Liming still positively influences sugar maple nutrition, vigor and growth, 20 years after a single application

Despite the decrease in acid deposition observed over the last decades, the health of sugar maple (SM; Acer saccharum Marshall), a species known as sensitive to base cation availability, is still a concern in many areas of northeastern North America. Twenty years after a single application of dolomitic lime, a widely available soil amendment, the effect of liming was evaluated on SM nutrition, vigor and growth in a declining stand affected by acid deposition. Lime doses of 0?50 t?ha? 1 were applied over a 5 m radius around each selected tree. This experiment is unique in that it monitors the effects of doses that are economically feasible (?lower doses?; 0, 0.5, 1, 2 and 5 t?ha? 1) and of higher ones (10, 20, 50 t?ha? 1). We found that lime still had a positive effect on all variables studied after 20 years. In addition, SM nutrition, stem growth and crown vigor improved as lime dose increased. On average, foliar Ca and Mg concentrations increased by 35% and 46% for trees that received the 2 and 5 t?ha? 1 doses, respectively, and by as much as 70% and 95% for those that received the 50 t?ha? 1 dose. Crown dieback decreased from 44% for the control trees to less than 5% for those that received lime doses ?5 t?ha? 1. Basal area increment increased by 93% and 144% for trees that received lower and higher doses, respectively, compared to non-limed trees. Results indicate that a lime dose of approximately 5 t?ha? 1, which is both potentially economic and operationally feasible, can have a beneficial effect on SM nutrition, vigor and growth for at least 20 years on such acidic and base-poor soils. Preserving SM tree health in this changing world is important to ensure its sustainability in maple forests.