So does the miner at first, when he has only to wrestle with the soil, sub-soil, and all that kind of thing.
It is well known that they may grow where the sub-soil is everlasting ice.
By the use of the sub-soil plow, they are rendered available.
Should it be free of stones, stumps, and other obstructions, the plough and sub-soil plough will be all-sufficient.
While I toyed there with the sub-soil, the unwearied James went to earth among the marrows.
On the same principle, the sub-soil plow renders the compact lower soil sufficiently fine for the requirements of fertility.
When the subsoil consists of a thin layer of clay on a sandy bed, what use may be made of the sub-soil plow?
There are now in New Jersey more foundries casting sub-soil plows than there were sub-soil plows in the State six years ago.
On top of this place the best of the sub-soil mixed with a generous dressing of well-rotted manure.
The expense of installing a sub-soil after the building is up and in use is great as well as inconvenient.