cultivator

thumb|F210 Honda tiller thumb|1949 Farmall C with C-254-A two-row cultivator thumb|A tractor-mounted tiller thumb|Tines close-up thumb|A cultivator pulled by a tractor in Canada in 1943 A cultivator (also known as a rotavator) is a piece of agricultural equipment used for secondary tillage. One sense of the name refers to frames with teeth (also called shanks) that pierce the soil as they are dragged through it linearly. Another sense of the name also refers to machines that use the rotary motion of disks or teeth to accomplish a similar result, such as a rotary tiller.

Cultivators stir and pulverize the soil, either before planting (to aerate the soil and prepare a smooth, loose seedbed) or after the crop has begun growing (to kill weeds—controlled disturbance of the topsoil close to the crop plants kills the surrounding weeds by uprooting them, burying their leaves to disrupt their photosynthesis or a combination of both). Unlike a harrow, which disturbs the entire surface of the soil, cultivators are designed to disturb the soil in careful patterns, sparing the crop plants but disrupting the weeds.