NU Water-Related Research in Jefferson County

The list below shows water-related research being conducted within your district or that affects your district. They are sorted by water topic, then by primary contact's last name.

Displaying 10 records found for Jefferson County


Topic Crop Water Use
Project's Primary Contact Information
Name Bernards, Mark
Unit Agronomy and Horticulture
Email mbernards2@unl.edu
Phone 402-472-1534
Web Page http://agronomy.unl.edu/bernards
Project Information
Title Water Use of Winter Annual Weeds
Other(s) Suat Irmak, Biological Systems Engineering, sirmak2@unl.edu 
Description

This study examines the water use of winter annual weeds. More winter annual weeds grow now than 20 years ago because of the adoption of reduced tillage systems, where the soil is not disturbed between harvest and planting. Winter annuals typically germinate in the fall, overwinter as small plants, and grow rapidly as temperatures warm in the spring; these weeds are especially well adapted to limited summer rainfall. Common winter annuals in Nebraska are downy brome, henbit, field pennycress, wild mustard, marestail (horseweed), foxtail barley, shepherdspurse, speedwell, and prickly lettuce. This project is investigating whether allowing winter annual weeds to grow too long in the spring depletes the soil of moisture that would benefit the crop later in the summer.

Estimated potential nitrogen immobilization by winter annual weeds may be calculated as:

  • 500 lbs/ac of winter annual biomass growth at planting time (this would be a relatively dense, uniform stand of weeds).
  • As a general statement, nitrogen composes approximately 3% of plant biomass.
  • $0.58/lb of nitrogen fertilizer (based on $950/ton of anhydrous ammonia)

Based on these assumptions, a dense, uniform stand of winter annuals could tie up approximately 15 lb of nitrogen per acre (500 x 0.03), or $8.70 per acre (15 x 0.58) of nitrogen intended for a corn crop.

Estimating the irrigation cost to replace water used by the same 500 lbs/A of winter annual biomass by assuming:

  • 500 lbs/A of winter annual weed biomass at planting time,
  • 800 lbs of water is required to produce 1 lb of winter annual weed biomass.
  • At $2.50 diesel fuel, applying 1 inch of irrigation water per acre would cost $9.66.

The 500 lbs of winter annual biomass would use 400,000 lbs of water per acre (500 x 800), or 47,920 gallons of water (400,000 lb x 0.1198 gal/lb). This equals 1.75 acre inches of soil water (47,920 gal /{27,158 gal/acre in}) used by these weeds. Based on a cost of $9.66 to apply 1 inch of irrigation water, it would cost approximately $17.00 per acre to replenish the water used by winter annual weeds in this scenario.

Project Support n/a
Project Website http://weedscience.unl.edu/
Report
Current Status Completed
Topic Extension
Project's Primary Contact Information
Name Irmak, Suat
Unit Biological Systems Engineering
Email sirmak2@unl.edu
Phone 402-472-4865
Web Page http://bse.unl.edu/sirmak2
Project Information
Title South Central Agricultural Laboratory - Crop Water Use Research
Description

The South Central Agricultural Laboratory is a University of Nebraska research farm located about 15 miles east of Hastings immediately south of Highway 6. The primary focus of this farm is the development and refinement of irrigated crop production practices for Nebraska agriculture and beyond. A number of research projects are currently underway on site and in conjunction with producers in the region.

  1. Crop water use efficiency, nitrogen use efficiency, and best irrigation and fertigation management practices for subsurface-irrigated corn and soybeans.
  2. Measurement of soil evaporation under no-till, conventional (disk) till, and ridge till practices for corn using frequency-domain reflectometers under three irrigation frequencies and five irrigation levels for corn.
  3. Development of best deficit irrigation management strategies for soybeans.
  4. Center pivot irrigation engineering and evapotranspiration research: measurement of crop coefficients, evapotranspiration, and yield of corn under deficit irrigation settings.
  5. Measurement of crop water use and crop water use efficiency of eight corn hybrids under full and deficit irrigation and dryland settings.
  6. Measurement of maximum allowable crop water stress that can be imposed on corn, stress versus crop growth-yield- and available soil water relationships.
  7. Crop canopy temperature measurements to quantify crop water stress index for corn and soybeans.
  8. Measurements of hydraulics and uniformity coefficients, crop water use efficiency of a new low pressure irrigation system for soybeans.
  9. Measurement of energy fluxes and crop coefficients using high frequency techniques such as Bowen ratio energy balance system and Eddy covariance system to provide improved evapotranspiration data for corn, soybeans, and natural grassland.
  10. Measurement of non-growing (dormant season) evaporative losses to quantify annual evaporation and other water balance components.
  11. Operational characteristics of atmometers (ETgage) to measure reference evapotranspiration and Watermark granular matrix sensors to monitor soil water status and their practical applications and demonstrations for effective irrigation management.
  12. Rootworm pressure effect on crop water uptake under center pivot irrigation.
  13. On-farm demonstration of limited irrigation strategies for making maximum use of water resources. The project is being conducted in partnership with the NRCS and Nebraska Corn Board in Hordville, Geneva, York, Edgar, Ord, West Point, Schuyler, and Mead in grower fields.
Project Support Varies according to program and project
Project Website http://scal.unl.edu/
Report
Current Status Continuous
Topic Extension
Project's Primary Contact Information
Name Skipton, Sharon
Unit Southeast Research and Extension Center
Email sskipton1@unl.edu
Phone 402-472-3662
Web Page http://www.southeast.unl.edu/staffdir/Skipton_Sharon
Project Information
Title Southeast Research and Extension Center
Other(s) Gary Zoubek, York County Extension, gzoubek@unl.edu 
Description Each day University of Nebraska Extension makes a difference in the lives of adults and youth. The faculty and staff in the Southeast Research and Extension Center and the 28 County Offices work to bring relevant researched based information to people in communities, towns and urban centers. Our efforts rely increasingly on partnerships with government agencies, business, industry, schools and community organizations. Working together with our partners Extension strives to strengthen the social, economic and environmental base of Nebraska's communities. Our programs must be ever-changing as Extension listens and responds to issues as they evolve. The Southeast Research and Extension District is unique because it serves both urban and rural communities Nebraska. The faculty and staff are committed to bringing the resources of the University and its research based information to the individuals and communities of Southeast Nebraska.
Project Support Varies according to program and project - for more information see http://www.southeast.unl.edu/
Project Website http://www.southeast.unl.edu/
Report
Current Status Continuous
Topic Hydrology
Project's Primary Contact Information
Name Chen, Xun-Hong
Unit School of Natural Resources
Email xchen2@unl.edu
Phone 402-472-0772
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=19
Project Information
Title Groundwater Flow Model for Franklin County
Description

Dr. Chen conducted a pumping test in the alluvial aquifer near Bloomington and streambed tests in the Republican River channel. This data was used to develop a groundwater flow model in Franklin County to simulate the impact of groundwater pumping on stream flow.

Project Support n/a
Project Website
Report
Current Status Completed
Topic Hydrology
Project's Primary Contact Information
Name Chen, Xun-Hong
Unit School of Natural Resources
Email xchen2@unl.edu
Phone 402-472-0772
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=19
Project Information
Title Hydrologic Connections in the Big and Little Blue River Basins
Other(s) Cheng Cheng, School of Natural Resources, ccheng2@unl.edu 
Description Over extraction of groundwater near a stream can lower stream stage and induce streamflow depletion when the stream and aquifer are hydrologically connected. The Little Blue River Basin is an area of intensive groundwater development for irrigation, and the streamflow depletion in this basin was determined by an analog model (Emery, 1966). However, the post audit of the model (Alley and Emery, 1986) suggested that the decline of water-levels was overestimated and streamflow depletion was underestimated. Therefore, it is necessary to re-evaluate stream-aquifer interactions in the basin. In this study, an area is chosen for this analysis from the basin and three main streams -- the Little Blue River, Big Sandy Creek, and Spring Creek are included. Channel sediments and structures play an important role in determining stream-aquifer interactions. Firstly, field and laboratory methods including geoprobe logging and permeameter tests are utilized to investigate the channel deposits in the three main streams in the Little Blue River Basin. Results show that channels have low hydraulic-permeable layers which reduce their hydraulic connections to the adjacent aquifers. Secondly, a groundwater flow model is constructed to identify the hydraulic properties of the aquifer and evaluate streamflow depletion under groundwater withdrawals in the study area. Modeling results indicate that streamflow depletion is very low and aquifer storage loss is the main source of groundwater pumpage.
Project Support Upper Big Blue Natural Resources Distrect, Lower Big Blue Natural Resources District, Little Blue Natural Resources District
Project Website
Report
Current Status Completed
Topic Production Agriculture
Project's Primary Contact Information
Name Burbach, Mark
Unit School of Natural Resources
Email mburbach1@unl.edu
Phone 402-472-8210
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=268
Project Information
Title Personality Characteristics and Conservation Tillage: Understanding Farmers to Improve Surface Water Quality in Tuttle Creek Lake, Kansas
Other(s) Courtney Quinn 
Description

Farmers chose to adopt conservation practices for varying reasons. There are many models of pro-environmental behaviors that include personal, physical, economic, and institutional factors. Models of farmer behavior that include personal factors often only examine farmers' education level and years farming. Testing additional factors would greatly improve our understanding of the relationship between farmers' knowledge, skills, and abilities and conservation tillage. This study examines three potential variables in relation to farmers' conservation tillage practices that benefit surface water quality, environmental attitude, work motivation, and moral reasoning about the environment.

This study focused on the Tuttle Creek Watershed, specifically Gage and Jefferson counties in southeast Nebraska and Washington and Marshall counties in northeast Kansas. Land use in this watershed is primarily agricultural, with approximately 72% in corn, soybean, grain sorghum or other crops, 10% in pastureland, and 10% in woodland. Herbicides are used extensively to control agricultural weeds. Soil infiltration rates in this area range from moderate to very slow. As a consequence, most soils have a moderate to very high potential of transporting contaminants to surface waters. As the base of the watershed, Tuttle Creek Reservoir is listed as impaired for siltation, eutrophication, atrazine and alachlor. Extremely high suspended solids and nutrient loads enter the reservoir during storm events and excessive siltation has occurred in the upper third of the original conservation pool reducing its volume by approximately 30%. In November 2007 4000 mail surveys were delivered to farmers in the study area. Data on the farmers' tillage practices and the personality variables, hypothesized to be antecedents to tillage practices, were collected. 505 surveys were used for this analysis.

Survey results suggest that farmers motivated by tangible rewards, personal standards, and a strong sense of purpose are likely to use conservation tillage. Farmers who obtained a higher degree of education have learned either a concern for the environment or the ability to apply newer conservation technologies. Farmers with higher sales also use more conservation practices. This suggests that income allows farmers to implement practices that may have high initial start-up costs. Farmers who earn a high percentage of their family income from farming also use more conservation practices. A heavy dependence on the success of the farm may cause farmers to have a long-term outlook and see the benefits of using conservation.

The negative relationship between use of conservation tillage and Self-concept External motivation suggests that efforts to encourage adoption of no-till practices need to target the entire farming community. The negative correlation between age and use of conservation tillage and between years farming and use of conservation tillage suggests than younger farmers, and those who have been farming for fewer years, are more interested and willing to use conservation practices. This may be because younger farmers have grown up during a time of concern for the natural environment. Younger farmers may also be less set in their ways and therefore willing to try new practices.

Other personal characteristics should be studied in addition to those studied as part of this project. For example, researchers should investigate whether farmers experience empathy with downstream residents and the distance of concern farmers consider when making decisions. Farmers' need for control, and their perceived ability to create desired change should be researched to discover if correlations or causations exist with likelihood to use conservation tillage.

Project Support USDA
Project Website
Report Burbach_Personality.pdf
Current Status Published in Great Plains Research 2008 Vol. 18:1, 103-114
Topic Water Quality
Project's Primary Contact Information
Name Gitelson, Anatoly
Unit Center for Advanced Land Management Information Technologies
Email agitelson2@unl.edu
Phone 402-472-8386
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=39
Project Information
Title Using Remote Sensing to Detect the Threat of Blue-Green Algae
Description

Remote sensing is a useful tool for providing regulatory officials with the data necessary to make decisions regarding recreational waters. In 2005, CALMIT scientists undertook a collaborative effort with the Nebraska Department of Environmental Quality aimed at developing a tool to identify lakes where blue-green algae populations are present. The overall purpose was to incorporate those affected lakes into a toxic-algae alert procedure to provide early warnings to the public about the potential danger. This project also served to promote coordination and information sharing about toxic-algae issues among local units of government, lake associations, lake owners, and the public.

Both in-situ (close-range) and remote techniques were employed to detect and quantify in real-time the algal phytoplankton pigment concentration and composition (i.e., chlorophyll-a and phycocyanin in the water column). Two criteria were used to identify lakes and reservoirs with high probability of toxic algae: 1) chlorophyll concentration above 50 mg/m3; and 2) existence of blue green algae (the phycocyanin absorption feature has been used to indicate remotely the presence of blue-green algae). These criteria were tested by analytical assessment of toxic algae and the tests were positive: when the sensor systems indicated high probability of toxins, they were found in water samples.

Project Support Nebraska Department of Environmental Quality
Project Website http://www.calmit.unl.edu/research.php
Report
Current Status Completed
Topic Water Quality
Project's Primary Contact Information
Name Shea, Patrick
Unit School of Natural Resources
Email pshea1@unl.edu
Phone 402-472-1533
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=109
Project Information
Title Model to Identify Watershed Vulnerability and High Impact Programs
Other(s) Maribeth Milner, Agronomy and Horticulture, mmilner1@unl.edu; Gary D. Lynne, Agricultural Economics, glynne1@unl.edu; Mark E. Burbach, Conservation and Survey Division, mburbach1@unl.edu; Mark Bernards, Agronomy and Horticulture, mbernards2@unl.edu. 
Description

To protect water quality we need to better forecast environmental risks and guide conservation management decisions. Watershed vulnerability is determined by physical setting (soil, topography, and climate) and land management practices. If the most vulnerable areas can be determined, fields within those areas can be targeted for conservation management and mitigation of contamination. A model using the Soil Survey Geographic (SSURGO) Database is being developed to identify vulnerable areas and determine the potential impact of management practices on agrichemical runoff and leaching within impaired watersheds in Nebraska, Kansas, Missouri, and Iowa. Saunders County, NE is the primary site for development of the model, which will be applied in the Blue River watershed (Jefferson and Gage Counties in NE and Washington and Marshall Counties in KS).

To implement effective conservation practices it is necessary to understand what motivates the behaviors of producers and land managers. A survey tool will be used to determine what motivates the behaviors of producers and land managers in choosing practices and technologies in vulnerable areas. As part of this survey tool, an upstream individual's capacity and willingness to empathize with downstream water users about the quality and quantity of the water in Tuttle Creek Lake will be measured (see Cornhusker Economics article.) A statistical model will predict responsiveness to change and decision typologies will be mapped. A behavioral assessment model will be applied to selected areas upstream of Tuttle Creek, KS to predict the probability that producers and land managers will adopt the technologies and practices associated with total maximum daily load (TMDL) recommendations, as well as the extent of adoption. The information gained in this project can be used to design policy, incentive structures, and educational programs leading to the adoption of conservation management practices that improve and protect water quality.

Project Support USDA-CSREES National Integrated Water Quality Program.
Project Website http://www.agecon.unl.edu/Cornhuskereconomics/2008/8-20-08.pdf
Report Empathy Conditioned Conservation 1 14 09.pdf
Current Status Continuous
Topic Water Quality
Project's Primary Contact Information
Name Tang, Zhenghong
Unit Architecture
Email ztang2@unl.edu
Phone 402-472-9281
Web Page http://architecture.unl.edu/people/bios/tang_zhenghong.shtml
Project Information
Title Assessment of Sedimentation and Water Quality Conditions in the Rainwater Basin's Playa Wetlands
Other(s) Mark Kuzila, School of Natural Resources, mkuzila1@unl.edu; Xu Li, Department of Civil Engineering, xuli@unl.edu; Amy Burgin, School of Natural Resources, aburgin2@unl.edu 
Description

The overall goal of this project is to prioritize watershed restoration/acquisition programs in the Rainwater Basin (RWB) by examining playa wetlands’ sedimentation and water quality conditions using the Revised Universal Soil Loss Equation 2 (RUSLE2) and the fly ash technology.

Three specific tasks are included in this project:

  1. Calculate and map the sedimentation rates and the age of deposition for all playa wetlands in RWB
  2. Consolidate existing water quality data of the RWB playa wetlands and evaluate the key factors influencing playa wetland water quality
  3. Assess the effects of sedimentation control practices and prioritize future watershed restoration/acquisition programs

The final products of this project include:

  1. An atlas of wetland sedimentation maps and a risk report highlighting the areas in watersheds with the highest sedimentation rates
  2. A geodatabase and an evaluation report on the water quality conditions of the playa wetlands in the RWB
  3. A written assessment report for sedimentation control practices and a watershed index to prioritize future conservation/acquisition programs
Project Support U.S. Environmental Protection Agency
Project Website http://www.unl.edu/playawetlands/
Report
Current Status Underway
Topic Watershed Project
Project's Primary Contact Information
Name Shea, Patrick J.
Unit School of Natural Resources
Email pshea1@unl.edu
Phone 402-472-1533
Web Page http://snr.unl.edu/aboutus/who/people/faculty-member.asp?pid=109
Project Information
Title Application of Landscape Vulnerability Models to Assess Off-Site Pesticide Movement in a Nebraska-Kansas Watershed
Other(s) Maribeth Milner, Agronomy and Horticulture, mmilner1@unl.edu; Mark Bernards, Agronomy and Horticulture, mbernards2@unl.edu; Phil Barnes, Biological and Agricultural Engineering, Kansas State University, lbarnes@ksu.edu 
Description

Some landscape positions are more likely than others to contribute to ground and surface water contamination from agricultural inputs and management practices. By identifying these areas at a regional scale, resources can be optimally targeted to address potential problems at the field scale. We developed SSURGO (Soil Survey Geographic)-based models to assess vulnerability to pesticide contamination of ground or surface waters across the landscape. Upon application of the models to a four-county (NE-KS) study area (Blue River Basin), between-county discontinuities emerged. Each county soil map is based on the particular expression of soil-forming factors as interpreted by local mapping teams, but these teams may or may not have input on the mapping of adjacent counties. Soil map units are typically blended across county boundaries, but these changes will not correct fundamental differences in the models used to create soil maps. The discontinuities in our study area may be due to an end moraine that cuts northwest to southeast (predominantly through the western counties), differences in mapping dates (1975-2003), and variations in data interpretation by agencies in Kansas and Nebraska. By incorporating slope and slope length data generated from relatively high resolution 10 m DEMs (digital elevation models), we increased sensitivity to topography at the SSURGO polygon level. Model output between the SSURGO-based and the DEM-based topographic data differed substantially for the eastern glaciated counties, but were relatively similar for the western counties. Assuming that the DEM is correct, this suggests a lack of consistency in defining the SSURGO representative slope and (or) slope lengths among counties. Although discontinuities occur between counties, model output can be used to identify the most vulnerable areas within each county. Model utility is demonstrated by comparing model output with surface water quality measurements in the watershed.

Maps resulting from our models show relative landscape vulnerability to pesticide leaching and runoff. This information can be used to prioritize and target areas within a watershed for conservation management practices and other actions that will reduce contamination of water resources and improve water quality. We applied the models to a four-county NE-KS study area (Big Blue Basin) and propose solutions to discontinuities between counties resulting from variations in data intepretation due to differences in mapping teams and dates. We use surface water quality measurements to show the utility of our models.

Project Support USDA-CSREES National Integrated Water Quality Program.
Project Website http://www.usawaterquality.org/conferences/2009/PDF/Wshed-poster/Shea09.pdf
Report
Current Status Continuing