In Muskoka, we generate 100s of tonnes of ashes in our wood stoves and fireplaces every heating season. The ashes left over are a waste product, but they could be a local solution to the calcium decline problem, because they are roughly 30% calcium (Ca) by weight. Given that we lost half a tonne of Ca per hectare (ha) of soil over the last century, roughly 1.7 tonnes of wood ash per ha should provide all the Ca that was typically lost to acid rain, assuming it all becomes available where we spread it. (We might need more as it likely won’t all become available and won’t all stay put.) This “waste” ash can be re-purposed to solve the Ca decline problem, closing a recycling loop, i.e. the calcium in our fire wood came from the soil in the first place, and we would be returning it to the soil in the form of ash, hopefully restoring normal growth of the forest, and leaving enough Ca left over to restore levels in ground water.
by pg
