Ten of 20 farms had at least one full time farmer with no off-farm employment and the remaining 10 had farmers with off-farm jobs in addition to their farm business. Off-farm jobs were diverse and included professionals in the medical field, law, forestry, and agricultural extension. Farmer experience was also diverse. Farmers had been the principal operator of a farm for an average of 13 years (standard deviation = 11 years) with a maximum of 42 years, and a minimum of 2 years. Tenure on their current farm, regardless of being a principal operator, averaged 14 years (standard deviation = 13 years) with a maximum of 44 years, and a minimum of 2 years. Farmers interviewed included both owner/operators and hired workers.
Primary farm products were diverse between and within farms, although a primary farm product on 16 of 20 farms was some type of livestock for meat. Two farms had primary farm products of dairy cattle and the other two farms’ primary products were tree crops, including a tree nursery. Timber sales were cited as additional primary farm product on six of the farms. The size of farms practicing silvopasture varied in both land holdings (12–486 ha), percent of land in silvopasture (1–32 %), and number of livestock.
Farmer experience with silvopasture
Only three of 20 farmers interviewed in this study had experience practicing silvopasture prior to implementing it on their farms. All of these three farmers’ experiences with silvopasture prior to implementing it occurred in Europe or Central America. Four additional farmers claimed to have some knowledge of silvopasture prior to implementing it on their farm. The remaining 14 farmers had no, or extremely limited, prior knowledge and experience with silvopasture before implementing it on their farms. Three farmers had been practicing silvopasture on their farms over 30 years in the region and the rest were new to silvopasture in the past 10 years. The longest silvopasture documented had been in production for 42 years (in this case a forest was converted to silvopasture and trees were over 42 years old), although the median age of land managed as silvopasture was 4 years.
Silvopasture was a fairly new concept to most farmers, becoming familiar with the practice over the last decade. However, seven farms had been practicing silvopasture prior to finding out it was an agroforestry practice. For example, one farmer who had been utilizing silvopastures for 30 years had first heard the term when an extension professional in his region suggested him to be a part of this study. A misconception that any integration of livestock in a wooded area would be silvopasture was held by four farmers in this study. Three farms were continuously pasturing pigs in woodlands. One farm was continuously grazing dairy cattle and horses in wooded areas. Two of the four farms utilizing wooded livestock paddocks also had well managed silvopastures being grazed by other species. Additionally, a misconception was found to exist among practitioners in the region that any use of livestock to actively eliminate or manage woody vegetation could be called silvopasture.
Reasons for, timing, and challenges of silvopasture utilization
Farmers were utilizing silvopasture for a variety of reasons (Table 1). Shade for livestock was the most commonly stated reason for incorporating silvopastures into farms with 16 of 20 farmers independently citing this as a reason for use. Expanding pasture acreage and diversity was also greatly cited by farmers, 14 of 20. Utilizing and incorporating woodlands into primary farming ventures was a reason for silvopasture adoption by 12 of 20 farmers.
Incorporation of silvopasture into farm management systems was also diverse. Farms were primarily utilizing silvopastures during the grazing periods of late-spring, summer, and fall. All farmers used silvopastures during the hot periods of the summer. All farms, except one, utilized both silvopastures and open pastures in their grazing operations, but not necessarily in the same paddock. Some farms reserved silvopastures for certain times of the year, such as hot periods in the summer or inclement winter weather, while others kept them as a patchwork within on-farm livestock rotations. Farmers identified the early spring (mud season) as a time when livestock were excluded from silvopastures (although one farm utilized silvopastures year round). During mid-summer and times of droughts, farmers were utilizing silvopastures because they perceived that silvopastures had greater forage availability during these periods (Table 1).
Fencing establishment, such as type to utilize and methods of construction, and maintenance of fencing of paddocks was stated as a challenge by 9 of 20 farmers interviewed when asked what their major challenges were when managing silvopastures (Table 1). Lack of knowledge toward silvopasture and lack of time for silvopasture management were cited as challenges by six and five farmers of 20 interviewed, respectively. Forage management and unknown forage quality was another area farmers expressed as a challenge toward managing silvopastures. One of 20 farmers interviewed was not planning to continue practicing silvopasture in the future. This farmer intended to phase out practicing silvopasture in order to create a better view through tree removal, increase options for his agricultural land, and make fencing more time efficient. However, the 19 other farmers interviewed were pleased with the practice, and 14 of these farmers intended to increase the amount of land on their farm in silvopasture.
The amount of silvopastures on farms ranged from less than 1 ha to 73 ha, with a median of 5 ha per farm. Sizes of individual silvopastures on farms were typically less than 1–2 ha. Forest conversion to silvopasture was the primary starting point for silvopastures observed on regional farms (Table 2). The most common of these was a conversion to uniform tree spacing. In these systems mature hardwood, softwood, and mixedwood forests were heavily thinned from the lower canopy classes, leaving well-formed co-dominant and dominant stems as residuals. Oak, maple, and eastern white pine were the most common species favored as residuals in silvopasture converted from forests. Farmer goals for these species were primarily timber, but in the case of oak, acorns were also favored by many farmers as a livestock supplement. Residual basal area of forests converted to uniformly spaced silvopastures ranged from 6 m2 ha−1 (546 trees ha−1) to 30 m2 ha−1 (282 trees ha−1), with an average basal area of 17 m2 ha−1 (343 trees ha−1).
Five silvopasture systems converted from forestland utilized patched grouping of residual trees. Patch sizes were small, <0.25 ha, and greatly variable in shape. Multiple patches of trees were interspersed within similarly sized patches of open pasture in these systems. Farmers’ reasons for choosing grouped tree retention in silvopastures included working with unequal distribution of quality trees in the pre-silvopasture forest, ease of creation, and ease of management. Tree spacing was so heterogeneous in three hardwood silvopastures that these were classified as irregular tree density due to their difference from both uniformly spaced systems and patch systems.
Seven farms in this study were incorporating silvopastures into the edges of open pastures (Table 2). To benefit from forest edge encroachment into open pastures, some farmers had converted overgrown field edges into silvopastures by thinning trees. Others had converted portions of (non-encroaching) forest adjacent to open pastures to silvopastures in an effort to diversify the shade conditions of regularly used open pastures. Grazing partitioning of these edge silvopastures contained both open areas and wooded areas, as opposed to grazing the silvopasture edge separately from the open pasture area. Thinned and managed trees in the field border was also valued for aesthetic reasons by practitioners.
Three types of plantation silvopastures were observed in this study. One, conifer plantations, were being utilized as outdoor living barns and will be discussed in a following paragraph. The other two types were hardwood plantations. Two farms had established black walnut (Juglans nigra) in open pastures and were utilizing the plantations as a silvopasture. Black locust was the other hardwood silvopasture plantation documented. These plantations had basal areas of 17 m2 ha−1 (734 trees ha−1) and 21 m2 ha−1 (974 trees ha−1). Trees were being grown primarily for use as fence posts, and harvested through commercial thinnings at years 15, 20, and 25. Initial establishment of trees in these systems was through seedlings, but on one farm the next cohort was being established through a coppice system.
Four farms in this study were utilizing outdoor living barns (Table 2). Outdoor living barns are silvopasture systems in which tree density is maintained at an abundant level to maximize the amount of shelter that trees provide to livestock. Forages in all of these outdoor living barns documented were very sparse or non-existent. Outdoor living barns consisted of areas of dense conifers. Farmers stated the purpose of their outdoor living barns were to produce timber or fence posts, in the case of northern white cedar (Thuja occidentalis), while also providing shelter for livestock during exceptionally cold periods of the year. Farmers stated that outdoor living barns were not utilized as permanent winter paddocks nor did these areas experience livestock pressure during the spring thaw of frozen ground. One farm maintained an outdoor living barn to provide shelter and biting fly relief for livestock during the summer grazing period.
Six farms in this study incorporated livestock into orchards as a form of silvopasture. Farmers stated the value of these systems were fertilization to trees, grass management, livestock nutrition, and reduction in rodent habitat. Orchards were primarily comprised of apple trees (Malus spp.) and, in some cases, with lesser components of other fruit or nut trees. Farmers were using fruit products from orchards for on-farm consumption, direct marketing to consumers, livestock feed, and scion wood. Spacing between trees in orchard silvopastures were typically uniform in pattern with space between tree crowns, but variable in terms of actual distance between trees.
Primarily sheep or cattle were incorporated into orchard silvopastures by grazing in the summer months, and in the fall after excess fruit has dropped. Farmers grazing sheep in orchard systems did not express a fear of damage to fruit trees from livestock while farmers utilizing cattle stated the importance of short grazing periods to avoid tree damage in orchards. Regeneration of new fruit trees was accomplished through individual tree protection mechanisms. Farmers did not mention any food safety concerns regarding livestock and orchard integration.
One farm in this study was utilizing a maple sugarbush as a silvopasture for beef cattle to keep brush down in the sugarbush and provide shade for livestock. This farmer was periodically grazing a herd of around 90 beef cattle in a 6 ha production sugarbush for over 25 years. Cattle were only introduced to the sugarbush during dry periods of the summer, such as late July and early August. The farmer stated that he intentionally installed sap lines as high as possible to avoid livestock damage. The farmer attributed low forage availability in the sugarbush to high tree density.
Livestock management in silvopastures
Livestock type raised on farms in this study was diverse and ranged from 1 to 6 varieties of livestock on each farm and incorporated into silvopastures. Livestock incorporated into silvopastures included beef (12 farms) and dairy cattle (2 farms), sheep for meat and/or fiber (6 farms), meat (3 farms) and dairy goats (1 farm), chickens for meat or eggs (4 farms), turkeys (2 farms), and horses (2 farms). Pigs were used in the establishment phase of silvopastures on 4 farms. Four other farms were raising pigs in wooded areas for a month or longer without pasture rotation, these areas were not considered silvopastures due to a lack of forage and tree management. Number of livestock was diverse between farms with maximum values of 130 beef cattle, 8900 poultry, or 200 dairy goats. The minimum end of the range for livestock on farms included two dairy cattle, 30 poultry, or nine sheep.
Only one of 20 farmers interviewed was not using rotational grazing techniques when managing livestock, although this farm was planning to transition to a rotational grazing system. Some farmers considered moving animals once a year as rotational grazing, while others understood rotational grazing to mean moving animals at least every few days. Rotations lengths used for cattle, sheep, goats, and horses in silvopastures ranged from less than one day to a maximum of 21 days. Rotation lengths utilized by farms for pigs ranged from two days to 365 days. Poultry were integrated into silvopastures on six farms, but four of these farms simply allowed poultry to free-range into silvopastures. The other two farms integrating poultry into silvopastures rotated them on a one to three day rotation.
With the exception for pigs, farmers were using forage height and availability as a measure of when to move livestock into and out of silvopasture paddocks. All farmers pasturing pigs utilized signs of site or tree damage as indicators for when to move them. Site damage included muddy ground, visible soil erosion, and visible soil compaction. Challenges of moving pig fencing, housing, and watering systems were referenced by farmers as a primary reason for long (or no) rotations of pigs in wooded areas.
The primary reason for pig incorporation into wooded areas was for the welfare of the pig from the shade of trees and as a form of vegetation management. Farmers saw the forest as a foraging area for pigs to consume roots, nuts, and insects. Where pigs were utilized in the first year of silvopasture establishment and in wooded paddock situations, between 32 and 100 % of inventoried trees had some form of basal damage or root exposure due to livestock. Three farms had damage on 100 % of the trees in pastures where pigs were incorporated. Additionally, bare mineral soil exposure ranged from 20 to 100 % within areas actively pastured with pigs.
When asked about animal health concerns in silvopastures compared with open pastures, nine of 20 farmers explicitly stated that they felt animal health was improved in silvopastures, primarily because of shelter and a diversified diet. Farmers expressed the following concerns regarding animal health in silvopastures: predators (3 farms), falling tree branches (2 farms), hunters (2 farms), parasites (2 farms), toxic plants (2 farms), physical injuries to livestock (1 farm), and limited visibility and access to livestock (1 farm). Only two farmers had livestock injury actually occur in treed pastures; one farmer stated hoof injury to pigs and the other farmer stated two cows’ tails being caught and torn-off by woody vegetation.
Forage management in silvopastures
Orchardgrass (Dactylis glomerata), bentgrasses (Agrostis spp.), bluegrasses (Poa spp.), red clover (Trifolium pretense), white clover (Trifolium repens), timothy (Phleum pretense), and fescues (Festuca spp.) were commonly observed in silvopastures (Table 3). In newly established silvopastures converted from forests bentgrasses and poverty oatgrass (Danthonia spicata) were common volunteer grasses inventoried. Eleven of 20 farms interviewed were actively seeding forages into silvopastures. Broadcast seeding in the spring and fall and out-feeding of hay in silvopastures were being used to establish forages. Across the region, forage species observed in silvopastures were similar to those commonly found in open pastures on similar quality soils. Three farms were specifically managing woody browse as a component of forage in their silvopastures, but these farms did not provide specifics in terms of preferred woody browse species. Twelve of 20 farmers considered woody invasive alien shrubs as undesirable plants in their silvopastures. Eight of these 12 farms specifically named multiflora rose (Rosa multiflora) as challenging weed in their silvopastures. Other undesirable plants, native and introduced, that were mentioned by more than one farm are listed in Table 4.
Tree management in silvopastures
Farmers were primarily managing trees in silvopastures for sawtimber, firewood, and nuts/fruit (Table 5). Other management goals for trees in silvopastures are listed in Table 5. Trees species/groups stated as favorable by multiple silvopasture practitioners included oak, maple, fruit trees, eastern white pine, and others (Table 5).
Ten of 20 farms in this study did not receive direct financial benefit from the trees in their pastures. Four farms had only received financial benefits from trees in their silvopastures when timber was sold as part of the initial timber harvest converting a forest to silvopasture. Five farms received direct financial income from trees in their silvopastures; these were a commercial tree nursery, farm with black locust thinned for fence posts, fruit from orchards, and maple sap.
Six farms were actively regenerating trees in their silvopastures, the remaining 14 farms stated that they were not actively regenerating trees at that time. Individual tree fencing was being utilized by six farms to regenerate trees in silvopastures, one farm was also using a coppice system for black locust, and another farm was allowing hardwood sprouts to regenerate in the piles of slash left over from the initial conversion of forest to silvopasture.
When asked about concerns regarding tree health in silvopastures, nine of 20 farmers stated concerns related to invasive alien forest pests, such as emerald ash borer (Agrilus planipennis) and hemlock woolly adelgid (Adelges tsugae). Four farmers also found the springtime to be a high risk for tree damage from livestock perceived to be caused by sap flow at this time. Stripping of bark was of concern, and observed, by farmers with goats and pigs, although not all farmers were taking action to prevent it. Pig farmers recognized that their pigs may be damaging tree roots, but they were uncertain as to how much, if any, damage was being done. A cattle, goat, and sheep farmer expressed the importance of management: “We’ve never really seen any debarking, or girdling by livestock, at least in areas that are being managed.”
Twelve of 20 farms had worked directly with a forester when developing silvopastures, and eight of those 12 found the forester to be supportive of silvopasture. One farmer actively avoided working with a forester in silvopastures, stating that foresters did not know much about silvopasture. Three farmers had switched the foresters they were working with and hired new foresters who were more open to the practice of silvopasture. The two foresters interviewed in this study stated their involvement with silvopasture was due to demand for the practice from clients.
Farmer needs for silvopasture optimization
Three farmers expressed lack of support from agricultural extension agencies for silvopasture as a major challenge they faced in adopting the practice (Table 1). Farmers were especially frustrated when extension personnel confused their silvopastures with poorly managed wooded livestock paddocks. However, the converse confusion also occurred by farmers practicing continuous pasturing of woodlands with pigs and calling it silvopasture.
Areas of research desired by farmers on silvopasture were diverse (Table 6). Eight farmers requested visuals and commercially viable case studies of regional silvopastures. When asked what resources they would utilize to learn about silvopasture, farmers varied greatly in their responses. Farm tours were cited as important educational opportunities by 12 farmers, but timing of these tours was cited as a challenge. Farmers were split between desiring online resources such as webinars and web pages while others preferred printed material. Extension personnel, conferences, and other farmers were cited as educational resources farmers would utilize in obtaining information about silvopastures.