Cooperative Extension Service The University of Georgia College of Agricultural and Environmental Sciences HARVESTING, DRYING AND STORAGE SOYBEANS Paul E. Sumner, Extension Engineer Producing a high-quality soybean crop is one thing. Harvesting those soybeans with minimum losses and then drying and storing them in a way that maintains quality until the soybeans are marketed is another. A reduction in harvest losses of three bushels per acre when harvesting three acres per hour can result in a savings of $54 per harvesting hour based on $6 per bushel. Proper drying and storage will maintain quality soybeans and assure minimum losses. Harvesting Harvesting Losses The grain-combine harvester has been used for soybeans since the mid-twenties but little progress was made in reducing harvesting losses until about 1970. Until then, the average combine using a rigid grain platform header resulted in as much as 10 percent losses during the harvesting operation. The introduction of attachments such as the floating cutter bar and pick-up reel reduced harvesting losses to 7 or 8 percent. More recently combine headers that have a built-in, flexible cutterbar have been designed and developed specifically for use in soybeans. A low profile, row-crop header was introduced by John Deere and Company in 1974. Harvesting losses can be reduced to about four percent of yield with these new headers. The types of harvesting losses should be identified and measured so that proper combine adjustments can be made to increase soybean harvesting efficiency. Preharvest losses are those that occur from natural causes before harvest. These losses result from soybeans that have fallen to the ground by the time harvest begins. If soybeans that are ready for harvest are subjected to several alternating periods of wet and dry weather, preharvest losses could be as high as 25 percent. Gathering or header losses are soybeans that are not gathered into the combine. These losses are caused by the action of the cutter bar, reel and auger and account for more than 85 percent of the total soybean losses at harvest. There are four kinds of gathering losses. Shatter losses are shelled soybeans and detached soybean pods that are shattered from stalks by the header. Stubble losses are soybeans in podsremaining on the stubble because of operating the cutterbar too high, etc. Stalk losses are soybeans remaining in pods attached to stalks that were cut but not delivered into the combine. Lodged losses are soybeans remaining in pods attached to stalks that were not cut or that were cut at heights greater than that of the stubble. Soybeans are easy to thresh, separate and clean. Soybeans can be rubbed out of the pod readily and their size and shape are ideal for cleaning. Even so, small errors in the adjustment of the combine can result in disastrous losses during the threshing, separating, and cleaning operations. Threshing or cylinder losses occur when shelled soybeans are carried out the back of the machine with the stalks. Separating losses are usually insignificant unless the combine is overloaded. Cleaning or shoe losses occur when shelled soybeans are carried over the chaffer or top sieve and out the back of the combine. Measuring Losses Harvesting losses can be measured by enclosing a ten square foot area with a rectangular frame and counting the soybeans remaining in that area after harvest. A count of 40 beans within the frame represents approximately one bushel per acre. Make the frame from heavy cord or cloth line so it can be coiled and carried on the combine. The length of the frame should be equal to the cutting width of the combine header (see table below). Make four pins 3 to 4 inches long from No. 9 wire and tie them to the frame to mark the corners. The pins should be pushed into the ground to hold the frame tight. FRAME WIDTH BASED ON COMBINE HEADER WIDTH. Header width (feet) Frame width (inches) 16 7 1/2 18 6 3/4 20 6 22 5 1/2 24 5 The procedure for determining field losses can be seen in the figure below. Operating the combine in the normal way, move into the crop until well away from the edge of the field. Then, the combine should be stopped, the platform drive disengaged, the platform raised and the combine backed up 15 to 20 feet. In measuring total losses the frame should be placed across the harvested rows behind the combine and the loose soybeans, soybeans in pods on or off the stalks and soybeans on the stubble inside the frame should be counted. This figure divided by 40 represents an estimate of the losses in bushels per acre, and it includes both preharvest and harvest losses. If the loss is near three percent of the yield, continue harvesting.To measure preharvest losses, the frame should be placed across the rows of standing soybeans in front of the combine and loose soybeans and soybeans in pods on the ground should be counted and divided by 40. To determine the total harvesting losses the preharvest losses should be subtracted from the total losses found behind the combine. The shaded areas indicate frame placement for measuring total soybean loss, preharvested loss, and gathering loss. Reducing Losses Preharvest losses can be minimized by planting shatter-resistant varieties and early harvest. Soybeans should be harvested shortly after their moisture content first reaches 14-16 percent. Header designs play an important role in reducing harvesting losses. The row-crop header has proven to be more efficient than platform type headers. Of the platform type headers, the flexible floating cutterbar header is the most efficient but slightly less efficient than the row-crop header. The flexible floating cutterbar header has several features that enable it to reduce soybean losses: its long dividing points help prevent problems that occur in lodged soybeans; its extended platform and low profile reduce shatter and stalk losses; and its large-diameter auger rapidly moves plant material to the center and helps reduce stalk losses. To take full advantage of the time available for harvesting, make all necessary repairs and major adjustments well before the harvest season. The combine should be thoroughly repaired, lubricated and adjusted as instructed in the operator's manual. Reduction in gathering losses can be accomplished only if the header is adjusted to cut close to the ground to avoid leaving soybeans on the stubble and shattering them from the stalks. To further reduce shatter losses, set