The Natural Philosopher wrote:

Not sure how limestone 'leaches'


As it crushes some of the material dissolves and carries calcium ions into
the surrounding area, which in our case is a sensitive acid heath, calcium
ions raise the pH and affect the plant life, on which some rare insects are
dependent.

Overkill it may be but the terrram was only a couple of hundred quid to
treat 100 metres of wet patch, inert MOT type 1 was GBP8/tonne more than
limestone and it is working.

AJH