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Effects of soil and foliar applications of nitrogen fertilizers on a 20-year-old Douglas-fir stand

Informally Refereed
Download (PDF 400 KB): https://research.fs.usda.gov/download/treesearch/40646.pdf

Abstract

We compared growth and cone production of Douglas-fir treated 4 years earlier with ISO pounds N per acre applied as urea prill by hand and as a 32-percent N solution applied by helicopter. Nitrogen fertilization increased growth by 3 88 ft per acre during the 4 years after treatment; this 3S-percent gain was similar for both soil (prill) and foliar (solution) applications. Although cone production on the prill-treated plots averaged twofold to fourfold greater than on the control plots, these differences were not statistically significant.

Citation

Miller, Richard E.; Wert, Steve. 1979. Effects of soil and foliar applications of nitrogen fertilizers on a 20-year-old Douglas-fir stand. Res. Note PNW-RN-329. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 12 p.