Forest fertilization has been adopted as the primary means of controlling sugar maple (Acer saccharum Marsh.) dieback in southern Quebec. Following foliar analysis, treatments containing appropriate mixtures of K, Ca, Mg, and (or) P have been used on commercial sugar groves. This study was undertaken to identify the impact of base cation additions on nutrient cycling in a sugar maple stand in the Lower Laurentians, Quebec, and to quantify the amounts of added nutrients that were retained in the stand or lost by leaching. In 1988, six 40 x 40 m plots were established; three were kept as controls and the other three received a mixture of 500 kg-ha-1 of K2SO4, 250 kg.ha-1 of Ca,Mg(CO3)2 and 250 kg.ha-1 of CaCO3 applied as fine particulate matter in June 1989. Soil solutions were collected weekly during the spring and fall from October 1988 until November 1992. Soil solution chemistry indicated that there was increased biocycling of both K and Mg as a result of the treatment. The application of appropriate mixtures of base cation will improve the fertility of the soils and decrease nutrient imbalances. The amount of added material lost from the rooting zone was a small proportion of the amount added: over a 4-year period following treatment only 12.1, 9.5, and 1.4% of added Ca, Mg, and K were lost, respectively.