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Natchez Silt Loam- Mississippi State Soil

Mississippi state map showing 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 (.56% of the state) of the landscape in Mississippi.

The Natchez soils formed in very deep loess; material under a woodland environment and a climate that was warm and humid. These soils have natural fertility and desirable tilth but usually, occur on slopes that limit their use to trees. In areas where slopes are less, pasture and row crops are grown and the soil is very productive when good management is applied.

A typical Natchez soil profile consists of a 3 inch topsoil of dark grayish brown silt loam and to 8 inches, a subsurface of brown silt loam, a yellowish brown and dark yellowish brown silt loam subsoil to 36 inches and a substratum that is yellowish brown, and dark yellowish brown silt loam down to 80 inches.

Soil Family Classification: Coarse-silty, mixed, superactive, thermic Typic Eutrudepts:

Natchez Silt Loam

Natchez soils are in the Inceptisols soil order. Inceptisols soils have developed in relatively young material that has an Ochric epipedon overlying a Cambic horizon. This soil is developed in very deep wind-blown loess that is rich in weatherable minerals. The term coarse-silty indicates that the subsoil has less than 18 percent clay with less than 15 percent sand coarser than very fine. The term mixed suggests that no one mineral is over 60 percent. Thermic refers to an average annual soil temperature between 15-22 degrees C(59-72 degrees F) and differs more than 5 degrees C between winter and summer at 50 cm (20 inches) below the surface.

Natchez soils are on strongly sloping to very steep hillsides in the highly dissected parts of 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 degrees F. The soil has developed in the upper Pleistocene age material.

On March 13, 2003, Mississippi lawmakers designated the Natchez Silt Loam as the official state soil.

(Approximate graphic distribution of the Natchez Soils of Mississippi)