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51	Nitrogen Balance for a 23-Square Mile Minnesota Watershed Johnson, Jack D. 23 April 1971 (has links) From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / The nitrogen balance of a watershed near the city of New Prague, Minnesota was evaluated as part of an overall study on lake and stream eutrophication. Although the n-balance of a humid Midwest watershed cannot be expected to be identical to that of an arid watershed, the processes are the same and differences should be mainly quantitive. Sources of input and causes of depletion are reviewed for 4 points in the nitrogen cycle: the atmospheric zone, the soil-atmosphere interface, the plant-root and soil-water zone and the surface water zone. In the New Prague watershed, commercial fertilizer and bulk precipitation were the major sources of input, contributing, respectively, 53% and 34.4% of the total input of 2.34 million lb/yr. Crop yield and soil or groundwater storage contributed 52.1% and 20.4% of non-enrichment depletions. The closeness of the values of crop yield and commercial fertilizer application was an unfortunate coincidence and is certainly not an indication that the entire fertilizer supply was taken up cry crops. In an arid environment, free from fertilized agriculture, bulk precipitation probably provides the major source of nitrogen compounds. Water resources development -- Arizona. Hydrology -- Arizona. Hydrology -- Southwestern states. Nitrogen cycle Watersheds Minnesota Soil environment Atmosphere Ammonium compounds Nitrogen fixation Nitrogen compounds Nitrates Nitrites Groundwater Surface waters Water chemistry Arid lands Denitrification Precipitation (atmospheric) Subsurface drainage Fertilizers On-site data collections

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Nitrogen Balance for a 23-Square Mile Minnesota Watershed