Restoration Agriculture (Acres U.S.A., 2013) by Mark Shepard reveals how to sustainably grow perennial food crops that can feed us in our resource-compromised future. The goal of a restoration agriculture system is to take advantage of all the benefits of natural, perennial ecosystems by creating agricultural systems that imitate nature in form and function while still providing for our food, building, fuel and other needs, and this book is a guide to creating such a system based on real-world practices. The following excerpt from chapter 7, “The Steps Toward Restoration Agriculture,” deals with identifying the natural system in your area.
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Identify Your Biome
In order to successfully create a restoration agriculture farm, you must first have a basic understanding of what the biome is where the farm is to be established.
Simply defined, a biome is a region on planet Earth that has similar communities of plants and animals, similar rainfall patterns, and relatively similar soil types. If you were to walk around and observe the plants and animals of your region, you would get a specific list for your area. If you live in coastal Georgia, you would expect to be surrounded by certain trees and shrubs. You would expect the temperature or humidity to be one particular way in early versus late summer and to be different in the winter. If you were to be transported instantly to New Mexico, you would realize that you are in a radically different place. The change in biomes would be quite different in this case.
Biomes are identified by particular patterns and arrangements of trees, shrubs and grasses, as well as which species of those plants live there. One species of wide-spaced trees growing with grasses of another, surrounded by particular shrubs might define one biome, while another biome might have close-growing trees creating deep shade, shrubs of another kind and grasses of yet a different species. The spruce, fir and pine woods of eastern Ontario are different than the oak, hickory and pecan forests of Arkansas. Even within the same state and region the difference in biomes is fairly obvious. The spruce, white pine and fir woods of northeastern Maine are different than the sugar maple, beech and birch region of central Maine, which in turn is different than the mixed hardwoods of southern Maine.
In addition to the particular species of a place, biomes are also defined by the particular successional pathway that occurs in that region. The particulars of succession in each biome are different. Different species play out the dance of succession differently in each region. Knowing your biome is important in order for you to choose the particular species for your restoration agriculture project. Knowing your biome and knowing the individual species that take part in the successional progression of your place will give you the highest likelihood of success. Think about it. If you plant trees, shrubs, canes, vines and forage that would naturally occur in your region anyways, don’t you think that they would have a greater chance of success than if you grew other plants that are not adapted to the region? Would I have much success establishing a saguaro cactus farm in the moist, snowy Upper Peninsula of Michigan instead of in sunny, warm Arizona? Would I have much success growing bananas at 8,000 feet in the Rocky Mountains of Colorado? Although we could manipulate the microclimate and build facilities that would enable us to grow bananas in the Rockies (and there are those who are doing this), doesn’t it make a whole lot more sense to grow plants that are adapted to the Rocky Mountains instead, such as the piñon pine tree?
The change from one biome to the next is quite subtle and does not conform to any clear indication defining where one biome starts and the other ends. The transitions are gradual, and sometimes punctuated. The shapes of the trees may be different, or it may begin to feel drier. The plants that used to dominate just to the east are now only scattered here and there and other plants are beginning to dominate. The change in biomes between coastal Georgia and New Mexico are obvious and dramatic, but nature is even more subtle than that. Coastal Georgia is quite different than the hills of north Georgia which is quite different than southwest Georgia. The change can be perceived within hundreds of miles. In the mountains of New Mexico the change might even occur within a few feet. Plant communities might change dramatically with an elevation change of only a thousand feet.
Find the “Key” Economic Species
In most biomes, the entire character of that biome is most influenced by its trees. Trees, being the largest and longest-lived members of that particular plant community, have the longest time to affect an area. Annually they pull mineral nutrients up from deep layers in the earth and through the magic of photosynthesis combine those mineral nutrients with carbon dioxide that they inhale from the atmosphere. The atmosphere and the earth are combined to create masses of leaves that are eventually shed and dropped to the ground. Most North American broad-leaved trees drop their leaves to the ground every single year. There, leaves are acted upon by creatures seen and unseen, colonized by fungi and molds until eventually they compost completely and add their nutrients and carbon to the soil. Even the “evergreens,” most needle-leaved trees and some broad-leaved trees in the South, still shed their leaves, just not all of their leaves every season. Only the oldest, least effective leaves are shed and this is often done in the spring when new growth starts.
Below ground, the trees are changing the subsurface environment in equally profound ways. The roots of trees, beginning with the tiniest of root hairs, will find their way between soil particles and into the cracks of the bedrock itself. As the years go by and the roots grow, they apply a hydraulically powered mechanical force to the soil and rocks — creating a lifting action. The roots can actually inflate and elevate the level of the soil. You can imagine that tree roots in the soil are like a biological balloon being pumped full of air from above ground. The thinnest root hairs, as they are inflated by sugars and fluids manufactured in the process of photosynthesis, snake and worm their way between soil particles in any space afforded to them (think of the tip of a balloon being pumped into popcorn). Over time, they use those very same atmospherically produced sugars to construct lignin and cellulose, vessels, stone cells, xylem, phloem and other structures. That portion of the root solidifies and firmly establishes itself in its location. Meanwhile some of the root hairs, through mechanical damage or the gnawing of a billion microscopic creatures, burst their cell walls, die in the process, and release sugars to the surrounding soil. Microscopic fungi, bacteria, nematodes and other organisms move in and dine on the sugary bounty. Each of these in turn excrete their bodily wastes which becomes fertilizer for the tree. During the years that trees exist in one place they totally change the soil conditions where they live.
Over time certain tree species come to chemically dominate a site. The surface soil created by their leaf drop and then increasingly deeper soil layers become “flavored” to that particular tree species (and any associates who can tolerate or thrive in this new condition). Some trees, like the Juglandaceae family (walnuts, hickories, pecans, etc.) ooze chemicals called juglones that are actual herbicides that kill many other plants. They don’t kill all the plants around them, however; they just exclude the plants that aren’t in their family. This change in the soil chemistry and soil life is one of the reasons why we are able to distinguish changes between biomes. If anyone has been up close to an ancient oak, you can now include soil chemistry to your understanding. The soil surrounding and underneath a 300-year-old oak tree has become “thoroughly oaked” over time. Plants that don’t like oak soil will not grow there. The largest and most dominant tree species are what set the rules for the site.
Restoration Agriculture Imitates the System
Learn your biome. Get to know the soil types, the rainfall patterns and what kinds of trees live (or have lived pre-European settlement) in your location so that you can learn how to fit into the site in the most effective way possible. Wherever you live, and whatever biome it is, you will have greater success if you imitate what was there. It would take a several thousand page book to address every biome in North America and to design a biome-appropriate agriculture system for each region. The work of ecosystem mimicry in agriculture should continue and someday each biome will have its own agricultural systems in place on the ground — complete with ongoing Ph.D. level research. We are not there yet, but this book is intended to begin the discussion and stimulate more implementation and eventually the research will follow.
As mentioned before, the biome that has the widest distribution across North America is the savanna. It was and is the biome that supports the most mammal life and is the historic biome into which we, the human family, were born as a species.
The particular form of savanna that is most widespread in North America is the oak savanna. After moving to Wisconsin to establish our restoration agriculture farm, we first consulted research material that supplied us with the general outline of what “crops” we would plant in order to genuinely restore the ecology and simultaneously produce food. In the various research papers and textbooks that we read about oak savanna ecology, we discovered some remarkable coincidences.
Over and over again in the oak savannas, the same species appeared.
This list of species and their arrangement from taller to shorter is somewhat of a Rosetta Stone for perennial agriculture systems in North America. Here we have a natural system, the oak savanna, that is perennial, took care of itself naturally for millions of years without human intervention, and never needed expensive fossil-fuel inputs. It produces nuts and animal meat as staple foods and a wide variety of vitamins, minerals, antioxidants and more. If you were wondering about whether climate change has changed the composition of oak savannas over time, rest assured. Evidence shows that the current species that make up the North American oak savanna have ebbed and flowed through no less than four different ice ages.
There were, and are, a large number of plants that are common to the oak savanna that are not included in the above list, and many of them have food, fiber, medicinal, or other marketable characteristics that would, of course, fit in well on a restoration agriculture farm. Some of the species not listed, such as the wild rose and honey locust, produce edible fruit, but neither currently have simple, easily accessible, mass markets to tap into. One of the keys to success for a restoration agriculture farm is to have recognizable, marketable products. And preferably these products have large, fairly consistent markets. My focus has been primarily food, which you will see reflected throughout all of what I present here, but many other types of products are possible from a restoration agriculture farm.
Oak Savanna Restoration
The “natural” oak savannas of the late Pleistocene/early Holocene period contained exactly the same species that we see across North America today. Some of the older individual plants may have actually been witness to the wanderings of mastodon and possibly even browsed by glyptodonts (large armadillo type animals). The plant species found in a wild savanna weren’t necessarily the ones that produced the most seeds for consumption, though. Wild seedlings are more programmed toward individual survival and perpetuation of the species and this doesn’t always mean producing the most nuts or the biggest fruit for human consumption. Oaks and apples are prime examples of this. The fruit on native crabapples is small — some of them no larger than your fingernail. I’ve tasted fruit from hundreds of wild crabapple trees and almost without exception the fruit is very sour and often quite astringent. Being small and sour doesn’t really enamor humans to wild crabapples as a food source, so it’s no wonder that the native crabapple was only a minor part of the early North American diet.
Oaks exhibit a bearing characteristic known as “masting” where they have abundant, then intermittent or synchronized reproduction. Trees that reproduce this way typically have no or very few nuts for several years in a row to be followed by a year of bumper crops. This would make sense in the wild. During most years, if trees produce little or few seeds, most of them would get eaten by squirrels, mice or blue jays. This keeps the populations of nut and seed predators small. Then “suddenly” if trees produce a harvest that is so gigantic that it overwhelms the nibbler’s ability to harvest all the seeds, some seeds will end up being offspring. During a mast, or bumper, year many seeds will lie on the ground where they will germinate and root into the soil, often within weeks of falling from the tree. Other overabundant seeds are buried by squirrels or lie in chipmunk caches where they sprout the next spring.
Trees with small, bitter fruit and trees that produce big nuts high in protein and oil, but only once in a while, functioned just fine for seasonally nomadic hunter-gatherers who followed their food sources around when there was plenty of wide open spaces in which to do so. Today with our suburbs, highways, privately owned real estate, and food grown on farms, these inconsistent cropping traits will not work as a significant source for human food. These are not characteristics that we want in a food crop. Agriculture, the big, important way that humanity is fed, needs to have plants that produce large crops every single season, beginning early in their lives.
With restoration agriculture we are not necessarily creating a savanna restoration in the purist sense of the word. Restoration work is important for the overall health and well being of the planet and should be done, but for our purposes we are not talking about restoration in the common usage of the word. Instead of restoring degraded savannas into a more historically common form, the land we are restoring is agricultural land, land that has been under the plow in some cases for centuries. What we are doing is designing an agricultural system that closely mimics the savanna in its structure (vertical structure as well as spatial distribution), the species mix (with cultivated substitutions), and in ecological function. For each individual species in the system, we will be using far more domesticated plants, plants that have been bred through the years to produce high crop yields every single year. We will substitute higher yielding varieties of the species in question and we will choose which species or varieties to plant in higher quantities, depending on the markets available to us, or because of our own personal preferences.
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Reprinted with permission from Restoration Agriculture: Real-World Permaculture for Farmers by Mark Shepard and published by Acres U.S.A., 2013. Buy this book from our store: Restoration Agriculture.