Chemical properties of soil(N, P, K, Ca, Na, Mg, CEC, and pH) were studied after annual additions of NH₄NO₃(336㎏/㏊ N), treble superphosphate(112㎏/㏊ P), and KCl(224㎏/㏊ K) fertilizers in a willow(Salix spp.) bioenergy plantation. Soil samples were collected from November through December 1992 from previously established the fertilized and non-fertilized willow plantation at Tully, New York, U.S.A. in 1987. Total fertilizer additions from 1987 through 1991 were 1,680㎏/㏊ N and 560㎏/㏊ P and 1.120㎏/㏊ K. Fertilization with N, P, and K resulted in no difference in total soil N content between the fertilized and non-fertilized plots, increased soil P and K, decreased base cations (Ca^(2+) and Mg^(2+)) and soil pH, and increased soil pH with soil depth. Strong positive con-elations of soil carbon to soil N, Ca, Mg, and CEC were noted. Soil C/N ratio in the study plots ranged from 9.6 to 11.2 for all treatment combinations. Significant differences in soil P, K, Ca, and pH between the fertilized and non-fertilized plots indicate that fertilization had changed chemical properties of soil in this fertilizer trial.