Soil survey. The systematic examination, description, classification, and 

 mapping of soils in an area. 



Soil texture. Refers to the relative proportions of the various soil sepa- 

 rates (sands, silt, and clay) in a soil. Twenty-one textural classes are 

 recognized by the U.S. Department of Agriculture. 



Stony . Containing sufficient stones to interfere with or to prevent tillage. 



Surficial (geological). The unconsolidated sediments that overlie the 

 bedrock. 



Terrace (geological). An old alluvial plain, generally flat or undulating, 

 bordering a river, lake, or the sea; seldom subject to overflow by the 

 adjacent body of water. 



Upland (geological). Land consisting of materials unworked by water in 

 recent geological time and ordinarily lying at a higher elevation than the 

 flood plain or stream terrace. 



Water table. The upper limit of the soil that is wholly saturated with 

 water. In some places a perched water table may be separated from a lower 

 one by a seasonally unsaturated zone. 



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