Effects of a controlled release fertilizer on the nitrogen dynamics of mid-rotation loblolly pine plantation in the Piedmont, VirginiaThis article is part of a larger document. View the larger document here.
Nitrogen deficiency is characteristic of many mid-rotation loblolly pine (Pinus taeda L.) plantations in the Piedmont region of the Southeast. Fertilization with urea is the most common method used to correct this deficiency. Previous studies show that urea fertilization produces a rapid pulse of available nitrogen (N) with only a portion being utilized by plantation trees. Controlled release fertilizers release available N slowly over a longer period of time and therefore may result in a greater uptake efficiency. The objective of this study was to compare a controlled-release N fertilizer (ureaform) versus urea by measuring the effects of the two fertilizer treatments on total extractable-N, mineralized-N, and ion resin exchangeable-N. Fertilization with the controlled release ureaform resulted in significantly greater and prolonged availability of total extractable-N, mineralized-N, and ion resin exchangeable-N than the fertilization with urea or the control.