Prairie Restoration Experiments Update
Updated: Aug 14
One mishap. It was silly, even comical, but the aftermath has seen me babying a gashed up knee for two weeks now. The buffalo, somehow sensing my incapacitation, have been breaking through interior gates - of course. We've got miles of fence line to clear before we can get the full charge back on our fence so the animals will stay where they're supposed to - of course. Today, I was able to help clear fence for only a few hours before finding myself right back on the couch. Amy is out there now, 108 heat index, finishing up temporary fencing arrangements for the animals that I wasn't able to complete. What a committed life partner. We've got a committed friend who's been helping too. I'm a blessed man.
I'm using the down time that has been granted me by the hard work of others in what's hopefully a productive way by writing this post. Over the years, we've done a number of experiments at Nan Awaya Farm to learn how to better restore our degraded upland pastures. From the remnants in these pastures and our nearby roadsides, it appears that these uplands were once tallgrass prairie. Most prairie plants grow slowly, and restoration work is a patient process. It usually takes a few years before we really know how one of our experiments turns out. We like to provide updates every now and then and link them to the original posts about those experiments so people can see the ultimate results and also see how our understanding of the land has evolved. This post comes from close to home, it shares our efforts to restore a remnant prairie in the pastures surrounding our house. The images in this post were taken on a walk to check on the progress of these experiments just before my mishap.
When we started managing these pastures they were covered in a mix of ragweed, goatweed, camphorweed, and spotted horse mint. Though called "weeds", all four are fine native plants that support birds and pollinators and hold the soil together in places where the land has been disturbed. However, a landscape that has only disturbance-loving plants like these is neither healthy nor stable. Around here, if left to their own, such spots usually grow up into a dense, thorny thicket.
When we acquired the farm, we let the area around where our house sits now rest from grazing for three years to see what other plants might come up if given a chance to recover from past over-grazing. These pastures ultimately sprouted about three dozen native prairie species and relatively few invasive ones. Tallgrass prairie is dominated by perennial warm season grasses - ones like Indiangrass, big bluestem, and little bluestem. These grasses are the matrix that holds a prairie together. Except for a few small patches, resting the land did not see these grasses return to the pastures around our house. They had been grazed to death. We basically had a remnant prairie without its matrix. Some other common and palatable prairie species, things like compass plant, were missing too, although they grow in the right-of way just up the road.
A given prairie naturally varies in appearance from year to year according to a number of variables like rainfall and disturbance history. The Prairie Ecologist, Chris Helzer, describes prairies as being like a bowl with a ball in it. The ball's position in the bowl represents the configuration of that prairie during a given season. As long as the ball remains in the bowl, it's still a prairie. Prairies are resilient, and it takes a lot to remove the ball from the bowl. Once that happens though, say through over-grazing, it takes a lot to put the ball back into the bowl and restore the land to being prairie.
That's where our experiments come in: learning what inputs we need to get the ball back into the bowl. We wanted to do it without destroying the dozens of species of native plants that are still growing there. Obviously, we wanted to do it as efficiently and economically as possible too.
First, we tried mob-grazing. This is marketed in the ranching community as an ecologically beneficial way to restore degraded landscapes and soils. The basic premise is that ranchers divide their land up into small paddocks. Putting a cattle or sheep herd into a small paddock concentrates animal impact. They graze aggressively (eating plants they otherwise wouldn't); they trample and fertilize what they don't eat. Then, they are quickly rotated on to another paddock, giving the first paddock a chance to rest. As the grass rebuilds its leaves, it's roots shrink a little bit, depositing carbon in the soil. When the leaves rebuild and take in energy and carbon, the roots rebuild for a net carbon gain. In the period of just a few years, the land is restored as a grassland and soil carbon is restored. - So the thought goes.
Right before buying the land that became Nan Awaya Farm, we'd taken a class on holistic pasture management that emphasized mob grazing. We hired the teacher of the course to come out to Nan Awaya and help guide us in setting it up. He created a plan where we would divide the land into a number of paddocks. After the year of rest, we'd bring out our animals and rotate them between the paddocks, allowing each to rest about 40 days before rotating the animals back in to graze again. We were told that after 3 years, the farm would be covered in lush grass and be able to support a heard of 30 bison grazing year-round.
We met and exceeded the protocols called for in the plan within the first year, and have continued on for the past 8 years, but these pastures never made the kind of transition that was envisioned. What has the experience taught us? According to the philosophy of mob grazing, temporarily packing animals into a small area is supposed to pound organic matter into the soil through trampling. That's not what we're actually seeing. With the exception of the action from scarab beetles, organic material actually just sits on the surface of the soil. When it breaks down, a lot of it blows away as dust on the wind in the first drought. The rest eventually combines with carbon, creating CO2 and escapes into the air. Well meaning mob-grazers tried to help us overcome our issues by recommending that we pack the animals in even more tightly or that we feed hay in the paddocks one time to get ecological processes kick-started. We tried both. Neither changed anything.
It's definitely good to rest over-grazed areas, but the 40-day grazing rotation was the worst thing we could do for the dominant native grasses. Ranchers have planted invasive pasture grasses over millions of acres of land. These have very little ecological benefit, and their shallow roots don't do much for soil biology. They are, however, adapted to take lots and lots of abuse from grazing and still come back from it. At our latitude, 40 days of rest is sufficient for them. Native perennial grasses, on the other hand, are designed for an entirely different grazing pattern. For most of the year, they're slow-growing. 40 days after getting grazed, they're just rebuilding their leaves and haven't yet had time to replace the resources taken from their roots to do that. Grazing them on a 40-day rotation pulls more and more resources from their roots and eventually kills them.
With what we learned, we've switched to a grazing rotation in these pastures where we hit them each for a week or so in the spring, avoid grazing them between July 4 and frost, and then graze or burn them in the dormant season. This gives as much opportunity as possible for the native warm season perennial grasses in these pastures to rebuild and produce seed. When these grasses eventually start to dominate, we'll change up our grazing rotation in a way that will continue to foster plant diversity.
The right grazing rotation helped our little remnant patches of prairie grass to thrive, but it was clear we were going to have to do some planting if we wanted to get the land back in balance this decade. We tried seed bombs, which seem like a great idea. You mix seeds with clay and organic soil; roll them into small balls; let them dry, and push the hardened balls halfway into the ground. We made 250 seed bombs and planted them across our land. Only about 2% produced a viable plant. We tried to improve our success rate by mixing in soil from the locations where the seeds were harvested in order to provide the right soil microbes for those types of plants to grow. We planted 750 more, but had no noticeable improvement in germination. Observation suggests that the bombs make easy targets for creatures to pick through and take out the seeds and young plants.
Next, we came up with a method of using a garden hoe to churn up a patch of soil 1-2ft in diameter, picking out the roots, and planting 100-200 prairie seeds. Success with this method has been variable. In some areas, with species including cowpen daisy, Indiangrass, partridge pea, and little bluestem, our success rate in getting something to come up using this approach is pushing 75%. With other species it's a totally different story. For example, we planted 587 patches of pure Eastern Gamagrass (EGG) using the garden hoe. We panted pounds more EGG seeds in hundreds of other mixed seed patches. We experimented with dibbling individual EGG seeds into the ground, and with raking EGG seeds into places where wild hogs have rooted. With all of that work, only one single Eastern Gamagrass plant has come up so far - in an area where the hogs rooted. Using the garden hoe method, we've planted pale purple coneflower, blazing star, rattlesnake master, rosinweed, Illinois bundleflower, and compass plant seeds hand-collected from right across the road. Not a single plant has come up yet, although some of these species may take as long as 10 years to come up and bloom after planting.
Micro area seems to have a lot to do with the success of the garden hoe seeding method. In some places, 75% of these patches have come up, most with multiple plants. In other areas that seemingly have the same soil and same plant cover, almost none of these plantings have been successful to date. I noticed that in some of these latter spots, dozens of little plants came up initially, but turned brown in the summer heat, and have never made another appearance. It may be that with no cover, they were unable to grow their roots deep enough to sustain themselves before drought dried out our sandy hills.
With their diversity, there's a perennial sunflower for just about every kind of landscape. We planted 373 patches of perennial sunflowers in our uplands (Maximillian, tall, downy, and showy); we also raked seeds into hog rooting areas and put them in the previously-mentioned seed bombs. From all of that, only 5 plants ever came up and bloomed. All of those went on to disappear during the growing season or failed to reemerge after winter. Since we started this experiment, we've noticed that you don't see many perennial sunflowers along the roadsides in our immediate area. The uplands of Nan Awaya Farm may be in a rare place where none of these plants grow well.
In total, I’d estimate that out of 10,000 patches planted with the garden hoe technique around 3,000 plants that have come up and matured so far. Many of the seeds sewn in this way will still be popping up over the next few years. Already, this has proven to be a much more effective technique for us overall than seed bombs. I wouldn’t recommend it as a primary reseeding method for large areas, but if you want to seed a small area and cannot do a controlled burn, or if you want to surgically reintroduce key species into a landscape and those species happen to be ones that have a high success rate using the garden hoe planting technique, this could be a very effective tool.
Another technique we experimented with was planting live sprigs. We planted each one with compost, put red mulch around them so we could find them in the pasture, and watered them daily for several months. Again, the success rate varied by species. Most of the EGG planted in this way survived, including the plant shown pollinating in the title image of this post. The EGG sprigs did just as well in our sandy uplands as in our best bottom land soils. Protecting the young plants from getting grazed for the first couple of years helped them to attain size and presumably root mass quickly. Only a single switchgrass plant and none of the Maximillian sunflowers or big bluestem planted as sprigs survived. Sprigs are a costly, labor intensive way to go. From what we’ve heard from other people, if you grow the sprigs yourself and don’t keep watering after planting, they can be an effective way to reintroduce targeted missing species back to a landscape.
In early spring '22, we burned two and a half pastures near our house. Shortly after, our area got a rare snow. We broadcast seeds on top of the snow wherever the plant cover had burned down to bare dirt. There's a lot to be said for this method. Fire helps many types of prairie plants; it sets back trees and brush, and it can be hard on invasives. You can hand-broadcast more seed in one day than you can plant with the garden hoe method in a whole year. In order for an area to carry a fire, it has to have grass or combustible sedges. If a landscape is covered in camphorweed with no understory, fire won't go through it. Dominant prairie grasses can make flames 10ft tall or more, but land doesn't necessarily have to be covered in them to burn. Much smaller grasses like sandbur can carry the flame. In the months following our spring burn, the native grasses thrived. The perennials did quite well in the D4 drought that followed. This year, the spring burn area is back to being covered in camphorweed. It seems like the drought was too much for the more ephemeral grasses, so camphor has filled in. From a distance, some of it looks a lot like it did 8 years ago, but up close, dominant grasses and other plants we've seeded are pushing up through the camphorweed canopy. It's still too soon to tell how effective our painting after the burn was, but I have a feeling this is going to become our favorite planting method.
To see how the effects of a summer burn differ from a winter burn, we burned two pastures by our house last summer. As it happened, a D4 drought hit immediately afterwards. The summer burn was great for clearing out dead wood and undergrowth along the prairie edge, which made it easy to finish clearing with a chainsaw later. The summer burn top killed every small tree in its path. This spring, we had an explosion of some wild flowers like scrambled eggs and Carolina anemone that had been very rare on the farm previously. It seems that the summer fire followed by high temperatures and severe drought killed some of the young dominant grasses that had started coming in. When the drought hit, I put a sprinkler on a section just to see how these young plants would have responded to a summer burn if it had been followed up with regular rain. A lot of young grass in both the watered and unwatered sections apparently died; grass in both areas also survived to come back next year, especially mature little bluestem.
The land restoration experiments continue to teach us a lot of specifics, like the ones we've shared here. We'll keep doing them as long as we live on this land. After 8 years, they're also teaching us that there's a lot we just don't know. Maybe the biggest lesson learned, given how much goes into restoring a damaged native landscape, is just how important it is to preserve every healthy native landscape that still exists.
Post Script - Amy is done with the fencing project and doing well. Hopefully, the buffalo will stay in their temporary fencing until I can get back out there.