| Long-term response of groundwater nitrate concentrations to management regulations in Nebraska's central Platte valley. | |
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MedLine Citation:
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PMID: 20191240 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The impact of 16 years (1988-2003) of management practices on high groundwater nitrate concentrations in Nebraska's central Platte River valley was assessed in a 58,812-ha (145,215-ac) groundwater quality management area intensively cropped to irrigated corn (Zea mays L.). Crop production and groundwater nitrate data were obtained from approximately 23,800 producer reports. The terrace, comprising approximately 56% of the study area, is much more intensively cropped to irrigated corn than the bottomland. From 1987 to 2003, average groundwater nitrate concentrations in the primary aquifer beneath the bottomland remained static at approximately 8 mg N/l. During the same period, average groundwater nitrate concentrations in the primary aquifer beneath the terrace decreased from 26.4 to 22.0 mg N/l at a slow, but significant (p < 0.0001), rate of 0.26 mg N/l/year. Approximately 20% of the decrease in nitrate concentrations can be attributed to increases in the amount of N removed from fields as a consequence of small annual increases in yield. During the study, producers converted approximately 15% of the approximately 28,300 furrow-irrigated terrace hectares (approximately 69,800 ac) to sprinkler irrigation. The conversion is associated with about an additional 50% of the decline in the nitrate concentration, and demonstrates the importance of both improved water and N management. Average N fertilizer application rates on the terrace were essentially unchanged during the study. The data indicate that groundwater nitrate concentrations have responded to improved management practices instituted by the Central Platte Natural Resources District. |
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Authors:
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Mary E Exner; Hugo Perea-Estrada; Roy F Spalding |
Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, Non-P.H.S. Date: 2010-02-17 |
Journal Detail:
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Title: TheScientificWorldJournal Volume: 10 ISSN: 1537-744X ISO Abbreviation: ScientificWorldJournal Publication Date: 2010 |
Date Detail:
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Created Date: 2010-03-01 Completed Date: 2010-06-24 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 101131163 Medline TA: ScientificWorldJournal Country: England |
Other Details:
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Languages: eng Pagination: 286-97 Citation Subset: IM |
Affiliation:
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School of Natural Resources and 2Department of Agronomy and Horticulture, Institute of Agriculture and Natural Resources, University of Nebraska, Lincoln, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Agriculture Fertilizers / analysis Nebraska Nitrates / analysis* Water Pollutants, Chemical / analysis* |
| Chemical | |
Reg. No./Substance:
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0/Fertilizers; 0/Nitrates; 0/Water Pollutants, Chemical |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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