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ARS Home » Southeast Area » Booneville, Arkansas » Dale Bumpers Small Farms Research Center » Research » Research Project #436698

Research Project: Sustainable Small Farm and Organic Grass and Forage Production Systems for Livestock and Agroforestry

Location: Dale Bumpers Small Farms Research Center

2020 Annual Report


Objectives
Objective 1. Management systems for improved growth, handling and storage of harvested biomass for optimized quality and utilization for improved livestock management and positive environmental benefits. Sub-objective 1A. Forage and biomass production systems that better utilize nutrients to increase productivity and/or reduce energy and nutrient input requirements. Sub-objective 1B. Biomass harvest and storage systems that enhance the value of the feedstock for livestock production. Sub-objective 1C. Efficient strategies for producing livestock on forage-based diets, targeting optimal productivity. Sub-objective 1C1. Identification and selection of animal phenotypes that are productive and thrive on low-input pasture systems to minimize management inputs. Sub-objective 1C2. Understanding grazing behavior and spatial distribution of sheep naturally infected with gastrointestinal nematodes. Objective 2: Develop integrated tools to foster improved management of pasture and forages which maintain productivity while providing economic and environmental benefits. Sub-objective 2A. Measuring and monitoring system status and function at various scales. Sub-objective 2A1. Develop tools to identify environmental factors affecting forage production to maximize productivity and environmental/ecosystem benefits in diverse environments. Sub-objective 2A2. Utilize spatial information to develop site specific recommendations for warm season forage species, nutrient requirements and economic inputs for improved farm management. Sub-objective 2B. Provide tools that support management decisions and aid implementation. Sub-objective 2B1. Determine site specific recommendations coupling soil water availability with nutrient requirements to optimize forage production for economic sustainability. Sub-objective 2B2. Farm-scale recommendations that provides a decision support tools for producers that will allow optimization of farm management for whole farm productivity, economic viability and environmental sustainability. Sub-objective 2C. Pasture-based livestock management practices that improve resilience to climate change, conserve soil or protect water quality, optimizing production, conservation and environmental goals. Sub-objective 2D. Targeted grazing strategies to reduce invasive grasses and forbs and promote desirable perennial grasses and woody species. Sub-objective 2E. Grazing management strategies for maintenance of a diverse native plant pasture that serves livestock and wildlife including native pollinators. Sub-objective 2E1. Impact of grazing on insect pollinators and beneficial arthropod community in pasture ecosystems designed for multiple use of livestock grazing and pollinator habitat. Sub-objective 2E2. Impact of native forbs and grasses on insect pollinators and beneficial arthropods and plant- pollinator interactions in pasture ecosystems designed for multiple use of livestock grazing and pollinator habitat.


Approach
Our goal is to increase long-term sustainability of small farms by integrating management of pasture and silvopasture-based livestock systems to augment whole-farm productivity and profitability, encourage crop diversification which spreads biological and financial risk, and enhances ecosystem services. Involving both short- and long-term studies, we will determine practices that provide environmental and economic benefit to small farms. Studies will focus on improving forage and/or livestock production while enhancing soil, landscape and forage attributes at multiple scales. These studies include examining conventional and nonchemical parasite control on sheep production efficiency, grazing management on forage finished beef and lamb, and improving nutrient-use efficiency on forage pastures. Additionally spatial information will be used to understand interactions at multiple scales to develop decision support tools for increasing efficiency for soil-forage system management. We will also continue a long-term study that utilizes controlled watersheds to determine the impacts of various pasture management strategies (rotational grazing, overgrazing, haying, tree buffers) on pasture hydrology and nutrient runoff. To evaluate diversification, we will examine effects of integrating agroforestry management with crop and/or livestock production.


Progress Report
Objective 1. A project was initiated on determining the effects of seeding date, population, and environment on intermediate wheatgrass establishment, phenology, and grain yield. ARS scientists networked with Kernza researchers, which has led to many productive outcomes. This includes participation in a multi-state study with scientists from the University of Minnesota, The Land Institute, Montana State University, and Texas A&M University. Treatments, which consist of four lines of intermediate wheatgrass developed by The Land Institute, the University of Minnesota, and USDA-ARS and five fall planting dates, were established in the fall of 2019 and data collection began earlier this spring. Treatments will be harvested and shipped to a collaborator who is processing grain samples this summer. Subobjective 1C1.1. In order to understand limitations to the success of out-of-season breeding, up to 200 ewes in 2018, 2019, and 2020 from both organic and conventional management systems were studied. Age of ewes ranged from 8 months to up to 10 years. Ewes were exposed to rams in May/June (out-of-season) and August/September (natural breeding period) in each year. Pregnancy rate was determined 30 days after ram removal each breeding period. Body weights, body condition, hair coat score, rectal temperature, pregnancy and lambing rate were recorded in each year. Blood samples were collected and analyzed in 2018 and 2019 to determine serum concentrations of progesterone, prolactin and cytochrome P450. Statistical analyses are pending. Another small study on a subset of ewes was conducted in 2019 and 2020 to determine the effect of endophyte-free or -infected tall fescue on serum concentrations of prolactin, rectal temperature weekly during breeding. Once spring 2020 samples have been analyzed, data will be analyzed statistically, and manuscripts prepared. A related study was completed and published that examined the concentrations of anti-Mullerian hormone in serum as an indicator of fertility. No relationship was found, but estimated breeding values determined by flock data submitted to the National Sheep Improvement Program were highly correlated with the lambing rate of ewes. Subobjective 1C1.3. Five thousand sheep from 21 farms across the U.S. have been genotyped. All sheep had phenotypes for parasite resistance (fecal egg counts determined around the time of weaning). Quality control measures will be applied before genome-wide association studies will be conducted which will identify possible genetic loci associated with resistance to gastrointestinal nematodes. A study on a smaller sub-population has been published. An additional 600 samples from the same population will be genotyped for a more in depth look at genes responsible for parasite resistance. Subobjective 1C2. Weaned lambs that were naturally infected with gastrointestinal nematodes (GIN) were fitted with GPS collars for 72 hours weekly for six weeks to examine behavior. Measures of GIN infection (fecal egg counts, packed cell volume), rectal temperature and body weights were determined every 7 days. The study did not occur in 2020 due to the pandemic. Previously obtained data is being analyzed this year. The study will be repeated in 2021. Subobjective 2A1. Develop tools to identify environmental factors affecting forage production to maximize productivity and environmental/ecosystem benefits in diverse environments. The sites for this research project have been identified and tall fescue and bermudagrass forages have been established in the spring of 2020. This experiment will use a split-split-split plot treatment design, with the forage species being the whole block, soil type/landscape position being the split-plot, and fertility rate being the sub-plot. 2A2. Utilize spatial information to develop site specific recommendations for warm season forage species, nutrient requirements and economic inputs for improved farm management. The study is being conducted in a silvopasture research site at the University of Arkansas located in Fayetteville, AR. It consists of 16 east-west oriented tree rows on variable topography. The alleys between the tree rows were seeded to with forages and are utilized for grazing. In 2020, maps of digital soil properties have been created using fuzzy k-means clustering and inference models. Additionally, an electromagnetic conductivity survey has been completed as an input layer for the co-variates in summer of 2020. Additionally in the winter of 2020, ground penetrating radar was used within 5 transects to identify depth to restrictive layers within the site. Point data has been collected and analyzed for 51 points using a stratified sampling scheme. Subobjective 2B. Provide tools that support management decisions and aid implementation. Replicated fields have received applications of fertilizers and herbicides with tractor guidance on and with tractor guidance off. The goal is to determine the efficiency of GPS guided tractors to minimize gaps and overlaps on field. % fields were driven with 3 different employees with different levels of experience. The field shapes and topography are different and are added to the analysis. The data are currently being analyzed and prepared for publications. 2B1. Determine site specific recommendations coupling soil water availability with nutrient requirements to optimize forage production for economic sustainability. The study is being conducted in a silvopasture research site at the University of Arkansas located in Fayetteville, Arkansas, which is the same site used for subobjective 2A2. Maps of digital soil properties have been created using mathematical clustering and computer models. Additionally, a survey was completed using an instrument to continuously record the electromagnetic conductivity at multiple depths in an agroforestry site. Additionally, ground penetrating radar was used within 5 transects to identify depth to root restrictive layers within the site. Point data has been collected and analyzed for 51 points using a stratified sampling scheme. The continuous property maps are in the process of being clustered to identify soil populations that function similarly. Subobjective 2B2. To determine farm-scale recommendations for a decision support tool has been initiated. The goal is to provide optimization of farm management for whole farm productivity, economic viability and environmental sustainability. Our Center is the location for the initial project and samples have been collected based on a stratified soil landscape sampling scheme. The data is in the process of being analyzed. Subobjective 2B2. Currently, data from a cover crop termination study has been compiled and a full trial began summer 2020. Currently, an okra cover crop has been established and baseline soil samples have been collected in collaboration with a scientist with the Department of Crop, Soil, and Environmental Sciences at the University of Arkansas. Termination and fertilization treatments, which include no-till methods for terminating a cover crop and the use of the sub-surfer, developed at DBSFRC, to apply poultry litter will be applied in the fall of 2020. The goal of this research is to identify cover crop management approaches that conserve soil resources while reducing pest pressure to produce high quality, profitable organic small grains. Preliminary data has been used to drive treatment selections for the full trial and will be used to pursue grant funding. The COVID-19 pandemic has delayed the full trial, but efforts are currently being made to establish an okra cover crop, a newly emerging cover crop in the U.S., to continue as planned. Subobjective 2C. One project has been initiated in FY20 to evaluate Silphium as a potential alternative warm season forage. ARS scientist have successfully formed collaborations with scientists at The Land Institute to conduct research on Silphium as a multi-use, perennial oilseed and forage crop. A team of scientists from the University of Florida, various ARS locations including Gainesville, Florida, Mandan, North Dakota, and Fargo, North Dakota, are working to evaluate more of Silphium’s ecological (pollinators and other beneficial insects) and livestock-related benefits (plant secondary compound production and greenhouse gas emission reductions). Currently, three species of Silphium have been established in the greenhouse by ARS scientists and an initial greenhouse trial to evaluate its response to defoliation and fertilization is planned this year. Subobjective 2E1. A study was conducted to examine the effects of grazing or no grazing of plots planted with native grasses and forbs important for pollinator habitat. Arthropod samples were collected using multiple collection devices (pan traps, nets, blue vein traps) to determine species and prevalence of pollinators within each grazing management treatment in 2018 and 2019. In 2020, thousands of arthropod samples are being speciated and counted, and statistical analyses will follow. Subobjective 2E2. A study was conducted to examine sampling methods (use of four different color pan traps) of collecting arthropods (pollinators) in native grass and forb plots. A total of 16 pan traps (n=4/plot/color type) were randomly deployed from mid-July to mid-August 2018 and 2019. These traps were placed in an elevated platform (~1.25 m) at the distance of 25 m apart in each sampling transect. Traps were filled with soapy water at ~ 24 hours before the sample collection, and samples were collected 4 times a week. All samples collected from pan traps were stored in plastic vial containing ethyl alcohol until processed in 2020. Preliminary results reveal bees as a major pollinator in different color pan traps, followed by other groups of flowers visiting insects such as beetles, flies, and butterflies. Thousands of arthropod samples are being speciated. Statistical analyses will follow.


Accomplishments
1. Development of genomic tools to identify gastrointestinal parasite resistant sheep. Perhaps the most important means of parasite control is parasite resistance within an animal. Genetic resistance to parasitic nematode infection (measured by low fecal egg counts relative to flock/herd mates) varies among individuals within a breed and is known to be moderately heritable; identification of genetic markers of resistance will have wide benefit in the sheep industry as dewormers are largely ineffective to control parasites in the animal. As the lead for a multi-institutional, multi-disciplinary team funded by NIFA's Organic Agriculture Research and Extension Initiative, ARS researchers in Booneville, Arkansas, along with research colleagues from Louisiana State University, Virginia Tech, Katahdin Hair Sheep International, University of Nebraska-Lincoln, and University of Idaho, used genomic techniques to identify potential sites on genes (chromosomes 2, 3, 16, and 23) associated with resistance to gastrointestinal parasites in sheep. This information is important to sheep producers, scientists, veterinarians, and extension specialists aiming to improve genetic parameters and parasite resistance in sheep without the use of dewormers.

2. Selection for fertility and ability to breed out-of-season in sheep permits maximized reproductive performance. Concentrations of a specific hormone called, anti-Mullerian hormone (AMH), has been shown to predict fertility in beef cattle; breeding values generated by data collection over generations is valued as well. ARS researchers in Booneville, Arkansas, and colleagues from the University of Arkansas determined that AMH was not useful in predicting fertility or out-of-season breeding (breeding during spring or long days vs. short) ability in sheep, but estimated breeding values generated by the National Sheep Improvement Program were useful in predicting performance of first time lambing. This information is important to sheep producers, scientists, veterinarians, and extension specialists aiming to improve reproductive performance in sheep.

3. Many tractors are now equipped with GPS technology linked to the steering mechanism to guide tractors for field operations. A new method for rapidly quantifying spatial overlaps and gaps for precision agriculture tools. Many tractors are now equipped with GPS technology linked to the steering mechanism to guide tractors for field operations. ARS researchers in Booneville and Fayetteville, Arkansas, along with colleagues from the University of Arkansas developed an automated method for rapid determination of spatial coverage of precision agriculture technologies, such as auto-guided tractors and other self-propelled machinery that reduce over-application of on-farm nutrients and inputs by 10-20%. It is estimated that auto-guided tractors reduce on-farm inputs by as much as 20% and can save producers $10.8-13.5 million annually by improving gains in equipment efficiency and enhancing yields. Currently, roughly half of large-scale row crop producers are using tractor guidance, however, 82% of the total farms in the US are small farms but are largely not adopting these cost and environmental saving technologies. This team: 1) developed a method to calculate overlaps and gaps, and 2) quantified overall gains by tractor guidance systems. Tractor guidance systems likely result in reduced input-use and shorter in-field operation time leading to improved economic and environmental savings. Our approach to estimate tractor guidance efficiency on small farms using actual field research is novel and may aid in adoption of tractor guidance, thus potentially improving efficiency gains on 82% of U.S. farms.

4. Digital soil mapping to enhance management of water in the dry corridor of Central America. With climate variability, soil management using technology is a novel method for mitigating the effects of water shortages for crops. The focus of the Water Smart Agriculture project is to develop a digital soil mapping platform for data-limited scenarios which includes data management, the production of soil property and interpretation maps, and a delivery mechanism for those maps. Since 2015, ARS researchers in Booneville, Arkansas, have been building local capacity through training and outreach in El Salvador, Guatemala, Honduras, and Nicaragua as part of the Water-Smart Agriculture in Mesoamerica (ASA) program. This project has trained 110 scientists and has provided over 1000 hours of direct training in field soil science, soil data management, digital soil mapping methodologies, and the construction of soil interpretations. As the initial yield production results of the Water-Smart Agriculture program indicate, managing soil to manage water within the dry corridor has resulted in 30-40% increase in yield for maize and beans when compared to business as usual. With increased episodic rainfalls, farmers retained more water within the soil that was available for crop production. The information-based management led to increased crop production as well as minimized erosion with less sedimentation in reservoirs which provide hydroelectric power. Water is available to crop production, forest health and increased carbon storage. Projects are continuing within the Southeast Area based on this concept which will focus on managing soil to manage water for mitigating climate impacts for small farms.


Review Publications
Richter, J., Owens, P.R., Libohova, Z., Adhikari, K., Fuentes Ponce, B. 2019. Mapping parent material as part of a nested approach to soil mapping in the Arkansas River Valley. Catena. 178:100-108. https://doi.org/10.1016/j.catena.2019.02.031.
Libohova, Z., Seybold, C., Adhikari, K., Wills, S., Beaudette, D., Peaslee, S., Lindbo, D., Owens, P.R. 2018. The anatomy of uncertainty for soil pH measurements and predictions: Implications for modellers and practitioners. European Journal of Soil Science. 70:185-199. https://doi.org/10.1111/ejss.12770.
Adhikari, K., Mishra, U., Owens, P.R., Libohova, Z., Wills, S.A., Riley, W.J., Hoffman, F.M., Smith, D.R. 2020. Importance and strength of environmental controllers of soil organic carbon changes with scale. Geoderma. 375:114472. Available: https://doi.org/10.1016/j.geoderma.2020.114472.
Ngunjiri, M., Libohova, Z., Minai, J., Serrem, C., Owens, P.R., Schulze, D. 2019. Predicting soils types and soil properties with limited data in the Uasin Gishu Plateau, Kenya. Geoderma Regional. 16:e00210. https://doi.org/10.1016/j.geodrs.2019.e00210.
Sun, Z., Jiang, Y., Wang, Q., Owens, P.R. 2018. Geochemical characterization of the loess-paleosol sequence in northeast China. Geoderma. 321:127-140. https://doi.org/10.1016/j.geoderma.2018.02.012.
Becker, G.M., Davenport, K.M., Burke, J.M., Lewis, R.M., Miller, J.E., Morgan, J.L., Notter, D.R., Murdoch, B.M. 2020. Genome-wide association study to identify genetic loci associated with gastrointestinal nematode resistance in Katahdin sheep. Animal Genetics. https://doi.org/10.1111/age.12895.
Burke, J.M., Schoenian, S., Freking, B., Semler, J., Gordon, D., Bennett, M.B., O'Brien, D., Woods, E. 2019. Complete anthelmintic resistance observed in U.S. meat goats. Sheep and Goat Research Journal. 34:1-5.
Amorim, H., Ashworth, A.J., Moore Jr, P.A., Wienhold, B.J., Savin, M.C., Owens, P.R., Jagadamma, S., Carvalho, T.S., Sutie, X. 2020. Soil quality indices following long-term conservation pasture management practices. Agriculture, Ecosystems and Environment. 301. Article 107060. https://doi.org/10.1016/j.agee.2020.107060.
Kharel, T.P., Ashworth, A.J., Shew, A., Popp, M.P., Owens, P.R. 2020. Tractor guidance improves production efficiency by reducing overlaps and gaps. Agricultural & Environmental Letters. 1(5). Article e20012. https://doi.org/10.1002/ael2.20012.
Amorim, H.C., Ashworth, A.J., Wienhold, B.J., Savin, M.C., Allen, F.L., Saxton, A.M., Owens, P.R., Curi, N. 2020. Soil quality indices based on long-term conservation cropping systems management. Agrosystems, Geosciences & Environment. 3(1). Article e20036. https://doi.org/10.1002/agg2.20036.
Ashworth, A.J., Owens, P.R., Allen, F. 2020. Long-term cropping systems management influences soil strength and nutrient cycling. Geoderma. https://doi.org/10.1016/j.geoderma.2019.114062.
Acharya, M., Ashworth, A.J., Burner, D., Burke, J.M., Pote, D.H., Muir, J.P. 2019. Browse potential of bristly locust, smooth sumac, and sericea lespedeza for small ruminants. Agroforestry Systems. https://doi.org/10.1007/s10457-019-00479-0.
Adams, T., Philipp, D., Burner, D.M., Jennings, J., McPeake, B., Ashworth, A.J., Pote, D.H., Burke, J.M., Rhein, R. 2019. White (Trifolium repens L.) and arrowleaf (Trifolium vesiculosum Savi) clover emergence in varying loblolly pine (Pinus taeda L.) tree alley spacings. American Journal of Plant Sciences. 10:659-669. https://doi.org/10.4236/ajps.2019.104048.
Nieman, C.C., Popp, M.P., Schaefer, D.M., Albrecht, K.A., Franco Jr, J.G. 2020. Economic feasibility of sod-seeded summer annuals in Wisconsin pastures using cow-calf simulation. Journal of American Society of Farm Managers and Rural Appraisers. 2020:177-186.
Burke, J.M., Miller, J.E. 2020. Sustainable approaches to parasite control in ruminant livestock. Veterinary Clinics of North America. 36(2):89-107. https://doi.org/10.1016/j.cvfa.2019.11.007.
Acharya, M., Burke, J.M., Ashworth, A.J., Rorie, R.W. 2020. Relationship of Anti-Mullerian hormone to reproductive traits in Katahdin ewes bred in late spring or fall. Advances in Reproductive Sciences. 8:48-56. https://doi.org/10.4236/arsci.2020.81005.
Acharya, M., Burke, J.M., Rorie, R.W. 2019. Effect of semen extender and storage temperature on motility of ram spermatozoa following liquid storage. Advances in Reproductive Sciences. 8(1):14-30.