Four-year Growth Responses of Plantation Red Pine to Potash Fertilization and Irrigation in New York

Abstract

Growth responses of 35- to 40-year-old Pinus resinosa Ait. to potash fertilization with and without irrigation were monitored non-destructively for four growing seasons after treatment. Total above-ground biomass was determined after the fourth growing season. Fertilization increased leader growth, radial growth at breast height, and radial growth at base of live crown mainly in the third and fourth growing seasons. In four years from start of treatment, growth responses of average dominant-codominant trees were: height growth of fertilized trees, 1.8 m or 0.4 m more than nonfertilized trees; cross-sectional area growth at breast height of fertilized trees, 43 cm² or 23 cm² more than nonfertilized trees; cross-sectional area growth at base of live crown of fertilized trees, 41 cm² or 13 cm² more than nonfertilized trees; and 5 m long butt log volume growth of fertilized trees, 21 dm³ or 9 dm³ more than nonfertilized trees. Fertilization increased above-ground biomass, particularly foliage, to a total of over 100,000 kg of foliage, branches, bolebark and bolewood per ha. Responses from irrigation were nil. Forest Sci. 21:88-96.