Reaction is typically neutral through moderately alkaline but is slightly acid in some pedons. This horizon is absent in some pedons. Exchangeable sodium is 3 to 12 percent. It is slightly or moderately alkaline. Textures are the same as for the Bt horizon.
Reaction is strongly or very strongly alkaline.
Exchangeable sodium is greater than 15 percent. Salinity is 4 to 15 mmhos. Exchangeable sodium is 10 to 30 percent. Calcium carbonate equivalent is 6 to 15 percent. Salinity ranges from 8 to 15 mmhos.