Update on Prairie Restoration Experiment
The tallgrass prairie is a fascinating and truly beautiful native place. It is a home to over 500 species of plants that build soil and produce oxygen, all while supporting an almost countless number of animal species that each fill their own special roles. Nearly 250 million acres of tallgrass prairie once graced the eastern edge of the Great Plains. It was also present in some areas farther to the east, including large stretches of the Choctaw homeland. Created by God, maintained by bison, drought, and the range fires set by Native Americans, the tallgrass prairie was a resilient web of life that had defined the American heartlands since the end of the Ice Age. It took less than one human lifetime for this treasure to be almost completely destroyed, farmed into oblivion. Today, only about 2% of the tallgrass prairie remains in scattered remnants.
Last year, we worked hard to learn how to identify the tallgrass prairie / savanna plants that have survived or started to come up on the Nan Awaya Farmstead as we have changed the way the land is managed. No doubt, there are some that we missed, but even so, we were able to document 23 native grass species and 63 species of native forbs. Not bad diversity over 160 acres, but unfortunately, many of these plants are currently only growing in small corners of the farm, rather than across it, and some important species are missing entirely.
There is tons of available information on how to restore a prairie... That is if you want to plow up the land, kill every plant, and do a restoration from scratch. Much less information is available if you want to build existing remnants of the prairie back into something healthy. Over the past 5 years, we've learned that one of the most important keys for doing this is proper pasture management. This means bringing fire and grazing animals back to the land in a variable way, allowing the plants proper rest periods from these forces, and closely monitoring. However, if certain species of plants have been completely eliminated from a landscape, no amount of judicious grazing or fire is going to bring them back. This winter, the Noble Foundation helped us use the information we had collected to make an assessment of our pastures, and they feel that in large areas, we just don't have enough of a native seed bank surviving in the soil for the prairie to restore itself to its full diversity. Their recommendation was to plant more seeds.
In a post last spring, we talked about the ups and (mostly) downs of our previous prairie seed planting experiments on the farm. At that time, we were trying out what was a new technique for us, seed bombs. With seed bombs, you package dry seeds into small, round balls of compost/clay, allow them to dry, and push them part way into the soil. The idea is that the compost/clay mixture protects the seeds until they are ready to sprout, and then provides a little nourishment to the young plant. We made and planted 1,000 seed bombs as an experiment. Seed bombs are a cool concept, and are widely available for purchase. However, we've been able to find very little information about their actual effectiveness, so we promised to share the results of our little experiment.
So far, the results are less than conclusive. In our seed bombs, we had planted a cocktail of locally collected prairie seeds. The fastest-growing and most visible of these plants is annual sunflower, of which there were none growing on the farm at the time of the experiment. Last summer, 5 annual sunflower plants sprang up in widely scattered pastures where the bombs had been planted (photo to the left). The experiment was successful in the sense of returning an important plant species to the landscape. While 5 plants out of 1,000 plantings is really underwhelming, the planting was probably more successful than that. It's likely that young perennial prairie plants came up unnoticed (so far) under the existing canopy, and that some of the seeds planted in the seed bombs are still to come up this year or even next. We've already seen something similar when we planted seeds for Indian blanket flowers around the farm. None of these plants came up until two summers after the seeds were planted.
This year, we're planting another 1,000 seed bombs, incorporating a few lessons learned that we hope will increase the success rate. Last year, we focused on using locally collected seeds. We did the same thing this year, but made our mixture of seeds heavier on early succession grasses that are specially adapted to our sandy soil, plants such as the aptly named sand lovegrass and sand dropseed. This is because we've learned that putting seed bombs filled with seeds from climax prairie plants (like big bluestem) on soil that has been chronically overgrazed is not likely to be successful. It seems to make sense that, just as in natural succession, the damaged soil first has to be covered in the types of colonizing plants that are adapted to it, before climax species can begin to thrive there. This year, we also tried adding a little dirt from the area where many of the seeds were collected into the seed bomb mixture in hopes of inoculating the bombs with the proper microbes to help the plants germinate. We planted 500 of the bombs much earlier this year than last, in hopes that the natural freeze/thaw might make for more effective stratification than our refrigerator did. Finally, rather than scattering the planting across the farm, we concentrated most of it into a 2 acre pasture that can easily be monitored and excluded from grazing to give the young plants a better fighting chance. Are these modifications going to unlock the full potential of the seed bomb and make a difference in our continuing fight to rehabilitate the native landscape on our place?... We'll keep you posted.