NU Water-Related Research in Dawes County

The purpose of this study was to review and analyze the entire universe of relatively recent agricultural real estate activity in the multi-county, Panhandle Region of Nebraska. This region - Banner, Box Butte, Cheyenne, Dawes, Deuel, Garden, Kimball, Morrill, Scotts Bluff, Sheridan, and Sioux counties - was chosen because of the widely-held perception that a considerable number of acquisitions in recent years were by absentee owners. By investigating all recorded agricultural land transfers (filed in public records) for the period 2003 through the first half of 2006, we were able to identify the true characteristics of the market and analyze the associated implications.

This multi-year study of the market for agricultural real estate properties in the Nebraska Panhandle region provides a solid perspective of the market. Among the key findings were:

• The rate of ownership turnover of agricultural holdings in the Nebraska Panhandle region is very thin, averaging less than 2 percent per year over the study period.
• Out-of-state buyers have a strong presence in the agricultural land market of the region, acquiring more than half of the transferred agricultural land.
• While out-of-state market participants were quite active on the buyer side of the market, they were also quite active on the seller side of the market. In fact, for every10 acres purchased by this group, they sold nearly 13 acres; thus leading to a net decrease in this group’s holdings of some 70,000 acres (equivalent to about one percent of the region’s total agricultural base). In short, there is no evidence to suggest a major shift in land tenure towards out-of-state owners.
• There are a variety of reasons for acquiring agricultural land, and this was certainly in evidence in this study. Moreover, the primary reasons tended to show marked differences across the buyer classes. Among the out-of-state buyer group, investment was reported as the primary reason for purchase. In contrast, local buyers most frequently reported expansion (of existing property holdings) as their primary motive.
• The overall dynamics of the market for agricultural real estate in the Panhandle area of the state show eclectic market conditions - markets no longer limited to local participants, but, instead, markets with a heavy presence of individuals from around the region and state and beyond. In turn, the motivations for buying and selling in the current market environment are highly variable, and are likely to remain so.

Winter wheat, long a mainstay of dryland agriculture in the Panhandle, is being grown on a growing number of irrigated fields because it will grow under limited irrigation and wheat prices have risen to cover irrigation costs. Nonetheless, limited irrigation and increasing fertilizer prices mean producers need to sharpen their management skills. Research is proving that soil testing, timing fertilizer applications and managing application rates are all very important to growing winter wheat.

Preliminary data from this research shows top yields come when one third of the fertilizer is applied in the fall and two-thirds at boot stage. Maximum yields have been produced when the amount of residual nitrogen in the top four feet of soil, along with the applied fertilizer, totals 200-210 pounds of nitrogen per acre. Top nitrogen rates to maximize yield have not been higher than 100 pounds per acre, which is lower than commonly used to produce high yields. These recommendations for white wheat should also apply to hard red wheat.

The Panhandle Research and Extension Center, located in the heart of western Nebraska in Scottsbluff, houses 19 faculty with appointments in agriculture and family and consumer science through the University of Nebraska-Lincoln. Most of the faculty hold joint appointments in research and extension. The Cooperative Extension program in a 17-county area of the Panhandle and north-central Nebraska is also administered at the Center.

The University of Nebraska-Lincoln has had a presence in western Nebraska for over 85 years. In 1909, the University of Nebraska Experiment Station and the USDA jointly homesteaded a quarter section of land five miles east of Mitchell. Initial research was in the area of crop production under gravity irrigation. Research emphasis increased and soon included studies in sheep, swine, dairy, and beef production, in addition to many other crop areas. The 800 acre Experimental Range in Sioux County was deeded to the University of Nebraska by President Woodrow Wilson in 1918. Satellite agricultural laboratories at Alliance and Sidney, Nebraska were added in 1967. Through a fortunate set of circumstances, the headquarters of the Panhandle Station moved to the former Hiram Scott College campus after the state had acquired the property after the school closed in the early 1970s. The headquarters and surrounding research plots are located just north of the city of Scottsbluff. To reflect the University's involvement throughout the Panhandle, the name was officially changed to the Panhandle Research and Extension Center in 1985. The addition of the Learning Center, a joint effort of the Division of Continuing Studies and Cooperative Extension, in 1987 significantly enhanced the educational opportunities for western Nebraska residents.

Limited irrigation and no-till cropping systems are the focus of an extension project for the Pumpkin Creek Watershed which has a yearly NRD allocation of 12-inches for well irrigation. The project objectives are to: 1) demonstrate limited irrigation and no-tillage cropping systems to maximize groundwater supplies, and 2) educate area producers, local government and agricultural businesses about different management scenarios. Drought over the past eight years has magnified the problems associated with declining ground water in Pumpkin Creek and the High Plains Aquifer and maintaining profitable agriculture while protecting surface and ground water supplies is a complex issue. The demonstration project has shown producers that they can manage with less water, but they must adapt to new cropping and no-till systems and irrigation management techniques.

June 4, 2010 CropWatch Article

Project presentation by Gary Stone at the 2008 Water Colloquium

The use of ground water, especially for irrigation, is becominng regulated in Nebraska, in response to several factors:

• Recurrent droughts across the High Plains and Inter-Mountain West have magnified the problem of declining ground water resources. The High Plains Aquifer (HPA), often referred to as the Ogallala aquifer, underlies Nebraska, Colorado, Kansas, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Nearly 30% of the ground water used for irrigation in the United States is extracted from the HPA. A significant proportion of the aquifer underlies Nebraska. In the North Platte Basin, the drought has resulted in reduced surface water deliveries, which in turn has led to less ground water recharge and declining water tables.
• Nebraska ground water law has evolved. Ground water levels began declining in some parts of Nebraska after extensive irrigation development began in the 1960s. LB108 in 1996 recognized the relationship between ground and surface water, and LB962 (2004) provided new regulatory measures for integrated management of ground water and surface water. Natural resources districts (NRDs) have adopted allocations for ground water pumping in some areas. The North Platte NRD has established ground water allocations of 12 acre-inches in the Pumpkin Creek Basin and 18 acre-inches in the North Platte Valley for 2009. New or expanded ground water uses are prohibited throughout the NRD unless they are offset with transfers of existing uses.

The goal of this project is to develop the expertise in remote sensing image acquisition and computing, using the METRIC(tm) procedure; to produce area-specific consumptive water use (CWU) maps; and to develop, test and demonstrate the tools that will take these CWU maps and turn them into immediately usable products for planning, managing and regulating groundwater. The CWU maps will be the primary product of this project. They are developed from LANDSAT images by applying Mapping EvapoTranspiration with High Resolution and Internalized Calibration (METRIC(tm)) algorithms.

This report describes the relationship between the geology and the groundwater supplies in Box Butte County. It also evaluates the aquifers with respect to waterbearing characteristics and groundwater in storage. It further describes recharge to and discharge from the aquifers, outlines the movement of groundwater in the county, and summarizes the changes in groundwater storage that have occurred since the advent of irrigation in the county. Brief descriptions of the topography and drainage are included. An evaluation of climatic data for Box Butte County and the Nebraska Panhandle is incorporated into this report and several observations are made about climate in relation to groundwater and the irrigation requirements of crops. Brief mention is made of the soils and agricultural activity in the county.

The report estimates that to date (1975-1976) the amount of groundwater in storage has decreased 2-3% since 1938 and perhaps 1/2 of this decrease has occurred since 1964. The most serious water level declines were immediately north of Alliance in an area where the groundwater resource is large. This area had the highest concentration of irrigation wells and is also the oldest irrigated part of the county.

The report explicitly does not answer the question, "How long will the water supply last?" Rather the authors make the point that economic considerations and social attitudes are just as important as the characteristics of local groundwater supplies in answering that question.

The main objective of these studies was to determine the effect, if any, of large-scale regional pumping on the base flow of the Niobrara River. One study involved the construction and implementation of a groundwater-flow model for Box Butte County and the surrounding region to simulate hydrogeologic and hydraulic conditions, including groundwater extraction by large-capacity wells. The other study focused on the upper reaches of the Niobrara River to obtain estimates of stream-bed hydraulic conductivity (i.e., the ease with which water can move through pore spaces or fractures in the stream-bed) to be used as input to the modeling effort.

The groundwater-flow model was calibrated to predevelopment by primarily adjusting recharge flux through a trial-and-error process until a reasonable fit was obtained to the observed water table configuration of 1938. Once calibrated to predevelopment heads, transient simulations (i.e., simulations taking into account real-life conditions, thus modeling potential real-life changes in the basin), were run to model the change in heads due to pumping for the time period between 1938 and 2005. Results from these simulations were compared with observed heads for available years. After satisfactory results were obtained from the transient simulations, two additional scenarios were tested. These were simulations where all wells were turned off and where only those wells in Box Butte County and its proximity were active. The computer program ZONEBUDGET, which computes the water budget for user-defined zones, was run coincident with all simulations. Both head and water budget computation results were then used to determine the effect of pumping on the base flow the Niobrara River.

Based on model results, reductions in the base flow of the Niobrara River is due primarily to localized pumping effects, rather than from groundwater extraction on a regional scale. A comparison of simulated outflow values for selected reaches of the Niobrara River indicates that 1) flow characteristics in the uppermost part of the basin did not change greatly over the period of pumping indicating that base flow is not significantly reduced by large-scale pumping, 2) significant changes in base flow appear to have occurred after about 1960 in the middle and lower reaches, 3) the maximum change in flow for the middle reach due to all wells pumping is 19.6% and only 4.4% for Box Butte wells, with both maximum reductions occurring at the end of the 2005 pumping season, 4) the maximum change in flow for the lower reach is about 24.4% for all wells and only 2.5% for Box Butte wells, again, both occur at the end of the 2005 pumping season. Overall, the Niobrara River appears to be a gaining stream along most of its flow path, with the exception of the uppermost part of the basin.

The conclusion is that the affects of large-scale regional pumping appears to not impact base flow in the Niobrara River to any significant degree. Rather, localized pumping, especially where irrigation wells are situated near the river, reduces base flow on the order of 20% to 25%. For the most part, the Niobrara River valley is somewhat isolated from the extensive pumping taking place in Box Butte County. The upper reach is sufficiently distant from the pumping center that the cone of depression has little effect on the water table. Much of the middle reach transects units of the White River group that are considered to be nearly impermeable, and thus, provide a hydrogeologic barrier, preventing the northward expansion of the cone of depression. Pumping along the lower reach of the Niobrara River has a much greater influence on base flow reduction simply due to the proximity of the extraction wells to the river.

This research explores variability in lake salinity in the Sand Hills, which is the largest vegetated sand dune field in the western hemisphere. Numerous lakes occur in topographic depressions under west-east regional groundwater flow. In Sheridan and Garden counties alone there are approximately 400 lakes with surface areas larger than 4 hectare. The concentration of total dissolved solids in lake water ranges from fresh to very saline (three times higher than the ocean salinity). At the same time, the groundwater is fresh. Although several hypotheses are available, causes of wide salinity variations within this large area have not been determined conclusively. Geographically, this project is focused on Crescent Lake National Refuge area and the vicinities.

Understanding salinization mechanisms will explain climate effects on lake salinity and the potential for their existence in the Sand Hills. In addition, results can be utilized for detection and prediction of the consequences of deposition of saline or contaminated water over shallow freshwater aquifers in environmental disasters, such as hurricanes (e.g., Mississippi and Louisiana, U.S., 2005), tsunamis (e.g., Indonesia, Bangladesh in 2005), and large-scale land salinization (e.g., Murray Basin, Australia).