Growth of Loblolly Pine and White Pine after Enrichment by Nutrient Loading

Abstract

Low nutrient availability often constrains the growth of young trees following planting to fields or forests. Nutrient loading of young tree seedlings increases their growth in outplanting. Loblolly pine (Pinus taeda L.) and white pine (Pinus strobus L.) were grown for one year on nutrient-loading regimes that varied from 13 to 410 mg N L⁻¹ in sand culture. Other nutrients varied in proportion to the nitrogen (N) concentrations. Resulting plant growth showed that an array of nutritional regimes from deficient to excessive was applied. The young plants were transplanted into containers of sandy loam and were grown for one year without fertilization. Growth of each species increased with enhanced nutrient loading. The optimum concentration of N for nutrient loading was about 1.5 to 1.8% leaf dry weight for either species. Nutrient loading during nursery culture imparts transplants with nutrient levels that will enable growth for at least a year after outplanting.

Keywords:

• Exponential nutrient addition
• luxury consumption
• nitrogen nutrition
• outplanting
• Pinus strobus
• Pinus taeda

Acknowledgments

This research is a contribution of the Massachusetts Agricultural Experiment Project MAS 00091.