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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

The Impact Of Accelerating Land-Use Change On The N-Cycle Of Tropical Aquatic Ecosystems: Current Conditions And Projected Changes, J. A. Downing, M. Mcclain, R. Twilley, J. M. Melack, J. Elser, Nancy N. Rabalais, W. M. Lewis Jr., R. Eugene Turner, J. Corredor, D. Soto, A. Yanez Arancibia, J. A. Kopaska, R. W. Howarth Jul 1999

The Impact Of Accelerating Land-Use Change On The N-Cycle Of Tropical Aquatic Ecosystems: Current Conditions And Projected Changes, J. A. Downing, M. Mcclain, R. Twilley, J. M. Melack, J. Elser, Nancy N. Rabalais, W. M. Lewis Jr., R. Eugene Turner, J. Corredor, D. Soto, A. Yanez Arancibia, J. A. Kopaska, R. W. Howarth

Faculty Publications

Published data and analyses from temperate and tropical aquatic systems are used to summarize knowledge about the potential impact of land-use alteration on the nitrogen biogeochemistry of tropical aquatic ecosystems, identify important patterns and recommend key needs for research. The tropical N-cycle is traced from pre-disturbance conditions through the phases of disturbance, highlighting major differences between tropical and temperate systems that might influence development strategies in the tropics. Analyses suggest that tropical freshwaters are more frequently N-limited than temperate zones, while tropical marine systems may show more frequent P limitation. These analyses indicate that disturbances to pristine tropical lands will …


Ground-Water Quality In Kentucky: Nitrate-Nitrogen, Philip G. Conrad, Daniel I. Carey, James S. Webb, James S. Dinger, Matthew J. Mccourt Jan 1999

Ground-Water Quality In Kentucky: Nitrate-Nitrogen, Philip G. Conrad, Daniel I. Carey, James S. Webb, James S. Dinger, Matthew J. Mccourt

Information Circular--KGS

No abstract provided.


1999 File Geodatabase Containing Photo Point Locations, Aerial Photos, And Flight Maps, City Of Tampa Department Of Sanitary Sewers Bay Study Group, Pete Reehling, Richard Mckenzie Jan 1999

1999 File Geodatabase Containing Photo Point Locations, Aerial Photos, And Flight Maps, City Of Tampa Department Of Sanitary Sewers Bay Study Group, Pete Reehling, Richard Mckenzie

Data Sets

The Bay Study Group was created by the City of Tampa in 1976 to monitor the effects of pollution abatement that occurred in Hillsborough Bay when the city’s wastewater treatment plant was upgraded from primary to advanced treatment in 1979. The Bay Study Group documented a remarkable restoration of water quality parameters and biological indicators in Hillsborough Bay from the mid 1980s until 2009, when it was disbanded. This zip Geodatabase file contains the photo point locations, aerial photos, and flight maps for the year 1999.


1999 File Geodatabase Containing Aerial Photos, Pete Reehling, Richard Mckenzie, City Of Tampa Department Of Sanitary Sewers Bay Study Group Jan 1999

1999 File Geodatabase Containing Aerial Photos, Pete Reehling, Richard Mckenzie, City Of Tampa Department Of Sanitary Sewers Bay Study Group

Images

The Bay Study Group was created by the City of Tampa in 1976 to monitor the effects of pollution abatement that occurred in Hillsborough Bay when the city’s wastewater treatment plant was upgraded from primary to advanced treatment in 1979. The Bay Study Group documented a remarkable restoration of water quality parameters and biological indicators in Hillsborough Bay from the mid 1980s until 2009, when it was disbanded. This zip Geodatabase file contains the aerial photos for the year 1999.


Chlorophyll Meter Assessments Of Corn Response To Nitrogen Management Practices, M. M. Siambi, D. L. Karlen, R. M. Shibles Jan 1999

Chlorophyll Meter Assessments Of Corn Response To Nitrogen Management Practices, M. M. Siambi, D. L. Karlen, R. M. Shibles

Journal of the Iowa Academy of Science: JIAS

Environmentally sound nitrogen (N) management is necessary to simultaneously achieve high crop yields and protect surface and groundwater quality. We evaluated a hand-held chlorophyll meter as a diagnostic tool for improving management for corn (Zea mays L.). Five N fertilizer rates (0, 67, 134, 201 and 280 kg N ha-1) were evaluated in one study, and in a second study, the meter was used to evaluate the N status of corn plants grown under varying tillage (chisel plow vs no-till), crop rotation (continuous corn vs corn-soybean [Glycine max (L.) Merr.]), and N management treatments. Meter readings were …