The differences between a conventional and zero tillage system are most apparent in the area of weed control. Controlling weeds without tillage is new and challenging but not impossible. The proof can be seen in the clean, healthy crops grown by no-till farmers over a wide range of conditions.

Ideally, in a zero till system (as in any crop production system) there are no weeds present as crops emerge. Weeds of economic importance which develop after the crop emerges are controlled with the same post-emergence herbicides used in conventional tillage systems.

Application of a non-selective herbicide at seeding time is often a component of the system, but there are other controls available to the no-till farmer. Any practice that favors crop development over weed development means cleaner fields and higher yields. Time of seeding, variety selection, optimum placement of seed and fertilizer, field border sanitation, and the selection and rotation of crops are all important in improving a crop's ability to compete with weeds.