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Articles 511 - 540 of 704

Full-Text Articles in Physical Sciences and Mathematics

Evapotranspiration Of Kentucky Bluegrass, Lynda L. Fenton May 2010

Evapotranspiration Of Kentucky Bluegrass, Lynda L. Fenton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rapid population growth in arid regions of the western US is placing increased demand on water resources. Variability in precipitation and common occurrence of drought have promoted scrutiny of water use in urban lawns and gardens. However, few reliable measurements of water use of these landscapes exist. Quantifying the amount of water used vs. required by landscapes such as turfgrass would allow significant water conservation. Evapotranspiration (ET) is affected by biophysical factors such as: available energy, turbulent mixing, saturation deficit, soil water, and stomatal conductance. In order to simulate the water use by turfgrass, the relative importance of these processes …


An Artesian Well System In Beaver Crossing, Nebraska, It's Development And Demise, Mary Lanik Apr 2010

An Artesian Well System In Beaver Crossing, Nebraska, It's Development And Demise, Mary Lanik

Department of Environmental Studies: Undergraduate Student Theses

ABSTRACT

Nebraska has a veritable wealth of groundwater. The High Plains Aquifer underlies most of the state, and within its sand and gravel deposits, many interconnected aquifers provide fresh water for a variety of uses.

One of the most spectacular examples of this resource is the artesian well. Beaver Crossing, Nebraska was once home to one of the most prolific artesian systems in the state before its demise. Founded in the 1880’s, Beaver Crossing soon became known for its many artesian wells, that provided leisure activities and supported profitable business ventures such as small farming, ice production and aquiculture. Eventually …


Cellulosic Ethanol: The Benefits, Obstacles, And Implications For Nebraska, Cassidee Lin Thompson Apr 2010

Cellulosic Ethanol: The Benefits, Obstacles, And Implications For Nebraska, Cassidee Lin Thompson

Department of Environmental Studies: Undergraduate Student Theses

Abstract Ethanol is a biofuel that has unique capabilities to mitigate global climate change by reducing greenhouse gas emissions while simultaneously supporting rural economies and decreasing the United States’ dependence on foreign oil. Currently, the state of Nebraska depends on corn ethanol, which may be unsustainable. Cellulosic ethanol is a promising alternative but it is not without its problems, including high production costs and potential environmental damage. This thesis is an attempt to understand the benefits, downfalls, and processes of corn-based and cellulosic ethanol and the potential implications to Nebraska. This research should shed some light on the current obstacles …


Interview With Bernard Smith, Full Of Life Farms, 2010 (Audio), Bernard Smith Feb 2010

Interview With Bernard Smith, Full Of Life Farms, 2010 (Audio), Bernard Smith

All Sustainability History Project Oral Histories

Interview of Bernard Smith by Kyle Dykstra on February 28th, 2010.

The interview index is available for download.


Colorado River Water: Mexico's Perspective On The Ongoing Negotiations, Mario López Pérez Feb 2010

Colorado River Water: Mexico's Perspective On The Ongoing Negotiations, Mario López Pérez

US-Mexico Negotiations on Improved Colorado River Management: An Update (February 19)

Presenter: Mario López, Engineering and Technical Standards Manager, National Water Commission of México

53 slides


Slides: Water For Oil (Shale)?, Bart Miller Feb 2010

Slides: Water For Oil (Shale)?, Bart Miller

The Promise and Peril of Oil Shale Development (February 5)

Presenter: Bart Miller, Water Program Director, Western Resource Advocates

10 slides


The Influence Of Nutrients And Physical Habitat In Regulating Algal Biomass In Agricultural Streams, Mark D. Munn, Jeffrey Frey, Anthony Tesoriero Jan 2010

The Influence Of Nutrients And Physical Habitat In Regulating Algal Biomass In Agricultural Streams, Mark D. Munn, Jeffrey Frey, Anthony Tesoriero

United States Geological Survey: Water Reports and Publications

This study examined the relative influence of nutrients (nitrogen and phosphorus) and habitat on algal biomass in five agricultural regions of the United States. Sites were selected to capture a range of nutrient conditions, with 136 sites distributed over five study areas. Samples were collected in either 2003 or 2004, and analyzed for nutrients (nitrogen and phosphorous) and algal biomass (chlorophyll a). Chlorophyll a was measured in three types of samples, fine-grained benthic material (CHLFG), coarse-grained stable substrate as in rock or wood (CHLCG), and water column (CHLS). Stream and riparian habitat were characterized at each site. TP ranged from …


Can R&D Investment Offset The Negative Impact Of Climate Change On Agricultural Productivity?, Nazrul Islam, Ruhul A. Salim Nov 2009

Can R&D Investment Offset The Negative Impact Of Climate Change On Agricultural Productivity?, Nazrul Islam, Ruhul A. Salim

Climate Science Published Reports

Productivity growth in agriculture helps maintain the nation's economic prosperity. However, long-run productivity growth in agriculture faces several challenges such as the potential worsening of climate due to global warming and the loss of productive land due to land use competition, salinity, wind erosion and soil acidity. Strategic policy making and appropriate funding for sustained productivity growth in agriculture is therefore crucial.

Research and development (R&D) to drive innovation is an acknowledged main source of productivity growth. The development and application of technologies generated through R&D boosts agriculture's productivity. Agricultural R&D activities in Australia and in most other developed economies …


Crop Yield Gaps: Their Importance, Magnitudes, And Causes, David B. Lobell, Kenneth G. Cassman, Christopher B. Field Oct 2009

Crop Yield Gaps: Their Importance, Magnitudes, And Causes, David B. Lobell, Kenneth G. Cassman, Christopher B. Field

Nebraska Center for Energy Sciences Research: Publications

Future trajectories of food prices, food security, and cropland expansion are closely linked to future average crop yields in the major agricultural regions of the world. Because the maximum possible yields achieved in farmers’ fields might level off or even decline in many regions over the next few decades, reducing the gap between average and potential yields is critical. In most major irrigated wheat, rice, and maize systems, yields appear to be at or near 80% of yield potential, with no evidence for yields having exceeded this threshold to date. A fundamental constraint in these systems appears to be uncertainty …


Applications And Potentials For Biogenic Methane Recovery Operations In Nebraska Agriculture, Industry, And Economic Development, David Micheal Dingman Jul 2009

Applications And Potentials For Biogenic Methane Recovery Operations In Nebraska Agriculture, Industry, And Economic Development, David Micheal Dingman

Department of Environmental Studies: Undergraduate Student Theses

ABSTRACT: This thesis report illustrates the applications and potentials of biogenic methane recovery in Nebraska’s agricultural and industrial sectors and as a means for increasing sustainable economic development in the state’s rural communities. As the nation moves toward a new green economy, biogenic methane recovery as a waste management strategy and renewable energy resource presents significant opportunities for Nebraska to be a national and world leader in agricultural and industrial innovation, advanced research and development of renewable energy technology, and generation of new product markets. Nebraska’s agricultural economy provides a distinct advantage to the state for supporting methane recovery operations …


Slides: Indian Water Rights, Robert T. Anderson Jun 2009

Slides: Indian Water Rights, Robert T. Anderson

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Robert T. Anderson, Native American Law Center, University of Washington Law School

19 slides


Slides: Status Of Southern Nevada Water Authority (Snwa): Third Intake Into Lake Mead And Groundwater Project, Kay Brothers Jun 2009

Slides: Status Of Southern Nevada Water Authority (Snwa): Third Intake Into Lake Mead And Groundwater Project, Kay Brothers

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Kay Brothers, Southern Nevada Water Authority (SNWA), Las Vegas, NV

37 slides


Slides: Northern Integrated Supply Project, Northern Front Range--Colorado, Don Carlson Jun 2009

Slides: Northern Integrated Supply Project, Northern Front Range--Colorado, Don Carlson

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Don Carlson, Northern Colorado Water Conservancy District

20 slides


Slides: Water Leasing In The Lower Arkansas Valley: The "Super Ditch Company", Peter Nichols Jun 2009

Slides: Water Leasing In The Lower Arkansas Valley: The "Super Ditch Company", Peter Nichols

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Peter NIchols, Trout, Raley, Montano, Witwer & Freeman, Denver, CO

28 slides


Slides: Finding Flows: Fish Still Need Water Everyday, Melinda Kassen Jun 2009

Slides: Finding Flows: Fish Still Need Water Everyday, Melinda Kassen

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Melinda Kassen, Director of the Western Water Project, Trout Unlimited

12 slides


Slides: Agricultural Resilience And Urban Growth: A Closer Look, William R. Travis Jun 2009

Slides: Agricultural Resilience And Urban Growth: A Closer Look, William R. Travis

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: William R. Travis, Department of Geography, Center for Science & Technology Policy Research, CIRES, University of Colorado at Boulder

30 slides


The Use Of Soil Enzyme Activities And Active Carbon As Indicators Of Soil Quality In Response To Management Practices, Tracy Marie Woodruff May 2009

The Use Of Soil Enzyme Activities And Active Carbon As Indicators Of Soil Quality In Response To Management Practices, Tracy Marie Woodruff

Student Theses and Dissertations

In order to meet the increasing needs of food, fiber, and fuel, management practices that enhance the soil health must be sought out. The two studies conducted examined the effects of management practices on soil enzyme activities and active carbon concentration. A forested ecosystem in Oregon was examined following nutrient treatments on forest plots. The effects of tillage, residue management and time on soil enzyme activities and active C were measured in a greenhouse study from the University of Arkansas in Fayetteville, AR, USA. In both studies, β-glucosidase, arylsulfatase, acid phosphatase, and active carbon were analyzed in soil samples. Results …


Soil Organic Carbon And Site Characteristics In Aspen And Evaluation Of The Potential Effects Of Conifer Encroachment On Soil Properties In Northern Utah, Mical K. Woldeselassie May 2009

Soil Organic Carbon And Site Characteristics In Aspen And Evaluation Of The Potential Effects Of Conifer Encroachment On Soil Properties In Northern Utah, Mical K. Woldeselassie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the Intermountain West, aspen (Populus tremuloides) has declined mainly due to a combination of successional processes, fire suppression and long-term use of ungulates which has led to replacement by conifers, sagebrush or other shrub communities. Conifer encroachment is believed to cause critical changes in the ecosystem properties. In order to understand the impacts of conifer encroachment on soil properties such as soil organic carbon (SOC) storage, soil morphology, and soil chemical properties, and the implications of such changes, it is very important to assess the soil properties under the two vegetation types. The objectives of this study …


Changes In Producer Attitudes Towards Windbreaks In Eastern Nebraska, 1983 To 2009, Kim Tomczak Apr 2009

Changes In Producer Attitudes Towards Windbreaks In Eastern Nebraska, 1983 To 2009, Kim Tomczak

Department of Environmental Studies: Undergraduate Student Theses

Abstract Windbreaks are rows of trees or shrubs arranged on the landscape to reduce wind speed. In agricultural landscapes we find them as farmstead windbreaks, livestock windbreaks and field windbreaks. While farmstead and livestock windbreaks are well accepted by the agricultural community, field windbreaks are often viewed differently. A 1982 study of the attitudes of farmers in Eastern Nebraska indicated that many of the producers were around the age of 50 and that they used different types of windbreaks. This study repeated that survey in the same. When compared to data from 1982, farmers today are not educated about the …


Historical Review Of Elk–Agriculture Conflicts In And Around Riding Mountain National Park, Manitoba, Canada, Ryan K. Brook Apr 2009

Historical Review Of Elk–Agriculture Conflicts In And Around Riding Mountain National Park, Manitoba, Canada, Ryan K. Brook

Human–Wildlife Interactions

Conflicts between elk (Cervus elaphus) and farmers have been occurring since the 1880s when agriculture began around what is now Riding Mountain National Park (RMNP). Initially, the conflicts were related to low elk numbers caused primarily by unregulated harvest of elk. The creation of RMNP in 1930 and the associated ban on hunting allowed elk numbers to reach critically high levels. Since farming began, elk have been associated with considerable damage to fences and crops around RMNP, with annual damage often >$240,000. Hunting on agricultural lands has been the most common approach to mitigating elk impacts, despite its limited success. …


Long-Term Agricultural Land-Use Trends In Nebraska, 1866–2007, Tim L. Hiller, Larkin A. Powell, Tim D. Mccoy, Jeffrey J. Lusk Jan 2009

Long-Term Agricultural Land-Use Trends In Nebraska, 1866–2007, Tim L. Hiller, Larkin A. Powell, Tim D. Mccoy, Jeffrey J. Lusk

School of Natural Resources: Faculty Publications

Although landscape changes from anthropogenic causes occur at much faster rates than those from natural processes (e.g., geological, vegetation succession), human perception of such changes is often subjective, inaccurate, or nonexistent. Given the large-scale land-use changes that have occurred throughout the Great Plains, the potential impacts of land-use changes on ecological systems, and the insight gained from knowledge of land-use trends (e.g., to compare to wildlife population trends), we synthesized information related to land-use trends in Nebraska during 1866–2007. We discussed and interpreted known and potential causes of short- and long-term land-use trends based on agricultural and weather data; farm …


Land Resources Series No 21 - Tambellup-Borden Area Land Resources Survey, Angela Stuart-Street, Rohan Marold Jan 2009

Land Resources Series No 21 - Tambellup-Borden Area Land Resources Survey, Angela Stuart-Street, Rohan Marold

Natural resources published reports

AGDEX 526

Land Resources Series No. 21

This report presents results from soil-landscape mapping at a scale of 1: 100,000 in the Tambellup- Borden area of Western Australia. It is accompanied by a soil-landscape map covering almost 511,000 hectares.

Most of the survey occurs within the upper Frankland-Gordon, Kent, North Stirlings Basin and upper reaches of the Pallinup and Kalgan River catchments. The survey falls within the Katanning and Albany Department of Agriculture and Food advisory districts.

Seventeen soil-landscape systems have been identified and are represented on the map on the accompanying CD-ROM. These systems have been further divided into …


Slides: Lower Arkansas Valley Super Ditch Company, Inc.: Water Leasing Program, Peter Nichols Dec 2008

Slides: Lower Arkansas Valley Super Ditch Company, Inc.: Water Leasing Program, Peter Nichols

Evolving Regional Frameworks for Ag-to-Urban Water Transfers (December 11)

Presenter: Peter Nichols, General Counsel of the Lower Arkansas Valley “Super Ditch” Company, Trout, Raley, Montano, Witwer & Freeman PC, Colorado

33 slides


Slides: Idaho Rental Pool: Rules And Procedures, Idaho Water Resource Board, Jerry R. Rigby Dec 2008

Slides: Idaho Rental Pool: Rules And Procedures, Idaho Water Resource Board, Jerry R. Rigby

Evolving Regional Frameworks for Ag-to-Urban Water Transfers (December 11)

Presenter: Jerry Rigby, Counsel for Fremont‐Madison Irrigation District, Rigby, Thatcher, Andrus, Rigby & Moeller, Idaho

25 slides


Agenda: Evolving Regional Frameworks For Ag-To-Urban Water Transfers, University Of Colorado Boulder. Natural Resources Law Center, Western Water Policy Program, Western Water Assessment (Program), Red Lodge Clearinghouse Dec 2008

Agenda: Evolving Regional Frameworks For Ag-To-Urban Water Transfers, University Of Colorado Boulder. Natural Resources Law Center, Western Water Policy Program, Western Water Assessment (Program), Red Lodge Clearinghouse

Evolving Regional Frameworks for Ag-to-Urban Water Transfers (December 11)

The permanent transfer of water from agricultural users to municipalities has become a common feature of water management in several western states. In many cases, these voluntary market‐based transfers provide significant benefits to both the buyers and sellers, but many third parties—including remaining irrigators, rural businesses and communities dependent upon agricultural economies—have been negatively impacted. While some impacts of these so‐called “buy and dry” transfers are largely unavoidable, many can be lessened by temporary arrangements that only shift water to cities in years when municipal supplies are inadequate, such as drought and post‐drought storage recovery, and by consolidating individual farm‐to‐city …


Slides: Pvid/Mwd Land Management, Crop Rotation And Water Supply Program, Ed Smith Dec 2008

Slides: Pvid/Mwd Land Management, Crop Rotation And Water Supply Program, Ed Smith

Evolving Regional Frameworks for Ag-to-Urban Water Transfers (December 11)

Presenter: Ed Smith, General Manager, Palo Verde Irrigation District, Southern California

25 slides


Hydrological Characterization Of A Riparian Vegetation Zone Using High Resolution Multi-Spectral Airborne Imagery, Osama Zaki Akasheh Dec 2008

Hydrological Characterization Of A Riparian Vegetation Zone Using High Resolution Multi-Spectral Airborne Imagery, Osama Zaki Akasheh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Rio Grande River (MRGR) is the main source of fresh water for the state of New Mexico. Located in an arid area with scarce local water resources, this has led to extensive diversions of river water to supply the high demand from municipalities and irrigated agricultural activities. The extensive water diversions over the last few decades have affected the composition of the native riparian vegetation by decreasing the area of cottonwood and coyote willow and increasing the spread of invasive species such as Tamarisk and Russian Olives, harmful to the river system, due to their high transpiration rates, …


Optimal Irrigation Management For Sloping, Blocked-End Borders, Jorge Jose Escurra Dec 2008

Optimal Irrigation Management For Sloping, Blocked-End Borders, Jorge Jose Escurra

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A robust mathematical model of one-dimensional flow for sloping, blocked-end border irrigation was developed using the four-point implicit method to solve the Saint-Venant equations, the volume-balance solution method, and the implementation of new algorithms to avoid numerical instability and solution divergence. The model has the capability of successfully simulating all surface irrigation phases in blocked-end borders for a range of inflow rates (0.01 - 0.05 m3/s per m), longitudinal slopes (up to 1.00%), and border lengths (100 - 500 m).

To achieve numerical stability over the specified parameter ranges, the model was divided into three parts: (1) advance-phase …


Non-Blackbird Avian Occurrence And Abundance In North Dakota Sunflower Fields, Dionn A. Schaaf, George M. Linz, Curt Doetkott, Mark W. Lutman, William J. Bleier Sep 2008

Non-Blackbird Avian Occurrence And Abundance In North Dakota Sunflower Fields, Dionn A. Schaaf, George M. Linz, Curt Doetkott, Mark W. Lutman, William J. Bleier

The Prairie Naturalist

Sunflower fields are well-documented as foraging habitat for fallmigrating blackbirds (Family Icteridae). There is, however, a paucity of information on the use of sunflower fields by non-blackbirds. We assessed non-blackbird use of 12 ripening sunflower fields in the Prairie Pothole Region of central North Dakota. From mid-August to mid-October 2000, we counted 4,129 individual birds, consisting of 22 families and 61 species, in the sample fields and within 5 m of the field edges. We saw the largest number of birds from 18 September to 27 September. The Family Emberizidae (sparrows) accounted for 26% of the species and 20% of …


Effects Of Global Irrigation On The Near-Surface Climate, William J. Sacks, Benjamin I. Cook, Nikolaus Buenning, Samuel Levis, Joseph H. Helkowski Jul 2008

Effects Of Global Irrigation On The Near-Surface Climate, William J. Sacks, Benjamin I. Cook, Nikolaus Buenning, Samuel Levis, Joseph H. Helkowski

United States National Aeronautics and Space Administration: Publications

Irrigation delivers about 2,600 km3 of water to the land surface each year, or about 2% of annual precipitation over land. We investigated how this redistribution of water affects the global climate, focusing on its effects on near-surface temperatures. Using the Community Atmosphere Model (CAM) coupled to the Community Land Model (CLM), we compared global simulations with and without irrigation. To approximate actual irrigation amounts and locations as closely as possible, we used national-level census data of agricultural water withdrawals, disaggregated with maps of croplands, areas equipped for irrigation, and climatic water deficits. We further investigated the sensitivity of …