2015 Annual Report for LS14-261
Long-term AgroEcosystems Research and Adoption in the Texas Southern High Plains – Phase II
This project funds the maintenance of the long-term field site at the Texas Tech New Deal Research Station in support of long-term sustainability objectives pertaining to the integration of forages and livestock into a predominant row-crop region. Doctoral research continued on 1) growth analysis and model development of Old World bluestem, 2) analysis of legume composition and responses of cattle growth and water-use efficiency of Old World bluestem with and without alfalfa, and 3) relation between Old World bluestem and insects in pastures and on cattle. New doctoral research was initiated on the introduction of alfalfa into dryland native pastures. Average weight gain of steers in 2015 was 1.82 lbs/day in the grass-alone system and 2.01 lbs/day in the grass-legume system, and gain per area was 439 lbs/acre and 302 lbs/acre, respectively. Efficiency of water use for steer weight gain was therefore greater on grass-legume than the grass-alone system. Fly density on steers was not significantly affected when grazing Old World bluestem alone compared with bluestem-alfalfa mixtures. A major field day was held on July 9 with 100 participants learning about soil health, pasture establishment, integration of low-irrigation-input grazing into cropping systems, and dryland pasture options.
The overall objectives of crop-livestock research and demonstration projects at Texas Tech University are to (1) understand the biological, environmental, social, economic, and policy issues impacting agricultural sustainability in the Southern High Plains, and (2) to translate research into adoption of more sustainable practices. 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 30 producers to demonstrate improved irrigation practices on 34 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.
We visualize the following trends in Southern High Plains agriculture in the coming decades in the context of transitioning to low-irrigation management: (1) smaller acreages of irrigation of value-added crops, (2) continual improvements in water use efficiency of major row crops such as cotton, (3) partial replacement of irrigated row crops with perennial grasses and legumes and with dryland crops, especially sorghum, (4) greater use of precision water management technologies such as ultra-low and variable-rate irrigation, (5) greater dependence on online decision aides for guiding inputs, and (6) warmer temperatures leading to greater evaporative demand and more droughts. These trends will require constant testing of forage systems across the range of weather conditions experienced to offer options to landowners on how to maintain profitability.
Total precipitation at the New Deal Research Station in Nov. 2014-Oct. 2015 (our cropping year) was 30.1 inches (long-term average is 18.5 inches), and April-September (pasture growing season) precipitation was 21.9 inches (long-term average is 13.2 inches). 19.2 of the 21.9 inches fell between May 5 and July 7. Abundant rain early in the grazing season reduced irrigation needs. The OWB growing alone received 7.3 inches of irrigation, and that growing with alfalfa received 4.7 inches. Alfalfa growing with tall wheatgrass received 7.1 inches. We normally target irrigation levels in April-September to not exceed 12 inches for alfalfa-tall wheatgrass pastures and 9 inches for the Old World bluestem pastures, with or without alfalfa. The normal amount of rain + irrigation is targeted at 22 to 25 inches, but in 2015 rain + irrigation ranged from 26.6 to 29.2 inches because of the excessive rain in May. The native grass pastures do not normally receive irrigation.
The sod-seeding of alfalfa and yellow sweetclover into Old World bluestem in September 2014 resulted in successful legume establishment. Legume growth was abundant in spring and early summer of 2015, thanks partially to the high rainfall in May. These pastures were mowed to an 8-inch height in May to control excess forage growth. Legume cover ranged from 5-50% among the three replications during the rest of 2015. This afforded an opportunity to compare different methods of quantifying legume ground cover in relation to manual separation of clipped samples: visual estimates, photographic, and multispectral reflectance. Visual estimates gave the most consistently high correlation with manual separations in taller canopies, but photographic and reflectance methods performed well in shorter canopies. The yellow sweetclover flowered in April-May and essentially disappeared after June.
The second year (2015) of grazing research in Phase II was carried out with steers to compare two forage systems: grasses only receiving 60 lbs/acre of nitrogen as fertilizer (60% of grazing days on pure OWB, 30% on native grass mixture, and 10% on teff) and grasses + legumes receiving no nitrogen (59% of grazing days on native grass mixture, 24% on alfalfa-tall wheatgrass, and 17% on OWB-legume mixture). Grazing occurred from June 9 to October 2. Average daily gain was 1.8 and 2.0 lbs/day for the two systems, respectively. Total gain was 302 and 439 lbs/acre, respectively. The productive advantage of the grass-legume system was due to a combination of exposure to high-quality legumes and a greater number of days in native grass mix compared with the grass-only system. The novel part of the grass-legume system was the inclusion of the alfalfa-tall wheatgrass mixture, which served as a supplemental protein bank in small acreage. This component was grazed for around 2 days per week and boosted protein intake over the grass alone.
A doctoral study characterized insect populations in the grass-only system and the grass-legume system for cattle flies and other insects to test whether OWB deters potentially harmful insects. This is in response to casual observations by producers that cattle harbor fewer flies when grazing WW-B.Dahl OWB. Despite the single 2014 observation that cattle grazing grass-alfalfa harbored more flies than cattle on OWB, no significant differences were found in 2015. Cattle arrived at the trial wearing fly-deterring ear tags, which mitigated fly infestations for several weeks. The ear tags were removed and fly populations were rated later in the summer, with no clear differences emerging.
Number of insects in pitfall traps in OWB (48 per pasture) was substantially lower then in traps in teff (88), alfalfa-tall wheatgrass (120), and native grass mixtures (175). The number of red and black imported fire ants in OWB was negligible, whereas fire ants were highly numerous in the other pasture species. This indicates that WW-B.Dahl bluestem reduces insect attractiveness and biodiversity. This observation strongly supports earlier published accounts that OWB is a strong fire-ant deterrent, a very undesirable pest in pastures. The effect of OWB on population structure of beneficial insects is being ascertained in 2016.
A new doctoral study was initiated in October 2015 in which diverse types of alfalfa varieties were sod-seeded into existing stands of native grasses. The objective was to identify planting densities and growth types of alfalfa which could provide a high-protein component of dryland native grass pasture without competing too much for soil water. Timely rains after the sod-seeding resulted in good seedling emergence.
Soil water content in all pastures is being monitored weekly at six depths down to 40 inches. Results from the grazing trial, the OWB growth modeling research, and the soil water monitoring will contribute to systems analysis of the water-use efficiency of pasture-based beef production in a severely water-limiting environment. This will lead to guidelines for producers for how to most effectively and profitably integrate grazing into their farming system while they transition from high-irrigation row-crop monoculture to allocating limited water to smaller acreages and to dryland production.
The Forage and Livestock Field Day was held on July 9 with 100 participants as an outreach effort sponsored by the Texas Alliance for Water Conservation (TAWC). Producers learned about soil health, pasture establishment, annual forages, integration of low-irrigation-input grazing into cropping systems, irrigation innovations, cattle handling, OWB hay and seed production, dryland native-pasture options, and cattle nutrition. The highlight of the field day was an after-lunch discussion and question-answer session with two prominent local producers who have successfully integrated the use of pastures into their annual cropping systems as a profitable method of dealing with reduced irrigation supply from the Ogallala aquifer. The producers were able to relate their decision-making on crop and forage diversification to the topics demonstrated in that morning’s field day tours. The event was recorded on video by the communications personnel and posted on the TAWC web site. A local television station recorded field scenes and interviews with participants for local programing. The field day was partially financially supported by SSARE with a $10,000 grant. We greatly appreciate this grant because it allowed us to hire buses, rent a tent with tables and chairs, and print programs and proceedings for participants.
Graduate student Lisa Baxter received a grant from the SSARE graduate student program GS15-152 titled “Evaluation of winter annual cover crops under multiple residue management: Impacts on land management, soil water depletion, and cash crop productivity.” The winter cover crops were planted in October of 2015. Soil water and plant measurements were made over the 2015-2016 winter period. This effort is an extension of the long-term research and outreach efforts supported by SSARE in this Large Systems program.
Impacts and Contributions/Outcomes
Over the entire history of this project since an initial SARE grant in 1997, the amount of information and student education, thesis, field days, instructional videos, handouts, presentations, and journal articles has been enormous and indicates the potential return on investment in long-term research and education. Output from this effort continued in 2015 as shown by the publications, presentations, and major grant proposals submitted.
A major effort in 2015 was our collaboration with SSARE Public Relations Coordinator, Candace Pollock, for the production of the Topic Room website called Water Conservation on the High Plains (http://www.southernsare.org/highplainswaterconservation). This Topic Room links to all the output from the TeCSIS program since created by its founder, Dr. Vivien Allen, in 1997. Of especially high impact, is a suite of 11 bulletins (accessed from the Education Resources link) which explain in detail the innovative approaches and results from SSARE-funded research by the Texas Tech forage program. We worked very closely with Candace to provide text and photographic content and editing the resulting bulletins and other content in the Topic Room. We greatly appreciate the efforts of Candace in pulling together the many years and volumes of output from this program.
Besides the use of SSARE funds to maintain research at the New Deal Research Station, another critical component of the Large Systems effort is occurring thanks to funding from the Texas Water Development Board for the outreach effort in the TAWC project. That project has been very successful in reaching farmers and disseminating information on best practices for managing irrigation. The Forage and Livestock Field Day of July 2015 showcased the advances in forage research and how we apply wise water management as an option for producers to sustain their operations amid the decline of groundwater supplies for row-crop irrigation. This is an example of how the support of research infrastructure at the Texas Tech New Deal Research Station has been leveraged to amplify the transfer of sustainable agricultural technology in the Southern High Plains.
Through SARE support for this Large Systems research we will continue to seek ways to conserve, cooperate, educate and strive to continue to solve the ever-pressing issues of sustainability and the challenges to agriculture today.
Creative Output and Presentations
West, C.P., S. Borgstedt. 2015. TAWC Infographic: Animated video on YouTube, 2:37 duration. Technical production by Ramar Communications, Lubbock, TX. https://www.youtube.com/watch?v=N9kOgTtmnVI.
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.
Xiong, Y., C.P. West, and C.P. Brown. 2015. Digital image analysis of Old World bluestem canopy cover to predict leaf area and yield. Poster presented at Ogallala Aquifer Program annual meeting, March 12-13, Manhattan, KS.
West, C.P., C.P. Brown, R.L. Kellison, D.M. Mitchell, P.N. Johnson, and W.J. Pate. 2015. Ten-Year Comparisons of irrigation use from the Ogallala Aquifer in the Texas South Plains. In Annual meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
Baxter, L.L., C.P. West. 2016. Comparison of productivity, efficiency, and profitability of grass-only and grass-legume beef stocker grazing systems in the Southern High Plains. American and Forage and Grassland Council Annual Conference, 10-13 January, Baton Rouge.
Baxter, L.L., and C.P. West. 2016. Comparison of traditional and novel non-destructive techniques for assessment of botanical composition in grass-legume pastures. American and Forage and Grassland Council Annual Conference, 10-13 January, Baton Rouge.
West, C.P., R. Kellison, C.P. Brown, P.N. Johnson, D.L. Doerfert, and S.J. Maas. 2015. Conservation of irrigation water in the Texas High Plains: Texas Alliance for Water Conservation. World Environmental & Water Resources Congress, 18 May, 2015, Austin, TX. Environmental & Water Resources Institute.
West, C.P. 2015. Co-organized and spoke on using alfalfa in low-irrigation pastures at Forage and Livestock Field Day, New Deal, TX, July 9, 2015.
West, C.P. 2015. Use of WW-B.Dahl pasture management at 3rd annual Southwest Ranchers Roundtable, Lubbock, TX, July, 2015.
Sustaining agriculture through adaptive management resilient to a declining Ogallala Aquifer and changing climate. Meagan Schipanski (CSU, Lead PI) and 12 co-PDs including C.P. West. USDA-NIFA-AFRI CAP. $10,000,000. My share $294,638 over 4 years. Funding starting in 2016.
West, C.P. received the Service/Outreach Award by the Texas Tech College of Agricultural Sciences and Natural Resources for high impact efforts at disseminating information on conservation of ground water for irrigated crops and pastures.