Loblolly pine response to drainage and fertilization of hydric soils

Loblolly pine (Pinus taeda) productivity on wet flats of the lower coastal plain of Virginia is largely affected by the presence of high water tables and infertile soil. Site preparation by bedding and ditching can alleviate high water tables and increase aerated soil rooting volume, enhancing pine productivity. Fertilizing and liming may improve soil fertility by increasing available nutrients and soil pH.

The purpose of this study was to evaluate two widely used site preparation methods, bedding and ditching, and to study the effects of fertilizer added at plantation age 9 years. Three site preparation treatments, on jurisdictional wetlands near Franklin, VA, were evaluated for their effects on water table depths and rotation-aged loblolly pine growth and yield. The study consisted of three blocks of three 4-ha plots each; all blocks had been harvested and chopped and burned in 1969. The treatments were none (control), bedded and ditched. In 1978, fertilizer treatments were applied to four-O.l0 ha subplots in the center of the 4-ha plots. Treatments were none (control); P; N and P; and N, P, and lime. Water table levels were measured biweekly during the growing season and monthly, thereafter, for the first three years and at age 23 years. A 12.5-percent inventory of overstory diameters with a subsample of total heights was completed for all species on each plot.