In many areas of western Kansas, prolonged drought has resulted in short wheat and thin stands. Harvesting wheat in these situations can be a challenge. Special attention needs to be given to cutting height, machine adjustments, and operator control. In short wheat, getting the heads into the combine with less straw will be a challenge. In some cases, the reel may not be able to effectively convey the wheat back from the cutter bar to the auger, nor hold it in place during cutting. Short cutting will also mean more contact potential with the ground.
In the case of material conveyance, stripper headers, air reels, and draper headers may be a great help.
Stripper headers allow the heads to be harvested efficiently while leaving the maximum amount of stalks in the field. This preservation of wheat residue can reduce evaporative losses of water after harvest, aid in the moisture retention of snow, and improve the yields of the next year’s crop.
To properly use a stripper header, note the following:
1) Operators need to be aware of the rotor height and the relative position of the hood to the rotor. This clearance needs to be set to correctly to curl the heads back for proper cutting.
2) Keep the nose of the hood orientated so that the top of the wheat heads are even with, or slightly below, the point of the nose. This may require operating the header with the nose in a slightly lower-than-normal position relative to the rotor. However, it’s important to note that running a stripper header lower than necessary will result in increased power consumption and finger wear.
3) Combine ground speeds should be kept high (3 to 6 mph) to maintain collection efficiency.
4) Several people have reported that adjusting header height with a stripper header is not as critical as it is with a conventional header, and that a stripper header could easily be run non-experienced people (see step 1).
Air reels will also aid in the material conveyance from the cutter bar to the auger in reel-type units when crops are light or thin. These units are made in several different types including finger air reels (Fig.1), non-reel (Fig. 2), and units that fit over existing reels. Examples of manufacturers are Crary (West Fargo, ND) and AWS (Mitchell, Ontario Canada). Non-reeled units have the advantage of less eye strain from the continuously rotating header reel, but all units have collection efficiencies compared to conventional reels even in sparse or short crops. These units do not control the amount of wheat stubble left in the field and the operator still has to control the cutting height. In short wheat this may mean little to no field stubble will be left for next season’s moisture collection and for these reason stripper headers may be better choice for certain areas of Kansas.
Draper headers and flex heads
Draper headers may also help with the conveyance of material since they have a very short distance between the cutter bar the conveyance belt. Flex heads will also help with the lower cutting heights and potential ground strikes.
Still for many farmers, new equipment may not be an economical choice and you may have to make do with a conventional head on your combine. In this case, adjust the reel to get the best movement of the heads from the cutter bar to the auger. Combining in slighter wetter conditions may help prevent shatter and decrease losses. If wheat heads flipped out of the header from the top of the auger, an extra “auger stripper bar” may necessary. A small strip of angle can be bolted slightly behind and below the auger to help with material conveyance.
In addition to material conveyance and cutting height, lower yields and uneven crop flow may also require performing combine adjustments to the concave clearance or fan speed. Follow the manufacturer’s recommendations. You may likely have to lower the fan speeds slightly or the threshing drum to accommodate the reduction in material volume. Once adjusted properly, try to keep material crop flow as constant as possible as most threshing and cleaning units work best under these constant flow conditions.
Losses can be quickly checked by looking at the number of seeds in the tailings and elsewhere around the combine. Typically, 20 seeds per square foot is equal to 1 bushel per acre for a sampling area equal to the cutting width of the combine. For the tailings area, where the material is concentrated, multiple the 20 seeds per square foot by the header-to-tailings width ratio. For example a combine with a 7-foot spreader width and 28-foot header would have a factor of 4, and 80 seeds per square foot would be the correct number for a bushel per acre loss. Also, a normal shoe length is typical one foot, so estimated measurements can be done with your foot. Individual field and header losses are determined by looking at areas before and under the combine. Actual combine threshing losses are determined by subtracting these numbers from the tailing loss.
If harvesting with a conventional header, maintain the cutting height as high as possible to preserve standing stubble. Typically, cutting wheat at two-thirds of its full height will result in losses of less than 0.05 percent as any missed heads contain grain that will be lost as tailings during the harvesting process.
Although this maybe a rough year for some farmers, some changes can be made to help maximize harvest efficiencies. If you have ever wanted to try an alternate header (stripper, draper, air flow, etc.), this maybe the year for you. For those not wanting to buy, renting may also be an option.
Producers in dryland production systems need to keep in mind that in very low-yielding wheat years anything that can be done to preserve what little crop residue is present will have huge impacts on evaporative losses and productivity of the next crop.