ABSTRACT

Tillage prepares the seedbed by mechanical disturbance to loosen and smooth the soil surface, often mixing topsoil with surface organic debris to aerate soil, assist in weed suppression, control insects and pests, and, in midlatitudes, promote springtime warming and drying. Tillage has been practiced, in varied forms, throughout the world since antiquity. During the 1700s and 1800s, innovations in designs of plowshares greatly increased tillage eff ctiveness by increasing depth of the disturbed soil and by turning the surface soil to more completely mix surface crop residue (also referred to as plant litter, senescent vegetation, or nonphotosynthetic vegetation [NPV]) with disturbed soil.