Analysis of Discrete vs. Composite Soil Sampling Across the Southeastern United States

This research project examines how soil sampling methodology influences the characterization of agricultural soil properties across the southeastern United States. Single-point and composite samples are compared using Mehlich-1 extractable nutrients and pH to evaluate differences in nutrient distributions and spatial variability. Analyses are stratified by land management type (cropped and pasture systems) and physiographic region, including the Coastal Plain, Piedmont, and Ridge and Valley.

In addition to sampling type, this chapter evaluates how nutrient estimates differ when soils are sampled by fixed depth (0–15 cm) versus horizon-based sampling, to determine the role the Ap soil profile development has in nutrient representation in an agricultural context. Together, these analyses aim to identify which sampling strategies best represent soil variability and the environmental and management factors that influence nutrient distributions, with implications for soil testing, precision agriculture, and management zone development.