The creation of silvopastures can be approached from either of two directions: adding trees into pastures, or pastures into trees. On our farm, we've spent most of our time up to this point focusing on thinning our woodlots and older plantations to create silvopastures. The main reasons were to expand our grazing capacity and to deal with invasive forest plant issues in a seemingly practical and cost-effective manner. With those projects well under way, we started to experiment last year with opportunities to add trees into our pastures in order to feasibly and viably create more shaded grazing for our black angus cattle. Livestock rarely seems to be uncomfortable from the cold weather where we live, but can be observed running to the shade most anytime the temperature is above ~ 70 degrees (that covers a good part of the grazing season in upstate NY). Therefore, we would like to turn the roughly 50 paddocks (~ 175 acres) of pastures on our farm that has little or no shade into silvopastures, and do so without breaking the bank and without detracting from the productive capacity of the farm.
I can think of many ways to get more trees and shade into pastures. There's no one right approach, and different things will work better on some farms than on others. But keeping in mind the goals on our farm of "feasible" and "viable", we have decided to experiment mostly with trees that can be established at relatively low cost, that will have significant future value, that are conducive to growing quality forages beneath, and which can be established in open pastures without extensive or long-term protection.
I'm dubious as to the "positive rate of return" of planting most fruit and nut trees due to their high costs of establishment and the challenges associated with establishing these species in a sod environment - which is also usually filled with herbivores. But it's certainly an option, and the cost:benefit analysis should include not only the value of the future timber products, but other services like shade, habitat, aesthetic enhancement, fodder, etc.
One tree that I'm increasingly enamored with for silvopasture creation is black locust. I listed some of its attributes in a separate post - but it's greatest advantage, in my opinion, is that a few locust can lead to many if properly managed. Locust is a clonal species, meaning it will sucker from the root system. This feature can allow it to gradually spread across pastures by establishing trees in strategic locations.
pictures to follow...
I agree with you regarding black locust and all its attributes. Just a note of caution to Massachusetts readers/farmers/landowners black locust is on the invasive plant list [unfairly in my humble opinion]. Apparently one of the threats is adding nitrogen to nutrient poor soils and threatening the native plants that thrive on these poor sites. It is not supposed to be sold or planted in the State. I guess the Ozarks and Southern Applachians are to exotic of a place for the black locust to be considered a native plant.
Brett and Jeff:
I'm with you regarding the many positive attributes of black locust. In two different seedling plantation trials I started this summer, black locust was the early winner, with the majority (?) of seedling emerging from tree tubes. From my perspective, the attitudes against locust are ill-informed and based largely on a reluctance to use herbicides to control locust in an area that might support the Karner blue butterfly. Locust is intolerant of shade, yet intolerant species are quite uncommon among the ranks of true invasive species.With its numerous positive attributes, I see locust as a clear winner. I wish I had more on my property.
And the finished product
Below are some examples of on-going experiments at our farm to get more trees into pastures...
The above picture shows an experiment with thornless honey locust growing in 3 different types of tree tubes with three different types of (individual) protection to keep animals from disturbing the tubes. Cattle can still graze up to within a couple feet of each tree. Near the tree tubes are big-tooth aspen posts that were pounded into the ground the previous winter to see if they would root and grow. It was unsuccessful, but it was also done prior to one of worst drought we've ever experienced in our area. The idea was to put large cuttings in the ground that would resist rubbing by the cows and sprout high enough to resist browsing. I would like to try this again with black willow and possibly some other species of Populus.
The only individual tree protection method that worked was to place a barbed cage (anchored with some resin posts) around the tree tube. The cages were made by using 2x4" wire and bending some of the verticals outward. A 3' diameter cage used about $10 worth of materials - but should be able to be used repeatedly on other trees. In one season the honey locust are already emerging from the 5' tree tubes, so I estimate that the cages will need to be left for at least ~ 5 years until the trees are a couple of inches or more in diameter to resist cattle that are being rotated rapidly through the paddock (slower rotation = larger diameter to resist bored and destructive animals). The other two protection methods that were unsuccessful were to wrap barb wire around the tree tube and to place a small triangle of un-electrified polytwine around the tube. The calves quickly dismantled those protection structures.
Regardless of the "outer protection" from livestock, I feel that it's important to protect the young hardwood trees from moles and mice with a tree tube - and from competing vegetation by spraying or mulching around the tube.
This spring we did a direct seeding of black locust in several paddocks. The strips were sprayed in the fall to kill the sod. In late-May during a week of warm and humid weather, we soaked the locust seed overnight (in initially hot water) and planted it in shallow furrows the next day using our old tree planter. I sprayed the rows again the next day with glyphosate to kill any residual vegetation. Each row was planted about 4' from an existing single-strand high-tensile paddock fence. A temporary fence of electrified polytwine was built about 4' on the opposite side of the row. Cattle have since rotated twice through these areas and were able to graze in from each side a couple of feet. It's hard to see in the photos, but a sufficient number of locust seedlings have emerged (as well as a lot of warm season weeds). I plan to spray again in the spring prior to leaf-out (fortunately, black locust leafs-out late!) The plan is to leave the locust enclosed for at least several years until they reach a "safe" height. The temporary fences will then be removed. We've observed that with long rest periods between grazings (in our case, about 10 weeks), the locust gradually will spread out into the pastures through root suckers to expand the shaded areas. I'll post a picture of that tomorrow near some older locust plantations. The advantages that I see to this method is that for relatively little cost and loss of grazing area we can establish a useful tree crop that gradually expands on its own.
The two pictures below show two locust plantations on our farm where we've harvested the straight trees for fence posts and girdled the few remaining trees that were too crooked to utilize. Girdling vs. felling leaves less slash on the ground to impede grazing, but now that I see how thick the suckering is I guess it doesn't really matter! Point of the photos though is to show how the suckers have expanded out into adjacent (treeless) pastures, despite periodic grazing (each paddock on the farm is grazed 4-5 times/year for about 1 day/time). New locust sprouts can be found up to 50' away from the cut trees. In the case of the first area below, the sprouts have already outgrown the grazing height of the cattle and are well on their way to forming a new nucleus of black locust for shade and posts. The second area below (another locust plantation that was harvested a year later) shows locust that are currently about 4-6' tall and should be free from browsing damage by this coming grazing season. With a little time and patience - and the right management - planting a few locust can eventually lead to many.