25. Classification Of Soils

The Bureau of Soils of the United States Department of Agriculture has established a system of soil classification which should be familiar to every student of vegetable gardening.

26. Soil Type

The unit of classification is known as a type. Soil Survey Field Book, 1906, p. 16: "In the determination of a type of soil there are many factors to be considered. Among the most important are the texture, which deals with the size of the particles; the structure, which deals with the arrangement; the organic matter-content, origin, color, depth, drainage, topography, native vegetation and natural productiveness. This classification is based primarily upon the physical properties, but all factors that influence the relation of soils to crops, so far as their influence can be determined, are taken into consideration".