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| Registros recuperados: 26 | |
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| King, B.A.; Bjorneberg, D.L.. |
| A 4-wheeled commercial irrigation boom was modified for use in investigating center pivot design and management effects on infiltration, runoff and erosion of specific soil types. The center pivot simulator used a hydraulic winch attached to the front of a tractor for mobilization and controlled travel speed. A 3 inch diameter 300 ft drag hose is used to supply water to the center pivot simulator. The center pivot simulator was used to conduct two studies to investigate infiltration, runoff and erosion differences of common commercially available center pivot sprinkler types on a Portneuf silt loam soil. Sprinklers used in the first study were: 1) Nelson R3000 with brown plate, 2) Nelson R3000 with red plate, 3) Nelson S3000 with purple plate, and... |
| Tipo: Conference or Workshop Item |
Palavras-chave: Erosion; Infiltration; Center pivot; Erosion; Mass Import - autoclassified (may be erroneous). |
| Ano: 2007 |
URL: http://eprints.nwisrl.ars.usda.gov/965/1/1236.pdf |
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| King, B.A.; Bjorneberg, D.L.. |
| The kinetic energy of discrete drops impacting a bare soil surface is generally observed to lead to a drastic reduction in water infiltration rate due to soil surface seal formation. Under center pivot sprinkler irrigation, kinetic energy transferred to the soil prior to crop canopy development can have a substantial effect on seasonal runoff and soil erosion. In the design of center pivot irrigation systems, selection of sprinklers with minimum applied kinetic energy could potentially minimize seasonal runoff and erosion hazard. Size and velocity of drops from five common center pivot sprinklers with flow rates of approximately 43 L/min were measured using a laser in the laboratory. The data were used to evaluate various approaches to characterize... |
| Tipo: Article |
Palavras-chave: Irrigation control; Sprinkler irrigation; Center pivot. |
| Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1566/1/1522.pdf |
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| SILVA, E. M. da; AZEVEDO, J. A. de. |
| Descricao do sistema; Taxas de aplicacao de agua; Caracteristicas dos aspersores; Capacidade do sistema; Caracterizacao da lateral: Vazao na linha de distribuicao, Velocidade de deslocamento; Localizacao dos aspersores na lateral: Vazao em funcao do espacamento, Espacamento em funcao da vazao; Pressao na lateral: Perda de carga na tubulacao, Diferencas de elevacao no terreno, Perdas de carga localizadas, Pressao no final da linha, Pressao na entrada da linha, Distribuicao da pressao ao longo da linha; Analise da uniformidade de aplicacao da agua: Taxa de aplicacao do aspersor estacionario, Taxa de aplicacao do aspersor em movimento, Taxa de aplicacao de varios aspersores em um ponto da lateral, Lamina total aplicada em um ponto da lateral. |
| Tipo: Documentos (INFOTECA-E) |
Palavras-chave: Aplicação; Center pivot; Central; Central pivot; Cerrado Irrigação; DF; Embrapa; Lateral; Pivô; Planaltina; Sistema.; Água; Aspersão; Cerrado; Irrigação; Irrigação por Pivô Central; Pivô Central.; Irrigation; Sprinkler irrigation.. |
| Ano: 1998 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/554798 |
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| King, B.A.; Bjorneberg, D.L.. |
| The kinetic energy of discrete water drops impacting a bare soil surface is generally observed to lead to a drastic reduction in water infiltration rate due to soil surface seal formation. Under center-pivot sprinkler irrigation, kinetic energy transferred to the soil prior to crop canopy development can have a substantial effect on seasonal runoff and soil erosion. In the design of center-pivot irrigation systems, selection of sprinklers with minimum applied kinetic energy could potentially minimize the seasonal runoff and erosion hazard. The size and velocity of drops from common rotating spray-plate sprinklers center-pivot sprinklers with flow rates of approximately 40 and 20 L/ min were measured using a laser in the laboratory. The data were used to... |
| Tipo: Conference or Workshop Item |
Palavras-chave: Sprinkler irrigation; Center pivot. |
| Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1426/1/1396.pdf |
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| King, B.A.; Bjorneberg, D.L.. |
| The kinetic energy of discrete water drops impacting a bare soil surface generally leads to a drastic reduction in water infiltration rate due to formation of a seal on the soil surface. Under center-pivot sprinkler irrigation, kinetic energy transferred to the soil prior to crop canopy development can have a substantial effect on seasonal runoff and soil erosion, especially when the soil is not protected by crop residue cover. Droplet kinetic energy of seven commercial off-center action rotating spray-plate sprinklers was characterized over a range of flow rates and pressures. Sprinkler droplet kinetic energy was characterized using two methods; droplet kinetic energy per unit sprinkler discharge and droplet kinetic energy applied per unit water depth... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Center pivot. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1457/1/1422.pdf |
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| Ferreira,Tomás de Aquino; Ferreira,Sílvia Costa; Barbosa,Jackson Antônio; Volpato,Carlos Eduardo Silva; Ferreira,Rute Costa; Silva,Marielle Jordane da; Barbosa,Leonardo Maia. |
| ABSTRACT: The aim of the present study is to evaluate the energy balance and energy efficiency of the silage maize crop in the Center for Research, Development and Technology Transfer of the Universidade Federal de Lavras (CDTT-UFLA). The crop was irrigated by center pivot and the stages of maize cultivation and energy inputs were monitored for the 1st and 2nd crops of the 2014/2015 harvest. Results from the energy analysis showed the crop had a total energy input of 45,643.85 MJ ha-1 and 47,303.60 MJ ha-1 for the 1st and 2nd crops and a significant predominance of direct energy type (about 92% of the matrix). Regarding direct energy inputs, the diesel oil was the most representative, contributing with approximately 38% of the total energy demand.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Energy efficiency; Energy in agriculture; Center pivot; Sustainability. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782018000500351 |
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| Dungan, R.S.. |
| In the western United States where dairy wastewaters are commonly land applied, there are concerns over individuals being exposed to airborne pathogens. In response, a quantitative microbial risk assessment (QMRA) was performed to estimate infectious risks after inhalation exposure of pathogens aerosolized during center pivot irrigation of diluted dairy wastewaters. The dispersion of pathogens (Campylobacter jejuni, Escherichia coli O157:H7, non-O157 E. coli, Listeria monocytogenes, and Salmonella spp.) was modeled using the atmospheric dispersion model, AERMOD. Pathogen concentrations at downwind receptors were used to calculate infectious risks during one-time (1, 8, and 24 h) and multi-day (7 d at 1 h/d) exposure events using a Beta-Poisson... |
| Tipo: Article |
Palavras-chave: Microbial Transport; Center pivot. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1538/1/1495.pdf |
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| King, B.A.; Dungan, R.S.; Bjorneberg, D.L.. |
| Wind drift and evaporation losses (WDELs) are an often discussed topic in regards to center pivot sprinkler irrigation efficiency. Opinions on the magnitude of WDELs vary widely, in part due to the wide variation in WDEL values published in the literature. The magnitude of WDELs reported in the literature range from 2 to 45%. The common technique employed to measure WDEL is to use catch cans and compare the measured volume of catch with the volume of water applied based on sprinkler nozzle size, operating pressure and spacing with the difference being WDEL. The inaccuracies of catch cans resulting from wind effects on catch efficiency and evaporation of water from the catch can prior to measurement have led to the wide range in WDEL reported in the... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Center pivot. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1470/1/1435.pdf |
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| King, B.A.; Bjorneberg, D.L.. |
| The operational characteristics of center pivot sprinklers are well documented but few studies have been conducted to evaluate the effects that operating characteristics of a particular sprinkler have on infiltration, runoff, and erosion for specific soil types. The objective of this study was to evaluate potential runoff and erosion from four commercial center pivot sprinklers on three widely distributed, south central Idaho soils. A modified commercial irrigation boom system was used to emulate center pivot irrigation on experimental runoff plots. Sprinklers used in the study were: 1) Nelson R3000 with brown plate, 2) Nelson R3000 with red plate, 3) Nelson S3000 with purple plate, and 4) Senninger I-Wob with standard 9-groove plate. Based on... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Erosion; Runoff losses; Center pivot. |
| Ano: 2011 |
URL: http://eprints.nwisrl.ars.usda.gov/1424/1/1394.pdf |
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| King, B.A.; Bjorneberg, D.L.. |
| The marked reduction in infiltration rate caused by formation of a soil surface seal is a well known phenomenon but often ignored in infiltration models. The effect sequential water application events have on infiltration rate and soil surface seal formation has rarely been investigated. The objective of this study was to investigate the effect sequential water application events have on the infiltration rate of a Portneuf silt loam soil with and without water droplet impact. The Portneuf silt loam soil developed a soil surface seal that reduced infiltration rate both with and without droplet impact on the bare soil surface. When the soil surface was protected during the first rainfall event, drying the soil did not increase infiltration rate for... |
| Tipo: Conference or Workshop Item |
Palavras-chave: Sprinkler irrigation; Infiltration; Center pivot. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1533/1/1467.pdf |
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| King, B.A.; Bjorneberg, D.L.. |
| The marked reduction in infiltration rate caused by formation of a soil surface seal due to water droplet impact on bare soil is a well known phenomenon but is rarely considered in infiltration models, especially under center pivot irrigation. The objective of this study was to develop a soil infiltration model for center pivot sprinkler irrigation that incorporates the transient reduction in soil surface seal hydraulic conductivity as affected by soil and sprinkler characteristics. A sealing soil infiltration model was developed using an explicit finite difference solution scheme with a transient soil seal formation model, which is unique from other studies in that it explicitly uses droplet specific power as the driving factor for formation of a soil... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Infiltration; Center pivot. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1469/1/1434.pdf |
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| King, Bradley A.; Bjorneberg, D.L.. |
| The marked reduction in infiltration rate caused by formation of a soil surface seal due to water droplet impact on bare soil is a well known phenomenon but is rarely considered in infiltration models, especially under center pivot irrigation. The objective of this study was to develop a soil infiltration model for center pivot sprinkler irrigation that incorporates the transient reduction in soil surface seal hydraulic conductivity as affected by soil and sprinkler characteristics. A sealing soil infiltration model was developed using an explicit finite difference solution scheme with a transient soil seal formation model, which is unique from other studies in that it explicitly uses droplet specific power as the driving factor for formation of a soil... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Infiltration; Center pivot. |
| Ano: 2011 |
URL: http://eprints.nwisrl.ars.usda.gov/1441/1/1407.pdf |
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| Almeida,Alex N. de; Coelho,Rubens D.; Costa,Jéfferson de O.; Farías,Asdrúbal J.. |
| ABSTRACT: In Brazil, the conventional center pivot is widely used for irrigation of agricultural crops and its use has grown continuously. However, when improperly managed, it facilitates the development of diseases in all parts of the plant, with a direct effect on productivity, besides favoring losses of water by evaporation. The drip may be an alternative, since it minimizes the losses and does not wet the aerial parts of the plants, thereby reducing the incidence of diseases. A new system called localized mobile drip irrigation (IRGMO) is being developed in an attempt to combine the practicality and rusticity of the center pivot with the efficiency and water savings of the dripping irrigation systems. This fusion system is the central pivot with drip... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Design; Drip irrigation; Center pivot. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000400828 |
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| King, B.A.. |
| Numerous moving spray-plate center-pivot sprinklers are commercially available providing a range of drop size distributions and wetted diameters. A means to quantitatively compare sprinkler choices in regards to maximizing infiltration and minimizing runoff is currently lacking. The objective of this study was to develop a soil independent quantitative runoff potential index to facilitate selection of sprinklers for center-pivot sprinkler irrigation systems. Drop sizes, velocities and water application rates of numerous moving spray-plate sprinklers were measured in the laboratory over a range of flow rates and operating pressures. The proposed sprinkler runoff index is based on application rates of kinetic energy and water computed by overlapping specific... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Infiltration; Center pivot. |
| Ano: 2016 |
URL: http://eprints.nwisrl.ars.usda.gov/1612/1/1569.pdf |
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| King, Bradley A.; Kincaid, Dennis C.. |
| A good supply of groundwater and the commercial development of center pivot irrigation systems significantly increased sprinkler-irrigated acreage in southern Idaho during the late 1960s and early 1970s. Today, center pivot systems, with their automation, large areal coverage, reliability, high application uniformity, and ability to operate on relatively rough topography, are replacing surface; handline, and wheelline systems. The irrigated area under a center pivot system expands substantially with increasing system length. To accommodate the increased area, the application rate increases linearly along the center pivot lateral through one of two methods: increased flow rates through equally spaced Sprinklers or gradually decreased spacing of... |
| Tipo: Technical Bulletin |
Palavras-chave: Center pivot; Sprinkler irrigation; Mass Import - autoclassified (may be erroneous). |
| Ano: 1997 |
URL: http://eprints.nwisrl.ars.usda.gov/1144/1/977.pdf |
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| Registros recuperados: 26 | |
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