tillage

The preparation of land for crop-bearing. Tillage loosens the soil, kills weeds, and improves the circulation of the water and air in the soil. Plant wastes from preceding crops enrich the soil with nutrients when the soil is tilled. Harrows may be employed to break up and pulverise strips of soil after ploughing. This aeration of the soil provides further circulation of oxygen and water and stimulates increased biological activity in the soil. Traditionally, tillage has been achieved by cutting and turning the soil with a plough blade. Deep ploughing may be harmful to the soil if practised over many years, especially if the fertile topsoil layer is thin. Today, many farmers use systems of reduced tillage to retain the topsoil near the surface and exploit the moisture produced by decomposing plants. The ultimate reduced tillage is no-till, when only a narrow band of earth is disturbed where the seed is to be planted and fertilized.

Tillage, or cultivation (a term which also has broader meanings related to the raising of plants in general) is the agricultural preparation of the soil by digging it up.

Primary tillage loosens the soil and mixes in fertilizer and/or plant material, resulting in soil with a rough texture. It can be done by a using various combinations of equipment: plough, disk plough, harrow, dibble, hoe, rotary tillers, subsoiler, ridge or bed forming tillers, roller.

Weed plants (seeds, tubers, etc.) may be exhausted by repeated tilling. The weeds expend energy to reach the surface, and then get turned into the soil by tilling. Crops can be grown for several years without any tillage through the use of herbicides to control weeds, genetically modified crops that tolerate packed soil, and equipment that can plant seeds or fumigate the soil without really digging it up. This practice, called no-till farming, reduces costs and environmental change by reducing soil erosion and diesel fuel usage. Organic farming tends to require extensive tilling, as did most farming throughout history.

Tilling was first performed via human labor, sometimes involving slaves. Hoofed animals could also be used to till soil via trampling.