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Registros recuperados: 116 | |
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Koehn, A.C.; Lehrsch, G.A.; Busscher, W.J.; Evans, D.E.; King, B.A.; Stieneke, D.L.; Sojka, R.E.. |
Agricultural crops grown in southern Idaho are furrow or sprinkler irrigated. Therefore, the soil experiences several wetting and drying cycles each growing season that can contribute to changes in aggregate tensile strength and friability. The objective of the research was to evaluate the influence of irrigation on soil structural properties. Four furrow irrigated fields were sampled at the top and bottom of the field, in the furrow and on the bed location of the furrow. Five sprinkler irrigated fields were sampled at 0-5 and 5-15 cm depth and at the top and bottom of the field. Results from this study indicate that differences in tensile strength in furrow irrigated fields were only evident soon after irrigation; otherwise, there were few differences in... |
Tipo: Article |
Palavras-chave: Furrow irrigation; Sprinkler irrigation. |
Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1567/1/1523.pdf |
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PINTO, J. M.; SOARES, J. M.. |
Este trabalho correspondeu a avaliacao do aspersor DANTAS modelo MD-20A com bocais, 3,1 mm x 2,5mm e 5,6 mm x 2,5mm, com as pressoes de 2, 3, 4 e 5 atm, conduzido no Campo Experimental de Bebedouro, Petrolina, PE. Foi determinada a uniformidade de distribuicao; o coeficiente de uniformidade de Christiansen e a eficiencia de irrigacao. A avaliacao da uniformidade do aspersor envolveu tambem a construcao de isoietas. Determinou-se a rotacao do aspersor, a velocidade e a direcao do vento predominante. Constatou-se que o aspersor modelo MD-20A com bocais 3,1mm x 2,5mm deve ser manejado satisfatoriamente com pressao de 3 atm no espacamento de 12m x 18m com pressao de servico de 5 atm. A rotacao minima (3 rpm) obtida com esse modelo de aspersores, com bocais de... |
Tipo: Parte de livro |
Palavras-chave: Aspersor DANTAS; Irrigação; Aspersão; Aspersor; Condutividade Hidráulica; Irrigation; Hydraulic conductivity; Sprinkler irrigation. |
Ano: 1989 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/132864 |
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Winward, T.W.; Hill, R.W.. |
A line-source sprinkler configuration provides a linearly decreasing irrigation application rate perpendicular to the sprinkler line and has been utilized to study crop response to variable irrigation amounts. The effect on measured irrigation application depths from using various types of catch-cans in those studies is not known. Derived relationships between crop yield and applied water is dependent on the accuracy of measured catch-can water volumes. The purpose of this study was to evaluate catch-can characteristic effects on measurement of sprinkler irrigation depths in a line source. This was accomplished by evaluating six types of catch-cans: (1) 83 mm diameter polypropylene separatory funnel (with evaporation-suppressing oil), (2) 82 mm... |
Tipo: Article |
Palavras-chave: Sprinkler irrigation; Mass Import - autoclassified (may be erroneous). |
Ano: 2007 |
URL: http://eprints.nwisrl.ars.usda.gov/63/1/1228.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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King, B.A.; Winward, T.W.; Bjorneberg, D.L.; Wall, R.W.. |
Peak water application rate in relation to soil water infiltration rate and soil surface storage capacity is important in the design of center pivot sprinkler irrigation systems for efficient irrigation and soil erosion control. Measurement of application rates of center pivot irrigation systems has traditionally used tipping bucket rain gauges. Calculation of application rate from tipping bucket rain gauge measurements restricts computed application rate to a discrete multiple of the rain gauge resolution and time interval. This limits the resolution of application rate measurement, especially for time intervals less than 15 minutes. A collector was designed to measure time variant high intensity sprinkler application rates under field conditions with... |
Tipo: Article |
Palavras-chave: Sprinkler irrigation; Soil; Water. |
Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1565/1/1521.pdf |
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King, B.A.; Winward, T.W.; Bjorneberg, D.L.. |
Kinetic energy of water droplets has a substantial effect on development of a soil surface seal and infiltration rate of bare soil. Methods for measuring sprinkler droplet size and velocity needed to calculate droplet kinetic energy have been developed and tested over the past 50 years, each with advantages, disadvantages, and limitations. Drop size and velocity of an impact sprinkler at three operating pressures and one nozzle size were measured using a laser precipitation meter and compared with published values obtained using a photographic method. Significant differences in cumulative volume drop size distributions derived from the two measurement methods were found, especially at the highest operating pressure. Significant differences in droplet... |
Tipo: Article |
Palavras-chave: Sprinkler irrigation. |
Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1543/1/1500.pdf |
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King, B.A.; Winward, T.W.; Bjorneberg, D.L.. |
Kinetic energy of water droplets has a substantial effect on development of a soil surface seal and infiltration rate of bare soil. Methods for measuring sprinkler droplet size and velocity needed to calculate droplet kinetic energy have been developed and tested over the past 50 years, each with advantages, disadvantages, and limitations. A laser precipitation meter and photographic method were used to measure droplet size and velocity from an impact sprinkler at three pressures and one nozzle size. Significant differences in cumulative volume drop size distributions derived from the two measurement methods were found, especially at the highest operating pressure. Significant differences in droplet velocities were found between measurement methods as... |
Tipo: Conference or Workshop Item |
Palavras-chave: Sprinkler irrigation; Soil water (soil moisture); Water management. |
Ano: 2013 |
URL: http://eprints.nwisrl.ars.usda.gov/1577/1/1533.pdf |
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Registros recuperados: 116 | |
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