Soil Order

Arable soils with water content suitable to grow a 3 month growing season. Takes a long time to develop. Covers 10% of the earth.

• Weakly weathered volcanic ejecta and vocaniclastic materials mixed with strongly weathered materials.
• Good for agriculture. covers 2% of the US.

Form in arid climate. prodominant in deserts. water deficient. low organic matter.

Of recent origin. Usually has no genetic horizons other thatn A or C.  covers 18% of the earth.

 Cold climate soil with permafrost. within the top 2 meters of soil surface.

Low density, Large carbon sink, dominated by organic matter. Found mainly in the midwest, atlantic gulf coast. less than 1% of US

Minimal horizon development. found on steep slopes and young geographic surfaces or resistant parent material.