Far from just cows in the woods; Silvopasture is the intensive integrated management of trees (forest products), forage (warm and cool season) and livestock production on a single parcel of land, at the same time. In this article we will focus our silvopastoral systems in conjunction with pine forest products grown in the southeastern U.S., specifically in south Alabama/Georgia and northern Florida, however silvopastoral systems can be implemented with other types of crop trees (pecans, walnut trees etc…).
In the southeast silvopastoral systems can be established either by planting loblolly, slash or longleaf pine trees in a particular arrangement in a pasture, or by thinning a stand of trees and planting a forage crop. Special tree arrangements in silvopastures allow for tree and forage growth, as well as for hay production and livestock grazing.
Establishment from a pasture
I have read many silvopastoral articles that site many different tree arrangements. I have my own arrangements that I prefer because it satisfies our specific area needs. Slash (Pinus elliotti) and longleaf (pinus palustris) pines are great species for silvopastural systems because their crowns are not as dense as loblolly and they provide more sunlight to the forest floor, which is necessary for livestock grazing. No matter which species you decide to plant, use only the best genetic stock. Slash and longleaf should be planted on row spacing ten or twelve feet apart, depending on the size of your ranch equipment (seeders, mowers, hay equipment etc…), and six feet in between trees. Seven rows should be planted with 50 foot alleyways (hay production and grazing areas) in between.
When it’s time for the first thinning a third row thinning should be implemented. The two outside rows should be removed and the middle row. A selective thinning, favoring the best crop trees should be performed on the remaining rows. Once implemented the alleyways will increase to 70 feet and the crop trees (future sawtimber & poles) will occupy only 60 feet, with plenty of sunlight reaching the forest floor.
Loblolly has become my favorite tree to use in a silvopasture system, not just any improved variety, but there are new types of loblolly available, clones and/or mass control pollinated. By using these new type of seedlings you know what you are getting, the best of the best. These seedlings show great promise. These new loblolly have pruning capabilities, excellent form class (pole potential) and straightness that rivals slash and longleaf, in addition they have better growth and disease resistance than slash or longleaf. Using a flex stand system (one row varietals and one row non-varietals), seedlings should be planted on row spacing 10 to 12 feet apart. Varietals should be planted ten feet between trees. Fill-in or trainer trees (non-varietal, a good genetic stock) should be planted five or six feet between trees. A total of nine rows should be planted, with the two outer rows as trainer rows; again 50 foot alleyways should be planned.
When it’s time for the first thinning all trainer rows should be removed leaving only the well space varietals (20’ between rows and 10’ between trees) for your future crop trees. Once implemented the alleyways will increase to 70 feet and the crop trees (future sawtimber & poles) will occupy 60 feet, with plenty of sunlight reaching the forest floor.
Livestock should be kept out of the planted pine areas until trees are at least 10’ in height, generally three to four years, depending on tree species and soil productivity. During this time alleyways can be used for hay production.
Establishment from a stand of existing trees
If you are implementing a silvopasture from an existing stand of trees, thin as if performing a third row thinning. Leave 4 rows of thinned pines and then cut out a 70 foot alleyway, repeat this process until the entire stand is thinned. As a rule, alleyways should be adjacent to all perimeter fences (established or planned).
Forages for Silvopasture
Silvopasture grass species that will work best in south Georgia will be one of the Bahia grasses and ryegrass in winter. One of the improved Pensacola Bahia grasses will be best, Tifton-9 or TifQuik or UF Riata. They green up early and keep growing late in the fall. One of the hybrid Bermuda’s (Tift 85 or Russell) could be used, but won’t do quite as well and they are expensive to establish.
Ryegrass over-seeded into the Bahia grass stand will give some good winter and spring grazing. Ryegrass will give a longer time of grazing in the spring than other winter forages. Also, it’s been noticed that ryegrass planted in trees will even provide forage a little longer into May and early June than where there are no trees. Of course if you want the most from your Bahia grass, graze or mow down the ryegrass when you want the Bahia to come out strong in the spring.
Cool season grasses may tolerate a higher tree density and still maintain their production levels. When seasonal rainfall quantity and distribution are less than optimal, forage production in silvopastures may be 10 to 15 percent less than open pastures. Bahia grass will tend to do much better under pines than Bermuda grass, as evidenced by the more recent observations at Americus, GA. However, I think the best silvopasture work is lightly stocked with cattle, and better use of co-grazing with goats,” says UGA scientist Dennis Hancock.
The best time to plant Bahia grass is in the early spring on upland soils or in late spring on low, moist soils. Plantings made later in the summer can be successful, but weed competition (primarily aggressive summer annual grasses, such as crabgrass, goosegrass, and crowsfootgrass) can be a problem. Dry weather can also slow Bahia grass establishment. Bahia grass can be successfully seeded in early fall in South Georgia, South Alabama and Northern Florida.
Bahia grass seed are small and should be planted shallow, no more than ¼ – to ½ inch deep. This will allow for quicker emergence and promote seedling vigor.
Bahia grass seed have variable germination rates. Some seeds germinate quickly after planting while others may not germinate until the following year. Generally, 50 to 60 percent of the seed will germinate within 30 days. TifQuik and possibly the new Riata are exceptions, as most of their seed will germinate readily within one to two weeks after planting if soil conditions are favorable. Seed dormancy is much lower in some varieties, resulting in the need for higher seeding rates.
Bahia grass may be planted in several ways. No-till planting methods should be employed if there is a risk of soil erosion (e.g., sloping land). No-till establishment methods can result in an acceptable stand of Bahia grass, but often require high seeding rates and control of existing vegetation. It is critical that the existing stand/crop and any weeds are destroyed. Sometimes this requires two applications of a non-selective herbicide (four to six weeks apart).
If the risk of soil erosion is minimal, conventionally-tilled seedbed preparation can be used to establish Bahia grass. When conventional seedbed preparation and establishment techniques are employed, it is recommended that the “stale-seedbed” method be used. In this method, the first step is to destroy the existing vegetation by spraying with a non-selective herbicide. Next, recommended levels of lime and/or nutrients (based on soil test results) should be added so that they can be incorporated into the soil during the tillage phase. The land can then be tilled, disked, and packed. This also allows for any leveling or smoothing of the soil surface that may be necessary. The tillage and packing steps should be completed at least one month prior to planting so that the soil can settle/firm before planting. Properly packing and firming of the soil is necessary to prevent the seed from being planted too deeply. As a rule of thumb, footprints left in prepared soil that are approximately 1/4-inch deep indicate a firm seedbed. In addition to allowing the soil to become firm, this will allow many of the weeds in the disturbed soil to germinate and emerge. These weeds can then be destroyed using a non-selective herbicide within a few days of planting.
Once the seedbed is prepared, seed may be drilled into the soil or broadcast on top of the soil. When broadcasted, the seed must be covered with soil (no more than ¼ – to ½ -inch deep) with either a light disking or a cultipacker Seeding and cultipacking at the same time using a cultipacker-seeder (e.g., Brillion seeder) also works quite well. Seed can be more precisely placed into the seedbed when drilled. However, the small seedbox attachment must be used to plant Bahia grass because the seed are too small to be accurately measured in the grain drill seed cups.
Seeding rates vary with variety and planting method. When using a Pensacola-type variety, the seeding rate should be 12 to 15 pounds of seeds per acre when the seeds are drilled into a prepared seedbed. When broadcasting seed onto a prepared seedbed or using no-till methods, increase the seeding rate of Pensacola-type varieties to 18 to 20 pounds per acre.
Tifton-9, TifQuik and UF Riata have much better seedling vigor than other Pensacola-type varieties and lower seeding rates can be used for these varieties. As a result, the seeding rate for Tifton-9 and TifQuik is 8 to 10 pounds per acre on prepared seedbeds and 12 to 15 pounds per acre when broadcasting or planting with a no-till drill.
Mack Evans (pictured right) has been practicing silvopasture for many years. Mack has used the Tifton-9 and TifQuik in the past. He also recommends over-seeding in the winter with ryegrass, crimson clover and radish. The clover is a nitrogen fixing legume; the radish produces a long thick root system, when the dead root dries out and decays it acts as a soil-aerator.
Fertility at Establishment
Prior to planting, apply any needed lime, P, or K (according to soil test recommendations). Avoid applying N before or at planting, as this may increase annual grass emergence before Bahia grass. Apply 35 to 50 pounds of N per acre after the seedlings emerge and start to grow. With early planting dates, a second application of 50 to 75 pounds of N per acre in early- to mid-summer may be necessary to promote rapid coverage.
Link to More Bahia establishment info
Bermuda Establishment link
Annual Ryegrass (Lolium multiflorum)
Annual ryegrass (commonly referred to as simply “ryegrass” in Georgia) is a well-adapted winter annual that can be planted in prepared seedbeds or overseeded onto perennial grass sods for late winter and spring grazing. Some newer varieties may even provide some late fall grazing if planted early and/or into a prepared seedbed. Ryegrass is also often seeded in mixtures with a small grain and/or clover. It is a prolific seed producer and will reseed in pastures (if allowed to go to seed). Ryegrass has a later grazing season than the small grains and can be grazed until early May in South Georgia and late May or early June in north Georgia when moisture is adequate.
Ryegrass is one of the highest quality forages that can be grown in Georgia, often providing more than 70 percent total digestible Nutrients (TDN) and 18 percent crude protein (CP) if grazed in the late vegetative stage. High quality (56 to 64 percent TDN and 10 to 16 percent CP) can also be expected in the early stages of seed-head development. However, quality and palatability of late season forage can be low due to disease (mainly rust) and maturity.
It is also commonly planted into dormant pastures or hayfields. This is a recommended practice, but the ryegrass should be mowed, cut for hay, or grazed before the summer perennial grass comes out of dormancy. Ryegrass harvesting could be timed (usually late March in South Georgia and late April in north Georgia) to prevent it from suppressing the spring emergence of your perennial grass.
Much of the above taken from and more information can be found at UGA Forages.
Rotationally Grazing Livestock
No matter which grazing species you choose to manage, a rotational grazing system is a must. Five to twelve grazing units depending on stocking rates and soil productivity will be necessary to effectively manage a silvopastoral system. Short rotational grazing periods followed by long recovery/rest periods are important to the overall health of the forage, and inevitably the herd. Do not use fixed grazing time schedules. Short-term over-grazing needs will have long-term forage production consequences, ultimately decreasing long term revenues. It is important to match the rotational grazing time to forage production. Carefully observe the forage to maintain sufficient leaf area for photosynthesis, and rotate the animals to a new grazing unit before regrowth of grazed forage develops. Forage quality diminishes with increased maturity; therefore it is imperative to plan the entire silvopastoral system around the forage program to maximize forage quality at its peak, ultimately benefiting the entire herd.
Silvopasture involves the combined knowledge of timber, forage, and livestock production integrated simultaneously on a single tract. It can be an attractive management alternative, merging short-term annual cash flows from forage and livestock production with long-term, periodic income from timber sales. This is certainly not a complete guide to silvopasture, and silvopasture is not for everyone. Silvopasture is an active investment approach, as opposed to a passive investment approach, it involves an intensive management system designed to combine short and long term revenue streams. If you need additional information regarding silvopasture, contact Alan Emmons with Southern Forestry Consultants, or Rome Ethredge, Seminole County, Georgia Extension Agent.
Alan W. Emmons is Partner and Treasurer of Southern Forestry Consultants, Inc., a Certified Forester with the Society of American Foresters, a Georgia Registered Forester and Certified Burner in Georgia and Florida. Alan is also an active Realtor, and partner in Southern Forestry Realty. A 1985 graduate of North Carolina State University, he has 30 years of extensive forestry experience, up and down the east coast of the United States. You can contact Alan at (229) 220-1790 or email@example.com.
Rome Ethredge is a University of Georgia Extension agent in Seminole County, Georgia. He has been working in Agriculture and Environmental Sciences for more than 30 years. He’s a graduate of ABAC and University of Georgia with B.S. and M.S. degrees in Agronomy. Contact your local county agent or if in Seminole county at Seminole County Extension 229-524-2326 or firstname.lastname@example.org