiences in Teacher Education: Possibilities for a Pedagogical Third Space

    Science.gov (United States)

    Hallman, Heidi L.

    2012-01-01

    The present article discusses the importance of community-based field experiences as a feature of teacher education programs. Through a qualitative case study, prospective teachers' work with homeless youth in an after-school initiative is presented. Framing community-based field experiences in teacher education through "third space" theory, the…

  8. ROOT CANAL IRRIGANTS AND IRRIGATION TECHNIQUES: A REVIEW

    OpenAIRE

    Aniketh; Mohamed; Geeta; Nandakishore; Gourav Kumar; Patrick Timothy; Jayson Mathew; Sahle Abdul

    2015-01-01

    Root canal irrigation is not much emphasised in endodontic therapy. Most articles discussed are on root canal shaping and obturation not much emphasis is given for irrigation. There are many irrigation solutions which are introduced into market. The primary objective of root canal therapy is the ret ention of the pulpless or pulpally involved tooth with its associated periapical tissues in a healthy state. Achievement of this objective requires that the pulpal spaces and con...

  9. The Application of Drip Irrigation System on Tomato (Lycopersicum Esculentum Mill)

    OpenAIRE

    Setyaningrum, Diah Ayu

    2014-01-01

    This study aimed to analyze the performance of drip irrigation systems, determine performance of tomato treated under the irrigation systems.Field research was conducted at the Laboratory of Land and Water Resources Engineering; and at the Laboratory ofintegrated field, Faculty of Agriculture, University of Lampung in August 2013 to December 2013.Irrigation systems consisted of main componens: water supplies, Polythilene lateral tube, and emitters. Emitter on every pot, were made of Polythile...

  10. An experience in the field of training in radiological protection

    International Nuclear Information System (INIS)

    Fluchere, J.

    1983-01-01

    The author, a former head of an EdF training center, gives his thoughts on the training of EdF nuclear power plant radiation workers whose number was increased fourfold in 6 years and whose initial qualifications varied considerably. The orientation already taken and the directions that experience has suggested to be promising are indicated. Attention is also drawn on psychological problems that should be taken into consideration in order to work efficiently [fr

  11. Poloidal field system design for the ZT-H reversed field pinch experiment

    International Nuclear Information System (INIS)

    Schoenberg, K.F.; Gribble, R.F.; Linton, T.W.; Reass, W.R.

    1983-01-01

    This report discusses each of the following areas: (1) equilibrium specification, (2) the equilibrium winding, (3) the magnetizing winding, (4) numerical poloidal field system analysis, (5) coil cross section, turns, minimum field error, (6) coil stresses and cooling, (7) the upper structure, (8) the loads, (9) boundary conditions and method of analysis, and (10) design description

  12. New Approaches to Irrigation Scheduling of Vegetables