Browsing by Subject "nitrate"
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Item Evaluating relationships between plant traits and nitrogen use to help predict species' responses to climate change(2020-08) King, RachelIn many ecosystems, nitrogen (N) is the predominant nutrient limiting plant growth. Plants have therefore developed diverse strategies to compete for and partition soil N resources to ensure an adequate N supply. Differences in how plants acquire N may be important for predicting plant responses to different global changes. In particular, how species respond to climate change may depend on their N use strategy since climate change will likely alter the forms of N available to plants as well as total N availability. However, there remain key gaps in our understanding of plant N acquisition that impede our ability to project the impacts of climate change on plant communities. My research focuses on one of these gaps, the variation in plant use of different chemical forms of N, and examines how that variation can influence plant responses to climate change. Specifically, my research aims to increase our understanding of N acquisition in trees by examining whether plant traits can improve our ability to identify and explain differences in the use of different N forms. My first three chapters explore (1) the relationship between N uptake rates and root morphology for different N forms; (2) whether plant traits can help explain how species vary in their growth on different N forms; and (3) whether warming and drought alter patterns of N use in a regenerating forest. I then examine (4) how plant nutrient acquisition strategies and traits influence links between ecosystem carbon (C) and N cycling. Together, my research highlights that plants differ in their capacity to use different forms of N, which are in some cases associated with their traits. I also show that plants differ in how they partition N resources in the field, especially between mycorrhizal types. Finally, I show that both species’ mycorrhizal type and phylogeny contribute to differences in C and N cycling in ecosystems where they dominate. Overall, my research adds to our knowledge of how plants acquire N and shows that these strategies are an important influence on species and ecosystem responses to global change.Item From spring to stream: water quality analysis in Trout Brook, Dakota County, MN(2018-04) Pencak, Edward S; Alexander, Scott C; Alexander, E CalvinItem Gap-filled USGS sensor data for nitrate, discharge and temperature for selected sites in Iowa, U.S.A.(2018-03-22) Singh, Arvind; Hansen, Amy, T; Arvind.Singh@ucf.edu; Singh, ArvindItem Intermediate Wheatgrass Nitrogen Dynamics: Nitrate Leaching Prevention and Nitrogen Supply via Legume Intercrops(2021-07) Reilly, EvelynWe compared soil and soil water nitrate concentrations, root biomass, and yield in intermediate wheatgrass (IWG; Thinopyrum intermedium) and a corn-soybean rotation over three years. Nitrate was 77-96% lower under IWG than the annual system, while root biomass was higher. IWG grain yields were 854, 434, and 222 kg ha-1 for Years 1-3 and biomass averaged 4.65 Mg ha-1 yr-1. IWG effectively reduces soil solution NO3--N concentrations even on sandy soils, supporting its potential for broader adoption on vulnerable land. We also assessed grain and biomass yield and N dynamics in response to mineral fertilizer and six legume intercrops. Treatments affected N dynamics and IWG biomass but not grain yields. N transfer rates ranged from 0 to 27% but legume biomass was negatively associated with IWG grain yield, suggesting competition in addition to nitrogen supply. Overall, alfalfa, red clover, and birdsfoot trefoil were among the best options for intercrops.Item Managing nitrogen from manure with a winter rye cover crop: Research dataset(2020-02-17) Everett, Leslie A.; Wilson, Melissa L.; Pepin, Randall J.; Coulter, Jeffrey A.; mlw@umn.edu; Wilson, MelissaThis data is from 19 on-farm studies in Minnesota to evaluate the use of cover crops to trap nutrients from fall manure applications and release them during the growing season for the following cash crop. It includes the amount of above-ground biomass that was produced by the cover crop (CC), soil nitrate in the top 24 inches of soil in plots with and without CC, and yields of the following cash crop in plots with and without CC. There is also data on CC and corn nitrogen uptake. This data was published in a peer-reviewed journal article and is now released.Item Nitrate Concentration in Streams as Related to Major Ion Chemistry(2016-05) Gao, YuanNitrate (NO3-) is a reactive nitrogen compound and can be utilized by living organisms. Industrial nitrogen fixation methods have greatly increased the production of reactive nitrogen and ultimately increased concentration of nitrate in natural waters. In natural streams, nitrate is recognized as a pollutant that can lead to some serious health issue for humans. Therefore, knowing the nitrate concentration in streams is critical to the environment and human health. Nitrate is not a major ion in natural waters. It would be very helpful if nitrate concentration could be estimated from other frequently measured parameters of stream, allowing ones to predict the nitrate concentration from other, more easily measure parameters. The largest data set of ionic composition of streams that has ever been compiled was used to examine the relationships among nitrate concentrations, major ion concentrations, and two bulk measurements of ionic content, ionic strength and specific conductance.Item OFR14-02, Geologic controls on groundwater and surface water flow in southeastern Minnesota and its impact on nitrate concentrations in streams(Minnesota Geological Survey, 2014) Runkel, Anthony C.; Steenberg, Julia R.; Tipping, Robert G.; Retzler, Andrew J.This report summarizes the results of a Minnesota Geological Survey (MGS) investigation conducted for the Minnesota Pollution Control Agency (MPCA) designed to support watershed planning efforts in southeast Minnesota. Specifically it provides better understanding of the geologic controls on nitrate transport in the region, including nitrate in groundwater that is the source of baseflow to streams. Nitrate contamination of surface water and groundwater is a long- standing issue in southeastern Minnesota. We focused much of our investigation on an evaluation of nitrate (NO3 ion) transport in the Root River watershed because of the relatively advanced understanding of the karstic conditions in that area. However, the overall scope of the project includes the entire bedrock-dominated landscape of southeast Minnesota. Our results therefore support a broader MPCA watershed planning effort that directly pertains to the Root River, as well as to other watersheds within the Lower Mississippi River Basin in Minnesota.Item OFR14-03, Geologic Controls on Groundwater and Surface Water Flow in Southeastern Minnesota and its Impact on Nitrate Concentrations in Streams: Local Project Area Report(Minnesota Geological Survey, 2014) Steenberg, Julia R.; Tipping, Robert G.; Runkel, Anthony C.This report summarizes the results of part of a Minnesota Geological Survey (MGS) investigation conducted for the Minnesota Pollution Control Agency (MPCA) designed to support watershed planning efforts in southeast Minnesota. The broader project provides better understanding of the geologic controls on nitrate transport in the region, including nitrate in groundwater that is the source of baseflow to streams. This report describes a local scale subproject focused on a relatively small part of the Root River watershed in Fillmore County. We conducted new mapping that provides a more detailed depiction of the geologic conditions in a three dimensional electronic format suitable for groundwater-surface water modeling. In addition, we used existing maps and reports along with new field data collected during the course of this project to improve the hydrostratigraphic characterization of the bedrock. This led to a more comprehensive understanding of the hydrostratigraphic attributes of bedrock that forms the Upper Carbonate Plateau, which dominates the landscape in the local project area. Cross sections within the local project area are used to illustrate how nitrate is transported in the ground and surface water system.Item Proceedings of the 2nd Agricultural Drainage and Water Quality Field Day(2005-08-19) Strock, Jeffrey S.; Fausey, Norm; Kanwar, Ramesh; Skaggs, Wayne; Gupta, Satish; Moncrief, JohnItem Proceedings of the 3rd Soil and Water Management Field Day and Workshop(2008-08-13) Strock, Jeffrey S.; Baker, John; Pitts, Don; Birr, Adam; Rice, Pam; Venterea, RodItem Proceedings of the 4th Drainage Water Management Field Day(2011-08-23) Strock, Jeffrey S.; Gupta, Satish; Sands, Gary; Ranaivoson, Andry; Hay, Chris; Talbot, Mike; Magner, JoeItem Proceedings of the 5th Soil and Water Management Field Day(2014-07-23) Strock, Jeffrey S.; Baker, John; Hatfield, Jerry; Sereg, Catherine; Todey, Dennis; Wohnoutka, Shawn; Castellano, Mike; Ingels, Chad; Tollefson, DavidItem South Orion Township Dye Trace(2021-09) Barry, John D.; Larsen, Martin R.; Stacken, Jacob C.; Stacken, Adele C.; Stacken, Ansel A.; Alexander, E. Calvin, Jr.; Green, Jeffrey A.