This is because of the inherent inability of certain types of fruit trees to survive when planted in imperfectly drained soils. Apples are intermediate and pears can survive on the more poorly drained soils. One classification of soils is based upon the mineral part of soil and consists of four sizes of particles. Clay particles are the smallest, followed by silt, sand, and gravel. The USDA has devised another system of classifying soil particles.
Soil texture is determined by the percentage of sand, silt, and clay in the soil.
Steinsberg sandy loam are examples of soil types having different textures. The structure of a soil is influenced by soil texture and also by the aggregation of small soil particles into larger particles. The amount of aggregation in a soil is strongly influenced by the amount of organic matter present. The pore spaces in a soil are normally filled with air or water. As the amount of water increases, the amount of air must therefore decrease.