Bob’s goal in this project was to reduce the amount of herbicide applied to no-till corn by 1) using “row cleaners” to open a passage through the residue of the previous year’s crop, and then 2) applying herbicide in a band along the corn row. A row cleaner looks something like a coulter. It shoves crop residue aside, and is pulled behind the tractor, but ahead of the planter. The idea was that pushing the crop residue out of the corn rows would create a mat thick enough to suppress weeds between the rows. Bob would then have to apply herbicide only right in the corn rows.
Bob planted 24 rows of corn at 30” spacing, using a no-till planter. He used the row cleaner with the planter on twelve of these. Where the row cleaner was not used he broadcast sprayed Microtech for control of annual grasses, and Atrazine, for control of broadleaf weeds and grasses. He applied the Microtech at the rate of 2¼ quarts per acre, and Atrazine at 1 quart per acre. He then installed drop tubes and even-fan nozzles on the sprayer, and sprayed in 10-inch wide bands along the other 12 rows. The same rate was applied, then, within the narrow bands, but since they were only 10” wide, the overall rate in the banded area was one-third that of the broadcast area. From time to time over the season he counted weeds in both treatments in randomly selected 12 x 30 inch areas, and he measured yield at harvest.
Weed control was generally very good throughout the year in both treatment areas, and did not differ significantly between them. Yield was measured at 129 bushels per acre where the herbicides were band-applied, and 135 where they were broadcast. These figures are each the mean of six measurements, and do not differ significantly either.
Bob reports that by applying the herbicides in bands he saved $16 per acre over the cost of broadcasting. He says it was as fast and easy as broadcasting, and changing the sprayer from one to the other took less than an hour.