Submitted to: International Soil Conservation Organization Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/27/2000
Publication Date: N/A
Technical Abstract: Soil translocation on cultivated lands from erosion processes can have a substantial effect on soil properties and crop production potentials. This study was conducted to determine the relative variation in productivity of soil that could be the result from long-term intensive tillage on a typical landscape found in the western Corn Belt of the USA. The objectives were to oexamine soil profile characteristics along an undulating landscape and determine the relationship between these soil characteristics and soil translocation by tillage. A 16 ha field located in west central Minnesota with a long history of a moldboard plow-based tillage management and evidence of prior erosion was selected for measurement. Annual tillage erosion for a fall moldboard and spring tandem disk tillage sequence were determined using a modified version of the Tillage Erosion Prediction (TEP) model. Detailed soil profile descriptions were made in a series of transects where past erosion appeared evident. Soil carbon (total and inorganic), pH, and plant available phosphorus where determined in conjunction with the soil descriptions. The mechanics of tillage erosion has resulted in the loss of the original A horizon, starting first in the shoulder landscape position. The area of exposure of less productive subsoil material then increases as tillage erosion continues. Exposure of subsoil material high in free CaCO3 and subsequent redistribution over the landscape and mixing in the tilled layer has increased pH and altered plant nutrient availability. A reduction in organic carbon was observed at site locations experiencing high rates of tillage erosion (25 to 40 t ha**-1 yr**-1). This loss of the original topsoil and subsequent exposure of less productive soil material will have a pronounced effect on soil quality.