• Schomaker, Charles
  UMaine School of Forest Resources
  
• Giddings, Edwin
  UMaine School of Forest Resources
  
• Struchtemeyer, Roland
  UMaine Department of Plants and Soils
  

The results reported here are prelimary. A final statement of the results and conclusions from this experiment must wait until the completion of the study after two or more growing seasons.

After three seasons of growth following the fertilization of a spruce fir stand in Baileyville Township near Princeton, Maine in the spring of 1970, a highly statistically significant response in basal area growth was found for applications of a 10-10-10 commercial fertilizer at an equivalent rate of 150 pounds per acre of elemental N in the form of urea. Gains in basal area growth for the NPK treatment were nearly 70 percent higher than that of the unfertilized control plot trees. This is roughly equivalent to an increase of one-half (0.5) a cord per acre per year. Average basal area increment per tree on the nitrogen plot was about 42 percent greater than the unfertilized control trees, roughly equivalent to a gain of one-third (0.33) a cord per acre per year. All treatments grew somewhat better than the controls but the differences of the others were not statistically different.