Calcium (Ca) concentrations in lakes have declined in many regions, and concerns have been expressed that Ca levels are falling below biologically significant thresholds. Wood ash additions to soil are typically used to combat soil acidification, and it is unclear whether wood ash additions to upland soils will lead to higher Ca leaching to surface waters. In this study we applied fly ash or bottom ash at 4 Mg ha⁻¹ and 8 Mg ha⁻¹ to upland soils at replicated plots in Haliburton Forest in central Ontario and measured soil water chemistry at 3 depths over 4 years. Increases in soil water Ca concentration following application were quite modest and occurred primarily in the fly ash treatments in the upper depth (0.3 m) during the first 2 years following application. There was no concomitant increase in pH or acid-neutralizing capacity primarily because of the high sulphate leaching associated with the fly ash treatments. Overall, these results show that wood ash addition to soils at moderate doses will have little impact on soil export to lakes.

湖泊中的钙（Ca）浓度在许多地区都有所下降，人们担心钙的含量已降至生物学上的重要阈值以下。向土壤中添加木灰通常用于抵抗土壤酸化，目前尚不清楚向旱地土壤中添加木灰是否会导致较高的Ca淋溶到地表水中。在这项研究中，我们在4 Mg ha ^-1和8 Mg ha ^-1下施用了粉煤灰或底灰在安大略省中部哈利伯顿森林（Haliburton Forest）的重复样地中研究高地土壤，并在4年中测量了3个深度的土壤水化学。施肥后土壤水Ca浓度的增加相当适度，主要发生在施肥后的头2年内在较高深度（0.3 m）的粉煤灰处理中。pH值或酸中和能力没有随之增加，这主要是由于与粉煤灰处理相关的高硫酸盐浸出。总体而言，这些结果表明，向土壤中添加适量的木灰对土壤向湖泊的出口影响很小。