Variability of Corn/Soybean Yield and Soil/Landscape Properties across A Southwestern Minnesota Landscape

Abstract

Site-specific management of fertilizer depends upon accurate knowledge about the source of spatial variability in crop yield. Variations in landscape characteristics and soil properties are thought to be responsible for much of the variation in crop yield. Landscape characteristics, soil properties, and corn/soybean yield data were collected from four transects (320 to 365 m long) at 30 m intervals. Corn/soybean yields were less at eroded slopes than at the nearly level summit or at the foot/toeslope positions. Corn yield was positively correlated with A horizon thickness and negatively correlated with surface pH. A horizon thickness, surface pH, tillage system, and growing season precipitation explained 72% of the variability in corn yield. Slope gradient, depth to free CaCO3, soil profile water storage, surface available K and growing season precipitation explained 44% of the variability in soybean yield.