Abstract
A fertilization rate of 2 or 3 mg nitrogen (N) per week for 20 weeks yielded longleaf pine (
Pinus palustris) seedlings grown inside a greenhouse that survived well and produced good root collar diameter (RCD) growth the first year after outplanting. Of a range of fertilization rates (0.5 to 4 mg N/week), the 2 mg rate yielded seedlings that did not require needle clipping during nursery production, but increased their RCD by 150% the first year after outplanting. The lower rates (<1 mg N) also survived well, but RCD growth was poorer than the 2 mg rate. In the nursery, the 3 mg rate was borderline for requiring clipping to reduce lodging; under customary nursery practices, the 4 mg rate seedlings would have been clipped; root collar diameter growth in the nursery was similar to that of seedlings grown with the 2 mg N rate. Seedlings receiving >3 mg N also survived well and RCD growth after one season in the field was 14% more than that of the 2 mg N rate. We are continuing to monitor seedlings to determine when they exit the grass stage.
Keywords
Pinus palustris,
container nursery,
field performance,
fertilization
Citation
Jackson, D. Paul; Dumroese, R. Kasten; Barnett, James P.; Patterson, William B. 2007. Container longleaf pine seedling morphology in response to varying rates of nitrogen fertilization in the nursery and subsequent growth after outplanting. In: Riley, L.E.; Dumroese, R.K.; Landis, T.D. National Proceedings: Forest and Conservation Nursery Associations - 2006. Proceedings RMRS-P-50. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 114-119