Mower-Conditioner Wide Swath- Conditioning vs. Not Conditioning
Ronald T. Schuler
Extension Agricultural Engineer

Wide swaths will dry more rapidly than a narrow swath when mower-conditioning forages. Since many mower-conditioners on the North American market are unable to produce wide swaths, the option of not-conditioning and creating a wide swath is an alternative. Some producers are considering not-conditioning by disconnecting or removing the conditioning system on their mower-conditioner. The question becomes under what conditions should the conditioning system be by-passed or removed. Also the wide swath may have implications regarding added field operations such raking or merging.

In a field study by Shinners and others in Wisconsin, they compared conditioned and not-conditioned swaths at the different swath widths. They evaluated swathes of 100 percent (135 inches), 65 percent (88 inches) and 33 percent (45 inches) of the cutting width, which was 135 inches. After cutting the crop at 11:00 am, they collected samples at three and six hours later for moisture content determination. After six hours the moisture contents ranged from 57 percent for conditioned and full swath width to 69.5 percent for the not-conditioned and 33 percent swath width. The order of drying from fastest to slowest for three and six hours after cutting was:

Based on these results, the suggested swath width for not-conditioning should be nearly twice the swath width of a conditioned crop to obtain an equivalent drying rate. Therefore disconnecting or removing the condition system from a mower-conditioner is not recommended for the purposes of faster drying unless the resultant not-conditioned swath is nearly twice as wide as conditioned swath width. For most mower-conditioners on the market today this cannot be done. The average maximum swath width adjustment on the machines available is about 61 percent of the cutting width and ranges from 28 to 87 percent.

For some large mower conditioners with a maximum swath width of 30 to 35 percent of the cutting width and cross conveyors (apron or auger), wide not-conditioned swath widths may be obtained. In one case, a custom operator near Monticello removed the apron cross conveyors and the cut crop dropped onto the ground immediately behind the cutterbar. The result is a not-conditioned swath width of more than 90 percent which will dry much faster than a swath having a conditioned width of 25 to 30 percent of the cutting width.

As forage producers go to wider swaths, the cost of added operations required to create a windrow to meet the needs of the pickup of the harvesting equipment must be considered. A raking or merging operation may be needed which adds cost and should be weighed against the advantages of faster drying.

Before even considering removing or disconnecting the conditioning systems, the machine operator should check to ensure the maximum swath width adjustment has been made and the conditioning system is adjusted for the it best performance with respect to drying rate and crop loss. The conditioning adjustments will include roll pressure and clearance on roll conditioners and deflector on impeller conditioners. Then they can evaluate whether a swath twice the width can be produced by not using the conditioning system. For many machines, such a swath will not be possible.