Two fertilization experiments were conducted with first-year seedlings of baldcypress [Taxodium distichum (L.) Rich.] in containers (substrate = composted pine bark). First, seedlings were subjected to factorial combinations of dolomitic lime, soluble fertilizer (SF), and incorporated controlled-release fertilizer (CRF) (19.0N–2.6P–8.8K; 8- to 9-month release). Lime decreased growth. Incorporated CRF [4.8 kg/m3 (8 lbs/yd3)] yielded more growth than a single weekly application of SF (N = 0.5 g/liter). In the second experiment, most of the potential height growth and total plant dry weight were realized with 2.4 kg/m3 (4 lbs/yd3) and 4.8 kg/m3 (8 lbs/yd3), respectively, of incorporated CRF. At optimal growth, foliar N concentrations were 3.0%.
This work was funded in part by the North Carolina Agricultural Research Service, Raleigh, NC 27695-7643, and by Grant 1448-40181-99-G-048 from the Dept. of the Interior, U.S. Fish and Wildlife Service, Washington, DC.
2Professor and research technician, respectively.
3Biologist. U. S. Fish and Wildlife Service, 551-F Pylon Drive, Raleigh, NC 27606.