Yesterday I spread a small bucket of woodstove ashes in one of the tomato beds and one of the sweetcorn beds. I had to pull back the leaf mulch for the tomatoes. I hand-tilled and turned over the corn bed. That one is in the footprint of a former raised bed. The raised bed was one that I had built the first summer here, 2012 or 2013. I don't know whether being where a raised bed was, is good for the soil or not. The soil here is low in calcium, good in potassium, low in phosphorus, low in magnesium. The wood ashes are a combination of trees that grew here that were cut and burned for firewood, and the bones that resulted from making dog food from chicken thighs. Those will be high in calcium, phosphorus, and trace minerals. Potassium too from the wood ashes. It kind of averages out to a decent mineral supplement for those vegetables. Plus, the soil here is very acidic. The ashes are alkaline, so moderate that. I apply a dusting of ashes, and let it mellow for two or three months before using.
Potatoes should not be given alkaline supplements, so I did not apply in potato areas.
The bone fragments are still visible, but after burning them they are soft and fragile like chalk. They break down very quickly.
After rains, turning the soil and tilling in, the minerals will be pretty evenly dispersed.