Tree establishment is one of the primary challenges farmers face when adopting agroforestry techniques. More specifically, a major critique of silvopasture, by non-silvopasture practitioners, is that regeneration is overly challenging in the face of livestock damage and deer browse. This study has three primary objectives: 1) to determine the effectiveness of different apical bud protection methods during the establishment phase of silvopasture from treeless pasture and during enrichment planting of a sugarbush 2) to determine the tradeoffs between organic, chemical, and mechanical control of grass when establishing silvopasture from treeless pasture 3) to establish an on-farm demonstration area in New England of silvopasture regeneration techniques. We will compare the use of no bud protection, paper bud caps, woody shrubs, and tree tubes in the protection of hardwood tree seedlings from deer in silvopasture and sugarbush applications to accomplish the first objective. We will accomplish the second objective by comparing the effects of white clover living mulch, glyphosate, composted hay mulch, and grass clippings on height growth of fruit trees planted in silvopasture establishment from treeless pasture. The third part of this project will be optimized through on-farm educational events and outreach at professional meetings. The benefits of this project in establishing on-farm, scientifically robust, demonstrations of silvopasture regeneration strategies will extend beyond the scope of this project’s timeframe. This project will also serve to advance science-based tree establishment methods applicable to many different agroforestry practices in the Northeast United States and beyond.
This project seeks to address the following three objectives:
1) To determine the effectiveness of different apical bud protection methods during the establishment phase of silvopasture from treeless pasture and during enrichment planting of a sugarbush. The impact of this objective will be to better inform farmers about the effectiveness of bud caps, no bud protection, tree tubes, and the use of shrubs to protect trees from deer and livestock during silvopasture regeneration and enrichment planting of a sugarbush.
2) To determine the tradeoffs between organic, chemical, and mechanical control of grass when establishing silvopasture from treeless pasture. This objective will inform farmers of the tradeoffs between four methods of minimizing grass competition with trees: clover as a living mulch, clipping of grass, glyphosate, and manure/waste hay as a mulch.
3) To establish an on-farm demonstration area in New England of silvopasture and sugarbush regeneration techniques. The impact of this objective will be to provide farmers with information and a go-to location for learning about how to regenerate and establish silvopastures on their farm and how to enrich poorly managed sugarbushes with valuable species.
Silvopasture has received significant interest in the Northeastern United States over the past decade. Farmers in the region are recognizing that woodland on their farm may serve a grazing purpose in addition to growing trees. My past research on North Branch Farm, funded through the SARE program, had documented the benefits and tradeoffs of converting forest to silvopasture (Orefice et al 2017a, Orefice et al in-press). One result of this work showed that silvopasture, when compared to treeless pasture, holds many soil and livestock benefits. However, much of the focus of silvopasture in our region has been on forest conversion while little work has been conducted on converting treeless pasture to silvopasture. Establishing trees in pasture is arguably the most environmentally friendly method of creating silvopasture and is likely to provide the most ecosystem services in terms of water quality and soil health. My past work in New York and New England found that lack of knowledge toward management of silvopasture systems and toward tree care were major inhibitors to silvopasture adoption (Orefice et al 2017b).
I have been independently farming for nine years. The first eight of those years were on North Branch Farm in Saranac, NY. On that farm I practiced and conducted research on silvopasture and also grew vegetables and fruit. The farm served as a demonstration area for silvopasture and I hosted over 30 tours and multiple classes during the course of my time there. I hold a Ph.D. in silvopasture from the University of New Hampshire, was an Associate Professor of Forestry at Paul Smith’s College, and served as Director of Cornell University’s Uihlein Sugar Maple Research Forest and Northern New York Maple Specialist.
In 2018 I accepted a position with Yale University as Director of Forest & Agricultural Operations and Lecturer in Agroforestry. I have since sold North Branch Farm and have moved my farm business to 134 acres of land I purchased in Union, Connecticut, called Hidden Blossom Farm. I am currently raising and rebuilding my herd of 11 beef cattle there and developing new silvopasture systems both from open pasture and forested land. The farm also has a degraded sugarbush that I am working to get back into production over the long-term. Like much of the Northeast, the sugarbush has an understory of invasive shrubs from unmanaged woodland grazing and a lack of regeneration due to deer browse. My farm is well set up to meet all the mechanical and infrastructure needs of this project.
Part one of this study is a randomized complete block design to investigate strategies for apical bud protection from deer for trees planted in silvopasture and sugarbush systems. Six blocks were established, two in a shrubby grazed area being converted to silvopasture through planting and four in a formerly high-graded sugarbush with an understory of Japanese barberry and multiflora rose. The main factor of the randomized complete block design is an apical bud protection strategies of planted trees (Figure 1). This factor consists of four treatment groups: 1) control, no apical bud protection 2) paper bud caps in all blocks with additional polywire protection during the grazing season in silvopasture blocks (post-it notes stapled around the terminal bud during the dormant season) 3) planted in the center of a Japanese barberry or multiflora rose cluster 4) and 5’ tall tree tubes in all blocks with additional polywire protection during the grazing season in silvopasture blocks. Each treatment is of 10 trees, totaling 40 trees per block. Walnuts and hybrid chestnuts were established in the silvopasture blocks and oaks, walnuts, and sugar maples were established in the sugarbush areas.
All trees were tagged and initial height measurements were collected when they were planted in the spring of 2019. Tree height, browse damage, and mortality will be recorded in the spring of 2020 and 2021 and compared to initial measurements. Statistical analysis will be conducted for the study in 2021 to determine the effectiveness of treatments.
Part two of this study is to assess the value of living mulch when converting treeless pasture to silvopasture. We used a randomized complete block for this design. Five complete blocks were established in areas that are currently in treeless pasture. Fruit trees were planted in four, 5 tree rows within each block at a 20 foot by 20 foot spacing (Figure 1). Apples, pears, and stone fruit were the species planted and varieties were consistent between treatment groups within a block. Each block consists of four treatment groups: 1) control, pasture grasses regularly clipped around the base of trees 2) white clover established and regularly clipped as a living mulch 3) glyphosate sprayed around the base of trees 4) waste hay and manure layered as mulch around each tree in the spring.
Trees in these systems were protected from livestock during the grazing season with the use of temporary polywire and small paddock rotational grazing. Please note that Joseph Orefice has had excellent success with this method of tree protection in the silvopastures on his former farm, North Branch Farm in New York. Mesh tubes were used to protect trees from deer until they are above browse height and plastic screen was placed around the base of trees to protect them from rodents.
All trees were tagged and initial height measurements were collected when they are planted in the spring of 2019. Tree height, browse damage, and mortality will be recorded in the spring of 2020 and 2021 and compared to initial measurements. Statistical analysis will be conducted for the study in 2021 to determine the effectiveness of treatments.
Part three of this project will be to document tree establishment costs and estimates of time involved for tree care during parts 1 and 2. Actual costs and labor hours involved in planting, protecting, and managing grazing around trees is being documented over the course of this project. These costs will be analyzed to provide farmers real numbers related to tree establishment and the time involved when converting areas to silvopasture.
One unexpected turn in this project is that deer browse was heavy during the growing season. I made a poor assumption that deer browse would be a problem only in the winter, however we had many issues with deer browse year-round. This led to the bud-cap portion of the study not functioning as the bud caps were for winter protection of buds, and leaves/shoots were consumed during the growing season by deer. Portable polywire was useful for protecting seedlings in the orchards from cattle but it needed to be hot. This project is ongoing and we do not yet have results to share beyond deer browse being a problem year round instead of in the winter.
Bud caps were an issue. The project results are still to be determined but in the future I would also look at full exclusion of deer from plots to see the cost differences.
These are still to be determined beyond that deer protection needs to exist year round
Education & Outreach Activities and Participation Summary
50 farmers and extension agents attended a silvopasutre 101 workshop we hosted on the farm in August 2019. A quarter of this workshop was devoted to silvopasture regeneration and the research plots here were the highlight of that. They were valuable in demonstrating different strategies for establishing trees in open pastures as well as the challenges of deer browse.
Results of this research are still pending so we can’t yet say much about change in knowledge beyond sharing ideas.