The other replies make fair points, but tillage does still have it's uses.
Quick examples:
- Inversion tillage (ploughing) to bury green manure crops or bulky organic manure
- Subsoiling (deep tillage) can help break underground compaction, to allow better root penetration
- Working with soils prone to surface capping
There's also a spectrum: - Full inversion tillage
- Low/min-till
- No-till
With a wide range of operations you can perform from one end to the other. You might end up taking a mix-and-match approach as years/fields demand it.EDIT: This is a response to the question "why do it?" rather than anything in the context of the article itself.