NAAC_1-5C Silvopasture

Southern pines are important tree species in both silvopasture and woodland systems. Information on the dynamics of soil quality and growth of southern pines in these systems, especially when grazing animals are included in the system, is limited. Hypothesis of the study was that the soil quality and the growth of southern-pine trees would be better in silvopastures vs. woodlands. The study objective was to evaluate the soil quality and growth of southern pines (loblolly, Pinus taeda and longleaf, Pinus palustris) in silvopastures and woodlands. Studies were conducted in silvopastures and woodlands, with six plots in each system (0.4-ha per plot). Silvopastures were developed from the existing woodlands in 2014 by removing the non-pine vegetation, thinning the pines, and planting suitable cool- and warm-season forages. Woodlands consisted of longleaf and loblolly pines, hardwood trees, and several understory plant species. Understory vegetation present in both systems was managed with the rotational stocking of meat goats (Kiko) and hair sheep (Katahdin and Katahdin St. Croix cross). Soil bulk density and moisture were evaluated in 2019 and both plus carbon and nitrogen were measured in 2020. Tree height and diameter at breast height (DBH) were measured from 2018 to 2020. Soil carbon and nitrogen were greater in silvopastures versus woodlands (p<0.05). Both loblolly and longleaf pines performed better in silvopastures versus woodlands, with a greater DBH (16-35%) and basal area (35-78%) in the former system (p<0.0001). Tree species showed a significant effect (p<0.001) on all growth parameters within each system, with loblolly pines having the greater height (6-9%), DBH (27-43%), and basal area (62-107) than longleaf pines. Results show that silvopastures offer a better environment for a faster growth of southern pine trees versus woodlands, when the understory vegetation present in both systems is managed with small ruminants.

Uma Karki, Department of Agricultural and Environmental Sciences, College of Agriculture, Environment and Nutrition Science, Tuskegee University, Tuskegee, AL

Bidur Paneru, Department of Agricultural and Environmental Sciences, College of Agriculture, Environment and Nutrition Science, Tuskegee University, Tuskegee, AL; Currently at the Department of Crop and Soil Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA
Anand Tiwari, Department of Agricultural and Environmental Sciences, College of Agriculture, Environment and Nutrition Science, Tuskegee University, Tuskegee, AL
Nevershi Ellis, Department of Agricultural and Environmental Sciences, College of Agriculture, Environment and Nutrition Science, Tuskegee University, Tuskegee, AL
Shailes Bhattrai, Department of Agricultural and Environmental Sciences, College of Agriculture, Environment and Nutrition Science, Tuskegee University, Tuskegee, AL; Currently at the Department of Poultry Science, University of Georgia, Athens, GA
Lila Karki, Department of Agricultural and Environmental Sciences, College of Agriculture, Environment and Nutrition Science, Tuskegee University, Tuskegee, AL; Currently at the Department of Agriculture, Food, and Resource Sciences, UMES Cooperative Extension University of Maryland Eastern Shore, Princess Anne, MD
Sanjok Poudel, Department of Agricultural and Environmental Sciences, College of Agriculture, Environment and Nutrition Science, Tuskegee University, Tuskegee, AL; Currently at the Department of Crop and Soil Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA

Integrating livestock into orchard systems offers many potential benefits, including fertilization, weed control, removal of fallen produce, and pest control. However, introducing livestock into orchards also poses a potential food safety risk. As the new Food Safety Modernization Act (FSMA) and Produce Safety Rule take effect, many growers are unsure what guidelines or regulations exist for managing livestock in orchards. The Savanna Institute, in partnership with Farm Commons and the Wisconsin Department of Agriculture, Trade, and Consumer Protection, is developing a grower guide and a video series to address the existing knowledge and the knowledge gaps surrounding this topic. This presentation will provide an overview of what we do and don’t know about food safety management for livestock in orchards, what practices growers are currently using, and paths forward for addressing this issue.

Jacob Grace, Grazing and Food Safety Program Manager, Savanna Institute

Overgrazing by domestic livestock has historically degraded woodlands, but herbivory more generally represents a source of disturbance important to ecosystem structure and function. Oak ecosystems in the Driftless Area, and the eastern US more broadly, lack appropriate disturbance and are undergoing successional mesophication. Silvopasture potentially offers a land management strategy to mitigate the degrading effects of overgrazing and to restore successional heterogeneity to the landscape. In this study, we evaluated impacts of prescribed grazing and vegetation management on plants and soils in oak-dominant mixed species woodlands. Specifically, we assessed the influence of cattle, thinning canopies, and planting forages on shrub cover, floristic diversity, forage nutritive quality, soil cover, soil fertility, and soil microbial community structure. This was done on farms with already established rotational grazing management systems. Grazing reduced shrub cover where initial thinning occurred and more so with native than introduced shrub species. Planting agricultural forages reduced floristic diversity but did not increase forage quality. Bare soil exposure and soil compaction was greater in grazed areas, but canopy thinning appeared to moderate the former. No effects were detected on soil moisture or macronutrients. Impacts on soil microbial community composition were mixed. In grazed areas soil actinomycetes were more abundant, soil fungi were less abundant, and fungi to bacteria ratio was marginally greater in areas without any grazing or vegetation management. Arbuscular mycorrhizal fungi were less abundant in grazed areas when canopy and shrubs were thinned. Our findings suggest that management of existing woodland grazing can be improved by prescribed canopy thinning and targeted management of the shrub layer.

Keefe Keeley, Co-Executive Director, Savanna Institute

In Minnesota there are approximately 600,000 acres of unmanaged woodland grazing. These unmanaged landscapes can produce negative affects on the environment affecting native habitats, water quality, soil erosion and reduction in timber values. The University of Minnesota Extension with collaborating agroforestry and agricultural organizations are creating silvopasture educational programs that are reaching farmers and resource professionals who manage these woodlands. During 2020, many online webinars, workshops and COVID – safe field days were held. All webinars and field days were recorded and added to websites so that farmers who could not attend could review the material at their leisure. The success of this program was in part due to the collaboration or partnering with several agricultural organizations. Some of these organizations included, Sustainable Farming Association, Great River Greening, Savanna Institute, NRCS, SWCD, grazing and livestock organizations. Learn more about silvopasture educational programs and how to collaborate with other agricultural organizations to increase landowner awareness and impacts.

Gary Wyatt, University of Minnesota, Extension Educator, Agroforestry
Jeff Jackson, University of Minnesota, Extension Educator, Forestry