The Shrinking Coulter: When Heavy Metal Goes Underground
By Farmer John Peterson
We do deep tillage on the farm, every vegetable field at least once, sometimes twice per season. Our subsoiler (in some circles referred to as a ripper) penetrates the silty clay soil about 16 inches deep, slicing a channel through it which lets air in to stimulate microbial activity and lets water infiltrate, rather than pool on the surface or run off. In loosening the soil, the tillage machine makes it easier for roots to penetrate and spread out. It takes a lot of power to subsoil (hence the term rip), about 35 horsepower per shank.
Hardened steel points are bolted to the tips of the subsoiler shanks. There is a variety of point styles that a farmer can choose from, depending on how aggressively he wants to loosen and lift the soil. The points we use at Angelic Organics lift the soil just a little, not nearly so much as a mole making a classic burrow in a cartoon.
The subsoiler has coulters mounted on the front that slice through the ground ahead of the shanks, cutting through crop residue that might otherwise plug the machine. Our coulters had become badly worn over the years, so Primo replaced them this past week.
Soil is much softer than steel, yet the soil can shape the steel, wear it down, transform it. It makes one aware of what love can do in hard places.