Fall 2016 Soil, Water, & Climate Seminar Series
Sept 21 | 375 Borlaug Hall | 3:30 PM
Dr. Fernández joined the Department of Soil, Water, and Climate in August 2013 with a research vision to advance the efficiency of fertilizers through management practices that enhance profitability, productivity, and environmental protection. Nitrogen (N) represents an expensive input for farmers as N is required in large quantities to maximize productivity and profitability. Unfortunately, when N is not used by the crop or retained by the soil, it can contribute to environmental degradation as reactive N escapes to the atmosphere, or enters surface waters or groundwater. In view that financially a farmer cannot afford to over- or under-apply N, and unused N can negatively impact the environment, it is fundamentally important to apply the exact amount of N the crop needs. However, this is not an easy task as there are many environmental and management factors that impact N availability to the crop. In his research, Dr. Fernández studies various management factors that impact N availability, such as N rate and source, placement method, and time of application, with the main thrusts in understanding the N cycle processes of mineralization, leaching, and nitrous oxide emissions. His presentation will cover some of the recent findings of his research program.
Managing salt-affected soils and the organisms that inhabit them
Oct 5 | 375 Borlaug Hall | 3:30 PM
Dr. Heather Dose | USDA-ARS, Morris, MN
Salt-affected soils comprise 10% of the earth's surface and cause an estimated annual loss of $12 billion. In places where the potential evapotranspiration rate is greater than precipitation and where suitable irrigation water is not available alternative management strategies have been suggested to reduce the effects of salinity and sodicity. However, little information is available concerning the soil microorganisms that inhabit these soils and the effects of these alternative management practices on nutrient cycling. Enzyme assays and quantification of nitrifying and denitrifying organisms were used to study the effect of diverse cover crops and amendments on saline and sodic soils, respectively. A decrease in soil electrical conductivity occurred under all cover crop and control treatments in a saline soil but did not increase nitrogen cycling enzyme activities or nitrifiers/denitrifiers. However, cover crop treatments did alter the community structure of nitrifying and denitrifying organisms. The lack of a response is likely due to the chemistry of the salts along with the ability of the microorganisms to adapt to their environment. In a sodic soil, converting the land from hayland to annual row crop production resulted in a decrease in soil enzyme activity, while the application of gypsum resulted in a decrease of the sodium adsorption ratio applied gypsum also increased the quantity of ammonia oxidizing bacteria. These results are likely the result of the disturbance to the system when converting hayland to cropland. Understanding the effects of salt-affected soil management on microbial processes is important to ensure soil quality and environmental services are maintained or enhanced in the face of a growing world population.
Unfortunately, there were techinical difficulties during the recording of this seminar so a small section of the seminar was not recorded.
Oct 19 | 375 Borlaug Hall | 3:30 PM
The first set of lightening talks (5 minutes each) from faculty in the Department of Soil, Water, and Climate. Playlist for the talks can be found at: https://www.youtube.com/playlist?list=PLia6NZBK7dLIs9iLTRqppnq1TkxXGBSJX
This week featured:
Oct 26 | 375 Borlaug Hall | 3:30 PM
The second set of lightening talks (5 minutes each) from faculty in the Department of Soil, Water, and Climate.
This week features:
Nov 2 | 375 Borlaug Hall | 3:30 PM
The third and final set of lightening talks (5 minutes each) from faculty in the Department of Soil, Water, and Climate.
This week features:
Utilizing Landscape Design for Continual Improvement of Bioenergy Feedstock Supply Systems
Nov 16 | 375 Borlaug Hall | 3:30 PM
Dr. Doug Karlen | Soil Scientist | USDA-ARS, Ames, IA
Sustainable bioenergy and bio-product feedstock supplies must be produced in a sustainable manner. To be sustainable they must be (1) economically viable, (2) environmentally benign, and (3) socially acceptable. This presentation will review development of a landscape research vision and implementation of a multi-million dollar DOE investment in this research. Economic assessments must begin with the producers and can be accomplished by reviewing sub-field return on investment (ROI) calculations. Environmental impact is being assessed using soil health and water quality indicators. Social acceptance involves both the producer and his/her surrounding community.
Conservation and restoration of native freshwater mussels in the Upper Mississippi River: a research synopsis.
Nov 30 | 375 Borlaug Hall | 3:30 PM
Dr. Teresa Newton | Upper Midwest Environmental Sciences Center, La Crosse, WI | USGS
Co-investigators-Steve Zigler, and Patty Ries
Native freshwater mussels are the most imperiled group of animals in North America. As such, their conservation is a priority for numerous federal, state, and non-governmental organizations. In 2001, the Upper Midwest Environmental Sciences Center formed a native mussel team whose long-term goal is to provide information to conserve and restore healthy freshwater mussel populations in the Upper Mississippi River (UMR) basin and elsewhere. A major thrust of our efforts has been to determine the factors that might limit mussel populations in the UMR through a series of conceptually-related studies designed to improve conservation efforts by natural resource agencies. First, we sought to understand the potential for aquatic contaminants to adversely affect mussel assemblages. We focused on ammonia because it is highly toxic and ubiquitous in surface waters. Through a series of laboratory and field studies, we showed that un-ionized ammonia is toxic to juvenile mussels, at concentrations below the current national water quality critieria. Second, we sought to understand what constitutes mussel habitat in large rivers. Although habitat loss has been cited as one of the most critical threats to mussels, information needed to address conservation concerns is lacking compared to other aquatic fauna. We developed hydrophysical models to identify features and locations of patches of suitable habitat for mussels. Our models had high predictive success, and showed the importance of certain hydraulic variables in predicting mussel distributions in the UMR. Third, we now seek to estimate the viability of mussels within these patches by measuring a suite of vital rates including mortality, growth, and recruitment. Moreover, development of methods to assess vital rates will provide critical tools to resource managers seeking to evaluate the effects of management actions such as habitat restoration projects on mussels. We are currently estimating mortality, growth, and recruitment of mussels in a reach of the UMR near Kellogg, MN. Preliminary data suggest that vital rates, unlike traditional measures (i.e., species richness and abundance), may be sensitive indicators of subtle environmental changes. Collectively, these studies have helped scientists understand those factors limiting mussel assemblages in large rivers and have helped resource managers conserve and restore native mussel assemblages in the UMR.
Dr. Teresa J. Newton, Fishery Biologist with the U.S. Geological Survey's Upper Midwest Environmental Sciences Center in La Crosse, WI. Dr. Newton received a B.S. in Biology in 1985 from Central Michigan University, a M.S. in Biology in 1987 from Tennessee Technological University and a Ph.D. in Fisheries Biology and Toxicology in 1990 from Iowa State University. Dr. Newton has been employed at the USGS lab since 1990 with research interests on the conservation and ecology of freshwater mussels, a group of benthic animals in which 70% of the North American species are considered threatened. Mussels are keystone species in many rivers and their catastrophic decline may lead to the decline of other faunal groups and the alteration of ecosystem processes. Dr. Newton uses a combination of comparative and experimental approaches to understand factors affecting the distribution and abundance of freshwater mussels and to determine the roles that mussels may play in large river food webs. Dr. Newton also investigates the effects of sediment-associated contaminants on freshwater mussels.