2014 Annual Report for LS14-261
Long-term AgroEcosystems Research and Adoption in the Texas Southern High Plains – Phase II
Summary
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. A Master’s thesis was completed and doctoral research initiated on growth analysis of Old World bluestem. Two other doctoral projects were initiated involving 1) cattle grazing Old World bluestem with and without alfalfa, and 2) relation between Old World bluestem and insects in pasture and on cattle. Steers gained weight at 1.8 lbs/day in both pasture treatments. Fly density on steers was reduced when grazing Old World bluestem compared with bluestem-alfalfa mixtures. The annual grass teff produced 1.86 tons/acre of hay in one cutting with 0.6 inches of irrigation. Outreach presentations included descriptions of forage establishment and how pasture systems can reduce water use for irrigation.
Objectives/Performance Targets
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.
Accomplishments/Milestones
Total precipitation at the New Deal Research Station in Nov. 2013-Oct. 2014 (our cropping year) was 22.8 inches (long-term average is 18.5 inches), and April-September precipitation was 21.8 inches (long-term average is 13.2 inches). Thus practically all the annual rainfall occurred during the April-September growing season thereby affording relief from drought and reducing irrigation needs. We normally target irrigation levels in April-September to not exceed 12 inches for alfalfa/tall wheatgrass pastures and 9 inches for the WW-B.Dahl Old World bluestem pastures, with or without alfalfa. The native grass pastures do not normally receive irrigation.
Favorable rainfall in September (5.55 inches) coincided with the reseeding of alfalfa and yellow sweet clover in the WW-B.Dahl pastures that constituted the Old World bluestem-legume mixtures. Those mixtures were created in 2009 by sod-seeding those same legume species into an old stand of WW-B.Dahl. The sod-seeding in September 2014 was very successful in that there was excellent emergence, and spring 2015 observations indicate good winter survival and seedling growth. We expect this effort to result in an increase in legume cover from 9% in December 2013 to around 50% in 2015.
Other activities in the 2014 reporting year included the second (final) year of a Master’s thesis on the use of a digital camera to record overhead images of WW-BDahl grass throughout its growing season. The objective was to determine whether a free, image analysis software (ImageJ) could process the photos to distinguish between live, green leaf area and background dead and bare areas, calculate live cover area, and establish relationships between those values and leaf area index and forage yield. Results indicate that image analysis provided rapid ground cover data, and that positive predictive relationships to leaf area and forage yield were obtained. Figure 1 shows an example of a photo of the grass canopy. Figure 2 shows a processed image of that photo in which green leaf area is converted to black on white for calculating green leaf area. This technique allowed calculation of a large number of photos for accurate ground cover measurements, thus obviating the need for very labor-intensive measurements. Figures 3 shows linear trends in growth in 2014 in early summer (Period 1) and late summer (Period 2). Figures 4 and 5 indicate how ground cover (based on image analysis) was a good predictor of percent light interception and leaf area index. These data and the ensuing doctoral research will lead to enhanced predictive models of WW-BDahl growth and water use to be used by farmers in planning grass yields and water needs.
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 included grass-only consisting of cattle spending 75% of the time grazing Old World bluestem (receiving 60 lbs/acre of nitrogen) and 25% native grass mix, and grass-alfalfa mixture (no nitrogen added) with cattle having three-times-per-week access to grazing alfalfa/tall wheatgrass (95% alfalfa) for half a day each time, as a supplemental protein bank. Over the entire season, steer weight gains averaged 1.9 lbs/head per day and were not affected by the presence or absence of alfalfa. In addition to all pastures receiving 14.6 inches of rain in June through August, irrigation was applied at 5.1 inches for alfalfa/tall wheatgrass, 6.1 inches for bluestem/alfalfa, and 7.1 inches for pure bluestem. Therefore total amounts of water received over the grazing months ranged from 19.7 to 21.7 inches, which was within the normal range we expect to provide.
Another doctoral study characterized insect populations in WW-B.Dahl 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 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.
We harvested one cutting of hay from extra (ungrazed) bluestem fields, teff, and alfalfa/tall wheatgrass. Yields averaged 2.63 tons/acre for bluestem, 1.86 tons/acre for teff, and 1.03 tons/acre for alfalfa/tall wheatgrass. We also harvested 80 lbs/acre of bluestem seed (bulk basis). We expect that seed harvest to clean out at 50% pure live seed. We observed that the annual grass teff established easily, provided one good hay cutting under only 3.1 inches of irrigation, and provided a residual stubble that afforded excellent soil protection from wind.
A small-plot trial was planted with alfalfa to evaluate cultivars and experimental lines for drought tolerance, in collaboration with Dr. Ian Ray of New Mexico State University. Unfortunately, a late planting in mid-October followed by several severe frosts during the winter resulted in loss of the alfalfa stands. The trial will be replanted in 2015.
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 2014 as shown by the publications, presentations, and major grant proposals submitted.
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. A forage and livestock field day is planned for July 2015 to showcase 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.
Numerous presentations were made by TeCSIS and TAWC personnel to local commodity groups, producers, researchers, and elementary schools.
Through SARE support for this 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.
Journal articles published:
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.
International, national, and regional presentations:
West, C.P., R. Kellison, S.J. Maas, C.P. Brown, S. Borgstedt, P.N. Johnson, D.L. Doerfert. 2014. Regional opportunities and challenges - High Plains. D. Reible (ed.). p. 36-39. 2014 Texas Water Summit Report: Securing our Economic Future. The Academy of Medicine, Engineering, and Science of Texas (TAMEST), Austin, TX. Available at: http://www.tamest.org/publications/event-publications.html, 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. 2014. Promoting conservation of irrigation water in the Texas High Plains. In Annual Meetings abstracts [CD-ROM]. ASA, CSSA, and SSSA, Madison, WI.
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.
West, C., R. Kellison, S.J. Maas, C.P. Brown, S. Borgstedt, P.N. Johnson. 2014. TAWC 2013 Annual report to Texas Water Development Board, Austin, TX.
West, C.P. 2014. Changes in irrigation practices in High Plains crop production. Texas Tech Climate Science Center Seminar series. May 6, 2014.
West, C.P., and R.L. Kellison. 2014. Impacts and recommendations of TAWC project. Region O planning meeting on water policy. April 23.
West, C.P. 2014. Forage and water research at Texas Tech. North Central Coordinating Committee-31, Ecophysiological Aspects of Forage Management. Grand Rapids, MI. June 17-18.
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.
Master’s Thesis:
Yedon, Xiong, 2014. Digital image analysis of Old World bluestem canopy cover and leaf area. M.S. Thesis. Texas Tech University, Lubbock.
Proposals submitted:
Enhancing the viability of forage sorghum for beef cattle production in the Southern Great Plains. S. Trojan, C.P. West. Advanta US. $149,952. Funded.
Improving alfalfa productivity for water-limited environments of the U.S. Great Plains. C.P. West, I.M. Ray, and A. Boe. USDA-NIFA-AFRI. $156,051. Not funded.
Circles of live buffer strips in a center pivot to improve multiple ecosystem services and sustainability of irrigated agriculture in the Southern Great Plains S. Angadi, P. Gowda, C.P. West, T. Zobeck. USDA-NIFA-AFRI. $499,946.
Sustaining agriculture through adaptive management resilient to a declining Ogallala aquifer and changing climate. C. Rice, D. Devlin, K. Wagner, B. Guerrero, P. Gowda, M. Marsalis, C.P. West. USDA-NIFA-AFRI Water Challenge CAP. $4,999,432. Not funded.
Water-renewable energy nexus for empowering women smallholder farmers in rural Ethiopia. C.P. West, S. Misra, V. Uddemari, C. McKenney. Securing Water for Food: A Grand Challenge for Development Competition. $200,000.
Systems based strategies to improve our ability to plan and respond to water scarcity and drought in groundwater dependent arid and semi-arid regions of the US. V. Uddameri, D. Reible, K, Hayhoe, C. West, G. Cummins, A. Hernandez, T. Udeigwe. $1,000,000. U.S. EPA. Pending.
Improving water productivity and new water management strategies to sustain rural economies. C.P. West, et al.. Ogallala Aquifer Program (USDA-ARS). $67,851 requested, $20,000 funded.
Pre-proposals submitted:
Transitioning Texas High Plains agriculture toward low water use with integrated pastures and livestock. C.P. West, S. Trojan. USDA-Southern SARE. $219,942. Not promoted.