Soil response to S and N treatments in a northern New England low elevation coniferous forest

A field experiment was designed to evaluate the effects of differing forms of acidifying S and N compounds on the chemistry of soils and soil solutions in a low elevation coniferous forest in northern New England. Treatments consisted of O, 1500, 3000, and 6000 eq of SO sub(4) super(2-) or NO sub(3) super(-) ha super(-1) for the 1987 growing season applied biweekly as H sub(2)SO sub(4) or HNO sub(3), or in a single application as dry (NH sub(4)) sub(2)SO sub(4). Acidifying treatments resulted in a significant increase in soil solution SO sub(4) super(2-) (1.2 to 2.6) or NO sub(3) super(-) (12 to 80) in the upper B horizon. Excess strong acid anion leaching was associated with an accelerated loss of base cations, particularly MG super(2+). As solutions passed through the upper 25 cm of the soil profile, mean SO sub(4) super(2-) concentrations decreased by 5 to 50% of the initial values, indicating that much of the applied SO sub(4) super(2-) was immobilized in the upper portion of the pedon.