Abstract
A nursery study was conducted to observe the effects of altering the amount of nitrogen fertilizer at each application on bareroot loblolly pine (
Pinus taeda L.) seedling morphology, survival and growth. The treatments were an equal amount of fertilizer applied each time, an increasing amount each time, and a schedule characterized by low amounts, high amounts, and low amounts. Six applications of ammonium nitrate (32.5 percent N) were applied between June and August 2000, and for all treatments, a total of 169 kg N per ha was applied. In addition, for each growing season treatment, the seedlings were treated either in October or November with a one-time application of 56 kg N per ha or 113 kg N per ha as ammonium nitrate. The seedlings were lifted in January 2001, for morphology measurements and field planting. The seedlings treated with an increasing amount of N during the growing season had greater foliage, stem and root weights. Seedlings treated with 113 kg N per ha in October had the largest root collar diameters. First-year survival exceeded 90 percent for all treatments. First-year height growth was greatest for the seedlings that received 113 kg N per ha in October in the nursery.
Parent Publication
Citation
Williams, Hans; Woodard, Karen; Stewart, Tim. 2004. The Response of Bareroot Loblolly Pine Seedlings to the Amount and Timing of Nitrogen Fertilization in the Nursery. Gen. Tech. Rep. SRS–71. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. pp. 425-428