Successful farming today depends upon a good understanding of the basic soil resources we have to work with.

Detailed information about your soil and the capabilities of your land is made available through the Conservation District and Natural Resources Conservation Service offices.

Soil technicians study the soil by making boring holes and then record the information on aerial photographs.

This then becomes a soil map, which shows specific information about each soil type and where each is located.

Because of the importance of the surface soil, this layer is examined in considerable detail. The map shows the surface texture and general workability.

Soil texture refers to the amount of sand, silt and clay, which determines, directly or indirectly, the erosion hazard, crop adaptability and water infiltration.

No less important is the subsoil layer since this is an important part of the crop-rooting zone. In this layer, such characteristics as water and air, texture and available water are extremely important.

Soil depth is another important property that is examined and recorded on soil maps. The depth determines how much soil is available for the plants' roots to get their food and water.

The slope of the land probably has more effect on erosion than any other soil feature, although texture, fertility, soil structure and many other factors influence erosion indirectly.

On a soil map, the slope is recorded for each soil type as determined by the average percent fall in a 100-foot distance. Greater runoff caused by an increase in slope can prevent water from reaching plant roots during a shower of short duration.

Erosion that has occurred is recorded for each soil by indicating the amount of topsoil removed.

The information on slope and erosion, when evaluated with the previously mentioned soil properties of various soil layers, points not only to the specific hazards for each soil type, but to the conservation measures that need to be instigated to protect the land.

Another important soil feature shown on the map is the degree of drainage. General relative soil drainage classes are given. Seven drainage classes have been defined ranging from very poorly drained to excessively drained.

When these features are shown on a soil map, they reflect specific hazards to the cultivation and growth of crops. Many of these hazards can be corrected and this is indicated.

When all the known data about soils is gathered and recorded and the effects of local climate are evaluated, a land use capability classification is made.

These land use classes are used to express the soil's capabilities and hazards.

Crop yields, therefore, depend on the soil characteristics as well as the climate and the management level.

Ron Fodor is district manager of the Butler County Conservation District.