Soil survey is a systematic study of the soil of an area including classification and mapping of the properties and the distribution of various soil units.  Systematic soil survey has been carried out for over one hundred years. As in other applied sciences, conceptual and technological advances are making soil survey more reliable, cheaper and useful. The practical purpose of soil survey is to enable more numerous, more accurate and more useful predictions to be make for specific purposes than could have been made otherwise [i.e., in the absence of location-specific information about soils]. To achieve this purpose, it is necessary to:

• determine the pattern of the soil cover;
• divide this pattern into relatively homogeneous units; 
• map the distribution of these units, so enabling the soil properties over any area to be predicted; and
• characterize the mapped units in such a way that useful statements can be made about their land use potential and response to changes in management.