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| Registros recuperados: 118 | |
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| Cary, J.W.; Kohl, R.A.; Westermann, D.T.; Rickman, R.W.. |
| One of the most effective ways to prevent the wind erosion of sandy soils is to maintain a continuous crop cover. Summer row cropping following a winter grain cover offers several attractive features, although it does present management problems. The grain cover must be established in the fall after harvesting the row crop, and the transition back to a row crop in the spring must be made without leaving the soil surface unprotected from the wind. This report summarizes 4 years of observations and exploratory studies in which a variety of cover-row cropping management systems were tested with emphasis on methods for establishing row crops directly in the winter cover. Pertinent literature and observations of other field trials are also discussed. |
| Tipo: Technical Bulletin |
Palavras-chave: Sprinkler irrigation; Erosion; Mass Import - autoclassified (may be erroneous). |
| Ano: 1975 |
URL: http://eprints.nwisrl.ars.usda.gov/1129/1/302.pdf |
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| Sneva, F.A.; Britton, C.M.; Mayland, H.F.; Buckhouse, J.; Evans, R.A.; Young, J.A.; Vavra, M.. |
| Field and laboratory studies were conducted on volcanic ash from Yakima, Moses Lake, Spokane, Washington, and Moscow, Idaho, three weeks after the May 18, 1980, eruption of Mt. St. Helens in southwestern Washington. These studies examined 1) the chemical, physical, and water retentivity properties of the ash, 2) the effect of the ash upon germination and emergence of crested wheatgrass and cheatgrass, 3) the impact of ash upon in vitro digestion of common forages fed to cattle and the rate-of-passage of ash in steers, and 4) the influence of the ash layer on water infiltration into a range soil and the amount of sediments in the runoff water. In addition to the above short term studies, small field plots of various ash treatments were initiated... |
| Tipo: Technical Bulletin |
Palavras-chave: Mass Import - unclassified. |
| Ano: 1982 |
URL: http://eprints.nwisrl.ars.usda.gov/1128/1/615.pdf |
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| Carter, David L.; Bondurant, James A.. |
| The technology available for the control of sediments, nutrients, and adsorbed biocides in surface irrigation return flows has been reviewed and evaluated. Some of this technology could be applied immediately to reduce sediment and associated nutrient and biocide concentrations in surface irrigation return flows. Much of the available information needs to be integrated to develop improved control practices. New ideas and new control technology are needed. Economic incentive programs are needed to improve acceptance of control technology. The factors controlling erosion and subsequent sediment concentrations in surface irrigation return flows, and how these factors can be managed to reduce erosion and sediment concentrations are reviewed and... |
| Tipo: Technical Bulletin |
Palavras-chave: Sediment; Mass Import - autoclassified (may be erroneous). |
| Ano: 1976 |
URL: http://eprints.nwisrl.ars.usda.gov/1115/1/378.pdf |
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| Robinson, A.R.; Lauritzen, C.W.; Muckel, D.C.; Phelan, Jack. |
| An irrigation system should be designed to provide correct distribution, control, and measurement of the irrigation water. Usually a farmer takes his irrigation water from a canal through a headgate. Or he may receive it from a pipeline regulated by a valve, or perhaps from his own well and pump. Open ditches are most commonly used to carry the water to the fields. Water control structures are used to get it out of the ditches and onto the fields. Measurement devices are needed so the farmer can tell how much water he has applied to his field at any irrigation or over the season. Several types of structures are used to divert, convey, control, or measure irrigation water. Some of these are described, and their functions... |
| Tipo: Technical Bulletin |
Palavras-chave: Irrigation control; Research methodology; Mass Import - autoclassified (may be erroneous). |
| Ano: 1963 |
URL: http://eprints.nwisrl.ars.usda.gov/1140/1/7.pdf |
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| Lemon, E.R.; Wright, J.L.. |
| In two previous communications (Wright and Lemon 1966a, 1966b) an aerodynamic method was described for evaluating the source and sink distribution of carbon dioxide in plant communities. Some data were presented for a corn crop, giving quantitative information about photosynthetic fixation and respiration release of carbon dioxide, layer by layer, within the crop. In the method, CO2 concentration profiles and windspeed measurements of the bulk air were made within and above the crop. The analysis of the windspeed measurements to calculate diffusivity coefficients required tedious analysis of windspeed fluctuations and the application of complicated statistical and mixing length theories. It is our purpose to present here a simpler method,... |
| Tipo: Technical Bulletin |
Palavras-chave: Corn / maize; Research methodology; Mass Import - autoclassified (may be erroneous). |
| Ano: 1967 |
URL: http://eprints.nwisrl.ars.usda.gov/1187/1/107.pdf |
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| Registros recuperados: 118 | |
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