Plowing and the like is very out of fashion in big agriculture: the harm that hoeing is bad for the soil has been well known to farmers for a long time. (as long as I can remember which puts us in the 1970s) That isn't to say plowing isn't part of big ag, but they have found ways to plow that disturb less soil while still getting the benefits they want.
Glyphosate is a major part of big ag's anti-plowing system: by killing weeds they don't have to plow them up. Thus saving the soil. As a bonus, spraying uses much less fuel ($$$ for farmers, CO2 and global warming for the rest of us) than plowing.
More generally, mechanical manipulation of the soil. I learned at a recent Rutgers University seminar that overworking of soil is surprisingly hazardous to its health.
