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 was finished and degrees were conferred in 2018 for 1) analysis of soil microbial communities and horn flies on cattle in pastures (Krishna Bhandari), and 2) cattle grazing teff grass with different protein supplements (Dusty Sugg). Doctoral research in the field was finished and degrees were conferred in 2019 on 1) growth analysis and model development of old world bluestem (OWB) ‘WW-B.Dahl’ (Yedan Xiong), and 2) introduction of alfalfa into dryland native pastures (Madhav Dhakal). Doctoral research was initiated in 2018 on determining the effect of including alfalfa in old world bluestem-based pastures on enteric methane emissions from beef cattle and on whole-system water footprint (Kathryn Radicke).
We continued to integrate our efforts with the Texas Alliance for Water Conservation (TAWC) to broaden the impact of grassland water use efficiency. The TAWC involves demonstration and education for local producers on efficient irrigation systems. It is funded by the State of Texas but intersects with this Large Systems SARE-funded project, which serves as a platform for consulting with producers on converting land from irrigated, cultivated row crops to perennial forages as an option to reduce reliance on the Ogallala Aquifer. Visits to the site by producers, students, and other professionals were also conducted during the year.
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 is the TAWC, which partners with 20-30 producers to demonstrate improved irrigation practices on around 30 fields near Lubbock, TX. TAWC produces field days, field walks, conferences, radio and TV reports, Twitter and Facebook messages, e-newsletters, and web-based management tools 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) fewer acres of irrigation overall and increased acres of limited-acreage, high-value crops, (2) continual improvements in water use efficiency of major row crops such as cotton and corn, (3) partial replacement of irrigated row crops with perennial grasses and legumes, water-efficient sorghum and millet crops at low irrigation, and with dryland crops, (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, (6) greater use of cover crops with dual use as forages, and (7) 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.
The final analyses of data from the insect and soil health trials of 2016 and 2017 were accomplished, plus analysis of essential oils in old world bluestem were run in 2018.
The third year of field data were taken in a trial to test the effects of interseeding alfalfa into dryland native grass pastures on forage yield, quality, and competition for soil water. The treatments consisted of high and low density row spacings (14 inch and 28 inch spacings), and three contrasting alfalfa cultivars (two hay types and one grazing type). The first year of new grazing trial was initiated comparing old world bluestem grass growing alone but receiving 60 lbs/acre of N fertilizer per year vs. bluestem growing with interseeded alfalfa but receiving no N fertilizer. Soils were sampled for methane emissions, and enteric methane emissions were measure on grazing steers. This trial will be continued in 2019 and 2020.
Old World bluestem strongly deterred the deleterious fire ants and harvester ants, even when alfalfa was growing with this grass. This deterrence effect contributes to the resilience of Old World bluestem and to its favorable use as a companion grass with alfalfa. Native grass pastures contained the greatest number of pollinator insects such as native bees, but also contained the most deleterious-type ants. Old World bluestem contained only modestly fewer pollinators than the native grass pastures. Old World bluestem contained essential (volatile) oils that gave off a characteristic aroma in late summer, which have been linked to deterrence of various deleterious insects. The most consistently found oils were acorenone-B, camphene, and naphthalene, which may have caused the deterrence of fire ants. Measurements of microbial and enzyme activities and organic matter content of soil indicated the greatest level of soil health in the mixtures of Old World bluestem and alfalfa, even out-performing monoculture stands of those two forages. Results provide strong evidence of WW-B.Dahl Old World bluestem as a sustainable perennial grass for the water-limited Texas High Plains. Six journal articles were published in 2018 on research pertaining to insects and soil health in relation to forage production and water conservation. Two articles were published in 2019 pertaining to essential oils in bluestem and the role of interseeding alfalfa into bluestem on increasing fungal populations that improve soil quality. This body of work builds on previous work on pasture soil health started by Dr. Vivien Allen in collaboration with Drs. Acosta-Martinez and Moore-Kucera, previous recipients of Southern SARE funding.
An extensive field trial was completed in 2018 on the effects of interseeding alfalfa on the water use, forage yield, and forage quality of nonirrigated native grassland. Results after 3 years showed that alfalfa can survive with native grasses without irrigation on a good soil in west Texas when growing at low density. Widely spaced plantings of alfalfa (28-inch spacing) caused only mild depletion of soil water compared to the non-alfalfa (pure grass) control; whereas the narrowly spaced planting (14 inch) significantly reduced soil water content, indicating excessive competition against the grass for soil water. The higher-density planting of alfalfa thinned down to the lower-density planting within 3 years. The low-density alfalfa substantially increased forage yields of dry matter, protein, and digestible energy over the pure grass control, at only half the seed cost of the dense planting. Results indicate that a well-adapted variety of alfalfa can significantly improve dryland pasture in the Texas High Plains at very low cost without depleting soil water reserves. Four journal papers were accepted for publication in 2019, and a fifth paper will be accepted in 2020.
A short study was undertaken in 2018 as part of the Harrison Hill Jr. Young Scholar Enhancement Grant program (grant LS17-286). Under the supervision of Drs. Lindsey Slaughter and Chuck West, Paxton Hughes measured methane gas exchange between pasture soils and atmosphere in the New Deal pastures. Pastures consisting of Old World bluestem with alfalfa (received no N fertilizer) net-absorbed methane from the atmosphere, whereas bluestem without alfalfa (received N fertilizer) net-emitted methane. Results indicate that interseeding alfalfa into perennial grass pastures grazed by cattle can reduce the net amount of methane emitted from the pasture-livestock system relative to pastures with no legume and obtaining its N from synthetic fertilizer instead of from biological fixation.
In 2018 we initiated a grazing trial comparing two systems, perennial + annual grasses with no legumes but receiving 60 lbs./acre of N fertilizer, and perennial + annual grasses with legumes. The perennial grass was WW-B.Dahl Old World bluestem and the annual was peal millet, growing in separate pastures to allow rotation grazing between the two grass types. The legumes were alfalfa and yellow sweet clover with the bluestem and cowpea with the pearl millet. Cattle gained an average of 2.46 lbs/steer-day on the grass + N system and 2.55 lbs./steer-day on the grass-legume system. Those means were not statistically different, and are both considered quite high for these pastures. Enteric methane production per steer-day did not differ between treatments. This trial was repeated in 2019 and will be summarized in next year’s report. Data analysis will include ratios of methane produced per lb. of forage dry matter intake and ratios of amounts of irrigation water applied per unit of liveweight gain and per unit of methane produced.
Graduate student, Kathryn Radicke, was awarded a graduate student grant (SARE# GS18-196) in late 2018 titled “Effects of cumulative cattle trampling on soil bulk density and infiltration on an annual pasture.” The field tasks were carried out in 2019. She will provide a final report in April, 2020 that includes analysis of the 29019 results.
The grazing and related forage research at the Texas Tech New Deal Field Research Station is a Large Systems project for which Southern SARE supports the maintenance and routines supplies for conducting integrated forage-livestock research. We superimpose educational activities on the pasture facilities which include visits by farmers and ranchers, foreign visitors, TTU classes in forage and livestock production, and training of graduate students. In 2018 we hosted 30 agricultural students and instructors from the University of Queensland, Australia, who were touring several universities. These students were here on a course for credit for which they had to write term papers. For that reason, they were highly motivated to ask questions on the management of water, nutrient cycling, greenhouse gases, and other factors related to grassland sustainability. Dr. West’s two classes titled Forage and Pasture Crops, and Forages and Livestock Pasture Ecosystems met at the pastures for instructions on plant identification and grazing management. Threes graduate students of Dr. West and one graduate student of Dr. L. Slaughter conducted research on the same pastures pertaining to soil health. Dr. Slaughter and Dr. West supervised an undergraduate student to conduct a short research project on methane emission from soil as part of the Southern SARE Young Scholar Enhancement Grant Program. Finally, summaries of the research and demonstration results were included in electronic newsletters that were distributed to 500 subscribers who follow the outreach activities of the Texas Alliance for Water Conservation.
Educational & Outreach Activities
Invited as the Leu Distinguished Lecturer at the University of Nebraska, Center for Grassland Studies, on sustainable forage-livestock systems with limited resources.
Speaking to community group on reducing water use in beef production, and to individual farmers on agronomic methods of establishing improved pastures and how to use alfalfa to enhance forage quality at low water input.
Co-investigator of a 6-state USDA-NIFA funded project on irrigation efficiency to which I bring in integrated crop-livestock aspects.
Directing undergraduate and graduate students in applied research on grassland soil health and cover crops.
Research summaries in the e-newsletter of Texas Alliance for Water Conservation (TAWC).
Farm tours and grazing demonstrations for classes from Texas Tech University and other universities.
Presentations or co-authorships for 7 water conservation conference and 1 grassland conference on the role of forage-livestock systems in conserving irrigation water and adapting to climate change.
Co-advised one undergraduate student on a Southern SARE Young Scholar Enhancement Grant.
The same types of activities are planned for 2019-2020.
Publication citations in 2018 on work related to water conservation in irrigation and in grassland-livestock systems; senior authors noted by * are advisees of Dr. West:
Cano, Amanda, A. Núñez, V. Acosta-Martinez, M. Schipanski, R. Ghimire, C. Rice, and C. West. 2018. Current knowledge and future research directions to link soil health and water conservation in the Ogallala Aquifer region. Geoderma 328:109-118. doi:10.1016/j.geoderma.2018.04.027
*Bhandari, Krishna B., C.P. West, and S.D. Longing. 2018. Fly densities on cattle grazing ‘WW-B.Dahl’ old world bluestem pasture systems. Texas J. Agric. Nat. Res. 31:T1-T5.
*Bhandari, K.B., C.P. West, S.D. Longing, C.P. Brown, and P.E. Green. 2018. Comparison of arthropod communities among different forage types on the Texas High Plains using pitfall traps. Crop Forage Turfgrass Management Vol. 4(2):180005. doi:10.2134/cftm2018.01.0005.
West, C.P., and L.L. Baxter. 2018. Water footprint of beef production on Texas High Plains pasture. Water International 43:887-891. doi:10.1080/02508060.2018.1515574
*Bhandari, K.B., C.P. West, V. Acosta-Martinez, J. Cotton, and A. Cano. 2018. Soil microbial communities, enzyme activities, and total carbon and nitrogen as affected by diverse grasses and grass-alfalfa in pastures. Appl. Soil Ecol. 132:179-186. doi:10.1016/j.apsoil.2018.09.002
*Bhandari, K.B., C.P. West, S.D. Longing, C.P. Brown, P.E. Green, and E. Barkowsky. 2018. Pollinator abundances in semi-arid pastures as affected by forage species. Crop Sci. 58:2665-2671. doi:10.2135/cropsci2018.06.0393
*Bhandari, K.B., C.P. West, and S.D. Longing. 2018. Communities of canopy-dwelling arthropods in response to diverse forages. Agric. Environ. Letters 3(1):180037 (online) doi:10.2134/ael2018.07.0037
Rudnick, D.R., S. Irmak, C.P. West, I. Kisekka, T.H. Marek, J.P. Schneekloth, D.M. McCallister, V. Sharma, K. Djaman, J. Aguilar, J.L. Chávez, M. Schipanski, D.H. Rogers, and A. Schlegel. 2018. Deficit irrigation management of maize above the High Plains Aquifer: A review. J. Am. Water Res. Asso. 55:38-55.
Significant interest in how to transition from monoculture cropping to diversified crop-forage-livestock systems as a means of coping with the reduction of the Ogallala Aquifer.
Conversion of formerly irrigated row cropland to perennial grasses for grazing
Improving dryland forage yield and quality by interseeding alfalfa into grasslands
Management of reduced irrigation use on forages
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. The research output and education events at the New Deal research farm tie into broad-scale efforts to disseminate scientifically tested advances in water use, soil management, and integration of crops and livestock in an environment where the main driver of farm profitability and rural economy has been the Ogallala Aquifer, now in decline. These broader efforts include the TAWC, which directly impacts landowners and decision-makers, commercial companies dealing with crop consulting, irrigation equipment, and improved cultivars, collaboration with other institutions with complementary missions such as USDA-NRCS, and finally the greater mission of Texas Tech University in educating students and visitors on land and water sustainability. These efforts demonstrate that 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.
In the 2017 annual report, the significant finding was reported that a 3-year grazing trial analyzed by Lisa Baxter showed greater stocker steer liveweight gains when grazing a pasture rotation system that contained alfalfa compared to grazing grass only, and that the grass-legume system resulted in a lower water footprint for beef liveweight gain; all this with only 7-8 inches (average) of irrigation. These results were the core messages of two symposium talks that Dr. Chuck West was invited to give in 2018 on sustainable beef cattle systems, 1) annual meeting of the American Society of Animal Science, and 2) Leu Distinguished Lecture Series at the Center for Grassland Studies at the University of Nebraska. The current grazing trial (2018-2020) follows up on the relationship between legume presence and efficient was use. Other studies by graduate students Krishna Bhandari, Madhav Dhakal, and Yedan Xiong deepened our knowledge on insects, soil health, drought tolerance of Old World bluestem, and the strong role that alfalfa can play in enhancing forage yield and quality and cattle productivity at very low water input and without nitrogen fertilization. Collaboration with Dr. Lindsey Slaughter, soil microbial ecologist, has expanded our study of greenhouse gas emissions from soil. Collaboration with Dr. Darren Henry, ruminant nutritionist, opened up the technology for measuring enteric methane emissions from grazing cattle. Collaboration continued with Dr. Sanjit Deb on soil physics and hydrology to better understand how water moves and is stored in these pasture soils. These collaborations enable us to integrate more thoroughly the aspects of water, nitrogen, and carbon cycling at the soil, plant and animal levels so that efficiency of all resources are maximizing in the fragile environment of the Texas High Plains.
WW-B.Dahl old world bluestem is the best perennial grass forage to grazing by beef cattle because of its low water needs, persistence, deterrence of harmful insects (e.g. fire ants), tolerance to continuous grazing, flexibility in use for grazing, stockpiling, and hay, and its good nutritional quality. Plus, it is compatible with alfalfa in mixture.
Alfalfa is the most productive and reliable legume to use in forage systems in the Texas High Plains thanks to its extremely high nutritional quality, persistence with moderate to low irrigation input, compatibility with old world bluestem and rainfed native grasses, and deep roots to extracting water. Alfalfa has excellent potential as a low cost (with low seeding rate) addition to rangeland having appropriate soils to improve forage yield and quality without causing significant additional soil water extraction.