Agriculture Reference
In-Depth Information
Stones
Stones and gravel provide some benefits in that they protect the soil from erosion and
decrease evaporation, but they don't breakdown into humus and don't allow organic matter
to get down to the soil, so they don't do much to improve soil health.
That being said, there is an aside here. If you have certain bigger plants that are special
to you, like a new fruit tree for example, there is a technique called rock mulching that can
improve the soil extremely quickly, resulting in amazing plant growth. Place a few inches
of leaves around the root zone of the new tree, which might be a few feet in diameter.
Cover those leaves with round stones or flagstones that are small enough so that you can
handle them, but big enough to cover some of the leaves, i.e. not pebbles and not 50 pound
boulders.
Doing this facilitates rapid breakdown of the leaves. They may take, for example, eight
months to break down normally, but the rock might bring it down to two months or even
less. Whether it is because of the pressure exerted on the leaves, or the prolonged moisture
the stone cover provides, or the heat stored by the rocks during the day and radiated back to
the soil overnight, or the explosion in the earthworm population under them that often hap-
pens, I don't know, but it works.
The key to success here is doing it a few times. Yes, you have to remove the rocks by
hand every couple of months and apply more leaves and place the rocks back by hand. The
first time, the leaves may disappear fairly quickly and that will be interesting enough on its
own. But subsequent times, you'll start to notice a thick layer of worm castings where the
leaves once were. This is a bit of work. Not much, but it might take 15 minutes to do a tree.
It's not a practice most of us will wish to do long term, but we may want to do it for the
first growing season to give the trees an incredible boost in organic matter.
