The Influence of Forest and Pasture on the Genesis of a Humid Temperate‐Region Ultisol

Abstract

AbstractThe influence of pasture vs. forest vegetation on the properties of a Typic Hapludult from the Blue Ridge Province of Virginia was examined. Three study sites containing both forest and pasture cover were chosen from a group of 20 randomly selected initial sites by a typical pedon computer program which used A horizon thickness, Bt horizon clay content, Ca + Mg content at a depth of 145 cm, and slope as selection parameters. Detailed soil analyses were conducted under pasture and forest vegetation at each of the three final study sites. Pasture B horizons were deeper, higher in clay content, and weaker in structure grade than forest B horizons. The influence of liming was pronounced in the pasture soils and resulted in significant downward movement of Ca and Mg over time. Residual liming and P fertilization effects were apparent after 25 years of forest occupancy on a formerly cropped site. These data indicate that morphological and chemical changes occur in these soils following forest to pasture conversion. These changes, particularly in B horizon morphology, may occur much more rapidly than commonly assumed.