Fig. 1. Soil organic matter, 1:1 soil to water pH, and water- and Bray-extractable soil P at several depths in April 1995 (i.e., 0–30, 30–60, 60–90, and 90–120 cm) and November 2000 (i.e., 0–5, 5–15, 15–30, 30–60, 60–90, and 90–120 cm) for the prairie and N-fertilized (f) or unfertilized (nf) and no-tillage (NT) or chisel-plowed (CP) corn ecosystems.