Fine root distribution in a young loblolly pine (Pinus taeda L.) stand: Effects of preplant phosphorus fertilization

The effects of preplant phosphorus fertilization on fine root (2 mm) distribution were examined in an 11-year-old stand of loblolly pine (Pinus taeda L.) located on the lower Coastal Plain of North Carolina. Root auger cores were collected from the planting bed and interbed areas from two depths (0–10 and 10–20 cm) from fertilized (45 kg P ha^–1 at time of planting) and nonfertilized plots. Root samples were collected and aboveground growth measured during the 11th year after fertilization. Despite significant increases in aboveground volume and biomass due to fertilization, fine root biomass was unaffected. No differences in rooting density (root length per volume of soil) due to phosphorus additions were detected. However, the ratio of fine root biomass to aboveground (shoot) biomass (R:S) was significantly smaller on plots receiving phosphorus fertilization.operated by Martin Marietta Energy Systems, Inc., under Contract No. DE-AC05-840 R21400 with the U.S. Department of Energy