TY - JOUR T1 - Corn yield: Erosion relationships of representative loess and till soils in the North Central United States JF - Journal of Soil and Water Conservation SP - 77 LP - 81 VL - 49 IS - 1 AU - Tom E. Schumacher AU - Michael J. Lindstrom AU - Delbert L. Mokma AU - Wallace W. Nelson Y1 - 1994/01/01 UR - http://www.jswconline.org/content/49/1/77.abstract N2 - A study was started in 1984 to examine erosion-productivity relationships on representative soils from the North Central United States. The project was designed to minimize the effects of landscape position and agronomic practices on data interpretation. Soil, climate, and agronomic data were collected according to standardized procedures on replicated erosion classes located in similar landscapes. Relative yield loss for erosion class 3 averaged 17 percent on glacial-till derived soils and 8 percent on loess derived soils during the study period. Growing season precipitation and productivity index (PI) gave the best fitting regression model for yield in the glacial-till derived soils (R2 = 0.61). On loess derived soils, addition of other variables to the regression equation did not greatly improve the R2 obtained from using growing season precipitation as the only predictor (R2 = 0.29). ER -