Often, tillage equipment is larger than the tractor can pull at the speeds necessary for proper incorporation. On hilly ground or when soil conditions are less than optimum, incorporation speeds are reduced and incorporation uniformity suffers. During implement selection, choose a tillage device smaller than typically matched with your tractor. This will allow for additional power required to transport the spray tank, spray solution and operate the sprayer accessories. Harrows improve horizontal distribution with single-pass complete incorporation because much of the herbicide is below the operating depth of the harrow.
Harrows add considerably, however, to the horizontal distribution of surface mixing.
In fact, without a good harrow, single-pass surface mixing would seldom be satisfactory. A minimum of a three-bar harrow is recommended. The method of attachment to an implement is very important in maintaining uniform incorporation. There should be at least two carrier arms per harrow section to maintain stability. The most aggressive mixing and tillage action is obtained with the tines perpendicular to the soil surface.