PARENT SESSION
Wednesday, August 9, 5:00-6:30 pm
Poster Session 18 - Forest ecology and management
Exhibit Hall, Ballroom Level, Cook Convention Center
Nutrient cycling in a 27 yr old loblolly pine plantation after multiple fertilizations and/or brush control.
Leggett, Zakiya*,1, Kumar, Venkatesh1, Campbell, Robert1, Duzan, Howard1, 1 Weyerhaeuser Company, New Bern, NC
ABSTRACT- Fertilization and brush control in loblolly pine (Pinus taeda) plantations are now the norm in the southeastern United States as forest managers become more aware of the opportunities to improve production through the manipulation of nutrient availability. These practices have been proven to improve stem growth of this species; however, it is still unknown how these intensive practices will affect long-term soil nutrient sustainability. It has been implied that multiple applications of fertilizer (especially on nutrient poor sites) can change the productive capacity of the site and influence future rotations. A study was conducted in a 27 year old loblolly pine (Pinus taeda L.) plantation that had received multiple fertilizations and/or brush control beginning at age 11. The study consisted of four treatments (control, brush control, fertilization, and brush control + fertilization) replicated four times. Foliar nutrition, forest floor and soil nutrient pools were inventoried throughout stand development and 16 years after treatments began. When evaluating these variables at age 27, brush control (BC) had a significant effect on forest floor mass and N (74% and 50% greater than the control, respectively). Fertilization (F) had a significant effect on forest floor N and soil P (51% and 30% greater than the control, respectively). When assessing foliar nutrition, the BC treatment had a significant effect on foliar N (8% greater than the control) and the F treatment had 15% and 9% greater foliar N and P, respectively, as compared to the control plots. These results imply that there are some positive effects of these treatments (fertilization and brush control) on the long-term productivity of the soil and maintaining good soil nutrition.
Key words: loblolly pine, fertilization, brush control