Abstract: In the subsurface application of herbicides, a plurality of upwardly directed nozzles having one millimeter openings are pulled beneath the soil surface behind the trailing side of a sweep in parallel paths two to four centimeters apart while jets of herbicide are emitted so that moving soil passing over each jet receives ample herbicide properly spaced to control germinating weeds. The pressure of application and speed of movement forms treated bands having widths before diffusion of five millimeters of soil and liquid uniformly mixed to a depth of approximately eight centimeters over the treated area. The sweep operates at a depth up to eight centimeters and pesticide incorporation depends on such variables as soil density, soil moisture, spacing of nozzles and injection pressure. A uniform distribution of chemicals in bands near or completely to the surface of the soil is made possible with a one-pass operation, while the soil and plant residue on the surface remain substantially undisturbed.

Abstract: To apply herbicide to weeds extending above a crop, a nylon carpet on the cylinder of a roller applicator has herbicide applied to it as a tractor or other vehicle carries it through a field. The roller is held just above the crop where it contacts weeds and is rotated in the opposite direction as the tractor. A moisture sensor is spaced from the applicator on the roller and controls a valve that applies the herbicide to the roller to maintain a preset moisture level in the roller carpet. The amount of moisture is set by experimentation to permit an adequate amount of herbicide to be applied to various weeds without causing dripping from the point of contact on the roller by the weeds.