soil, survey
The purpose of soil survey is to provide the data of soil resources of a given area. First the soils of the area must be classified. For this purpose it is necessary to make a field study of the properties of surface and subsoil layers at many locations. Typical soil samples are sent to the laboratory for physical and chemical examination. Than a map is prepared; it shows the locations of different soil groups given in the soil classification. Finally, a written report is prepared containing general information about the area, descriptions of the soils and recommendations of their use. Soil surveys are made by experienced soil scientists. Sinc.1935 most soil maps have been made with the help of aerial photographs. Maps and reports are usually prepared in cooperation with the state agricultural experimental stations.
