RNGR.net is sponsored by the USDA Forest Service and Southern Regional Extension Forestry and is a colloborative effort between these two agencies.

U.S. Department of Agriculture USDA Forest Service Southern Regional Extension Forestry Southern Regional Extension Forestry

Skip to content. | Skip to navigation

Home Publications Nursery Manuals Forest Nursery Manual—Bareroot Chapter 8: Soil and Tissue Analysis - Tools for Maintaining Soil Fertility

Chapter 8: Soil and Tissue Analysis - Tools for Maintaining Soil Fertility

Systematic monitoring through soil and plant analysis is essential for understanding and managing soil systems in forest nurseries. Analysis services are offered by Oregon State University, University of Idaho, and seven commercial laboratories )n the U.S. Northwest, as well as the British Columbia Ministry of Forests. Suggested target fertility levels for raising Douglas -fir in Northwest nurseries are: pH of 5.0 to 6.0, total nitrogen (N) of 0.18 to 0.23%, available phosphorus (P) of 25 to 50 ppm, available potassium (K) of 80 to 120 ppm, exchangeable calcium (Ca) of 2 to 4 meq1100 g, and exchangeable magnesium (Mg) of 1 to 2 meq1100 g. Suggested ranges in macronutrient concentrations in Douglas-fir needle tissue are: 1.2 to 2% N, 0.1 to 0.2% P, 0.3 to 0.8% K, 0.2 to 0.5% Ca, 0.10 to 0.15% Mg, and 0.1 to 0.2% sulfur (S). The lower levels indicate deficiencies and the higher levels adequacy. Success of the fertility monitoring program depends on careful sampling and handling, consistency in laboratory services used, and meticulous recordkeeping.

Download this file:

PDF document Download this file — PDF document, 53Kb


Author(s): Chet T. Youngberg

Publication: Nursery Manuals - Forest Nursery Manual—Bareroot