Egg mobiles in the rotational grazing dance
Joel Salatin raises chickens and cows at Polyface Farm near Swoope, Virginia, but if you ask what he does, he’ll tell you he’s a GRASS FARMER. Our day starts before sunrise. We walk in silence up a long, sloping field, passing a cluster of mildly curious cows as we approach two metal sheds. On closer inspection, I notice that the sheds have wheels, like on a school bus. Then come the chickens. Thousands of them. The chickens live on this pasture, and lay their eggs in these EGG MOBILES that Salatin moves each day.
Sustainable agriculture has no single figurehead—nor does this defiant, disparate movement have a center—but if it wants an able spokesperson, Salatin would be a safe bet. He’s a professional contrarian, a knowledgeable agricultural apostate who not only practices what he preaches but has the rare capacity to explain it to others. While his summers are devoted to farming, his winters are spent literally barnstorming the country—from grange hall to farm to classroom—as he expounds on the joys of grass farming. The science of it is simple enough. Grass is a solar collector. It uses photosynthesis to transform the sun’s rays into chlorophyll. When cows eat grass, they convert this energy into protein and fat. Field grass grows in three phases. The first, which Salatin refers to as the “diaper phase,” is typified by slow development. This is followed by a massive growth spurt, what he calls a “virulent, vibrant teenage phase,” as grass converts solar energy into chlorophyll. From there grass goes into senescence, or in Salatin’s words, “the nursing home phase.” If the grass can be kept in that highly productive middle stage, where it continually captures solar energy and turns that into biomass, it will produce in abundance, but how would you maintain this herbaceous fountain of youth in a perpetual state of production, or what Salatin calls the “BIOMASS ACCUMULATION ACCELERATION PHASE”? Salatin does it with steel rods and wire. He places them in a line that bisects the field, with each rod twenty feet apart. Then he attaches a length of wire from rod to rod. When he gets to the end, he wraps the wire around a battery cell that is continuously charged by a small solar panel. By flipping a switch he suddenly has a portable electric fence. When Salatin removes the fence closest to the cows, they cross into fresh new pasture and graze. Their manure is left behind to fertilize the soil, a process hastened by the aforementioned chickens. Salatin rolls their egg mobiles into pasture previously occupied by cows. By spreading the manure as they walk, these chickens accelerate the growth of new grass. This daily cycle, one of moving fence posts and opening up new pasture, follows a formula based on observation. The size of new pasture is determined by knowing how much the cows need to eat. With the proper allotments set, this ROTATIONAL GRAZING continues until Salatin reaches the end of the field. Then he simply brings the cows and egg mobiles back to the top of hill and the process repeats.