- Agronomic: general hay and forage crops, grass (misc. perennial), hay
- Additional Plants: native plants, trees
- Animals: bovine
- Animal Products: dairy
- Animal Production: housing, animal protection and health, grazing management, pasture fertility, pasture renovation, grazing - rotational, feed/forage
- Crop Production: agroforestry, forestry, intercropping, nutrient cycling
- Education and Training: demonstration, farmer to farmer, on-farm/ranch research, workshop
- Farm Business Management: whole farm planning, budgets/cost and returns, agricultural finance
- Natural Resources/Environment: carbon sequestration
- Production Systems: agroecosystems, holistic management, permaculture, integrated crop and livestock systems
- Soil Management: soil analysis, nutrient mineralization, soil chemistry, organic matter, soil physics, soil quality/health
The concept of integrating grazing systems with forest resources, silvopasture, is beginning to attract interest in the Northeastern United States. While silvopasture systems have proven to be productive and profitable practices in other parts of the country and world, little is known regarding the potential benefits and tradeoffs of incorporating silvopasture systems into farm management in the Northeastern United States. The research proposed here will test the environmental and economic impacts of converting a northern hardwoods stand into a silvopasture when compared to treating the stand as a managed forest or converting it to an open pasture. Additionally, six forage establishment treatments will be tested for productivity and influence on soil properties within the silvopastures and recently cleared open pastures. Data related to establishment costs, changes in soil properties, forage production, and timber quality will be collected and analyzed over a period of two years. Results of this study will be offered at agriculture and forestry professional meetings. Field tours will be held for the public and for college students in the fields of forestry, natural resources and culinary arts.
Project objectives from proposal:
Over the past few years there has been increasing interest in the practice of silvopasture in the Northeastern United States, especially in New York. This is evidenced by multiple presentations related to silvopasture practices, the most notable being the Northeastern Silvopasture Conference hosted by Cornell Cooperative Extension on November 7th and 8th 2011. Silvopasture is an agroforestry practice which intentionally incorporates livestock grazing with forest services; such as timber production, nut crops, or other forest products.
In an ideal system, silvopasture increases the quality and productivity of pastures and contributes to increases in tree growth and forest ecosystem services when compared to open pastures and livestock free forests, respectively. However, farms and forests are complex systems and how conversion to silvopasture will affect pastures and forest ecosystems in the Northeastern United States can only be speculated. Currently there is no formal research available on silvopasture in Northeastern agricultural systems, although it may be a valuable practice for farms in need of concurrent shade and pasture for their livestock in the summertime. Research in other parts of the country has shown that cattle which have access to shade during times of summer heat have less stress and higher productivity than cattle in the open (McDaniel and Roark, 1956; Mitlohner et al., 2002).
In the midst of all the current interest in silvopasture in the northeast, there is one main question that arises: What are the tradeoffs, related to farm productivity and ecosystem services of forests, when silvopasture systems are implemented? A follow up question to this is if silvopasture systems are a desirable farm practice in the Northeastern United States, what establishment and management practices should farm and forest managers utilize in these systems?
In a report on silvopasture recommendations for the Northeastern United States, the authors make a strong argument for more research to be conducted related to forage evaluation on Northeastern silvopastures (Chedzoy and Smallidge, 2011). The research proposed here will contribute to the answers to these questions from the perspective of converting a farm woodlot into a silvopasture and an open pasture.
While the “how-to” research is clearly lacking related to silvopasture in the northeast, economic analyses related to this practice are even scarcer. Diversified farm income is a staple to sustainable agriculture and silvopasture has the potential to contribute to this, through concurrent forest product and livestock production (Carroll, 2011). One unknown is the profitability differences between managing a farm woodlot for timber, timber and pasture (silvopasture), or converting it to an open pasture. The proposed economic analysis and on the ground demonstration of these three options will contribute to this economic question.
Silvopasture has been shown to be a productive management practice in the hardwood ecosystems of the Midwestern United States, and yet even there researchers are calling for better development of the practice and better understanding of its ecological interactions (Garrett et al., 2004). It is time for science in the northeast to seriously start investigating silvopasture systems.
This experiment will examine the productivity, environmental effects and economics of converting a northern hardwoods stand into a silvopasture. A 6.75 acre forest stand comprised of pole sized northern hardwoods (red maple, paper birch, white ash, black cherry, quaking aspen, American elm, and American basswood) will be the study area (see “Main Plot Locations” attachment). Prior to any treatments on the site, soil sampling, a 100% tally of all trees over 2 inches diameter at breast height (DBH), and a survey of ground cover flora will be conducted; the timeframe for this is May-June 2012.
The experimental design is a split-plot randomized complete block (see “Plot Design” attachment). The main plot factor will be overstory conditions and there will be three treatments: crop tree thinning (thinning), silvopasture, and open (all trees removed). Each main plot treatment will be replicated three times using ¾ acre plots, the locations of these plots will be randomized within each of the three blocks. The thinning treatment will allow me to compare silvopasture productivity and economics to that of a managed forest. The open treatment will allow me to compare silvopasture productivity and economics to a newly established pasture; it will also allow me to determine the effects of trees on forage productivity.
The thinning and silvopasture treatments will have the forest overstory basal area reduced to 30% of full stocking basal area, a level similar to stocking levels on silvopastures from other regions (Devkota et al., 2001; Garrett et al., 2004; Walter et al., 2007). Dominant and well-formed stems will be favored, American elm and white ash retention will be discouraged due to invasive alien species concerns. Black cherry, due to its high timber value, will be retained on the site in some cases, but will be monitored to prevent issues related to livestock consumption. In open treatments, 100% of trees will be removed. Slash will be left in the thinning treatments and lopped to 2 feet in height. All slash will be removed from the silvopasture and open treatments and burned offsite. The size of the timber on this site restricts it from being harvested commercially, but many stems from the treatments will be utilized in farm operations. Main plot treatments will be established in June and July of 2012.
The split-plot factor will be forage establishment (see “Plot Design” attachment). Forage treatments will be established the silvopasture and open main plot treatments only and will measure 12ft x 40ft. The forage establishment treatments will include: none, loose hay depositing, orchardgrass-white clover, perennial ryegrass-white clover, Kentucky bluegrass-white clover, and smooth bromegrass-white clover. Reed canarygrass was considered in this study, but excluded because of its status as an invasive alien species in some Northeastern states. Forages will be broadcast seeded. The loose hay treatment will have locally-sourced hay bales spread thinly over their respective split-plots to simulate on-pasture feeding of livestock. White clover will be broadcast seeded at a rate of 5 lbs per acre. Grasses will be broadcast seeded at rates of 20 lbs per acre. A broadcast seeder will be calibrated off-site for each species prior to on-site use. Livestock will be let into all open and silvopasture plots after seeding has taken place, briefly, to trample in seed. Site preparation and forage seeding will take place in August of 2012, with a target planting date of August 15th (subject to change based on soil moisture conditions in August).
Data on forage production will be collected within the center portions of the main and split plots so as to minimize potential edge effects. The edge buffer will be narrower on the north side of main plots due to the southern aspect of the site and forest canopy light dynamics related to the sun’s location in the northern hemisphere (Milakovsky et al., 2011).
Beginning in the spring and summer of 2013 all silvopasture and open treatments will be grazed with beef cattle to a height of two inches. The intensity of grazing will be dependent upon the overall condition of forages within the plots, but grazing intensity will remain constant between plots and preferential grazing of forage treatments by cattle will be monitored. Time, labor, equipment and other real costs (such as seed) will be recorded throughout the process of establishing and managing these treatments.
Response variables for the main plots include economic costs and returns, forage production (thinned treatments excluded), forest production (open treatments excluded), and soil properties. Economic costs related to all aspects of silvopasture, open pasture, and crop tree management will be assessed in net present dollars. Livestock production revenues will be extrapolated from dry ton per acre forage values in the different treatments. Economic comparisons will be made between main treatment groups and forage establishment treatments.
Revenues from timber will be extrapolated based on rates of unintended tree mortality and changes in timber quality. Timber quality will be assessed through mechanical damage and amount of epicormic branching pre-treatment and in 2013 and 2014, these measurements will also contribute to an understanding of forest production. Tree diameter measurements will be recorded in pre-treatments and two years post treatment, although due to the slow growth of trees, analyses of these data are not expected to yield any significant results. Long term study (beyond the scope of this proposal) will likely be needed for tree diameter response data. Trees with crowns on the edge of the main plots will be excluded from analyses due to edge effects between plots.
Forage production will be measured by compositing five samples of square foot clippings taken at 1” off the ground in each split-plot. Composite samples will then be dried and values will be converted to dry tons per acre. Sampling will take place in October 2012 and prior to grazing in May, July and September of 2013 and 2014. Forage production will be compared between silvopasture and open treatment groups as well as forage establishment treatments in split-plots.
Composite soil samples to a depth of 15cm (five samples per split-plot = 1 composite sample) will be collected prior to any treatments, totaling 54 soil samples in the establishment year. Soil samples will be analyzed for pH, particle size distribution, extractable bases, total C and N, and available N and P. Composite soil measurements related to soil infiltration rate, respiration, resistance, bulk density and particle size distribution will also be collected. Soil sampling will take place in main and split plots in June of 2012 and will be repeated two years post treatment in June of 2014, comprising a total of 108 soil samples over two years.