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| Registros recuperados: 167 | |
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| Entry, J.A.; Sojka, R.E.; Hicks, B.J.. |
| Water-soluble anionic polyacrylamide (PAM) is applied to millions of hectares worldwide as a highly effective erosion-preventing and infiltration-enhancing polymer, when applied at rates of 1 to 2 kg ha? 1 (i.e., 1 to 10 g m? 3) in furrow water. PAM degradation has not directly been measured in soil. We tested the ability of stable isotopes of C and N at natural abundance to estimate PAM degradation rates. Values of ?13C were related to anionic PAM concentration in a positive curvilinear relationship in a low-C, low-N, Durinodic Xeric Haplocalcid (Portneuf series) soil. The other soils with higher organic C or N concentrations did not show significant relationships between PAM concentrations and ?13C values. The ?15N values were not related to anionic PAM... |
| Tipo: Article |
Palavras-chave: Soil. |
| Ano: 2008 |
URL: http://eprints.nwisrl.ars.usda.gov/1276/1/1253.pdf |
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| Lehrsch, G.A.; Sojka, R.E.; Reed, J.L.; Henderson, R.A.; Kostka, S.J.. |
| Surfactants are chemical compounds that change the contact angle of water on solid surfaces and are commonly used to increase infiltration into hydrophobic soil. Since production fields with water-repellent soil often contain areas of wettable soil, surfactants applied to such fields will likely be applied to wettable soil, with unknown consequences for irrigation-induced erosion, runoff, or soil water relations. We evaluated surfactant and simulated sprinkler irrigation effects on these responses for three wettable, Pacific Northwest soils, Latahco and Rad silt loams and Quincy sandy loam. We studied three surfactants: an alkyl polyglycoside in solution at a concentration of 18 g a.i./kg, a block copolymer at 26 g/kg, and a blend of the two at 43 g/kg.... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation. |
| Ano: 2011 |
URL: http://eprints.nwisrl.ars.usda.gov/1429/1/1399.pdf |
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| Sojka, R.E.. |
| This overview will be familiar to anyone who has visited the "PAM page" of the Northwest Irrigation and Soils Research Laboratory's web site. The reader is encouraged to visit that web site, <http://kimberlv.ars.usda.qov/ pampaqe.shtml>, for graphics and photos that were used in this NAICC presentation in Orlando in January, 2001, as well as for other more detailed technical information. PAM has been sold in the United States since 1995 for reducing irrigation-induced erosion and enhancing infiltration. Its soil stabilizing and flocculating properties have also substantially improved runoff water quality by reducing sediments, N, ortho and total P, COD, pesticides, weed seeds, and microorganisms in runoff. The first series of practical field... |
| Tipo: Conference or Workshop Item |
Palavras-chave: Water-soluble PAM (WSPAM); Mass Import - autoclassified (may be erroneous). |
| Ano: 2002 |
URL: http://eprints.nwisrl.ars.usda.gov/1235/1/1075.pdf |
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| Sojka, R.E.; Entry, J.A.; Shewmaker, G.E.; Fuhrmann, J.J.. |
| Fossil fuel burning at the present rate, will double atmospheric carbon dioxide (CO 2 ) in this century, raising air temperature 1.5 to 5 °C. Sequestering carbon (C) in soil can reduce atmospheric CO2 concentration. We measured inorganic and organic C in southern Idaho soils having long term land use histories of native sagebrush vegetation (NSB), irrigated moldboard plowed crops (IMP), irrigated conservation- (chisel) tilled crops (ICT) and irrigated pasture systems (IP). Soil Organic C (SOC) decreased in the order IP>ICT>NSB>IMP. We used our findings to estimate potential amounts of organic C sequestered if irrigated agriculture expanded. If irrigated agricultural land was expanded by10°/0 worldwide and NSB was converted to ICT, 2.5 x 10... |
| Tipo: Conference or Workshop Item |
Palavras-chave: Mass Import - unclassified. |
| Ano: 2007 |
URL: http://eprints.nwisrl.ars.usda.gov/857/1/1225.pdf |
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| Registros recuperados: 167 | |
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