Erosional impact on organic matter content and productivity of selected Iowa soils

From 1983 to 1989 an erosion-productivity study was conducted in Iowa. The primary objective of this project was to determine the effects of accelerated erosion and its interactions with other variables on soil productivity, as measured by corn yields of loess and till-derived soils in Iowa. Multiple regression techniques were used to relate corn yields to erosion and selected soil, climatic, and weather variables. Organic matter content of the soils was significantly correlated with erosion phase. Yields of till-derived soils decreased more with increasing degree of erosion than loess-derived soils. The conclusions are based on data collected at 569 sites located in 44 Iowa counties.