In the absence of fire, oaks and hickories are gradually replaced by beech and magnolia, species that are fire-sensitive. There is a rare “climax” stand of almost pure beech on the University of Georgia campus, between the Veterinary Medicine School and Married Students housing. The stand has probably never been logged or cleared. There are many, big beech trees, some easily over 100 years old. On the forest floor, beech seedlings and saplings dominate. A thick layer of humus covers the forest floor. Within the humus is a network of fungal hyphae that connects the decomposing leaves to root hairs. This nutrient conserving mechanism recycles nutrients in decomposing leaves directly back into the trees.

Soil horizons in the Spring Valley Oak Grove suggest that the site was never cleared or cultivated. The profile resembles the soil that the pioneers first encountered in North Georgia. There is a top layer of undecomposed leaves, under which lies a layer of almost pure organic matter derived from decomposed leaves and wood. Beneath that there is an “A” horizon. This is topsoil. It gradually decreases in organic matter content to a depth of about 12-15 inches, at which point there is an abrupt transition to the underlying “B” horizon of pure red clay.

Over a century of intensive cotton cropping in Georgia resulted in the destruction of the land’s productive topsoil. Plowing of the fields resulted in oxidation of the organic matter in the topsoil. All that remained was red clay, very low in ability to supply nutrients to crops. Cotton fields were left barren after harvest. Winter rains caused gullies, because there was no vegetation to retain the soil. A combination of poor soil and the boll weevil invasion led to the end of the cotton era. Fields were abandoned, and loblolly pine moved in. The loblolly pine forests that cover much of the Georgia Piedmont today are a relatively recent historic phenomena. Before the pioneers began to clear the land for cotton plantations, these pines occurred only occasionally within the expanse of hardwood forests. Pine seeds need mineral soil to germinate, and they need full sunlight to survive, conditions that don’t usually exist under hardwoods. However, the habitat necessary for pine reproduction expanded greatly when thousands of acres of cotton farmland were abandoned in the first half of the 20th century. The barren, open fields provided ideal conditions.

But while these pines have commercial value, their production is not ecologically sustainable in the Piedmont. As the pine stands matured, a relatively thick layer of partially decomposed needles formed on the ground. The pine seed is relatively small, and does not have enough stored energy to send a root through this layer, and as a result, there is no pine reproduction beneath these stands. Instead, there are seedlings of oak and hickory. These species produce relatively large seeds, and their roots can penetrate the pine needle humus. Many landowners whose property was covered with loblolly contracted with logging companies to harvest the timber. After the harvest, the landowners often wished to establish a pine plantation, but the problem was that the saplings of oaks and other hardwood species that had established under the pines crowded out the pine seedlings. The only solution was to have bulldozers with “root rakes”, giant claws on the front of the machines, tear out the roots of the hardwoods to eliminate competition and expose the red clay sub soil. Today this subsoil clay is so apparent in Georgia that the legislature has named red clay as “the official soil of Georgia”. Unfortunately that red clay is the infertile remnant of the once productive Georgia soils, and is nothing to be proud of.

While red clay is ideal for producing pine, there are no agricultural crops that can be grown in this subsoil without heavy use of fertilizers and intensive plowing. In this era of escalating costs of fertilizers and petroleum, we must look for other ways to maintain production. The best way to do this is to restore the productive capacity of the soil, by regenerating the soil organic matter. This involves changing the whole agricultural paradigm, from working to overcome nature with plows, pesticides and fertilizers, to working with nature – that is, understanding what makes natural ecosystems productive, and using that understanding to better manage our fields, pastures, and forests. Researching methods to restore the top soil at Spring Valley Ecofarms while at the same time yielding an economic product is an overarching goal of our program.