College of Agriculture & Natural Resources
Permanent URI for this communityhttp://hdl.handle.net/1903/1598
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
Browse
4 results
Search Results
Item Saltwater intrusion alters nitrogen and phosphorus transformations in coastal agroecosystems(2020) Weissman, Dani; Tully, Katherine L; Plant Science and Landscape Architecture (PSLA); Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)As sea levels rise, coastal regions are becoming more vulnerable to saltwater intrusion (SWI). In coastal agricultural areas, SWI is causing changes in biogeochemical cycling in soil and waterways. These changes are leading to the release of excess nitrogen (N) and phosphorus (P) from farm fields, which in turn can cause impaired water quality downstream. I explored the effects of saltwater intrusion on N and P concentrations of surface water and soil porewater on Maryland’s Eastern Shore in the Chesapeake Bay Watershed on three spatial and temporal scales: 1) a three-year field study through farmland and various surrounding habitats; 2) a one-month laboratory soil incubation study; and 3) a regional study of tidal tributaries (sub-watersheds) along Maryland’s Eastern Shore where I utilized 35 years of observational data on nutrient concentrations and salinity from the Chesapeake Bay Water Quality Monitoring Program. The results of the field and incubation studies suggest that SWI can cause a large release of N and P from the soils of coastal landscapes to downstream water bodies such as tidal creeks and marshes. However, the results of the regional study suggest that the relative magnitude of SWI-driven contributions of N and P to waterways as compared to other sources and drivers of N and P differ depending on the spatial and temporal scale considered. Defining mechanisms through which SWI spurs nutrient release from soils of agricultural fields and surrounding habitats as well as the magnitude of these processes is critical for quantifying N and P export in coastal watersheds. The results of these three studies can potentially be used to inform water quality models for individual tidal tributaries, which would allow for more targeted approaches to nutrient load reductions in sub-watersheds of the Chesapeake Bay and other watersheds globally.Item Simulated Trading for Maryland’s Nitrogen Loadings in the Chesapeake Bay: A Policy Overlook(CANRP, 2012-04-13) Hanson, Jim; McConnell, TedJim Hanson and Ted McConnell looked at whether decreasing nutrients into the Bay could cost less if trading is permitted. Rather than having the sewage treatment plants install new technology (high cost), these sewage plants could pay farmers to plant more cover crops (low cost) to meet the nitrogen loading goals.Item Does it Matter Who Writes Your Nutrient Management Plan?(CANRP, 2012-03-02) Lichtenberg, Erik; Parker, Doug; Lawley, ChadDr. Erik Lichtenberg and Dr. Doug Parker of the University of Maryland, along with Dr. Chad Lawley of the University of Manitoba, studied the content of nutrient management plans written before they were required by law to see if that content varied according to the type of provider.Item EVALUATION OF BASE LINERS TO REDUCE NITROGEN AND SALT LEACHING FROM POULTRY LITTER STORAGE STOCKPILES TO THE UNDERLYING SOIL - A FIELD COLUMN STUDY(2011) Baranyai, Vitalia; McGrath, Joshua M; Environmental Science and Technology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Agriculture has been linked to the eutrophication of the Chesapeake Bay. The Delmarva Peninsula is an intensive poultry producing region, where poultry litter (PL, mix of manure and bedding material) is often stored in outdoor stockpiles. Continued development of management practices is required to achieve environmentally sound PL storage. This study evaluates base liners placed between the bottom of the pile and the soil to reduce nitrogen (N), potassium (K) and sodium (Na) movement from PL stockpiles after 15 and 91 days of storage. Six conically shaped stockpiles were established with five PVC pipe columns placed in the soil under each pile. The soil surface in each column was covered with one of five treatments: alum, gypsum, lime, plastic, or control (no material). Nitrogen, K and Na concentrations increased between 15 and 91 days of storage. Ammonium losses under alum and lime treatment were not different from the control. Alum created adverse conditions by dropping the pH to 3.8. After 91 days of storage, the surface 10 cm of the soil was severely salt affected: under alum, gypsum, lime and control the conditions became moderately to strongly saline. Plastic was most effective in preventing N, K and Na leaching to the soil.