OPTIMUM SETTINGS FOR ROTARY TOOLS USED FOR ON-THE-ROW MECHANICAL CULTIVATION IN CORN

Abstract

Mechanical cultivation is a proven weed control technique in corn and other row crops. On-the-rowmechanical cultivation however is still problematic mainly because of the risks of damaging the crop that are associatedwith this cultural practice. The objective of this study was to determine the optimum operational requirements for aspecific type of rotary tillage tool used for on-the-row cultivation that would result in an appropriate control of weeds andminimal damage to the corn plants. A first experiment was conducted to determine the effects of travel speed [3.0 to9.0 km/h (1.9 to 5.6 mph)], operating depth of the rotary tool [12.7 to 63.5 mm (0.5 to 2.5 in.)], and orientation of therotary tool axis relative to the travel direction (0 to 30) on the thickness of the tilled soil layer projected on the crop rows.In a second experiment, the effects of the relative position of two rotary tools placed on each side of a row (face-to-face orone in front of the other) on the covering of the corn rows by the projected soil were investigated. Based on theexperimental results, a regression model was developed in order to predict the thickness of the projected soil on the croprows as a function of the parameters under study. Results indicated that travel speed, operational depth, and relativeorientation of the rotary tool all had a linear effect on the thickness of the projected soil layer. For the particular soilconditions encountered during the study, results indicate that a rotary tool operated at 9.0 km/h (5.6 mph), at a depth of12.7 mm (0.5 in.) and rolling in a direction parallel to the direction of travel of the machine could provide adequate soilcoverage on the corn rows in order to control on-the-row weeds.