Silt three grades fine, medium and coarse 0.002 mm to 0.006 mm to 0.020 mm to 0.063 mm). In actuality, silt is chemically distinct from clay, and unlike clay, grains of silt are approximately the same size in all dimensions; furthermore, their size ranges overlap. Clays are formed from thin plate-shaped particles held together by electrostatic forces, so present a cohesion. Pure silts are not cohesive. According to the U.S. Department of Agriculture Soil Texture Classification system, the sand–silt distinction is made at the 0.05 mm particle size. The USDA system has been adopted by the Food and Agriculture Organization (FAO).
Natchez silt loam the bluff hills that border the Mississippi Delta floodplains. They formed in silty loess material that ranges from strongly acid to neutral in the upper part and neutral to slightly alkaline in lower parts. Average annual precipitation is 52 inches. Average annual air temperature is 63 °F (17 °C). The soil has developed in the upper Pleistocene age material. Natchez silt loam In 1988, the Professional Soil Classifiers Association of Mississippi selected Natchez silt loam soil to represent the soil resources of the State. These soils exist on 171,559 acres (0.56% of state) of landscape in Mississippi. The Natchez Silt