Final report for FNC19-1159
We have a 20 acre farm, however, 16 acres are classified as forest which has been heavily invaded by Asian Bush Honeysuckle (and other invasive plant species). The remaining 4 acres, we grow produce, raise laying hens, and house meat goats.
Invasive plants threaten native forests. While some livestock, such as goats, are known to keep invasive plants at bay, they also graze indiscriminately—eating invasive species and native hardwoods alike. Manual removal of invasive plants is laborious. Absent any meaningful use for invasive plants, the chore often goes undone. Why cut honeysuckle bush if the lumber is useless?
This project will put invasive plants to agricultural use, hence we are calling it systematic “harvesting” not merely removing. Indiana’s DNR forestry department will identify targeted species for removal. We will cut and remove plants weekly, bring them to the goat pasture for a week of free-choice forage, then chip and store for bedding.
Chips will bed goats and chickens, creating two different compost profiles of varying nitrogen density. The soiled bedding will be removed as needed and composted. Lab tests will measure the density of nutrients. Compost will be introduced as a soil amendment to vegetable production the following year. Special care will be taken to monitor for allelopathic effects of such species.
The first objective is to ascribe appreciable value to an otherwise useless timber, giving farmers a reason to manage it. Secondarily, conducting the project on a highly-trafficked suburban farm will expose consumers to sustainable agriculture and natural resource management.
- Control the spread and reduce the presence of invasive species in the 11-acre Certified Forest.
- Demonstrate a valuable agricultural use for invasive forest species as either (a) a supplemental source of roughage for goats, or (b) a valuable dry matter for bedding and later compost, or (c) ideally both.
- Separately record the nutrient value, established by laboratory testing, of compost from both chicken coop flooring and goat pen bedding using chipped wood as dry matter.
- Create an opportunity for over 10,000 households within 2 miles of Mud Creek Farm to learn about sustainable agriculture firsthand.
- Grazing, then chipping. It is unclear how much green matter the goats will choose to eat of the cuttings. However, this weed from cutting to chipping is not solely for foraging, it also allows limbs to dry before chipping in order to elongate storage time and bedding value.
- Separate composts. Goats and chickens produce vastly different manures and soil their bedding at different rates. We hypothesize that there will be less labor involved (fewer changes of bedding) with chickens, and a higher nutrient value in the compost. We can test with two different types of livestock side-by-side and fully expect to find different values for the effort.
- Sweet Corn. We chose sweet corn as a test crop for the mulch for two reasons. First, it’s direct-seeded, so we can measure germination. Invasive species are believed to have allelopathic qualities which prevent germination. We can demonstrate whether composting denatures allelopathic chemicals. Second, we can measure yield (dozen per acre) and, with proper soil amendments and irrigation, we can expect uniform results year after year.
- Test plots. We will test on 1 acre of sweet corn divided into 3 test plots. The first year, we will conventionally fertilize the entire acre uniformly, but measure the results from each plot separately for comparison. In year 2, we will amend one plot with conventional fertilizer according to lab recommendations and the other two plots using each form of compost plus any additional amendments according to lab recommendations. We will use consistent irrigation and extensive pest management to avoid outside factors affecting the comparison yields from year to year.
- Walking Trail. We will display brief summaries of this project on sign-boards and post on the farm where visitors can read and see the project in process.
- We were able to demonstrate that there are no allelopathic concerns when applying composted honeysuckle to fields or gardens. Market gardeners and farmers should, without reservation, accept wood chips of any provenance if they can be used first as bedding and composted before applied.
- We demonstrated that honeysuckle is a suitable forage for a goat rumen, with over 7% crude protein. Areas of the Midwest that are overgrown with Honeysuckle (or similar invasive species such as autumn olive, privet, multiflora rose, etc.) can be managed with goats.
- We found that clearing understory of invasive species, even when spraying herbicide on the stumps, can actually lead to more propagation of the plant. It became clear that more aggressive use of brush-killer after cutting would be required, or bringing the goats to the patch for repeated defoliation.
- We found that the process of harvesting honeysuckle bushes/trees and relocating them to a feeding location for the goats was not an efficient use of labor. If wood chips are desired for bedding and compost, they can be obtained far easier (often for free) from arborists. Woody forage is too difficult to move, so bringing grazers to the forest is ideal.
Ultimately, we have at least two permanent improvements to our sustainable farm operation that resulted from this study:
- We will, without reservation, accept any arborist drop-off at our farm and gladly use the chips as bedding, compost them for the following year, and apply liberally to our fields.
- In partnership with the Indiana DNR, we will establish a rotational grazing process to intensively graze down the invasive species in our forests for years to come in the hopes that they will eventually be reduced to the point that eradication is feasible.
Educational & Outreach Activities
October 5, 2018 – Visit with Zach Smith, Indiana DNR Forester, to discuss the project and outline objectives. Helped to identify invasive species (beyond Bush Honeysuckle) and discuss management techniques with goats.
January 30, 2019 – Visit with Ben Miller, Indiana DNR Wetlands, to discuss the project and explain objectives.
June 14, 2019 – Tour with neighboring after-school program, including parents and grandparents. ~20 adults in attendance. We walked the woods, showed the impact of invasives. Children took cuttings from honeysuckle and fed it to goats. We showed a Johnson-Su reactor and explained allelopathy and composting to the kids (and adults) present, and outlined the entire project.
3/5/2021 – Presentation at the Indiana Small Farms Conference
Here is the video we created to share the project results:
Here is the article our community published about us using regenerative ag practices in the neighborhood.
Year 1 Update:
We have seen that bush honeysuckle is, indeed, a great forage for goats. It’s early foliage means that it can dramatically reduce the need for hay by providing natural forage earlier than pastures are ready in the spring. It’s also 6% crude protein and high dry-matter, see attached feed analysis. Unfortunately, the goal of eradicating an invasive species means this is a short-lived benefit if the project is successful. DNR Foresters are categorically NOT interested in a management plan that would emulate grazing pastures, where the replenishment of the forage is desired. They want it eliminated by express over-harvesting (or over-grazing).
From a process management standpoint, the harvest approach of bringing the forage to the livestock is difficult to justify. Hay is baled and compressed, so each unit being carried (e.g. a hay bale) has a dense amount of forage. Cutting an entire mature honeysuckle tree and transporting it branch-by-branch is an equivalent labor to moving roughly 3 bales of hay, yet it packs far less nutrition. The goats can have it eaten in a matter of hours. The added value of bedding/mulch/compost may prove not to be enough to justify that labor gap, as less expensive means of getting wood chips exist with arborist drops (chip-drops). More efficient means of harvesting may be required, which could include grazing in-place and cutting/chipping after defoliaged by the goats.
This year will tell the results of the yield gains from applying the composted bedding, so final judgment is reserved until all results are in.
Year 2 Results
In year 2, we learned some encouraging results from the use of composted honeysuckle, and we modified our plan in order to mitigate the discouraging results from the ecological survey.
First, the sweet corn. First, we were unable to make a userful comparison of germination from year 2 against year 1 (the intended control group) because in Year 1, we had disastrous wet weather during May, record rainfall in the midwest, and significant drown-out. However, we spread approximately 7 cubic yards of honeysuckle mulch, which had been used as animal bedding, soiled with manure, and then composted over winter. The germination rate was over 95% that spring, indicating that no adverse allelopathic effects could have been at play.
The ecological survey in the forest was not as encouraging. Honeysuckle and Multiflora Rose both increased in population in the test plots measured. The brush killer applied to stumps did not appear to end the subterranean spread of the root system, or perhaps shed fruit during harvest was quickly able to germinate and establish new plants. In the end, clearing the understory of the forest seemed only to open the door to a larger number of invasive shoots emerging from the forest floor. The increase in natives, on the other hand, was not as fast. And 2/3 of the increased natives were Ash, not expected to survive due to the emerald ash borer.
The very reason that an invasive species is so invasive has to do with it’s ability to propagate faster than the natives. This held true in our limited experiment. So, we sought permission from the DNR to conduct a different experiment in 2020.
We marked native saplings in a 2-acre patch of forest. We sprayed their leaves with a pepper spray to deter goat grazing. Then, instead of harvesting the honeysuckle and bringing it to the goats, we turned them loose to graze. By allowing them to defoliate the understory multiple times throughout the year, we hope to be able to control invasives moving forward in this manner.
A Boer breeder from West-Central Indiana, in reference to the notion of harvesting honeysuckle: “If I could get that nutrition makeup in a bale, I’d buy it.”
A market gardener from Central Indiana, in reference to accepting arborist wood chips: “I’ve never accepted arborist drops because I’m afraid of what could be in it. If a year of decay eliminates the allelopathy, I’ve got a much easier source of garden mulch.”
It would be nice to know what blockers currently exist for sustainable agriculture so that we know what would be helpful to include in research. For example, in discussions about the project we learned that lots of market gardeners are not only worried about allelopathy, but also the presence of some woody plants that can sprout from cuttings. It’s believed that a live chip of wood from poplar, red bud, and even poison ivy can grow into a new plant. If we had considered that upfront, we could have tried to prove or disprove the objection in our project.