GEOG M107 Lecture Notes - Lecture 5: Natural Resources Conservation Service, Agricultural Research Service, Parent Material
Document Summary
Us soil conservation service (scs) began assessing levels of erosion in 1930s. Eventually led to soil loss prediction equations for water and wind erosion. Lakes: winds blow through lakes and accrue wind erosion near lakes. Urban areas: not a lot of erosion measured due to places being covered in cement. Maximum level of soil erosion that will permit a high level of crop productivity to be sustained economically and indefinitely (wischmeier and smith, 1978) This is mythical, because using soil indefinitely soil loss. Value is arbitrary; depends on soil properties and the fragility of soils. Tolerance (t) has a range of values based on fragility of soils. Depth of soil: thicker soil and greater thickness of material permeable to plant roots, faster erosion can occur without irreparable loss of soil productivity. Type of parent material: unconsolidated, fertile parent material more quickly converted into soil than bedrock. Parent material: bedrock- solid rock underlying loose deposits such as soil or alluvium.
