UI Extension Forestry Information Series II Forest Management No. 52 Silvopasture - Growing Trees in Your Pasture or Vive-Versa Randy Brooks Forestry and livestock posed silvopasture is no guarantee of successful production are main- tree establishment and growth. Local University stays of the natural of Idaho Extension and Natural Resource Conser- resource based econo- vation Service offi ces are good sources of infor- mies of North Central mation about soil suitability for specifi c pasture Idaho. There is also a and tree species. strong tradition of live- stock grazing in other Most folks would prefer planting trees into an forests across the West. Silvopasture, the combi- existing or recently seeded pasture due to ease of nation of forest management and improved for- operation. However, vegetation control is criti- age species, is a more intensive, controlled appli- cal, especially when planting trees into an estab- cation of this traditional use of livestock grazing lished pasture where grass roots form a fi brous and growing trees. Silvopasture is the deliberate mat throughout the upper soil layer. This can introduction of timber into a forage production allow grasses to out-compete tree seedlings for system, or vice-versa. With silvopasture, timber moisture. In dry summer climates, conifer seed- and pasture are managed as a single integrated lings grow best when competing vegetation is system. It is not utilized as much in the West as removed for the fi rst three years. This can be ac- it is in the Southeast, but is most often imple- complished through various means of site prepa- mented to increase profi tability, reduce risk, and ration. Apply an herbicide or plow a two to four augment environmental benefi ts from land man- foot wide strip for each row of trees to be plant- agement. Silvopasture systems are designed to ed. In some areas, a prescribed burn or pesticide produce high-value timber while providing short application may be needed to control rodents term cash fl ow from livestock. prior to and after tree planting. Follow-up with a selective herbicide may be needed for the next The ability of recently forested land to grow trees two to three years until trees are well established. can be predicted by the performance of the pre- vious stand. However, the ability of pasture or The desired pasture mix will vary with site char- rangeland to support commercial timber pro- acteristics and the desires of the land manager. duction is harder to predict. Many forage plants Orchardgrass, tall fescue, and perennial ryegrass are more shallowly rooted than trees are, and a along with a clover species are commonly used productive forage pasture may have soils that are silvopasture forages. Nitrogen fi xing clovers are too shallow to support commercial tree produc- often seeded to provide high quality feed for tion. Since soils can change signifi cantly over a livestock and to serve as a biological source of ni- short distance, the presence of trees near a pro- trogen for trees and associated grasses. Legumes Station Bulletin No. 96, Idaho Forestry Wildlife and Range Experiment Station, Moscow, ID often have more exacting nutrient requirements Multiple damage events may kill trees, but single than do grasses, making a soil test and possible events generally only slow growth. Conifers are subsequent fertilization an important part of the especially sensitive to the removal of the topmost management plan. The forage composition will leader (terminal bud). This is the most palatable, change over time as trees grow and modify the nutrient packed portion of the seedling. Leader environment. Trees generally have little impact loss results in dramatic loss of height and diame- on forage production until shading becomes ter growth and stimulates production of multiple dense enough to limit sunlight to the understory. leaders or forked tops. Most tree damage is likely Forage production of warm season species can to occur in the fi rst two to three years when they be reduced somewhat. Orchardgrass seems to are small and do not have their resinous chemical tolerate the environment under trees better than defense well established. The best way to reduce perennial ryegrass or Kentucky bluegrass. Al- the risk of damage during this period is by hay- though tall fescue does well under trees, it has ing rather than grazing. This approach does not the lowest forage value and highest degree of resolve the problem of damage by native wildlife competition of the forages. herbivores like deer and elk. Young trees may be protected with chemical repellants, mesh tubes, Douglas-fi r and ponderosa pine are the two or some type of appropriate fencing. Sheep, predominant timber species that grow best in our goats, and deer are more likely to eat needles area. Larch, as well as western white pine can than are cattle or elk. Established conifers are also be grown, but western white pine is subject not as attractive to large herbivores when other to white pine blister rust. Regardless of what forage is present. If heavy browsing is observed species is used, it is generally recommended that there may be a defi ciency in the livestock diet. seedlings are purchased locally or from a locally adapted seed source. Such seedlings are both Trees that provide shade or wind protection can quicker to establish, grow faster, and can be more have a climate stabilizing effect by reducing heat tolerant of browse and other damage. stress and wind chill of the livestock. Protec- tion from trees can reduce the direct cold effect Silvopastures are generally planted at about 200- by 50% or more and reduce wind velocity by as 300 trees per acre, and can be planted in grids or much as 70%. Livestock require less feed energy, in single rows, multiple rows, or even clusters. so their performance is improved and mortality This planting style provides for wide open alleys is reduced. In contrast to concentrated livestock for forage production and easy access for live- operations, silvopastoral systems are less likely stock grazing, hay harvesting, fertilizer spread- to raise environmental concerns related to water ing, spraying, and other agricultural practices. quality, odors, dust, noise, disease problems, and Alley width should be determined by width of animal treatment. farm equipment. For example, a 20 foot alley pro- vides easy access for cutting hay with a 16 foot For more information on silvopasture, contact swather. This same spacing allows for mecha- your local University of Idaho Extension Offi ce or nized harvesting later when trees mature. There Natural Resources Conservation Services Offi ces. is plenty of room for creativity when it comes to planting trees in combinations, however, rows of three or more are generally not recommended as This article fi rst appeared in Woodland NOTES, Vol. the inner rows of trees may be out-competed by 17, No. 1, Fall/Winter 2005-2006. the outer rows. About the Author: Randy Brooks is a Professor and Trees may be damaged by livestock or wild Area Extension Educator - Forestry at the University animals which can eat, rub, or step on them. of Idaho. The University of Idaho is an equal opportunity/affi rmative action employer and educational institution. We offer pro- grams to persons regardless of race, color, national origin, gender, religion, age, sexual orientation, or disability..