May 22-25, 2017
As farmers, our job is to covert solar energy into human nutrition. Cellular-level photosynthesis is where the action is. Plants harvest and store this solar energy in many forms: Some store their energy in the soil, others store it in tasty fruit, or roots or seeds. Our system of managing the plants to accomplish this task is an eight-year crop rotation of different plants in different places. By these means, we feed our livestock, our livestock feeds the soil, and the soil feeds the vegetables that, in turn, feed us and you.
Walking around Elmwood Stock Farm, you will see seemingly idle, verdant pastures. Much to the contrary of being idle, the individual plants in those fields are storing energy in their leaves to be consumed by livestock. In the Bluegrass region, perennial grass plants, like fescue and bluegrass, and orchardgrass predominate and have a predictable growth pattern each year. A native white clover cohabitates quite nicely with the grasses. White clover is more palatable to the livestock, and it is a legume, meaning it forms a symbiotic bond with soil bacteria to capture nitrogen from the air and make it available to all the plants in the field—self fertilizing, if you will. Livestock consume these plants and provide us protein and energy, stored in the right kind of fat.
Then we have alfalfa. “Queen” of the forage crops, it truly is a marvelous plant. It, too, is a legume. On the farm tour last week, I showed our guests the bacterial nodules attached to the roots where the nitrogen fixation that I mentioned above occurs. A good stand of alfalfa will generate hundreds of pounds of nitrogen each season to be shared with the soil food web. The soil food web is a vast, complex array of microbes (bacteria, fungi, yeasts, molds, viruses), microscopic insects, bigger bugs, and plant roots proliferate. The more robust the soil food web, the healthier the soil.
Alfalfa also produces several tons of leafy plant material, generally harvested as hay, several times each growing season, which provides the animals nourishment when the forage in their pastures stop growing in winter. Pretty cool, huh? Sow some seeds and, viola, you get grassfed, certified organic, USDA Choice Angus beef. All while improving soil health.
Alfalfa’s root structure is a tool unto itself. Its taproot spears deep into the ground several feet, maybe 6 to 8 feet deep in some soils. By doing so, it mines minerals and other nutrients from the depths, far below the rhizosphere, to be made available when the plants are plowed into the first few inches of the soil. The complex array of micronutrients in soil can be replenished in this way. In winter, we feed the cattle their hay in these fields, where their manure further enriches the soil. By keeping a field in alfalfa for 5 years, we can feed the soil, feed the livestock and prepare the field to grow wholesome, nutritious vegetables for us to consume.
In the very beginning of year six of this eight-year rotation (late winter), we plow down the alfalfa so the nutrients in the plants will decompose to further feed the soil microbial life. In the spring, we plant tomatoes, squash, potatoes, etc.—crops with a long growing period that benefit most from the nutrient-dense soil. After they are harvested in late summer, their leftover vegetative matter is tilled under, and annual grasses and legumes are sown to hold the soil in place in winter and provide their nutrients when incorporated into the soil in early year seven. In this soil, there are plenty of nutrients and micronutrients to grow kale, the lettuces, broccoli, etc.—short season crops, both spring and fall. Then in year eight, the over-wintered spinach, kale and garlic continue to do just fine, and we plant peas and beans, which are more self-fertilizing legumes.
There are many variations on this planting scheme, depending on our exact needs from year to year, but that’s the gist of it. When all produce has been harvested at the end of year eight, the field is planted back into clover, alfalfa and orchardgrass, starting the cycle again.
It takes some petroleum energy to move all this around and lots of human energy to make it work, but the human energy, at least, came from these same plants, as this food feeds us year-round. The University of Kentucky/ University of Georgia, yet to be published, food production energy efficiency study, for which we provided data, preliminarily indicates we are very efficient in our calories in: calories out ratio. So, that’s how we do our job. The funny thing is, the plants and animals and microbes do most of the work. —Mac Stone
In Your Share
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