A herd of livestock is useful as a tool to reduce the thatch and get seed-to-soil contact when broadcasting seed. However, livestock are NOT a tool kill existing, perennial plants. If the existing vegetation has not been killed to this point, reference the Establishment Timelines for more information on this procedure.
Why worry about seed-to-soil contact?
It is very important to achieve seed-to-soil contact – where the seed is embedded in the soil or even covered by about 1/8th of an inch and the ground is not covered by more than 50% thatch. Achieving this can be the difference between a successful and a failed planting. To get an overview of seed-to-soil contact, guiding principles of seedbed preparation, or the various methods often used, read the Seedbed Preparation Overview article. This article addresses one specific method of achieving seed-to-soil contact: using livestock.
How can livestock help achieve seed-to-soil?
Livestock hoof action can press seed into contact with the soil. But this is only part of the picture. The hooves also help break up thatch into smaller pieces and at times fluff up thatch to allow it to blow away (think of dry oak leaves). Additionally, if there is an excessive amount of thatch, say a cover crop, the livestock can remove part of this plant material by eating it.
When is it a good idea to use livestock?
- Mechanical means of seed-to-soil contact, such as dragging, are not practical – In savanna/ woodland restorations or silvopasture plantings, it is common for stumps and limbs or even standing dead trees to be scattered across the land. In these cases, mechanical means of achieving seed-to-soil contact, such as dragging or drilling, are not practical. Livestock can be paired with a seeding method that is either non-mechanical, such as hand seeding, or one that flies above the obstacles, such as the aerial drone spreader. After the planting process is complete, there should be no more than 50% of the soil covered by thatch. Livestock alone may achieve this, but it will probably be a lot of work. So, if the area is to be logged, use a feller buncher that carries logs to a central delimbing station so that there is more soil disturbance. After logging, or if there is no plan to log, consider using a controlled burn or two on the area if there enough fuel to carry a fire. One of the best livestock species to use for this project is hogs because they give additional disturbance to the leaves with their nose. However, cattle can also have some effect. Note that any type of livestock is not likely to have much effect under obstacles such as treetops.
- Tree leaves are on top of the soil – When tree leaves are layered upon the ground, they keep seeds from reaching the soil like shingles on a house keep water from reaching the people under the roof. To get seed-to-soil contact, these leaves need to disappear or be broken into smaller pieces. Livestock hooves can help achieve both, and hogs’ noses are quite an added benefit. Sturdy, flat leaves, such as oak leaves, that are dry can be “fluffed up” by the livestock and a good wind can blow these leaves – either removing them from the field or piling them up in one location. Additionally, livestock hooves help to break up leaves into smaller pieces. A controlled burn can also be helpful in removing leaves. Ideally the controlled burn is used before livestock are put on the site and before seeding. Where leaves have fallen on the ground for many years or the leaves are wet, it is often good to do the controlled burn (or even 2) then use livestock for their hoof action because a burn often leaves a layer of duff on the soil that still prevents seed-to-soil contact.
- Cover crop residue – Sometimes a cover crop is grown before planting native seeds. If large amounts of living or dead plant material remains that livestock will eat, the livestock can be utilized to consume the forage as well as give hoof action to thatch that is on the soil. Note that if the cover crop is not going to die because of the grazing or because of the natural lifecycle of the plant itself, it is advisable after removing the livestock to kill the cover crop before germination of the native seeds. Also, if other green, living plants remain (such as winter annual weeds), try to kill these as well. Herbicides can be used to kill green, growing plants. Another consideration, if there is enough fuel to carry a fire and if the fire will kill the cover crop or annual weeds, is to use a controlled burn.
- Capped or crusted-over soil – If the soil has been bare (no significant thatch covering the soil) and it has rained while it has been bare, it is likely that the soil has formed a crust or has become capped. In this case, livestock hooves can be helpful in breaking this crust and getting good seed-to-soil contact. Livestock can be used before or after seeding the native seeds.
- Planting large seeds – If the seed(s) being planted are particularly large, they tend to have more difficulty getting seed-to-soil contact than their smaller seeded counterparts. Eastern Gamagrass is of special note here as it is not only large seeded but prefers more soil coverage than most native seeds. Livestock hooves can help get seeds in contact with the soil if the livestock are put in the field after seeding. The hooves can help seeds that hang up on vegetation to filter down to the soil and press the seeds into contact with the soil.
- Compacted soil – If the soil is compacted, hogs may be a consideration to loosen it. It has been said that a hog carries a bulldozer on its nose, and the action of this nose can help loosen up the soil. To utilize hogs for this purpose, they should not be rung.
How to use the livestock to eat the plants?
If livestock are expected to consume the plant material, here are some helpful ideas:
- Make sure that the plant material in the area is palatable (e.g. don’t expect livestock to consume dry oak leaves). Cover crop residue is a good example of a palatable plant material.
- It is often easier to achieve a consistent graze by bunching up the livestock and rotating across the field.
- Movable, temporary hotwires and posts along with a solar hotwire fence charger are helpful tools in this effort. Depending on water availability, portable water may also be helpful.
- As long as it is known that when the livestock leave the area the thatch remaining on the ground will be no more than 50% coverage, the native seeds can be applied before or after using the livestock.
How to use the livestock’s hoof action?
For situations where the action of the livestock’s hooves is the aim, it is necessary to get the livestock to step on each area of the field – and maybe step on it multiple times to achieve the desired effect. (Note, however, that the livestock are not likely to impact areas where obstacles such as treetops are laying on the ground.) Following are some considerations for achieving this:
- Move water, salt and mineral tubs, and feed to new locations to create a reason for livestock to take new paths. Additionally, moving these elements as far apart from each other as possible can cause the livestock to travel more to get between them.
- Spread grain out in the area so that the livestock walk to new areas of the field in search of it.
- Use hogs. Hogs will search out feed better than other livestock species. If whole corn can be scattered over the area, hogs will search it out and, in the process, give quite a bit more thatch disturbance than other livestock will. The whole corn can be spread either by hand or with an aerial drone spreader, and to learn more about scattering in these ways reference the Hand Sowing Guide and the Aerial Spreader Guide.
- Unroll hay in the area as this can give the livestock reason to walk to new areas of the field and significantly increase the hoof disturbance across the field.
- Use temporary, portable hotwire fence, posts, and a fence charger to rotate the animals through the area of land. This will help get more even treatment of the whole area because they aren’t allowed to be in the same spot all the time. Concentrating the animals to a smaller area of land is also increasing the stock density, which is important. More animals in a smaller area will get the job done faster in that particular area, give more consistency of treatment across the area, and create more hoof impact as the livestock are jostling against each other.
- Use low-stress stockmanship to intentionally drive the animals around. This can be especially useful to target certain areas that need additional attention.
Cautions when using livestock to achieve seed-to-soil contact
- Consider if it is safe to apply the seed before using the livestock. In general, livestock can be used before and/or after seeding an area. For most folks, though, using livestock to get seed-to-soil contact and reduce the amount of thatch is a novel approach. This means that in many situations folks aren’t sure if they can achieve seed-to-soil contact and properly reduce the amount of thatch. Not having done this before, it can be hard to know what the area will look like when all is said and done. If you find yourself in this situation and have a lot of plant material on top of the soil and you’re not sure what effect the livestock will have, it is wise to use the livestock before seeding so that other options that would harm the seed, for example a controlled burn, are still viable. Also note that pigs should only be used before seeding.
- Feed often contains weed seeds. Livestock feed can be a source of weed seeds, and sometimes quite invasive weeds such as Johnsongrass or quite annoying weeds such as cocklebur. Not only can the weed seeds be scattered about as the feed is scattered about but many times it also survives the digestive tract of the animals. It may be possible to buy grain directly from a trusted and knowledgeable farmer who knows and will disclose the weeds that were not controlled during the production of the crop. Other options include grain that has either been extensively mechanically processed, distilled, or cooked. Examples of this include pelletized feeds, dried distillers’ grain (DDGs), and soybean meal. Note that feeds that are simply cracked or ground are often very weedy.
- Hay often contains weed seeds. Hay often contains seeds from either the crop that is being put up for hay (e.g. tall fescue, orchardgrass) or seeds from other plants in the field (e.g. curly dock, Queen Anne’s lace, Johnsongrass). Note that some of these plants may not be all bad when they are growing in a hayfield, but in a native planting they can cause problems in the future. Seeds in hay can become distributed into a field either as a haybale is unrolled on the area or as the seeds are consumed by the livestock and many survive their digestive tracts. Options to consider include certified weed free hay or possibly hay baled by a trusted farmer who knows plants and can disclose the weed seeds that may be present in the hay (however, most farmers are not this knowledgeable about plants). Lastly, some hay tends to be produced in monoculture stands where weeds may not be a problem. Considerations here include wheat hay or a glyphosate resistant alfalfa hay. Again, it is imperative to talk with the farmer and understand the problems that were in the field because there is no guarantee that these hays will be weed free either.
- Livestock have recently been eating weed seeds or walking through them. The concern about livestock eating weed seeds is that some of the seeds usually survive the digestive tract and can sprout in the area to be planted to natives. It can take a week or so for seeds that are consumed by a cow to come out in the manure. So, for about a week before the livestock are put onto the area to be planted, attention must be paid to the diet of the livestock. The seeds may be consumed from the hay, feed, or pasture that the livestock are eating. The second thing to think about is that the livestock can carry weed seeds on their bodies. Obvious examples of this are cocklebur and burdock. Less obvious examples are seeds such as sericea lespedeza clinging to wet animal fur. It is advisable to minimize exposure to weed seeds even if the livestock isn’t eating the seeds.
- It gets ugly when the ground gets too wet. Livestock and mud are not a good combination for this project. In wet situations, they can easily give too much disturbance and bury seeds too deep. Different soil types and the inherent wetness of the soil will determine how much rain is too much. For example, rocky soils or upland soils may tolerate some rain and not leave deep tracks while a soil without rocks or one that is “always a little seepy anyway” may take very little before there are unacceptable tracks. So, before using livestock to improve seed-to-soil contact, have a plan for what to do when the soil gets muddy and the livestock need to be removed from the area quickly.
- Don’t stay too late. It is important that the livestock are taken out of the planting before seeds start to germinate. Germination of the native seeds can be gauged with the Black Pot Method. Once germination is observed in the pot, the livestock should be removed.
Are there other tools that work well to get seed-to-soil contact?
There are a number of ways to achieve good seed-to-soil contact. A drill can often do this alone. When broadcasting the seed, however, some action to improve seed-to-soil contact is often desirable. To read more about commonly encountered problems with seedbeds and good tools to use for each, read the Seedbed Preparation Overview or see some of these techniques by watching the video Preparing Your Seedbed: Seed-to-Soil Contact.