Atlanta Daily World

What Other Farmers Are Doing Now
BY JAMES A. KNOWLES
(Soil Conservationist)
Soil erosion is as old as agriculture. It began when the first heavy rain struck the first furrow turned by a crude implement of tillage in the hands of pre-historic man. It has been going on ever since.
Water and wind are the active forces of soil erosion, differing in the nature of their actions but similar in the sense that both remove and transport surface soil.
Water erosion is the transportation of soil by rain water running rapidly over unprotected or exposed land surfaces. Sheet erosion, rill erosion and gully erosion are subdivisions of water erosion. To a lesser or greater extent, one or more types of water erosion will take place on sloping land areas left exposed to the heavy rains.
Sheet erosion is the more or less even removal of soil in thin layers over an entire segment of sloping land. It is the least noticed by farmers and the most insidious type of erosion. Frequently it causes a gradual change in color of the land from dark to light, as the dark top soil is removed, or, with most Piedmont soils, from gray to red - exposing the red humus deficient sub-soil.
Rill erosion is more apparent than sheet erosion, but almost as often neglected. Farmers are likely to forget or overlook the tiny gashes cut out in their cultivated crops or orchards, or to minimize their importance once they are smoothed out by the plow or harrow.
Gully erosion takes place either where the concentrated run-off from a bare slope increases sufficiently in volume and velocity to cut deep incisions or gullies in the land. or where the concentrated water continues cutting the same groove long enough to develop such incisions or gullies. Some alert farmers in the Southeast have become intelligent or aware of the fact that usually gullies follow sheet erosion or result from the neglect of rills; that frequently gullies have their beginning in slight depressions of the land surface, where run-off water normally concentrates. These farmers also know that gullies often develop from ruts by wheels of wagons driven up and down hill over soft ground frequently formed in livestock trails and along plow furrows up and down slopes.
Today, conscientious farmers are employing every time-tested and recommended erosion-control measure necessary to protect their land from the hazardous effects of water erosion. Terracing is an important measure only if properly used. Used temporarily, it may do more harm than good. Farmers have begun to realize that terracing alone cannot be regarded as a complete defense against erosion. Appropriate vegetative measures of control, consisting of water drainageways or disposals and terrace outlets planted to sodded grasses or other soil-binding plants, must be considered along with terracing or other mechanical measures employed if the treated land is to be safeguarded from erosion.
The present-day concept of soil conservation by agriculturists and farmers who know involves the systematic use of not one but many devices and measures, applied in accordance with the peculiar needs and adaptabilities of the various kinds of land needing protection. Deeply interested farmers realize that different soils, or types of soils, with varying slopes, in different climates impose limitations on land and require different land treatments, and they are relying on and accepting authoritative experimental advice.