There is a reason it is called a "keyline plow". The subject of keyline plowing is unconventional and sometimes hard to think of plowing in a new way. I'll cover the benefits of using a keyline plow, define keyline with a photo, and explain it in a way I hope you understand.
Keyline design is a landscaping technique of maximizing the beneficial use of the water resources of a tract of land. The "keyline" denominates a specific topographic feature related to the natural flow of water on the tract.
Keyline design - Wikipedia
https://en.wikipedia.org/wiki/Keyline_design

Above the use of a keylineplow to capture water high in the landscape along with utilizing the the natural shed of water to a pond. A combination of uses for this particular landscape that meets the needs of design functions.

Keylineplow slightly off contour allowing water to move to lower areas where the ridges meet. This is a great way to get water to areas that normally are dry.
Another use for the keyline plow would be to apply subsoil ripping on contour in large corn and soy fields where compaction and ponding occur. Acres of no crops or poor yield could be improved.
Unlike drain tiles, key-line plowing improves the natural qualities of soil, addressing both drought and flood conditions. In nature worms and ants tunnel in the landscape allowing the water to infiltrate into the soil. Today we find few of these friends in our soils because of the toxic chemicals used that kill them.
Do you need to key-line plow every year or just until nature like the worms and ants move back in to do their job? It may take awhile for them to multiply to the point where the numbers are reached to form the balance needed to maintain and create healthy soil.

Texas ranch soil BEFORE getting the benefits of using a keyline plow.

Texas ranch soil AFTER getting the benefits of using a keyline plow.
The following link has photos of keyline plows and various uses: Keyline Photos
Seeing results like this makes me wonder how fast can we recover the degraded soils adding keyline design to regenerative farming practices.
and More in the video below