Texas High Plains Initiative for Strategic and ... - Wiley Online Library

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Universities Council on Water Resources

Journal of Contemporary Water Research & Education Issue 151, Pages 43-49, August 2013

Texas High Plains Initiative for Strategic and Innovative Irrigation Management and Conservation Justin Weinheimer1, Phillip Johnson2, Donna Mitchell2, Jeff Johnson2, and Rick Kellison2 1

United Sorghum Checkoff Program, Lubbock, TX; 2 Texas Tech University, Lubbock, TX

Abstract: The strategic management of irrigation applications to improve water-use efficiency and meet economic objectives has been identified as a key factor in the conservation of water resources in the Texas High Plains region. Two field level demonstration projects have been ongoing in the Texas High Plains to evaluate advantages and disadvantages of irrigation water conservation methods. Since 2010, the North Plains Groundwater Conservation District has evaluated corn production using 12 acre-inches or less of applied irrigation water with a goal to produce 200 bushels per acre. In the South Plains, the Texas Alliance for Water Conservation (TAWC) has worked directly with 24 producers in Hale and Floyd Counties on 29 sites over the past seven years to monitor water use, soil moisture, crop productivity and economic returns on various cropping systems on over 4,000 acres. Both of these demonstration projects take an innovative approach to strategic irrigation management that uses new technologies with an overall goal to practice water conservation while maintaining economic profitability. Keywords: Irrigation management, water conservation, Ogallala

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he Texas High Plains is one of the most productive agricultural regions in the world. Fertile soils, favorable growing conditions and irrigation water from the Ogallala aquifer has allowed the Texas High Plains to become an important food and fiber production region in the Southern Great Plains. Crop production plays a crucial role in the Texas High Plains economy and provides the economic engine for the region. There are 13.5 million acres of cropland in the Texas High Plains, of which 4.6 million acres are irrigated (Farm Service Agency 2008). Recent estimates indicate that 5.6 million acre-feet of water is pumped annually for irrigation. This accounts for approximately 93 percent of the region’s total water use and is based on recent estimates from the Texas regional water planning groups “A,” located in the Panhandle, and “O,” located in the South Plains (Texas Water Development Board 2012a). More than 25 crops are commercially produced in the area with corn, cotton, grain sorghum, and wheat being the primary irrigated crops. Irrigated cotton and corn represent the greatest demand Journal of Contemporary Water Research & Education

for irrigation water with annual consumption in excess of 2.3 and 1.5 million acre-feet, respectively (Amosson et al. 2011). This region typically produces about one fourth of total U.S. cotton production and 65 percent of Texas corn production (USDA 2012). Furthermore, the Texas High Plains is home to one of the greatest concentrations of confined livestock operations in the world, with approximately 30 percent of total U.S.-fed beef being produced in the region (USDA and Texas Department of Agriculture 2009). Within the Texas High Plains there are two distinct agricultural production regions separated north to south by topography, climate, and hydrologic characteristics. The northern portion of the Texas High Plains, referred to as the Northern Panhandle, is more suited for grain production, while the southern portion, the South Plains, produces a variety of crops with cotton rotations as the predominant enterprise. As shown in Figure 1, the North Plains Groundwater Conservation District is located in the Northern Panhandle and serves all, or portions of, eight counties. The High UCOWR

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Weinheimer, Johnson, Mitchell, Johnson, and Kellison

Figure 1. Location of the North Plains and High Plains Underground Water Conservation Districts and the TAWC Demonstration Sites (Texas Water Development Board 2012b).

Plains Underground Water Conservation District No. 1 is located in the South Plains and serves all, or portions of, 16 counties. The Texas Alliance for Water Conservation (TAWC) demonstration project is located in Hale and Floyd Counties. Figure 2 shows the area of the Ogallala Aquifer, which underlies 174,000 square miles in portions of 8 states. Nebraska has approximately 69 percent of the total water volume in the Ogallala Aquifer, and Texas has 11 percent. Saturated thickness of aquifer formation is greatest in Nebraska, averaging 320 feet, and thins towards the southern region of the aquifer, with a saturated thickness of 98, 90, and 46 feet in Kansas, Texas, and New UCOWR

Mexico, respectively (McGuire et al. 2012). The Texas High Plains is on the cutting edge of change in the Great Plains region by using advanced water conservation methods. The semi-arid nature of the Texas High Plains, which typically receives from 8 to 12 inches of growing season rainfall, has resulted in dependency on the Ogallala Aquifer to support the intensive crop production in the region. The region’s ability to continue to produce irrigated crops has declined as water use has exceeded recharge, leading to the continued depletion of the aquifer. If the Ogallala Aquifer continues to decline at its current rate, the regional economy, rural communities, and the agricultural industries Journal of Contemporary Water Research & Education

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Figure 2. Map of the Ogallala Aquifer (USGS 2013).

that depend on agricultural production in the region will be detrimentally impacted. In recent years, the State of Texas has shown a strong commitment to water conservation and planning efforts, and has given local ground water conservation districts the authority to implement water use regulations. Whether agricultural water use from the Ogallala Aquifer is restricted by regulation or from depletion, agricultural producers in the Texas High Plains must continue to adopt water conservation technologies and practices to remain profitable and financially viable. Historically, conservation practices have been funded through programs such as the Environmental Quality Incentives Program and the Agricultural Water Enhancement Program. In the Texas High Plains, much of the funding for these programs has gone toward cost sharing of infrastructure related to center pivots and sub-surface drip systems. These investments in irrigation infrastructure have allowed farmers

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to increase their irrigation efficiencies, which create effective water delivery without losses to evapotranspiration. However, increased water application efficiency does not necessarily translate to water conservation. To achieve conservation of the water resources, there is a need to implement water management practices that target the application of irrigation to meet a crop’s water requirements, while optimizing production and profitability. The combination of efficient irrigation systems and strategic irrigation management will help maximize the return on the investment in conservation practices through these programs. Strategic irrigation management involves the timely application of the proper quantities of water to optimize production within a cropping system based on resource constraints. Strategic irrigation management incorporates the use of various technologies to measure crop water demand, soil moisture availability, irrigation application rates, and precipitation received. In addition, crop system management should take into account residue management, nutrient management, variety selection, planting density, pest management, and other best management practices. The strategic management of irrigation applications to achieve optimal economic returns has been identified as a key factor in the conservation of water resources in the region. Two field-level demonstration projects have been ongoing in the Texas High Plains to evaluate irrigation water conservation methods. The North Plains Groundwater Conservation District has evaluated corn production using 12 acre-inches or less of applied irrigation water with a goal of producing 200 bushels per acre. This project was initiated in 2010 with three corn production sites. With only a 3 acre-inch savings over the 1 million acres of irrigated crops in the North Plains Groundwater Conservation District, the result could be a savings of 250,000 acre-feet annually. The TAWC has worked with 24 producers in Hale and Floyd Counties on 29 sites in the South Plains over the past seven years to monitor water use, soil moisture, crop productivity, and economic return on various cropping systems over 4,000 acres. A wide range of observations and field records has been collected from the TAWC

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sites from 2005 through 2012. These observations include crop yields, irrigation application rates, precipitation received, soil moisture, and crop water demand based on evapotranspiration (ET) estimates. In addition, data for cultivation practices, varieties, fertilizer applications, and chemical applications were collected and analyzed. Results from the TAWC project have shown that managing irrigation within a cropping system can reduce applied water and maintain historical crop production levels. While the TAWC investigates many enterprise options for irrigated producers, cotton and corn are the predominant crops irrigated on the Texas High Plains. Over the period between 2006 and 2009, 55 cotton and 20 corn field level observations were collected. Figures 3 and 4 show the relationships between crop yield and the percent of ET provided by irrigation, precipitation, and soil moisture for corn and cotton, respectively. As shown in the figures, 40 percent and 35 percent of the corn and cotton Irrigated Corn Bushels per Acre

300 250 200 150 100 50 0 40

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% of Crop ET

Figure 3. Yield and percent Crop ET for Irrigated Corn in TAWC Demonstration Sites from 2006-2009.

Irrigated Cotton 3000

Lbs per Acre

2500 2000 1500 1000 500 0 40

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% of Crop ET

Figure 4. Yield and percent Crop ET for Irrigated Cotton in TAWC Demonstration Sites from 2006-2009.

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observations, respectively, had total water supplied from irrigation and precipitation greater than 100 percent of the crop demand. These graphs indicate that irrigation applications consistent with providing 70 percent to 90 percent of crop water demand for cotton and corn production resulted in yields equal to or greater than when total water supplied was greater than 100 percent of ET. The observations greater than 100 percent ET were often in years with higher rainfall, indicating that producers who do not have tools available to measure crop moisture often tend to over-irrigate in wet years. The implication of the measurements exceeding 100 percent ET illustrates that there are opportunities for producers who are currently not using the proposed methods of strategic irrigation management to conserve irrigation water while maintaining profitability and crop yield. The innovative approach of strategically managing irrigation water is unique in that the goal is to save water not by simply restricting use, but rather by optimally matching and timing irrigation applications to meet the needs of individual crops. This strategy of irrigation management recognizes that each crop year is different due to environmental factors such as precipitation and evapotranspiration. Producers that have adequate irrigation capacity to meet the needs of the crop tend to manage such that irrigation is not a limiting factor in crop production; therefore, they tend to over-irrigate in years with favorable precipitation. Reduction in over-irrigation in favorable crop years will amount to water savings over time as a result of the decrease in water pumping.

Objectives A consortium of the North Plains Groundwater Conservation District, the High Plains Underground Water Conservation District, the Texas Alliance for Water Conservation (TAWC), Texas Tech University, and Texas A&M Agrilife Extension and Research has been formed to address the issues of achieving water conservation while maintaining producer profitability. This project was funded by the Natural Resource Conservation Service by establishing new demonstration sites located in the Texas High Plains. The 2012 crop year was the initial year of the new Natural Resource Conservation Service project.


Texas High Plains Initiative The purpose of these demonstration projects is to establish strategic irrigation and crop system management technologies and practices that will result, not only in water savings across the region, but also best practices that may be applicable to other regions facing similar resource concerns. The primary objective is to quantify water savings that can be realized from strategic irrigation management.

Project Methods A total of 32 field level sites, 24 in the Northern Panhandle and 8 in the South Plains, have been selected to conduct the project over the 3-year period. The demonstration sites are distributed geographically and across diverse cropping systems and crop types. In the Northern Panhandle, 12 producers have each provided a control site and a managed site for the project. For the 2012 growing season, the twelve cooperators irrigated a total of 822 managed acres and 912 controlled acres primarily planted in corn. All of the acres are under center pivot irrigation. In the South Plains, five producers are participating in the project with a total of eight sites representing cotton and corn production systems. Five sites are under pivot and three sites use subsurface drip irrigation. Two producers have both pivot and subsurface drip sites that will be included in the project. Total acres for the sites are 610 under pivot and 157 under subsurface drip. The demonstration sites utilize a combination of real time innovative water monitoring technologies such as AquaSpy®, John Deere Water®, and PivoTrac®. Web based Decision Aids from TAWC, such as the Resource Allocation Tool and Irrigation Scheduling Tool, are available to producers to help allocate and manage available irrigation water. By using the TAWC Decision Aids in conjunction with other available monitoring systems, producers can create an individual profile of field records that allows for the management of irrigation over their entire operation by field or farm. Since a producer’s decision to grow and irrigate a particular crop is based on many criteria that must be considered prior to planting and during the growing season, the TAWC Decision


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Aids provide an innovative and comprehensive approach to irrigation management. The first of these tools, the Resource Allocation Tool, is an economics-based optimization model that assists producers in making cropping decisions based on the allocation of available irrigation water with the objective of maximizing profitability. This tool serves as a planning aid to give producers various enterprise options that maximize profit by taking into consideration water availability, production costs, yield potential, and expected commodity prices. Output from this model provides producers with cropping options and acreages, yield goals, and overall profit projections that maximize the potential return on an individual field. Once a producer has chosen to plant a particular crop, the Irrigation Scheduling Tool gives producers an in-season irrigation management aid that provides a checkbook style water balance output to help make irrigation scheduling decisions. The Irrigation Scheduling Tool utilizes information on crop specific ET, rainfall, applied irrigation, and other environmental factors. Utilizing local weather observations and crop specific ET coefficients, a producer will be able to manage irrigation scheduling that is customized to each field or farm within an individual’s operation. A producer initializes the process by setting up field-level irrigation schedules by planting and customizing the program to account for factors such as percent of effective rainfall, irrigation application efficiency, and soil moisture observations. The utilization of the TAWC Decision Aids, in conjunction with other water monitoring equipment, will give producers access to information to assist in making irrigation decisions. The documentation of water savings attributed to the water management practices utilized on each site is crucial to the success of the project. Crop ET will be utilized as the primary measurement for water demand and savings on the South Plains sites. Irrigation applications will be managed to meet approximately 70 to 90 percent of crop ET. The baseline irrigation demand will be 100 percent ET. The difference between the supplied level of ET and the baseline demand represents potential water savings. On the Northern Panhandle sites, historic annual irrigation production data will be

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used to determine water savings. The North Plains Groundwater Conservation District’s required production reports for the specific sites will be used to compare water applied, before and after the application of strategic water management practices, to determine actual water savings. The goal is to provide a level of irrigation that reduces irrigation demands while maintaining a profitable level of production. The optimal level of irrigation is not a static quantity applied, but rather adjusts to meet the water needs of the crop based upon the growing season demands dictated by weather factors. A total resource management approach that addresses additional factors, such as soil quality, pest, residue, and nutrient management, will be integrated into the demonstrations to aid in water savings. Total resource management will support the adoption of the best practices that most effectively address additional concerns over increasing greenhouse gas emissions.

Producer Participation Producer participation is an integral part of the project. Producers have installed appropriate technologies to measure water application and soil moisture, in addition to using the TAWC Resource Allocation Tool and Irrigation Scheduling Tool. Producers provide detailed field records regarding varieties, seeding rates, fertilizer, pesticides, tillage practices, and yields. These records are analyzed in detail to derive per acre profitability and the overall success of the demonstration. The cooperating producers serve on a Project Management Team for their area. Producer representation on these teams provide input into the project management that is extremely valuable, particularly with respect to their expertise in crop production and the transfer of results to other producers in the region. The producers on the Project Management Teams work closely with the personnel from North Plains Groundwater Conservation District, High Plains Underground Water Conservation District, Texas Tech University, and TAWC to not only provide direction and feedback for the project, but also to aid in the dissemination of the knowledge and practices gained from the project. Many of these producers are leaders in

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their communities and in the agricultural industry, holding memberships on cooperative boards and state and national commodity associations, that aid in the outreach and promotion of the innovative methods beyond the Texas High Plains.

Benefits and Results Benefits from the project include, but are not limited to, measurement of total water savings by individual demonstration sites, profitability comparisons to traditional irrigation methods, and alternative production strategies that aid in the conservation of the Ogallala Aquifer. The innovative approach of this project has the potential to impact 4.5 million acres of irrigated cropland throughout the Texas High Plains. Based on the current estimates of irrigation application rates, this project could reduce irrigation demand by as much as 10 percent, or 580,000 acre-feet annually, and approximately 1.75 million acre-feet over the life of the project. The innovative irrigation management practices and strategies to be demonstrated through this project will produce measureable decreases in irrigation water usage, thus reducing withdrawals from the Ogallala Aquifer while optimizing crop yield and increasing or maintaining field-level profits. Agricultural producers in the Texas High Plains benefit from the irrigation scheduling programs and technologies that prioritize crop irrigation demands based on crop requirements. Strategic irrigation management that reduces pumping will increase the life of the aquifer and help producers meet possible regulatory requirements regarding irrigation pumpage. In addition, the regional economy will benefit from the increased life of the aquifer given that the region is highly dependent on irrigated agricultural production. The on-the-ground knowledge gained from these demonstrations will be both transformative in nature and widely transferable to other regions of the U.S. with similar conservation needs, such as the other Great Plains states that also depend on the Ogallala Aquifer.

Acknowledgements This initiative was funded as a Conservation Innovation Grant by the Natural Resource Conservation Service-USDA over a 3-year period.


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Author Bio and Contact Information

References

Justin Weinheimer received his B.S. in Animal Science followed by a M.S. (2006) and a Ph.D. (2008) in Agriculture and Applied Economics from Texas Tech University. He has served as a Post-Doctoral Research Associate and Research Assistant Professor in the Department of Agriculture and Applied Economics. He was the Assistant Director of the College of Agricultural Sciences and Natural Resources Water Center at Texas Tech University. Dr. Weinheimer served on the Water Conservation Advisory Council for the Texas Water Development Board. He is currently the Crop Improvement Program Director for the United Sorghum Checkoff. He can be reached at [email protected].

Amosson, S., B. Guerrero, J. Smith, J. Johnson, P. Johnson, J. Weinheimer, L. Almas, and J. Roberts. 2011. Water Use By Confined Livestock Operations and Ethanol Plants in the Texas High Plains. Project Report. Texas AgriLife Extension, Amarillo, TX. McGuire, V.L., K.D. Lund, and B.K. Densmore. 2012. Saturated thickness and water in storage in the High Plains Aquifer, 2009, and water-level changes and changes in water in storage in the High Plains Aquifer, 10980 to 1995, 1995 to 2000, 2000 to 2005, and 2005 to 2009. U.S. Geological Survey Scientific Investigations Report 2012-5177: 28. Texas Water Development Board. 2012a. 2012 Water for Texas. Austin, TX. Available at: http://www. twdb.state.tx.us/waterplanning/swp/2012/index.asp. Texas Water Development Board. 2012b. Groundwater conservation districts. Available at: www.twdb. state.tx.us/mapping/maps.asp. U.S. Dept. of Agriculture (USDA) Farm Service Agency. 2008. Crop Acres by County. College Station, TX. Available at: http://www.fsa.usda. gov/FSA/webapp?area=newsroom&subject=landi ng&topic=foi-er-fri-cad. U.S. Dept. of Agriculture, National Agricultural Statistics Service. 2012. Texas crop acreage and production by county. Available at: www.nass. usda.gov/Statistics_by_State/Texas/Publications/ County_Estimates/ce_cp.htm. U.S. Dept. of Agriculture, National Agricultural Statistics Service, Texas Field Office and Texas Department of Agriculture. 2009. Texas Agricultural Statistics. Austin, TX. Available at: www.nass.usda.gov/tx. U.S. Geological Service. 2013. Aquifer basics: High Plains Aquifer. Available at: http://water.usgs.gov/ ogw/aquiferbasics/ext_hpaq.html.

Phillip Johnson is the Charles C. Thompson Chair of Agricultural Finance and Director of the Thornton Agricultural Finance Institute in the Department of Agricultural and Applied Economics at Texas Tech University. He received his B.S., M.S., and Ph.D. in Agricultural and Applied Economics at Texas Tech University. He can be reached at [email protected]. Donna Mitchell is currently a Ph.D. student in the Department of Agricultural and Applied Economics. Her research focus is international water and food scarcity. She received her B.S. in Agricultural and Applied Economics at Texas Tech University in 2007 and her M.S. in Agricultural Economics at Texas A&M University in 2009. She can be reached at [email protected]. Jeff Johnson is the Associate Director of the College of Agricultural Sciences and Natural Resources Water Center at Texas Tech University. He is also an Associate Professor in the Department of Agricultural and Applied Economics. Dr. Johnson serves as the project coordinator for Economic Assessment and Impacts team of USDA-ARS Ogallala Aquifer Program (OAP), and is the Managing Director for TTU Farm Operations. He can be reached at [email protected]. Rick Kellison is the Director of the Texas Alliance for Water Conservation. He has a B.S. in Animal Science and a M.S. in Nutrition from Texas Tech University. He can be reached at [email protected].


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