Biomass Yield of Short-Rotation American Sycamore as Influenced by Site, Fertilizers, Spacing, and Rotation Age

Abstract

Abstract American sycamore (Platanus occidentalis L.) was planted on bottomland and terrace sites in the Ohio River Valley region of western Kentucky to test the effects of various cultural treatments on yields over short rotation periods. Without fertilization, the bottomland site was more productive, but yields from the fertilized plots on the two sites were comparable. Fertilization significantly increased yields of all biomass components; the NP treatment did not increase yields over the N treatment. Yields of bolewood and bark were significantly increased by closer spacings. Average annual production, exclusive of leaves, for the most productive treatment combination (6 x 3 ft. spacing and N fertilization after five years on the terrace) was approximately 6 tons/acre/year on a green-weight basis. Without fertilization, the 1 x 3 ft. spacing was most productive, yielding nearly 4 tons/acre/year after either the three- or four-year rotation period on the bottom site.