Use of stable isotopes of carbon, nitrogen, and sulfur to identify sources of nitrogen in surface waters in the Lower Susquehanna River Basin, Pennsylvania

US Geological Survey Water Supply Paper

Volumn 2497, Issue , 1997, Pages 1-68

  Cravotta III, Charles A ^a  

^a NONE

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EID: 6044261466     PISSN: 00831131     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article

References (154)

1. American Society for Testing and Materials, 1990, Annual book of ASTM standards: Philadelphia, Pa., ASTM, v. 11.01, p. 321-326.
2. Aravena, R., Evans, M.L., and Cherry, J.A., 1993, Stable isotopes of oxygen and nitrogen in source identification of nitrate from septic systems: Ground Water, v. 31, p. 180-186.
3. Baedecker, M.J., and Back, W., 1979, Hydrogeological processes and chemical reactions at a landfill: Ground Water, v. 17, p. 429-437.
4. Balesdent, J., Wagner, G.H., and Mariotti, A., 1988, Soil organic matter turnover in long-term field experiments as revealed by carbon-13 natural abundance: Soil Science Society of America Journal, v. 52, p. 118-124.
5. Bender, M.L., 1972, Carbon isotope fractionation, in Fairbridge, R.W., ed., Encyclopedia of Geochemistry and Environmental Sciences: New York, Van Nostrand Reinhold Co., p. 133-136.
6. Berg, B., and Staaf, H., 1981, Leaching, accumulation and release of nitrogen in decomposing forest litter, in Clark, F.E., and Rosswell, T., eds., Terrestrial nitrogen cycles - Processes, ecosystem strategies, and management impacts: Swedish Natural Science Research Council (NFR), Ecological Bulletins (Stockholm) 33, p. 163-178.
7. Bigeleisen, Jacob, 1965, Chemistry of isotopes: Science, v. 147, no. 3657. p. 463-471.
8. Black, C.A., Evans, D.D., White, J.L., Ensminger, L.E., and Clark, E.E., eds., 1965, Methods of soil analysis, Part 2. Chemical and microbiological properties: Madison, Wis., American Society of Agronomy Monograph No. 9.
9. Bolin, Bert, 1970, The carbon cycle: Scientific American, v. 223, p. 125-132.
10. Bolin, Bert, and Cook. R.B., eds., 1983, The major biogeochemical cycles and their interactions: New York, John Wiley & Sons, SCOPE 21, 451 p.
11. Bowen, Robert, 1988, Isotopes in the earth sciences: New York, Elsevier Applied Science Publishers Ltd., 647 p.
12. Boynton, W.R., Kemp, W.M., and Keefe, C.W., 1982, A comparative analysis of nutrients and other factors influencing estuarine phytoplankton production, in Kennedy, V.S., ed., Estuarine comparisons: New York, Academic Press, p. 69-90.
13. Brady, N.C., 1974, The nature and property of soils: New York, MacMillan Publishing Co.. 639 p.
14. Bremner, J.M., and Tabatabai, M.A., 1973, Nitrogen-15 enrichment of soils and soil-derived nitrate: Journal of Environmental Quality, v. 2, p. 363-365.
15. Brezonik, P.L., 1973, Nitrogen sources and cycling in natural waters: U.S. Environmental Protection Agency EPA 660/3-73-002. 167 p.
16. Chambers, L.A., and Trudinger, P.A., 1979, Microbiological fractionation of stable sulfur isotopes - A review and critique: Geomicrobiology Journal, v. 1, p. 249-293.
17. - in the Aquia aquifer, Maryland: Ground Water, v. 23, p. 592-599.
18. Chichester, D.C., 1988, Evaluation of agricultural bestmanagement practices in the Conestoga River headwaters, Pennsylvania - Methods of data collection and analysis, and description of study areas: U.S. Geological Survey Open-File Report 88-96, 32 p.
19. Cifuentes, L.A., Fogel, M.L., Pennock, J.R., and Sharp, J.H., 1989, Biogeochemical factors that influence the stable nitrogen ratio of dissolved ammonium in the Delaware Estuary: Geochimica et Cosmochimica Acta, v. 53, p. 2713-2721.
20. Coplen, T.B., 1993, Uses of environmental isotopes, in Alley, W.M., ed., Regional ground-water quality: New York, Van Nostrand Reinhold, p. 227-254.
21. Coplen. T.B., Krouse, H.R., and Bohlke, J.K., 1992, Reporting of nitrogen-isotope abundances: Pure & Applied Chemistry, v. 64, p. 907-908.
22. Degens, E.T., 1969, Biogeochemistry of stable carbon isotopes, in Eglington, M.T., and Murphy, J., eds., Organic geochemistry: Berlin, Springer-Verlag, p. 304-329.
23. Deines, Peter, 1980, The isotopic composition of reduced organic carbon, in Fritz, P., and Fontes, J.Ch., eds., Handbook of environmental isotope geochemistry, v. 1. The terrestrial environment, A: Amsterdam, Elsevier, p. 329-406.
24. Delwiche, C.C., 1970. The nitrogen cycle: Scientific American, v. 223, p. 135-147.
25. Delwiche, C.C., and Steyn, P.L., 1970, Nitrogen isotope fractionation in soils and microbial reactions: Environmental Science & Technology, v. 4, no. 11, p. 929-935.
26. DeNiro, M.J., and Epstein, S., 1978, Influence of diet on the distribution of carbon isotopes in animals: Geochimica et Cosmochimica Acta, v. 42, p. 495-506.
27. _1981, Influence of diet on the distribution of nitrogen isotopes in animals: Geochimica et Cosmochimica Acta, v. 45, p. 341-351.
28. Denmeade, O.T., Nulsen, R., and Thurtell, G.W., 1978, Ammonia exchange over a corn crop: Soil Science Society of America Journal, v. 42, p. 840-842.
29. Denmeade, O.T., Simpson, J.R., and Freney, J.R., 1974, Ammonia flux into the atmosphere from a grazed pasture: Science, v. 185, p. 609-610.
30. Elliot, L.F., Schuman, G.E., and Viets, F.G., Jr., 1971, Volatilization of nitrogen-containing compounds from beef cattle areas: Soil Science Society of America Proceedings, v. 35, p. 752-755.
31. Exner, M.E., and Spalding, R.F., 1985, Ground-water contamination and well construction in southeast Nebraska: Ground Water, v. 23, p. 26-34.
32. Fairchild, J.F., Boyle, T.P., Robinson-Wilson, E., and Jones, J.R., 1983, Microbial action in detrital leaf processing and the effects of chemical perturbation, in Fontaine, T.D., III, and Bartell, S.M., eds., Dynamics of lotic ecosystems: Ann Arbor, Mich., Ann Arbor Science, p. 437-456.
33. Faure, Gunter, 1977, Principles of isotope geology: New York, John Wiley and Sons, 464 p.
34. Field, C.W., 1972, Sulfur - Element and geochemistry, in Fairbridge, R.W., ed., Encyclopedia of Geochemistry and Environmental Sciences: New York, Van Nostrand Reinhold Co., p. 1142-1148.
35. Fishel, O.K., Langland, M.J., and Truhlar, M.V., 1991, Hydrology and the hypothetical effects of reducing nutrient applications on water quality in the Bald Eagle Creek headwaters, southeastern Pennsylvania, prior to implementation of agricultural best-management practices: U.S. Geological Survey Water-Resources Investigations Report 91-4006, 59 p.
36. Fisher, D., Ceraso, J., Mathew, T., and Oppenheimer, M., 1988, Polluted coastal waters - The role of acid rain: New York, Environmental Defense Fund, 102 p.
37. Flipse, W.J., Jr., Katz, B.G., Lidner, J.B., and Markel, R., 1984, Sources of nitrate in ground water in a sewered housing development, central Long Island, New York: Ground Water, v. 22, p. 418-426.
38. Flipse, W.J., Jr., and Bonner, F.T., 1985, N-isotope ratios in ground water under fertilized fields, Long Island, New York: Ground Water, v. 23, p. 59-67.
39. 14N in microbiological nitrogen transformations - A theoretical model: Journal of Environmental Quality, v. 2, no. 2, p. 247-252.
40. - nitrogen isotope composition in rain collected at Julich, Germany: Tellus, v. 30, p. 83-92.
41. Freyer, H.D., and Aly, A.I.M., 1974, Nitrogen-15 variations in fertilizer nitrogen: Journal of Environmental Quality, v. 3, no. 4, p. 405-406.
42. Fritz, P., and Fontes, J.Ch., 1980, Introduction, in Fritz, P., and Fontes, J.Ch., eds., Handbook of environmental isotope geochemistry, v. 1. The terrestrial environment, A: Amsterdam, Elsevier, p. 1-19.
43. Fry, Brian, 1986, Stable sulfur isotopic distributions and sulfate reduction in lake sediments of the Adirondack Mountains, New York: Biogeochemistry, v. 2, p. 329-343.
44. _1988, Food web structure on Georges Bank from stable C, N, and S isotopic compositions: Limnology and Oceanography, v. 33, p. 1182-1190.
45. 15N measurements: Analytical Chemistry, v. 64, p. 288-291.
46. 32S during bacterial metabolism of inorganic sulfur compounds: Journal of Bacteriology, v. 165, p. 328-330.
47. Fry, Brian, Scanlan, R.S., and Parker, P.L., 1977, Stable carbon isotope evidence for two sources of organic matter in coastal sediments - Seagrasses and plankton: Geochimica et Cosmochimica Acta, v. 41, p. 1875-1877.
48. 13C measurements as indicators of carbon flow in marine and freshwater ecosystems: Contributions to Marine Science, v. 27, p. 13-17.
49. Gillham, R.W., Cherry, J.A., Hendry, M.J., Sklash, M.G., Frind, E.O., Blackport, R.J., and Pucovsky, M.G., 1978, Studies of the agricultural contribution to nitrate and the subsequent loading to surface waters: Ontario, University of Waterloo, International Reference Group on Great Lakes Pollution from Land Use Activities, Agricultural Watershed Studies.
50. Goodell, H.G., 1972, Carbon/nitrogen ratio, in Fairbridge, R.W., ed., Encyclopedia of Geochemistry and Environmental Sciences: New York, Van Nostrand Reinhold Co., p. 136-142.
51. Gormly. J.R., and Spalding, R.F., 1979, Sources and concentrations of nitrate-N in ground water of the central Platte region, Nebraska: Ground Water, v. 17, p. 291-301.
52. Hauck, R.D., 1982, Nitrogen-isotope-ratio analysis, in Page, A.L., ed., Methods of soil analysis, Part 2 (revised): Madison, Wis., American Society of Agronomy, p. 735-780.
53. Hauck, R.D., and Tanji, K.K., 1982, N transfers and mass balances, in Stevenson, F.J., ed., Nitrogen in agricultural soils: Madison, Wis., American Society of Agronomy Monograph 22, p. 891-925.
54. Heaton, T.H.E., 1984, Sources of the nitrate in phreatic groundwater in the western Kalahari: Journal of Hydrology, v. 67, p. 249-259.
55. _1986, Isotopic studies of nitrogen pollution in the hydrosphere and atmosphere - A review: Chemical Geology, v. 59, p. 87-102.
56. Heaton, T.H.E., Talma, A.S., and Vogel, J.C., 1983, Origin and history of nitrate in confined groundwater in the western Kalahari: Journal of Hydrology, v. 62, p. 243-262.
57. Helsel, D.R. 1987, Advantages of nonparametric procedures for analysis of water quality data: Hydrological Sciences Journal v. 32, no. 2, p. 179-190.
58. Hem, J.D., 1985, Study and interpretation of the chemical characteristics of natural water (3d): U.S. Geological Survey Water-Supply Paper 2254, 263 p.
59. Hoering, T.C., 1955, Variations of nitrogen-15 abundance in naturally occurring substances: Science, v. 122, p. 1233-1234.
60. Hoering, Thomas, 1957, The isotopic composition of the ammonia and the nitrate ion in rain: Geochimica et Cosmochimica Acta, v. 12, p. 97-102.
61. Horrigan, S.G., Montoya, J.P., Nevins, J.L., and McCarthy, J.J., 1990, Natural isotopic composition of dissolved inorganic nitrogen in the Chesapeake Bay: Estuarine, Coastal and Shelf Science, v. 30, p. 393-410.
62. Hubner, Heinrich, 1986, Isotope effects of nitrogen in the soil and biosphere, in Fritz, P., and Fontes, J.Ch., eds., Handbook of environmental isotope geochemistry, v. 2. The terrestrial environment, B: Amsterdam, Elsevier, p. 361-425.
63. James, W.F., Kennedy, R.H., Shain, W.E., and Myers, R.K., 1988, Leaf litter breakdown in a recently impounded reservoir: Water Resources Bulletin, v. 24, p. 831-837.
64. Jansson, S.L., and Persson, J., 1982, Mineralization and immobilization of soil N, in Stevenson, F.J., ed., Nitrogen in agricultural soils: Madison, Wis., American Society of Agronomy Monograph 22, p. 229-252.
65. Kaplan, I.R., 1972, Sulfur cycle, in Fairbridge, R.W., ed., Encyclopedia of Geochemistry and Environmental Sciences: New York, Van Nostrand Reinhold Co., p. 1148-1152.
66. _1983, Stable isotopes of sulfur, nitrogen, and deuterium in recent marine environments, in Arthur, M.A., and others, eds., Stable isotopes in sedimentary geology: Dallas, Society of Economic Paleontologists and Mineralogists, v. 2, p. 1-108.
67. Kaplan, I.R., and Rittenberg, S.C., 1964, Microbiological fractionation of sulphur isotopes: Journal of General Microbiology, v. 34, p. 195-212.
68. Karamanos, R.E., and Rennie, D.A., 1980, Variations in natural nitrogen-15 abundance as an aid in tracing fertilizer nitrogen transformations: Soil Science Society of America Journal, v. 44, p. 57-62.
69. _1981, The isotope composition of residual fertilizer nitrogen in soil columns: Soil Science Society of America Journal, v. 45, p. 316-322.
70. Keeney, D.R., and Bremner, J.M., 1964, Effect of cultivation on the nitrogen distribution in soils: Soil Science Society of America Journal, v. 28, p. 653-656.
71. Komor, S.C., and Anderson, H.W., Jr., 1993, Nitrogen isotopes as indicators of nitrate sources in Minnesota sand-plain aquifers: Ground Water, v. 31, p. 260-270.
72. Kreitler, C. W., 1975, Determining the source of nitrate in ground water by N isotope studies: Austin, Texas, University of Texas Austin, Bureau of Economic Geology Report of Investigations No. 83, 57 p.
73. _1979, Nitrogen-isotope ratio studies of soils and groundwater nitrate from alluvial fan aquifers in Texas: Journal of Hydrology, v. 42, p. 147-170.
74. Kreitler, C.W., and Browning, L.A., 1983, Nitrogen-isotope analysis of groundwater nitrate in carbonate aquifers - Natural sources versus human pollution: Journal of Hydrology, v. 61, p. 285-301.
75. Kreitler, C.W., and Jones, D.C., 1975, Natural soil nitrate - The cause of the nitrate contamination of ground water in Runnels County, Texas: Ground Water, v. 13, p. 53-61.
76. 14 ratios of ground-water nitrate, Long Island, New York: Ground Water, v. 16, p. 404-409.
77. Krouse, H.R., 1980, Sulphur isotopes in our environment, in Fritz, P., and Fontes, J.Ch., eds., Handbook of environmental isotope geochemistry, v. 1. The terrestrial environment, A: Amsterdam, Elsevier, p. 435-471.
78. Langland, Michael, 1992, Atmospheric deposition of ammonia from open manure-storage lagoons in south-central Pennsylvania: The Environmental Professional, v. 14, p. 28-37.
79. Legg, J.O., and Meisinger, J.J., 1982, Soil N budgets, in Stevenson, F.J., ed., Nitrogen in agricultural soils: Madison, Wis., American Society of Agronomy Monograph 22, p. 503-566.
80. Letolle, Rene, 1980, Nitrogen-15 in the natural environment, in Fritz, P., and Fontes, J.Ch., eds., Handbook of environmental isotope geochemistry, v. 1. The terrestrial environment, A: Amsterdam, Elsevier, p. 407-433.
81. Lindau, C.W., and Spalding, R.F., 1984, Major procedural discrepancies in soil extracted nitrate levels and N isotopic values: Ground Water, v. 22, p. 273-278.
82. Macko, S.A., Fogel, M.L., Hare, P.E., and Hoering, T.C., 1987, Isotopic fractionation of nitrogen and carbon in the synthesis of amino acids by microorganisms: Chemical Geology, v. 65, p. 79-92.
83. 15N abundance measurements: Nature, v. 303, p. 685-687.
84. Mariotti, Andre, Germon, J.C., Hubert, P., Kaiser, P., Letolle, R., Tardieux, A., and Tardieux, P., 1981, Experimental determination of nitrogen kinetic isotope fractionation - Some principles, illustration for the denitrification and nitrification processes: Plant and Soil, v. 62, p. 413-430.
85. Mariotti, Andre, Lancelot, Christiane, and Billen, Gilles, 1984, Natural isotopic composition of nitrogen as a tracer of origin for suspended organic matter in the Scheldt estuary: Geochimica et Cosmochimica Acta, v. 48, p. 549-555.
86. 15N isotope biogeochemistry and natural denitrification process in groundwater - Application to the chalk aquifer of northern France: Geochimica et Cosmochimica Acta, v. 52, p. 1869-1878.
87. Mariotti, Andre, Pierre, D., Vedy, J.C., Bruckert, S., and Guillemot, J., 1980, The abundance of natural nitrogen-15 in the organic matter of soils along an altitudinal gradient: Catena, v. 7, p. 293-300.
88. Mendenhall, William, 1975, Introduction to probability and statistics (4th): North Scituate, Mass., Duxbury Press, 460p.
89. Mook, W.G., Bommerson, J.C., and Staverman, W.H., 1974, Carbon isotope fractionation between dissolved bicarbonate and gaseous carbon dioxide: Earth and Planetary Science Letters, v. 22, p. 169-176.
90. Moore, Howard, 1974, Isotopic measurement of atmospheric nitrogen compounds: Tellus, v. 26B, p. 169-174.
91. _1977, The isotopic composition of ammonia, nitrogen dioxide, and nitrate in the atmosphere: Atmospheric Environment, v. 11, p. 1239-1243.
92. Nadelhoffer, K.J., and Fry, B., 1988, Controls on natural nitrogen-15 and carbon-13 abundances in forest soil organic matter: Soil Science Society of America Journal, v. 52, p. 1633-1640.
93. Nelson, D.W., 1982, Gaseous losses of N other than through denitrification, in Stevenson, F.J., ed., Nitrogen in agricultural soils: Madison, Wis., American Society of Agronomy Monograph 22, p. 327-363.
94. Nissenbaum, A., and Schallinger, K.M., 1974, The distribution of the stable carbon isotope (13C/12C) in fractions of soil organic matter: Geoderma, v. 11, p. 137-145.
95. Noll, D.A., Bergstresser, T.W., and Woodcock, J., 1988, Overburden sampling and testing manual: Pennsylvania Department of Environmental Resources Bureau of Mining and Reclamation, 78 p.
96. Nommik, Hans, and Vahtras, Kaarel, 1982, Retention and fixation of ammonium and ammonia in soils, in Stevenson, F.J., ed., Nitrogen in agricultural soils: Madison, Wis., American Society of Agronomy Monograph 22, p. 123-172.
97. Nriagu, J.O., 1974, Fractionation of sulfur isotopes by sediment adsorption of sulfate: Earth and Planetary Sciences Letters, v. 22, p. 366-370.
98. Nriagu, J.O., and Coker, R.D., 1978, Isotopic composition of sulphur in atmospheric precipitation around Sudbury, Ontario: Nature, v. 274, p. 883-885.
99. _1983, Sulphur in sediments chronicles past changes in lake acidification: Nature, v. 303. p. 692-694.
100. Nriagu, J.O., and Glooschenko, W.A., 1992, Isotopic composition of sulfur in mosses across Canada: Environmental Science & Technology, v. 26, p. 85-89.
101. Nriagu, J.O., and Harvey, H.H., 1978, Isotopic variation as an index of sulphur pollution in lakes around Sudbury, Ontario: Nature, v. 273, p. 223-224.
102. O'Deen, W.A., and Porter, L.K., 1979, Digestion and collection of ammonia for nitrogen-15 and total nitrogen determination: Analytical Chemistry, v. 4, p. 586-589.
103. Officer, C.B., Biggs. R.B., Taft, J.L., Cronin, L.E., Tyler, M.A., and Boynton, W.R., 1984, Chesapeake Bay anoxia - origin, development, and significance: Science, v. 223, p. 22-27.
104. O'Leary, M.H., 1981, Carbon isotope fractionation in plants: Phytochemistry, v. 20, p. 553-567.
105. Olson, R.A., and Kurtz, L.T., 1982, Crop nitrogen requirements, utilization, and fertilization, in Stevenson, F.J., ed., Nitrogen in agricultural soils: Madison, Wis., American Society of Agronomy, Agronomy Monograph 22, p. 567-604.
106. Ott, A.N., Takita, C.S., Edwards, R.E., and Bollinger, S.W., 1991, Loads and yields of nutrients and suspended sediment transported in the Susquehanna River Basin, 1985-89: Susquehanna River Basin Commission Publication No. 136, 254 p.
107. Park, R., and Epstein, S., 1960, Carbon isotope fractionation during photosynthesis: Geochimica et Cosmochimica Acta, v. 21, p. 110-126.
108. Pearson, F.J., Jr., and Rightmire. C.T., 1980, Sulphur and oxygen isotopes in aqueous S compounds, in Fritz, P., and Fontes, J.Ch., eds., Handbook of environmental isotope geochemistry, v. 1., The terrestrial environment, Amsterdam: Elsevier Scientific Publishing Company, p. 229-258.
109. Peterson, B.J., and Fry, Brian, 1987, Stable isotopes in ecosystems studies: Annual Reviews of Ecological Systems, v. 18, p. 293-320.
110. Peterson, B.J., Howarth, R.W., and Garritt, R.H., 1985, Multiple stable isotopes used to trace the flow of organic matter in estuarine food webs: Science, v. 227, p. 1361-1363.
111. _1986, Sulfur and carbon isotopes as tracers of saltmarsh organic matter flow: Ecology, v. 67, p. 865-874.
112. P-STAT, 1989, P-STAT user's manual: Princeton, N.J., P-STAT, Inc., 2 vols.
113. Rast, Walter, and Sutton, J.E., 1989, Use of stable carbon and nitrogen isotopes to trace the larval striped bass food chain in the Sacramento-San Joaquin Estuary, California, April to September 1985: U.S. Geological Survey Water-Resources Investigations Report 88-4164, 62 p.
114. 15N, and D abundance between a polluted and an unpolluted coastal site - Likely indicators of sewage uptake by a marine food web: Estuarine, Coastal and Shelf Science, v. 13, p. 701-707.
115. Reinhorn, Tova, and Avnimelech, Yoram, 1974, Nitrogen release associated with the decrease in soil organic matter in newly cultivated soils: Journal of Environmental Quality, v. 3, p. 118-121.
116. Rennie, D.A., and Paul, E.A., 1975, Nitrogen isotope ratios in surface and sub-surface soil horizons, in Isotope ratios as pollutant source and behavior indicators: Vienna, Austria, International Atomic Energy Agency, IAEA-SM-191, p. 441-454.
117. Rennie, D.A., Paul, E.A., and Johns, L.E., 1976, Natural nitrogen-15 abundance of soil and plant samples: Canadian Journal of Soil Science, v. 56, p. 43-50.
118. Ritter, W.F., and Chirnside, A.E.M., 1984, Impact of land use on ground-water quality in southern Delaware: Ground Water, v. 22, p. 38-47.
119. Rochow, E.G., 1977, Modern descriptive chemistry: Philadelphia, Pa., W.B. Saunders Co., 253 p.
120. Ryther, J.H., and Dunstan, W.M., 1971, Nitrogen, phosphorus, and eutrophication in the coastal marine environment: Science, v. 171, p. 1008-1013.
121. Sackett, W.M., 1989, Stable carbon isotope studies on organic matter in the marine environment, in Fritz, P., and Fontes, J.Ch., eds., Handbook of Environmental Isotope Geochemistry, v. 3, The marine environment, Amsterdam: Elsevier Scientific Publishing Company, p. 139-168.
122. SAS Institute, Inc., 1982a, SAS user's guide - Basics 1982 Edition: Cary, N.C., SAS Institute, Inc., 921 p.
123. _1982b, SAS user's guide - Statistics 1982 Edition: Cary, N.C., SAS Institute, Inc., 584 p.
124. _1988, Procedures guide, release 6.03 edition: Cary, N.C., SAS Institute Inc., 441 p.
125. Schwarcz, H.P., 1978, Isotopes in nature - Stable isotopes of carbon, in Wedepohl, K.H., ed., Handbook of geochemistry: Berlin, Springer-Verlag, v. II/1, chap. 6 p. B1-B15.
126. Shearer, G.B., Kohl, D.H., and Chien, S.H., 1978, The nitrogen-15 abundance in a wide variety of soils: Soil Science Society of America Journal, v. 42, p. 899-902.
127. Shearer, G.B., Kohl, D.H., and Commoner, B., 1974, The precision of determinations of the natural abundance of nitrogen-15 in soils, fertilizers, and shelf chemicals: Soil Science, v. 118, p. 308-316.
128. 12C ratios for higher plants: Plant Physiology, v. 47, p. 380-384.
129. Spalding, R.F., Exner, M.E., Lindau, C.W., and Eaton, D.W., 1982, Investigation of sources of groundwater nitrate contamination in the Burbank-Wallula area of Washington, U.S.A.: Journal of Hydrology, v. 58, p. 307-324.
130. Spalding, R.F., and Fulton, J.W., 1988, Groundwater munition residues and nitrate near Grand Island, Nebraska, U.S.A.: Journal of Contaminant Hydrology, v. 2, p. 139-153.
131. Spiker, E.C., and Kendall, Carol, 1983, C-13 and N-15 as source indicators of sedimentary organic matter in the Chesapeake Bay system [abs.]: Estuaries, v. 6, p. 305.
132. Sprent, J.I., 1987, The ecology of the nitrogen cycle: Great Britain, Cambridge University Press, Cambridge Studies in Ecology, 151 p.
133. Stam, A.C., Mitchell, M.J., Krouse, H.R., and Kahl, J.S., 1992, Stable sulfur isotopes of sulfate in precipitation and stream solutions in a northern hardwood watershed: Water Resources Research, v. 28, p. 231-236.
134. Steele, K.W., and Daniel, R.M., 1978, Fractionation of nitrogen isotopes by animals - A further complication to the use of variations in the natural abundance of N for tracer studies: Journal of Agricultural Science, v. 90, p. 7-9.
135. 4, and CAM plants growing near one another: Science, v. 220, p. 947-949.
136. Stevenson, F.J., 1962, Chemical state of the nitrogen in rocks: Geochimica et Cosmochimica Acta, v. 26, p. 797-809.
137. _1972a, Nitrogen - Element and geochemistry, in Fairbridge, R. W., ed., Encyclopedia of Geochemistry and Environmental Sciences: New York, Van Nostrand Reinhold Co., p. 795-801.
138. _1972b, Nitrogen cycle, in Fairbridge, R. W., ed., Encyclopedia of Geochemistry and Environmental Sciences: New York. Van Nostrand Reinhold Co., p. 801-806.
139. _1982, Origin and distribution of N in soil, in Stevenson, F.J., ed., Nitrogen in agricultural soils: American Society of Agronomy Monograph 22, p. 1-42.
140. Stumm, Werner, and Morgan, J.J., 1981, Aquatic chemistry - An introduction emphasizing chemical equilibria in natural waters (2d): New York, Wiley-Interscience, 780 p.
141. 4 plant carbon in its diet: Oecologia, v. 39, p. 197-200.
142. Teply, L.J., Alberty, R.A., Carter, H.E., Kucera, T.J., Nixon, A.C., Phillips, D.L., and Wilson, L.S., 1980, Chemistry and the food system - A study by the Committee on Chemistry and Public Affairs: Washington, D.C., American Chemical Society, 138 p.
143. Thode, H.G., 1972, Sulfur isotope fractionation in biological processes, in Fairbridge, R.W., ed., Encyclopedia of Geochemistry and Environmental Sciences: New York, Van Nostrand Reinhold Co., p. 1152-1157.
144. Thode, H.G., Monster, J., and Dunford, H.B., 1961, Sulphur isotope geochemistry: Geochimica et Cosmochimica Acta, v. 25, p. 150-174.
145. Tholander, Bent, 1977, An example of design of activated sludge plants with denitrification: Progress in Water Technology, v. 8, nos. 4/5, p. 661-672.
146. Tiessen, H., Karamanos, R.E., Stewart, J.W.B., and Selles, F., 1984, Natural nitrogen-15 abundance as an indicator of soil organic matter transformations in native and cultivated soils: Soil Science Society of America Journal, v. 48, p. 312-315.
147. Toran, Laura, 1982, Isotopes in ground-water investigations: Ground Water, v. 20, no. 6, p. 740-745.
148. U.S. Department of Agriculture, 1992, Conestoga headwaters project, Pennsylvania, Rural clean water program 10-year report, 1981-1991: U.S. Department of Agriculture, Agricultural Stabilization and Conservation Service, 329 p. (U.S. GPO: 1992-624-121:60346).
149. U.S. Environmental Protection Agency, 1979, Methods for chemical analysis of water and wastes: Cincinnati, Ohio, U.S. EPA, n.p.
150. Velinsky, D.J., Pennock, J.R., Sharp, J.H., Cifuentes, L.A., and Fogel, M.L., 1989, Determination of the isotopic composition of ammonium-nitrogen at the natural abundance level from estuarine waters: Marine Chemistry, v. 26, p. 351-361.
151. Velleman, P.F., and Hoaglin, D., 1981, Applications, basics, and computing of exploratory data analysis: Boston, Mass., Duxbury Press, 354 p.
152. White, J.R., Gubala, C.P., Fry, B., Owen, J., and Mitchell, M.J., 1989, Sediment biogeochemistry of iron and sulfur in an acidic lake: Geochimica et Cosmochimica Acta, v. 53, p. 2547-2559.
153. Wolterink, T.J., Williamson, H.J., Jones, D.C., Grimshaw, T.W., and Holland, W.F., 1979, Identifying sources of subsurface nitrate pollution with stable nitrogen isotopes: U.S. Environmental Protection Agency, EPA-600/4-79-050, 150p.
154. Yanagisawa, Fumitaka, and Sakai, Hitoshi, 1983, Thermal decomposition of barium sulfate-vanadium pentaoxide-silica glass mixtures for preparation of sulfur dioxide in sulfur isotope ratio measurements: Analytical Chemistry, v. 55, p. 985-987.