The fertilizers, Mg at a rate of 100 lbs/acre and K at 200 lbs/acre, were applied around each of 15 red pine (Pinus resinosa Ait.) to promote increased growth in a 20-year-old plantation which had failed to fulfil growth expectations. Successive measurements of diameter and height showed that the fertilizers stimulated diameter significantly after the second growing season, but height only after the third growing season. Beneficial effect of fertilizer applications on diameter and height persisted, and the differences in diameter and height between treated and untreated trees at the end of the seventh growing season was equivalent to two years' current growth.
Update on the Growth and Yield of the Rockland Red Pine Plantation