By Mark Shepard
An excerpt from Restoration Agriculture
By now it should be obvious that a restoration agriculture system is not merely how to grow one particular crop or another. Restoration agriculture is not about adopting conservation practices to put on your farm, nor is it about creating habitat islands for beneficial insects and wildlife. Restoration agriculture is the intentional design of productive agricultural ecosystems that are patterned after natural ecosystems. These productive agricultural ecosystems are deeply diverse and are full of beneficial synergies between the elements within the system.
A restoration agriculture system’s starting point is at the place in successional time where the farm currently exists and it develops its complexity and richness through the years, lifetimes, and potentially even centuries and millennia. Although you may be starting with row crops such as corn or wheat and evolving through the establishment phases of alley cropping (where an agricultural crop is grown simultaneously with a long-term tree crop), and silvopasture (combining trees with forage and livestock production), what I am discussing here is not a single agricultural technique, but a system of techniques. Instead of learning how to grow a new crop (hazelnuts, for example), farmers will be learning how to manage a system of crops with its own successional trajectory into the distant future. Since this is an interconnected group of crops, the old rules of monocultures don’t necessarily apply.
A restoration agriculture farmer growing a system that includes apples won’t necessarily be doing the same things at the same time as an apple orchardist (or even an organic apple grower). A deeply diverse system actually operates quite differently than an orchard of anything.
There are some things, however, that are universal to good agriculture whether you’re raising 100 acres of a single crop or are mimicking an ecosystem. These things should still be practiced in restoration agriculture and not be entirely ignored. Where possible, start with healthy soil. The first order of business in creating a healthy soil is water management, which I’ve already discussed.
Life as we know it is dependent upon water, and soil life is no exception. Capture and use the water that enters your farm property whether it is rainwater or water from streams (imported water) or from springs and ponds. Where there is water, there is life. Even in desert areas there is enough rainfall to support life. If we capture that water, store it in the soil, store it in the plant life and soil life, then recirculate it as many times as possible, deserts could support even more life as has been proven with permaculture projects around the world.
Greening the Desert
Plants can survive in some incredibly poor soils. Most of us have seen plants sprouting from cracks in roadside cliffs, joints in between the pieces of sidewalk, and even on the asphalt shingles of a roof. Plants will grow in some incredibly poor soils. However plants will be much happier, will grow more rapidly, and bear more abundant and more pest- and disease-free crops if they are actually growing in good soil and in soil with the proper balance of minerals.
Although 99 percent of a plant’s physical structure is carbon, hydrogen and oxygen (all of which the plant takes from the air), the plant needs certain mineral elements that it can only effectively obtain from the soil. These mineral elements come either from the original bedrock of the region, or if your soils were deposited by wind, sedimentation or volcanism, from the components found in the debris that has now become your soil. All soils have various mineral components in different percentages. Crushed granite bedrock in central Maine (and they do call it soil there) is quite low in calcium. However, the same granite-derived soil is typically quite sufficient in potassium, iron, magnesium, silica and other trace minerals. Plants living in granite-derived soils show in their bodies the results of having adequate potassium. In plants, potassium is essential for stalk strength, winter hardiness and disease resistance. It is also essential for good protein and carbohydrate synthesis as well as sugar translocation.
Soils derived from crushed limestone bedrock, as is found in much of the Midwest, has a different mineral composition than that of crushed granite in Maine. Many limestone-derived soils are deficient in potassium and silica and most are deficient in magnesium (except for soils derived from dolomite limestone). If you are a farmer or rancher, you are most likely already familiar with soil mineral balancing from reading frequent magazine articles in Acres U.S.A. on this topic. The same rules for building healthy, productive soils also apply to restoration agriculture with some slight modifications. For those who are not all that familiar with soil mineral balancing, I highly recommend the book, The Biological Farmer by Gary Zimmer, available at Acres U.S.A. When you manage your water resource and adequately hydrate your soil, plants can grow. When you balance your soil minerals, your plants can go beyond merely growing into a state of really thriving.
The slight modifications when building healthy soils that apply to a restoration agriculture system are these … remember, of course, that if your land were abandoned today, plants would continue to colonize the site ad infinitum — even if you had done no soil mineral balancing whatsoever. At first the only plants that would thrive on your site would be the ones that are adapted to do well there. If your soil is calcium-deficient, it will simply not be colonized by calcium-demanding plants. If your soil is high in calcium and deficient in potassium, it will only be colonized by plants that can survive and reproduce under those soil conditions. No matter what your soil type is and no matter what mineral balance/imbalance it has, there are economically valuable and food plants that will grow there. You just might not currently recognize them as food, however, since many of them do not appear on grocery store shelves.
Arguably the most cost-effective way to maintain plants on your site is to grow plants that are adapted to your particular soil chemistry. It is the patchy and irregular assortment of soil types with their own unique deficiencies and abundances that has, in part, been a selection pressure on plants and has contributed to the development of the wide variety of plant life across the planet. There are variants of each keystone species (a plant that plays a disproportionately large role in the community compared to its abundance) that are adapted to different conditions. Knowing the actual mineral composition of your soil will help you to guide your plant variety decisions, and a quality soil test is recommended.
ABOUT THE AUTHOR:
Mark Shepard heads Forest Agriculture Enterprises and runs New Forest Farm, an 106-acre commercial-scale perennial agricultural ecosystem that was converted from a row-crop grain farm. Trained in mechanical engineering and ecology, Mark has combined these two passions to develop equipment and processes for the cultivation, harvesting and processing of forest-derived agricultural products for human foods and biofuel production. Mark is a certified permaculture designer and teaches agroforestry and permaculture around the world.