The Effect of Different Methods of Tree Planting on Survival and Growth of Pine Plantations on Clay Soils

Abstract In the spring of 1952, 2 acres of Superior lacustrine clay (Ontonagon silty clay loam), comprising a part of the Ashland Branch Experiment Station, Wis., were planted to 3-0 white pine, Pinus strobus, using three different methods of ground preparation. A survey of duplicate plots 14 years later rendered the following results of paramount practical significance. Planting on the bottom of furrows: nearly complete failure, expressed in survival of less than 10% and average tree height of 4.6 feet. Planting on scalped soil: survival—52%, average height—10.5 feet, average DBH—1.2 inches, volume—24 cu. feet per acre. Planting on ridges made by two furrow slices turned inward: survival—80%, average height—16.9 feet, DBH—3.5 inches, volume—517 cu. feet per acre. In the spring of 1960, the trials were repeated on adjacent 2-acre area using slightly modified design and 3-0 red pine, Pinus resinosa, as the test plant. A record of duplicate plots, each consisting of 225 trees, was taken at the end of the 1965 growing season. Results are given in the following summary. Planting without ground preparation: survival—7%, average height—22.7 inches, total green weight (tops and roots)—4 lbs. per acre. Planting on soil rototilled to a depth of 5 inches: survival—49%, avg. height—22.9 in., green weight—182 lbs./a. Planting on ridges of two furrow slices: survival—70%, avg. height—27.9 in., green weight—597 lbs./a. Planting on ridges of disked soil: survival—77%, avg. height—29.5 in., green weight—676 lbs./a. Planting on ridges of rototilled soil: survival—67%, avg. height—32.5 in., green weight—740 lbs./a. Differences of this magnitude in the performance of trees can seldom be attainable by any other means of forest growth amelioration. The disking or rototilling prior to ridging failed to yield significant improvement in the growth of plantations and would not justify the extra cost of land preparation.