2009 Annual Report
1a.Objectives (from AD-416)
Develop small-scale ruminant production systems for the humid temperate Appalachian Region by managing interactions among forages, environment, and grazers. Emphasis is on hair sheep and meat goat production to satisfy consumer-driven and ethnic market demand. Systems are economically viable and environmentally benign. Specific objectives are:.
1)Identify and assemble combinations of plants that can supply forage in sufficient quantity and quality for small ruminants as a function of microsite capabilities;.
2)Integrate forage array components defined in Objective 1 into small-ruminant production systems that deliver carcass characteristics and meat quality defined by specialty market demand;.
3)Identify plant and landscape capabilities that support productive pasture plant communities improved ecosystem functions, and grazing practices that contribute to desirable water quality.
1b.Approach (from AD-416)
Controlled-environment, field-plot, and paddock-scale experiments will be conducted to determine sequences and combinations of forages that expand the duration of forage production, and deliver herbage mass with the energy-to-protein ratio required by grazing livestock when needed. Responses to site specific conditions encountered in traditional open pasture and silvopastoral management will be determined as a function of site conditions, seasonal forage productivity patterns and nutritive value, and the interactive relationship among plant species in the sward. Basic studies linking above- and below-ground processes in forage swards will be obtained by controlled environment and field experimentation on root development and the interaction of plant-derived biomolecules (e.g., polyphenolics) with soil chemical and physical processes. Grazing experiments will result in pasture management practices for economically viable lamb and meat goat production. Carcass and meat quality assessments will be made and evaluated relative to consumer preferences for lean cuts and desirable chemical composition. Small paddock and landscape-scale data mapping will be used to determine how landscape and grazing management practices interact to influence water quality. Findings will provide a framework for evaluating how local agricultural practices influence regional systems in terms of water, nutrient, and pathogen partitioning and transport at multiple scales. Decision support tools will aid in design of pasture systems that synchronize forage quantity and nutritive value with grazing animal requirements while maintaining or improving water resource quality.
Progress continues to determine pasture response to resource gradients, and within and among year weather patterns. Experiments with intensive or lax management practices define responses of forage plant combinations to improve seasonal distribution of herbage yield and nutritive value. Naturalized swards arising from the soil seed bank tended to produce more total herbage than the specifically designed forage arrays in a cool, wet year. Nutritive value was better when sown swards were clipped frequently. Botanical composition data from the establishment (2008) and initial treatment phases (2009) are being summarized to determine short-term responses of newly sown swards. Real-time photographic techniques are used to observe root growth patterns of the forage arrays. Growth of fine roots ceased and root tissues were lost within 12-24 hours of clipping. Root growth resumed 48 to 72 hours later.
Experiments are in progress to define the spatial-temporal patterns of inputs and pools of phenolics in woodlot and pasture on small farms. Measurements made thus far indicate: total phenolics are greater in woodlot than pasture soil but highest in the transition between these types of land use; water flowing along the stem of a tree may be a significant source of phenolic compounds; concentrations of phenolics are comparable in forages fed to goats and the manure; concentration of total phenolics varies among common forage mixtures; phenolics in soil decrease with depth and vary seasonally.
Nutritive analyses and continuous culture fermentation were conducted on forages from silvopasture and traditionally grazed pasture experiments. Samples analyses are underway and subsamples were collected during fermentation to characterize rumen microbial population features.
Root-zone water sampling instrumentation was installed in a replicated silvopasture experiment site to determine the impact of management on water quality. Yearling sheep consume 50 or 75% of available forage and root-zone water samples are collected from the grazed paddocks, and analyzed for pathogen and nitrogen content.
An experiment is underway to determine grazing practices to finish meat goats on chicory, birdsfoot trefoil, or prairiegrass/red clover pastures, and to evaluate the forages as natural control agents of gastrointestinal parasites. Laboratory studies were completed in 2009 combining in vitro digestion and metagenomic techniques to characterize herbage value and rumen microbial populations (bacteria, protozoa, methane producers, and fungi). A similar experiment is underway using rumen fluid from goats, and browse (tree leaves, weedy plants, vines) containing condensed tannins and other secondary plant compound. A method using forage fiber to predict forage energy use efficiency by livestock was validated using grazing meat goat data. Blood urea nitrogen concentrations can estimate N consumption relative to available energy. The energy:protein ratio in forage and blood urea nitrogen levels in grazing goats were correlated, indicating that nitrogen was excessive relative to energy when meat goats were finished on pastures managed for high forage nutritive value.
Silvopasture as a multi-functional agro-ecosystem. Silvopasture creates an opportunity to realize income from trees while at the same time obtaining short-term income from forage grown in the understory for livestock production. Multidisciplinary studies of plant growth, biophysical environment, and water quality showed that silvopasture provides opportunities for new grazing schemes to extend the duration of herbage production while increasing solar radiation-use efficiency on a given unit of land, and reducing nitrate leaching. Livestock productivity in terms of gain per animal is similar to that obtained from traditionally managed open pasture, but more land area is needed because herbage production is less in the shaded compared to open sites. Silvopastoral components of small-farm production systems provide agro-ecosystem function benefits in terms of improved resource-use efficiency and environmental quality. Research accomplishments are documented in peer-reviewed scientific journals and generate numerous invited producer-oriented presentations and publications on humid-temperate silvopasture management.
Plant compounds influence important soil processes. Tannins are plant derived products that link herbage production, nutritive value, animal physiology, pathogen survival, and environmental quality in a web of nutrient utilization and availability. We demonstrated that some specific tannins can attach to soil, affect the solubility of organic-N and may reduce the toxic effects of Al and Cu to plant roots. However, knowledge of tannin in agro-ecosystems and how tannins can be used in managed systems is fragmentary. We deployed a systematic campaign of sampling to determine patterns and magnitude of phenolic substances entering the soil. New methods were developed to measure phenolics in soils and plants and effects of these substances determined in soils collected from 25 ARS locations in the US, and from several sites in Canada. We seek to determine if plants in traditional pasture and silvo-pastoral systems are a source of phenolic substances, especially tannins, and how the substances influence soil formation and nutrient cycling processes. We found that tannin in soils affected soil cation exchange capacity and metal-related soil chemical processes, and that soil tannin patterns varied with plant species and soil depth. We continue to develop technical capacity through a dynamic Specific Cooperative Agreement with Miami University, Oxford, Ohio that include.
1)developing new analytical technology and discovery of mechanisms related to metal-phenolic interactions, and.
2)research and learning opportunities for students and scientists including summer-research intern opportunities at AFSRC. We initiated and are organizing a symposium “Biogeochemical Processes in Ecosystems: The Tannin Effect” for the Soil Chemistry division of the Soil Science Society of America 2009 national meeting.
5.Significant Activities that Support Special Target Populations
Numerous invitations were received to present practical information to small ruminant producers and farmers interested in silvopasture management. Many of the attendees are newcomers to small-scale production agriculture.
A one-day Mid-Atlantic Meat Goat Symposium was co-sponsored for meat producers on small farms. The event was designed to provide research-based production and marketing information for meat goat producers and those persons planning to begin raising meat goats. The event was attended by 143 meat goat producers from VA, NC, MD, and WV.
|Number of Other Technology Transfer||1|
Belesky, D.P., Ruckle, J.M., Bush, L.P. 2009. Microsite conditions influence nutritive value characteristics of a common tall fescue cultivar infected with either a native or a novel non-ergogenic endophyte. Environmental and Experimental Botany. 67:284-292.
Belesky, D.P., Bacon, C.W. 2009. TALL FESCUE AND ASSOCIATED MUTUALISTIC TOXIC FUNGAL ENDOPHYTES IN AGROECOSYSTEMS. Journal of Toxicology Toxins Reviews. 28(2-3):102-117.
Malinowski, D.P., Belesky, D.P., Kramp, B.A., Ruckle, J.M., Kigel, J., Pinchak, W.E. 2008. A method to differentiate summer-dormant from summer-active tall fescue and orchardgrass accessions at germination. Australian Journal of Agricultural Research. 59:1092-1102.
Burner, D.M., Pote, D.H., Belesky, D.P. 2009. Effect of loblolly pine root pruning on alley cropped herbage production and tree growth. Agronomy Journal. 101(1):184-192.
Burner, D.M., Tew, T.L., Harvey, J.J., Belesky, D.P. 2009. Dry matter partitioning and quality of Miscanthus, Panicum, and Saccharum genotypes in Arkansas, USA. Biomass and Bioenergy. 33(4):610-619.
Halvorson, J.J., Smith, J.L. 2009. CARBON AND NITROGEN ACCUMULATION AND MICROBIAL ACTIVITY IN MOUNT ST. HELENS PYROCLASTIC SUBSTRATES AFTER 25 YEARS. Plant and Soil Journal. 315(1)(2):211.228.
Cassida, K.A., Neel, J.P., Belesky, D.P. 2009. STOCKPILED PRAIRIEGRASS PROVIDES HIGH-QUALITY FALL GRAZING FOR LAMBS. Forage and Grazinglands. doi:10.1094/FG-2009-0318-01-RS.
Belesky, D.P., West, C.P. 2009. Abiotic stresses and endophyte effects. Chapter 4. In: Fribourg, H.A., et al., (eds.). Tall fescue for the twenty-first century. Agronomy Monograph 53. ASA-CSSA-SSSA. Madison, WI. p. 47-62. (September 2009. ISBN: 9780891181729).