Final Report for LS11-238
The Texas High Plains serves as a model region when studying factors affecting agricultural sustainability with respect to water, soil, nutrients, energy, and community stability. In this semi-arid region, agriculture accounts for over 40% of the economy but depends heavily on irrigation from the Ogallala Aquifer at non-sustainable rates of use. This project entailed the first 3 years (2011 to 2014) of maintenance for the Texas Tech Research Station at New Deal, TX, to preserve basic long-term research facilities, support forage and livestock systems research, and to serve as a bridge between research and outreach to producers. Historically severe droughts in 2011 and 2012 prevented adequate forage production to support grazing research, and grazing was further postponed in 2013 to allow pasture recovery, elimination of bermudagrass, irrigation system repair, and installation soil moisture monitors. Results of an associated 9-year outreach project on irrigation conservation (Texas Alliance for Water Conservation) were summarized and submitted to the Texas Water Development Board. Alfalfa and sweet clover were successfully interseeded back into old world bluestem pastures where severe drought had reduced the legume content. Research in 2013-2014 comprised a Master’s thesis study on the use to digital image analysis for tracking grass ground cover, leaf area, light interception, and forage yield. That work continued in 2014 as part of doctoral research to refine a simulation model for predicting grass growth in response to water supply and hay vs. grazing management. New grazing research was initiated with steers in 2014 to study the effects of alfalfa on cattle weight gain in old world bluestem pastures at low water input. Another study characterized insect populations in old world bluestem and alfalfa pastures and on cattle flies to test whether old world bluestem deters potentially harmful insects. Early testing of the suitability of teff grass indicates its great potential as a summer annual grass for hay and grazing under limited water supply.
The overall objective of our project is to (1) understand the biological, environmental, social, economic, and policy issues impacting agricultural sustainability in the Southern High Plains, and (2) translate research into adoption of more sustainable practices. Furthermore, we aim to transfer new knowledge into adoption of ecologically and economically sustainable crop production practices that use available water at maximum efficiency. The specific objective of this funding (2011 to 2014) was to provide supplies, equipment, and maintenance for the Texas Tech University New Deal Research Station to preserve basic long-term research facilities, support forage and livestock systems research, and to serve as a bridge between research and outreach to producers.
The performance targets were to 1) maintain productive stands of forages for testing their adaptability, animal production, and water use, 2) receive and manage beef cattle for grazing trials, 3) maintain infrastructure for irrigation systems, fencing, weather recording, roads, and stock waterers, controlling pests, 4) monitoring and correcting soil fertility deficiencies, and 5) conduct educational and demonstration activities related to the research and outreach missions.
The goal of U.S. agriculture is food and fiber security and an economically viable production system that does not deplete resources nor diminish the environment upon which this depends. Increasingly, agriculture is called on to provide additional services including clean air and water, wildlife habitat, recreational opportunities, and landscape esthetics, while agriculture is also blamed for using inordinate amounts of fresh water for irrigation. Agriculture uses 61% of the total U.S. withdrawals of fresh water (excluding that used for power plant cooling, http://pubs.usgs.gov/circ/1405/), and uses 95% of groundwater withdrawals in the Texas High Plains (http://www.twdb.texas.gov/). To meet these challenges, knowledge of the functioning of agricultural ecosystems is essential. Such knowledge must be derived from long-term systems-level research that leads to understanding interrelationships of basic biophysical processes, human needs and manipulation of the system, and impacts of policies, economics, and market forces.
The Texas High Plains serves as a model region when studying factors affecting agricultural sustainability, especially for the efficient use of water and protective management of soil. In this semi-arid region, agriculture accounts for over 40% of the economy, including support of numerous rural communities, but depends heavily on irrigation from the Ogallala Aquifer at non-sustainable withdrawal rates. Recharge is negligible and well output is dropping to the point that farmers are having to adopt new systems to maintain profitable survival of their businesses and the communities that depend on their economic activity. Conventional soil cultivation has led to organic matter depletion contributing to loss of fertility and release of carbon dioxide to the atmosphere. Soil erosion, primarily by wind, results in dust storms reminiscent of the Dust Bowl era.
The research conducted at the Texas Tech University New Deal research station covers the use of grazing systems with beef cattle that, when integrated into farming systems involving annual crops, can reduce inputs of irrigation water, fertilizers, and pesticides, while building up soil organic matter and microbial diversity. The impetus for this research is the declining supply of groundwater from the Ogallala Aquifer used in large scale, row-crop farming, and therefore the need for systems that use less water while building soil quality and maintaining profitability.
This project has supported infrastructure for conducting research on overall water use of forage systems. Results feed directly into a current outreach program (Texas Alliance for Water Conservation, http://tawc.us) and offer answers on how to reallocate diminishing irrigation water to annual row crops and forage systems to maximize economic returns. The premise is that there are novel methods of managing forages which are as climate-resilient as native grasslands but more economically productive, and which entail user-friendly technologies for monitoring use of water and making economic decisions. Maintenance of a top quality forage research facility serves as a glue for research and education collaborators to conduct short-term and long-term studies and outreach to stakeholders.
The Large Systems SARE grant contributes a critical piece of this effort by funding the maintenance of the long-term field research site at the New Deal Research Station, which is the basic platform for our collaborative research and education efforts. The research arm of our effort (Texas Coalition for Sustainable Integrated Systems, TeCSIS) focuses on the integration of forage-based beef production into the region’s predominantly row-crop agriculture as a means of reducing water extraction from the Ogallala Aquifer, building soil organic matter, stabilizing soil from wind erosion, and diversifying income. The outreach arm of our effort (Texas Alliance for Water Conservation, TAWC) partners with 20 producers to demonstrate improved irrigation practices on 30 fields near Lubbock, TX. TAWC produces field days, field walks, conferences, radio and TV reports, Twitter and Facebook messages, web-based management tools, and printed fact sheets to reach a diverse rural and urban populace on using practical technologies to sustain agriculture and communities. Research at the New Deal Research Station is a source of information pertaining to grazing systems that help meet producers’ goals of stretching water supplies and reverting cropland to perennial grasses in ways that meet their economic goals.
Pastures were not subjected to grazing trials during the severe droughts in 2011 and 2012, and were allowed to recover during 2013. Stands were evaluated for vegetative ground cover using a grid-frame quadrat in December 2013 to characterize stand condition for planning the 2014 grazing trial. ‘Tifton 85’ bermudagrass stands from previous trials were sprayed with glyphosate in 2013 and 2014 to eradicate this species and convert it to annual forages for future grazing studies. In 2013, pastures received irrigation at the normal target level of 12 inches for the alfalfa/tall wheatgrass pastures and 9 inches for the WW-B.Dahl Old World bluestem pastures, both with and without legume. The native grass pastures did not ever receive irrigation. Teff grass was planted in 2013 and 2014 in pastures that had previously grown wheat in rye, and was harvested for hay once in 2013 and twice in 2014. One hay harvest was taken off the bluestem pastures in 2013 and 2014.
Well pumps and water piping systems were repaired and put through routine winterizing and back-flushing practices each year. The subsurface drip irrigation system was repaired and winterized each year, including digging up field sites where rodents had caused leaks. Electronic controls were replaced where needed to update the computerized control and communication systems.
We installed capacitance probes in one Old World bluestem pasture to assess the practicality of soil moisture monitoring for improving the timing of irrigation. They probes were the AgSpy probe by AquaSpy, and the FieldConnect probe by Deere and Company.
Weather records were kept as part of the long-term archive for this site and to support existing research projects. Variables included wind speed at 1 and 2 meters, air temperature, relative humidity, solar radiation, and precipitation. Sensors were maintained and replaced as needed.
The WW-B.Dahl old world bluestem pastures were first established in 1998 as part of a previous trial, and alfalfa and sweet clover were interseeded into those for the beginning of the current SARE grant. By 2013, the sweet clover had disappeared, and the alfalfa had thinned down to about 10% of the stand. Therefore, in 2014 we interseeded alfalfa and sweet clover back into those old world bluestem pastures.
Research in 2013-2014 comprised a Master’s thesis study on the use to digital image analysis for tracking grass ground cover, leaf area, light interception, and forage yield. That work continued in 2014 as part of doctoral research to refine a simulation model for predicting grass growth in response to water supply and hay vs. grazing management. New grazing research was initiated with steers in 2014 to study the effects of alfalfa on cattle weight gain in old world bluestem pastures at low water input. Another study characterized insect populations in old world bluestem and alfalfa pastures and on cattle flies to test whether old world bluestem deters potentially harmful insects.
Historically severe droughts in 2011 and 2012 prevented adequate forage production to support grazing research, and grazing was further postponed in 2013 to allow pasture recovery, elimination of bermudagrass, irrigation system repair, and installation soil moisture monitors.
Results of the Texas Alliance for Water Conservation 9-year outreach project on irrigation conservation were summarized and submitted to the Texas Water Development Board. Phase 2 of that project was approved for an additional six years with $3.6 million of new funding from the Texas Water Development Board. That means we will continue to have a viable outreach program to extend the results of the TeCSIS research portion to area producers.
The following table summarizes the ground cover data taken in December 2013, as the average of two observers and three replications. There were two sets of native grass pastures, established in 2002 and 2008, as indicated.
Pasture type Species % cover
Native 2002 Blue grama 37
Sideoats grama 15
Bare ground 20
Native 2008 Blue grama 28
Sideoats grama 36
Bare ground 21
WW-BDahl WW-BDahl 73
Bare ground 26
BDahl/alfalfa WW-BDahl 78
Bare ground 13
Alfalfa/grass Alfalfa 64
Tall wheatgrass 15
Bare ground 20
The ground cover data indicate that the forage systems comprising introduced species are capable of surviving an intense drought as long as some supplemental irrigation is supplied or if the system consists of native grasses that have adapted to stresses associated with lack of irrigation. Low rainfall periods reduce forage production, but water is conserved while enabling the grasses to survive a drought of this magnitude. Initial observations and evaluation are positive; however, the lingering effects of such a drought could take several years to understand its full impact on production, persistence, the soil and producer attitudes and management decisions for the future.
In fall of 2014, alfalfa and sweet clover were successfully interseeded back into old world bluestem pastures where severe drought had reduced the legume content.
Research in 2013-2014 comprised a Master’s thesis study on the use to digital image analysis for tracking grass ground cover, leaf area, light interception, and forage yield. That work continued in 2014 as part of doctoral research to refine a simulation model for predicting grass growth in response to water supply and hay vs. grazing management. Figure 1 (uploaded file) shows the linear growth trends in early (Period 1) and late summer (Period 2) of 2013 and 2014. The late summer trends describe regrowth after an early-July mowing. The x coefficients in the linear equations indicate the growth rates in kilograms of dry matter per hectare per day, roughly equal to pounds per acre per day.
Figure 2 (uploaded file) describes linear relationships between percent light interception and percent ground cover. Ground cover was determined by analyzing a digital photograph for two-dimensional cover. The correlation was poor in Period 2 because of heavy density of seedhead production. The excellent relationships in Period 1 indicate that rapid analyses of grass ground cover can be made with fairly accurate predictions of light interception. These results will be used to refine a plant growth model that will allow calculations of forage growth in relation to time, temperature and soil water supply.
New grazing research was initiated with steers in 2014 to study the effects of alfalfa on cattle weight gain in old world bluestem pastures at low water input. The treatments consisted of grass-only consisting of cattle spending 75% of the time grazing old world bluestem and 25% native grass mix, and grass-alfalfa mixture with cattle having three-times-per-week access to grazing pure alfalfa for half a day each time. Figure 3 (uploaded file) shows the comparison of average daily gain of liveweight of the two treatments, with West pastures comprising the grass-only treatment and East pastures comprising the grass-alfalfa treatment, at three grazing periods. Rates of gain fluctuated so that the treatment ranking was inconsistent with the season-long mean showing no significant difference between grass-only and grass-alfalfa. The target mean ADG of 1.80 lbs/day was surpassed was by both treatments, and only six inches of irrigation was applied to both treatments.
Another study characterized insect populations in old world bluestem and alfalfa pastures and on cattle flies to test whether old world bluestem deters potentially harmful insects. In the bluestem pastures there were fewer numbers of insects in pitfall traps (35 in 6 taxa) compared to pure alfalfa (62 in 8 taxa), indicating that WW-B.Dahl bluestem reduces insect attractiveness and inhibits biodiversity. Face fly and horn fly numbers were visually scored for density on the sides and backs of the cattle, 1 indicating very low or absent numbers, and 5 indicating the highest fly density. Cattle grazing WW-B.Dahl bluestem had an average rating of 1.6, whereas cattle grazing alfalfa had a rating of 3.2. This observation constitutes the first quantifiable and statistically significant data that fly numbers on cattle are significantly reduced when grazing WW-B.Dahl old world bluestem, which supports previous casual observations. These trials will be repeated in 2015.
Early testing of the suitability of teff grass indicates it has excellent potential as a summer annual grass for hay and grazing under limited water supply.
Educational & Outreach Activities
Davinic, M., L.M. Fultz, V. Acosta-Martinez, F.J. Calderón, S.B. Cox, S.E. Dowd, V.G. Allen, J.C. Zak, and J. Moore-Kucera. 2011. Pyrosequencing and mid-infrared spectroscopy reveal distinct aggregate stratification of soil bacterial communities and organic matter composition. Soil Biology and Biochemistry 46:63-72.
Zilverberg, C.J., P. Johnson, J. Weinheimer, and V.G. Allen. 2011. Energy and carbon costs of selected cow-calf systems. Rangeland Ecology and Management 64:573-584.
Zobeck, T.M., V.G. Allen, J.J. Cox, and D. Philipp. 2011. Variation of soil and plant characteristics among old world bluestem species. Agricultural Sciences 2:347-356.
Allen, V.G., C.P. Brown, R. Kellison, P. Green, C.J. Zilverberg, P. Johnson, J. Weinheimer, T. Wheeler, E. Segarra, V. Acosta-Martinez, T.M. Zobeck, and J.C. Conkwright. 2012. Integrating cotton and beef production in the Texas Southern High Plains. I. Water use and measures of productivity. Agronomy Journal 104:1625-1642.
Zilverberg, C.J., V.G. Allen, C.P. Brown, P. Green, P. Johnson, and J. Weinheimer. 2012. Integrating cotton and beef production in the Texas Southern High Plains. II. Fossil fuel use. Agronomy Journal 104:1643-1651.
Benson, A., and C. Zilverberg. 2013. A bioeconomic model for sustainable grazing of Old World bluestem under uncertainty. Natural Resources 4:362-368.
Davinic, M., J. Moore-Kucera, V. Acosta-Martínez, J. Zak, V.G. Allen. 2013. Soil fungal distribution and functionality as affected by grazing and vegetation components of integrated crop-livestock agroecosystems. Applied Soil Ecology 66:61-70.
Fultz, L.M., J. Moore-Kuceraa, T.M. Zobeck, V. Acosta-Martínez, and V.G. Allen. 2013a. Aggregate carbon pools after 13 years of integrated crop-livestock management in semiarid soils. Soil Science Society of America Journal 77:1659-1666.
Fultz, L.M., J. Moore-Kuceraa, T.M. Zobeck, V. Acosta-Martínez, D.B. Wester, and V.G. Allen. 2013b. Organic carbon dynamics and soil stability in five semiarid agroecosystems. Agriculture, Ecosystems and Environment 181:231-240.
Johnson, P., Zilverberg, C.J., V.G. Allen, J. Weinheimer, P. Brown, R. Kellison, and E. Segarra. 2013. Integrating cotton and beef production in the Texas Southern High Plains: III. An economic evaluation. Agronomy Journal 105:929-937.
Li, Y., V.G. Allen, F. Hou, J. Chen, and C.P. Brown. 2013a. Steers grazing a rye cover crop influence growth of rye and no-till cotton. Agronomy Journal 105:1571-1580.
Li, Y., V.G. Allen, J. Chen, F. Hou, C.P. Brown, and P. Green. 2013b. Allelopathic influence of a wheat or rye cover crop on growth and yield of no-till cotton. Agronomy Journal 105:1581-1587.
Rajan, N., S. Maas and C. Song. 2013. Extreme drought effects on carbon dynamics of a semi-arid pasture. Agronomy Journal 105:1749-1760.
Cui, S., C.J. Zilverberg, V.G. Allen, C.P. Brown , J. Moore-Kucera, D.B. Wester, M. Mirik, S. Chaudhuri, and N. Phillips. 2014. Carbon and nitrogen responses of three old world bluestems to nitrogen fertilization or inclusion of a legume. Field Crops Research 164:45-53.
Zilverberg, C.J., C.P. Brown, P.E. Green, M.L. Galyean, and V.G. Allen. 2014. Integrated crop–livestock systems in the Texas High Plains: Productivity and water use. Agronomy Journal 106:831-843.
Zilverberg, Cody, P. Brown, P. Green, V. Allen, and M. Galyean. 2015. Forage performance in crop-livestock systems designed to reduce water withdrawals from a declining aquifer. Rangelands 37:55-61.
International, national, and regional presentations (proceedings and abstracts by year):
Davinic, M., L.M. Fultz, and J. Moore-Kucera. 2011. Soil microbial dynamics in alternative cropping systems to monoculture cotton in the Southern High Plains. In Annual Meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
Davinic, M., L.M. Fultz, and J. Moore-Kucera. 2011. Soil fungal community and functional diversity assessments of agroecosystems in the Southern High Plains. In Annual Meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
Davinic, M., L.M. Fultz, and J. Moore-Kucera. 2011. Aggregate stratification assessment of soil bacterial communities and organic matter composition: Coupling pyrosequencing and mid-infrared spectroscopy techniques. In Annual Meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
Fultz, L.M., M. Davinic, and J. Moore-Kucera. 2011. CO2 and N2O fluxes in integrated crop livestock systems. In Annual Meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
Fultz, L.M., M. Davinic, and J. Moore-Kucera. 2011. Dynamics of soil aggregation and carbon in long-term integrated crop-livestock agroeceosystems in the Southern High Plains. In Annual Meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
Fultz, L.M., M. Davinic, and J. Moore-Kucera. 2011. Long-term integrated crop-livestock agroecosystems and the effect on soil carbon. In Annual Meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
Maas, S., and N. Rajan. 2011. Comparison of carbon, water and energy fluxes between grassland and agricultural ecosystems. In Annual Meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, San Antonio, TX.
Brown, C. Philip, V.G. Allen, R. Kellison, P. Green, C.J. Zilverberg, P.N. Johnson, V. Acosta-Martinez, and C.P. West. 2013. Integrating beef and cotton production reduces irrigation needs in the Texas Southern High Plains. Proceedings 22nd International Grassland Congress, 15-19 September, Sydney, Australia.
Kellison, R., V.G. Allen, C.P. Brown, D.L. Doerfert, P.N. Johnson, S.J. Maas, and C.P. West. 2013. Using forages to conserve water in semi-arid irrigated cropping systems. Proceedings 22nd International Grassland Congress, 15-19 September, Sydney, Australia.
West, C.P., C.P. Brown, and V.G. Allen. 2013a. Integrated crop/forage/livestock systems for the Texas High Plains. 67th Southern Pasture and Forage Crop Improvement Conference. 22-24 Apr., 2013, Tyler, Texas.
West, C.P., R. Kellison, S.J. Maas, C.P. Brown, S. Borgstedt, P.N. Johnson, D.L. Doerfert. 2014a. Regional opportunities and challenges – High Plains. Texas Water Summit, May 19. Austin, TX.
West, C.P., S.J. Maas, R. Kellison, C.P. Brown, S. Borgstedt, P.N. Johnson, D.L. Doerfert, J. Pate, and J. Yates. 2014b. Promoting conservation of irrigation water in the Texas High Plains. In Annual Meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
Xiong, Y., C.P. West, and C.P. Brown. 2013. Digital image analysis of Old World bluestem canopy cover and leaf area. In Annual meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
Xiong, Y., C.P. West, and C.P. Brown. 2014. Digital image analysis of Old World bluestem canopy cover, yield, and leaf area. In Annual meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
Oral presentations and posters (those with abstracts are listed above, by year):
Brown, C.P., V.G. Allen, and R. Kellison. 2011. Integrating forages and grazing animals to reduce agricultural water use UCOWR/NIWR Conference:, Boulder, CO.
Doerfert, D. 2011. What we know about disseminating water management information to various stakeholders. UCOWR/NIWR Conference, Boulder, CO.
Kellison, R., V.G. Allen, and C.P. Brown. 2011a. Texas Alliance for Water Conservation: An innovative approach to water conservation. UCOWR/NIWR Conference: An Overview, Boulder, CO.
Kellison, R., V.G. Allen, and C.P. Brown. 2011b. Assessment of improved pasture alternatives on Texas Alliance for Water Conservation. UCOWR/NIWR Conference:, Boulder, CO.
Maas, S. 2011. Determining crop water use in the Texas Alliance for Water Conservation Project. UCOWR/NIWR Conference, Boulder, CO.
Weinheimer, J. 2011. Economic considerations for water conservation: The Texas Alliance for Water Conservation. UCOWR/NIWR Conference, Boulder, CO.
Doerfert, D. 2012. The Texas Alliance for Water Conservation: An integrated water resources management model for agriculture. 48th annual American Water Resources Association (AWRA) conference in Jacksonville, FL, November, 2012.
Doerfert, D., R. Kellison, R., S. Maas, P. Johnson, and J. Weinheimer. 2012. Crop production water management tools for West Texas farmers. 48th annual American Water Resources Association (AWRA) conference in Jacksonville, FL, November 2012.
West, C.P. 2013. Comparing perennial warm-season grasses for efficient water use. TAWC field day at Eddie Teeter’s farm, Lockney, TX. August 15.
West, C.P., C.P. Brown, R. Kellison, S. Trojan. 2013b. Benefits and challenges of grassland and cattle management in the Texas High Plains: Research on integrating forage and crops. West Texas Ranchers Association, July 19.
West, C.P., R. Kellison, C.P. Brown. 2014. An integrated approach to water conservation for agriculture in Texas Southern High Plains. Nebraska Independent Crop Consultants Assoc., Feb 13. Nebraska City, NE.
Angadi, S., J. Idowu, P. Gowda, T. Zobeck, and C. West. 2015. Circular grass buffer strips in pivot irrigation systems to improve system resiliency under future climate. Conference on Agriculture and Climate Change: Adapting Crops to Increased Uncertainty. 15-17 February, 2015, Amsterdam, The Netherlands.
Feature and popular press articles on our project (by year):
Southwest Farm Press. 22 February 2011. Water growing concern for Texas producers. http://southwestfarmpress.com/management/water-growing-concern-texas-producers
Black, Emily. KCBD NewsChannel 11. 2 March 2011. New website helps farmers battle drought. http://www.kcbd.com/story/15136451/new-website-helps-farmers-battle-drought.
Martin, Norman. 15 March 2011. Wise Water Use; New irrigation, economic management tools launched. http://www.depts.ttu.edu/agriculturalsciences/news/?p=866.
Lubbock Avalanche-Journal Lubbock Online local news. 17 March 2011. TAWC project offers irrigation management tools for farmers. http://lubbockonline.com/local-news/2011-03-17/tawc-project-offers-irrigation-management-tools-farmers.
Porter, Richard, Plainview Herald. 20 March 2011. Researcher: Area farmers should manage for maximum profit. http://www.myplainview.com/news/article_631b5c12-5243-11e0-8e54-001cc4c03286.html#user-comment-area
Tietz, Neil. 2011. Water Worries: Declining Aquifers Threaten Agriculture. http://hayandforage.com/hay/alfalfa/declining-aquifers-threaten-agriculture-0501. Hay & Forage Grower, Volume 26, No. 5, 2 May.
Fletcher, Kelsey. 2011. China agriculture prof joins ongoing Texas Tech water management project. CASNR News Center. http://www.depts.ttu.edu/agriculturalsciences/news. 23 September.
Trojan, S., and C. West. 2012. Conserving water while maintaining economic viability by grazing introduced perennial grasses. Rangeland Issues 1(3):1-6.
Ehmke, Tanner. 2013. More crop per drop: Integrating crops, livestock and new water saving technology. Sept-Oct 2013:6-12 Crops and Soils. American Society of Agronomy.
Fisher, Madeline. 2013. Tiny indicators of change. Microbes in the Texas High Plains may lead to better understanding of how changes in production, environment affect soil health. Crop Soil Agronomy News. August 2013:4-10. doi:10.2134/csa2013-58-8-1.
Theses and Dissertations:
Cui, Song. 2011. Finding forage legumes adapted to West Texas for reduction of water and energy use and improvement of nutritive value for livestock. Ph.D. Dissertation. Texas Tech University, Lubbock.
Li, Yue. 2011. Allelopathy in an integrated rye-cotton-beef cattle system. Ph.D. Dissertation. Texas Tech University, Lubbock.
Zilverberg, Cody J. 2012. Agroecology of three integrated crop-livestock systems in the Texa High Plains. Ph.D. Dissertation, Texas Tech University, Lubbock.
Yedon, Xiong, 2014. Digital image analysis of Old World bluestem canopy cover and leaf area. M.S. Thesis. Texas Tech University, Lubbock.
The results have direct and indirect outcomes which are visible over short and long time spans, but difficult to quantify. Direct impacts are that the Texas Tech University TeCSIS-TAWC program has gained a regional reputation for reliable information on forage and livestock productivity in the face of declining water supply. In the short term, we note that an increasing number of producers request information from our program on how to convert irrigated row-crop systems to perennial forages; specifically, how to wisely use the current low well outputs to successfully establish the grasses, which grasses to choose, and which aspects of livestock production (stocker vs. cow-calf, and even horses) lends itself most reliably to forage production.
The indirect effects of the long-term funding of the New Deal research center is that a we have reliable infrastructure for obtaining more forage-livestock production data using innovations in new forages, and across wildly fluctuating weather and economic conditions. Climate change scenarios agree the Southern Great Plains will become (and has become) hotter and drier, which will increase to producers even more the value of information on integrating forages into the existing cropping systems.
Results from the economic analyses of grazing and grass seed harvests (described in the Economic Analysis section below) have been delivered in presentations and publications to area farmers, water resource managers (e.g. High Plains Water District), and scientific peers in the High Plains region facing similar declines in the Ogallala Aquifer. A major medium for transferring these results to local decision-makers is via TAWC. We are expanding the TAWC online preseason planning tool (Resource Allocation Analyzer) to include old world bluestem in comparison with predominant row crops. This will allow producers to put together profit-maximizing mixes of row crops and livestock grazing options for their particular fields within the limits of a declining source of irrigation water. The integrated system had other benefits that are impossible to pin short-term economic benefits on, such as improve soil quality, less wind erosion of soil, improved wildlife habitat, and less input of synthetic pesticides and fertilizers.
Research from SARE-funded projects on integrated cotton-livestock grazing vs. cotton monoculture systems spanning 10 years was analyzed and published during this reporting period (Johnson et al., 2013). They reported that profitability (gross margin, or cash receipts minus cash outlay) was not different between the two systems over the 10 years; however, in the latter years, cotton monoculture was more profitable with the advent of higher-yielding cotton cultivars. Currently (2014-2015), cotton prices are depressed while beef prices are very high, which would lead to more favorable profit potential for the integrated cotton-livestock grazing system. Irrigation applied in the integrated system was 24% less than in the cotton monoculture system while profitability per unit of irrigation was unchanged. These results indicate that integrating forages and beef cattle into a heavily dominant row-crop system will provide producers with greater options in managing a profitable living enterprise as agriculture tends toward low irrigation and dryland managements.
Results of that economic analysis were presented at extension events and professional conferences (Brown et al., 2011; Kellison et al., 2011; Weinheimer, 2011; Brown et al., 2013; Kellison et al., 2013; West, 2013; West et al., 2013a; West et al., 2013b; West et al., 2014a and 2014b). There have also been popular articles and presentations on the economic options when integrating forages and grazing into a row-crop dominant environment (Trojan and West, 2012; Ehmke, 2013; Fisher, 2013).
In the Impact of Results/Outcomes section above, we stated that increasing numbers of producers request information from our program on how to convert irrigated row-crop systems to perennial forages with lower water inputs, as they transition to dryland agriculture. We transfer usable information via conference, field days, and multiple communication media such as radio and Internet. Farmers are being forced to concentrate their high-input row crop practices onto fewer acres, for example on to half pivot circles instead of full circles. That means forage options for hay, silage, grazing and seed production are being considered in those pivot sections that will receive substantially less water than the high-input row crop sections. Farmers are being forced to weigh new diversified cropping options because of the Ogallala decline, and thus look to this program for answers on establishment methods, irrigation rates, expected levels forage quality and cattle weight gains, and costs and returns.
Areas needing additional study
We are focusing current research on predicting water use by alfalfa and WW-B.Dahl old world bluestem to give producers better expectations of forage productivity in response to water supply and the effect of grazing vs. haying on water use. From that we will calculate water footprints of various forage options (amount of irrigation water used per unit of forage growth and per unit of beef cattle weight gain). We will also add to the TAWC online Irrigation Scheduler an option for tracking water use of old world bluestem so that acceptable forage growth can be produced at low rates. Alfalfa will receive close attention because it is the most persistent legume that can be maintained in mixture with old world bluestem. We will collaborate with an alfalfa breeder from New Mexico State University to measure water use of new breeding lines he has developed. The expectation is that new lines can be identified that persist and produce well with less irrigation than needed by older cultivars. We then plan to put those promising new alfalfas under grazing with the bluestem to verify their persistence and productivity under low water input (9-12 inches per year) and their ability to provide higher forage quality to the grazing cattle. An important question to investigate is how growing those forages in competitive mixtures affects the water requirements of both species, i.e. how to manage the water to favor a sustainable and high quality forage mix.