Physical Sciences and Mathematics Commons^™

Long-Term Impacts Of Conservation Management Practices On Soil Carbon Storage, Stability, And Utilization Under Cotton Production In West Tennessee, Candace Brooke Wilson

Masters Theses

Biogeochemical cycling of soil carbon (C) is heavily influenced by conservation agricultural (CA) practices. This study examined SOC stability under three CA practices: reduced nitrogen (N) fertilizer application rate, cover cropping, and zero-tillage implemented for 31 years. Respiration rates measured from a 602-day incubation period were fitted to a double-pool first order exponential model of SOC decomposition. The active [respired] SOC pool showed distinct differences between applications of reduced (34N kg ha^-1 [-1]) and high fertilization rates (101N kg ha^-1) combined with tillage, and suggest that high fertilizer applications with conventional tillage allocated more C into a …

The Phosphorus Paradox: Productive Agricultural And Water Quality, Andrew N. Sharpley

21st International Conference on Environmental Indicators (ICEI 2015)

No abstract provided.

Impacts Of Changing Snowmelt Timing On Non-Irrigated Crop Yield, Erin Murray

Boise State University Theses and Dissertations

As climate changes, the final date of spring snowmelt is projected to occur earlier in the year within the western United States. This earlier snowmelt timing may impact crop yield in snow-dominated watersheds by changing the timing of water delivery to agricultural fields. There is considerable uncertainty about how agricultural impacts of snowmelt timing may vary by region, crop type, and practices like irrigation vs. dryland farming. We utilize parametric regression techniques to isolate the magnitude of impact snowmelt timing has had on historical crop yield independently of climate and physiographic variables that also impact yield. To do this, we …

Slides: Ag Water Sharing: Legal Challenges And Considerations, Peter D. Nichols

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Peter D. Nichols, Esq., Partner, Berg, Hill, Greenleaf and Ruscitti, Boulder, CO

25 slides

Slides: The (Largely) Untold Success Story Of Urban Water Conservation, Peter Mayer

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Peter Mayer, P.E., Water Demand Management

20 slides

Slides: Colorado's Water Plan, Lauren Ris

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Lauren Ris, Assistant Director for Water, Colorado Department of Natural Resources

23 slides

Slides: Six Decades Of Texas Water Planning, Ronald Kaiser

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Ronald Kaiser, Professor of Water Law and Policy, Chair of Graduate Water Degree Program, Texas A&M University

32 slides

Slides: Food Production: Technical Challenges In Agricultural Water Conservation, Perry Cabot

Innovations in Managing Western Water: New Approaches for Balancing Environmental, Social and Economic Outcomes (Martz Summer Conference, June 11-12)

Presenter: Dr. Perry Cabot, Research Scientist and Extension Specialist, Colorado Water Institute, Colorado State University

35 slides

Model Of Residence Time And Analysis Of Nitrogen Removal For Two Constructed Wetlands At The Franklin Demonstration Farm In Lexington, Illinois, Emma Singh Baghel

Theses and Dissertations

Pollution from nonpoint agricultural runoff has become a major problem facing our streams and rivers today. Not only are fish and aquatic life affected, but so is the quality of our drinking and recreational water resources. Studies have shown that wetlands have proven to be the most cost-effective and low maintenance method of removing nonpoint or diffused contaminate inputs. The biological processes and removal of nutrients in wetlands depend on the total surface area available for microbial activity in the soil and a certain period of water retention time. Since chemical processes take time, the measure of residence time is …

Stoichiometric Controls On Denitrification In High Nitrate Watersheds, Brian Grebliunas

Theses and Dissertations

Watershed biogeochemistry throughout Midwestern agroecosystems have been altered through hydrologic manipulation and over-application of nitrogenous fertilizers. As a result, nitrate (NO3-N) export from subsurface drainage has negative impacts on local and downstream ecosystem health. Wetland installation has proven to be a viable option for targeted management where a large proportion of NO3-N is removed through the bacterially mediated process denitrification. For denitrification to maintain high rates under prolonged NO3-N saturation, a stable supply of labile dissolved organic carbon (DOC) is required. The focus of this dissertation was to study how the stoichiometry of agricultural wetlands limits denitrification within a controlled …

Regional Scale Cropland Carbon Budgets: Evaluating A Geospatial Agricultural Modeling System Using Inventory Data, Xuesong Zhang, Roberto C. Izaurralde, David H. Manowitz, Ritvik Sahajpal, Tristram O. West, Allison M. Thomson, Min Xu, Kaiguang Zhao, Stephen D. Leduc, Jimmy R. Williams

United States Environmental Protection Agency: Staff Publications

Accurate quantification and clear understanding of regional scale cropland carbon (C) cycling is critical for designing effective policies and management practices that can contribute toward stabilizing atmospheric CO₂ concentrations. However, extrapolating site-scale observations to regional scales represents a major challenge confronting the agricultural modeling community. This study introduces a novel geospatial agricultural modeling system (GAMS) exploring the integration of the mechanistic Environmental Policy Integrated Climate model, spatially-resolved data, surveyed management data, and supercomputing functions for cropland C budgets estimates. This modeling system creates spatiallyexplicit modeling units at a spatial resolution consistent with remotely-sensed crop identification and assigns cropping systems …

A Historical Perspective On Nebraska’S Variable And Changing Climate, Martha Shulski, William Baule, Crystal J. Stiles, Natalie A. Umphlett

HPRCC Personnel Publications

Nebraska is situated at the intersection of the northern and southern Great Plains, exhibiting a dramatic longitudinal gradient for precipitation and humidity, and benefiting from groundwater resources. The continental climate is highly variable temporally both for temperature and precipitation. Our assessment of long-term meteorological observations shows that over the last century the annual average temperature in Nebraska has warmed approximately 0.6°C, which is similar to the increase in the global average temperature over the same time period. Furthermore, we found minimum temperatures have warmed more than maximum temperatures, and winter and spring show the strongest warming. We found no significant …