Conservation tillage is defined as any tillage and planting system that covers 30 per cent or more of the soil surface with crop residue, after planting, to reduce soil erosion by water. The various tillage methods worldwide have been described by different names such as no-till, zero-till, minimum till, incomplete tillage, reduced tillage or direct drill. The systems differ mainly in the degree to which the soil is disturbed prior to sowing.

The term conservation tillage is often used to describe one or more of these tillage systems.  The no-till and zero till systems generally have the least amount of soil disturbance and greatest soil cover remaining from previous crop residues.