Direct sowing, direct drilling
Planting crops in a non-inverted soil without seedbed preparation (i.e. under no-tillage).
Conventional Tillage
Full width tillage that disturbs the entire soil surface which is generally performed prior to planting. It usually involves a primary operation by depth ploughing or chiselling (commonly to 20-30 cm depth), followed by secondary operation such as rotavating or harrowing that pulverizes, flattens, and firms the surface.
Conservation agriculture (CA)
A farming method including minimum soil disturbance (no tillage, minimum tillage, reduced tillage, strip tillage, direct drill), crop rotation, and permanent soil cover (http://www.fao.org/ag/ca/).