Growth response of 35-year-old, site V Douglas-fir to nitrogen fertilizer

Abstract

During the first 4 years following application, addition of 200 to 600 pounds of nitrogen per acre increased height increment 62 percent and d.b.h. increment 79 to 160 percent. Gross basal area increment was greater with heavier fertilizer applications, but severe snowbreakage wa also increased. Thus, net production tended to be greatest with the addition of 200 pounds of nitrogen. Indications are that heavier application rates will have a longer lasting beneficial effect.

Keywords

Douglas-fir, nitrogen fertilizer, Wind River Experimental Forest, Washington

Citation

Reukema, Donald L. 1968. Growth response of 35-year-old, site V Douglas-fir to nitrogen fertilizer. Res. Note PNW-RN-86. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 9 p.