"Numerous tests of soybean combine losses have shown that as much as 12 percent of the soybeans remain in the field after harvest. Harvesting losses cannot be reduced to zero, but they can be reduced to an acceptable level of about 5 percent the harvesting rate. This Guide describes the major sources of loss."--First page.Charles W. Shay, Lyle Ellis and William Hires (Department of Agricultural Engineering, College of Agriculture)New 9/82/10

Ellis, Lyle

Hires, WIlliam

Shay, Charles W.

University of Missouri: MOspace

" u M C Seie11,e 1111d l:et/111"/"III NOV O 5 1982 GUIDE P116/islted 611 tlte ll11iversit11 "I )liss"11ri - C"/111116i11tKte11si"111Jivisi"11 Measuring and Reducing Soybean Harvesting Losses Charles W. Shay, Lyle Ellis and William Hires Department of Agricultural Engineering College of Agriculture Numerous tests of soybean combine losses have shown that as much as 12 percent of the soybeans remain in the field after harvest. Harvesting losses cannot be reduced to zero , but they can be reduced to an acceptable level of about 5 percent. Combines can be operated to reduce losses without affecting the harvesting rate. This Guide describes the major sources of loss. Pre-harvest losses. These losses are beyond the combine operator's control and cannot be called harvesting losses. Pre-harvest losses are caused by lodging and shattering. In most years, 0. 25 percent of the total crop yield is lost before harvesting begins . Shatter loss at combine header. These losses occur when the header is operated improperly or when the crop has a tendency to shatter easily. Shatter losses increase with crop dryness . When the reel speed is too fast or the reel is positioned too far forward, soybeans are shelled in front of the combine . Reel peripheral speed should not exceed forward speed of the combine by more than 25 percent. Peripheral speed is easier to adjust on combines with variable speed reel controls . Consider shatter losses of 2 percent as acceptable. Average losses are 5 percent or more . Stubble loss. Often many pods are left on the stubble because they have been missed by the cutterbar and were not gathered into the combine. Overcome this problem by keeping the field level and using a flexible cutterbar or special row-crop head for soybeans. Stubble losses should be no more than 0 . 75 percent of the total crop yield . Average losses are 1.5 percent or more . Lodged or loose stalk loss. Beans left in the pods on downed stalks or those that are cut but do not pass through the combine should be only about I percent of the total crop yield. Minimum losses occur when the machine is in top condition, the knife is sharp, and the correct reel height is used . A pickup reel reduces these losses. Average losses are 2 to 5 percent of the crop yield. Cylinder loss. Beans left in pods that have passed through 1280 Figure 1. Tests show that as much as 12 percent of the soybeans remain in the field after harvesting. the machine are the result of harvesting when the moisture content is too high or with incorrect cylinder-concave settings. There should be no loss, but improper operation can cause losses as high as 0.5 percent of the crop yield. Separation loss. Loose beans passing out of the machine can be held to a minimum with the correct blower and sieve settings. These losses can be as high as 0.5 percent but should be held to 0.25 percent of the crop yield. How to Measure Losses To get satisfactory combine operation , you need to identify and measure losses. Alone, you can check losses in about 10 minutes . If you have help, even less time will be required. The extra soybeans in your grain tank will more than pay for the delay. To determine losses , count the unharvested beans in an area of IO square feet. An average of four beans per square Archiv version - chck fr updatesTable 1. Rectangular dimensions for 10-square-foot plot. Common Distance to enclose machine swath 10 square feet 8' 15" 10' 12" 12' 10" 13' 9.25" 14' 8.6" 15' 8" 16' 7.5" 20' 6" 22' 5.45" 24' 5" foot equals one bushel per acre loss. Make the area of 10 square feet equal in width to the combine header. (See Table l . ) A plastic clothes line and four pins made from #9 wire make excellent material for forming the rectangle . (See Figure 2.) Procedure. Before checking for losses, disconnect the straw spreader or chopper, so you can get a more accurate count . Stop the combine where the crop is representative of the entire field. Stop the header and threshing mechanism. Back the combine a distance equal to its length. Shut off the engine. Place the rectangular frame across the machine swath as shown in Figure 3 and make counts for • total crop loss (Step I), • preharvest loss (Step 2), and • header loss (Step 4). Step 1 : total crop loss. Place the rectangular frame across the swath harvested at rear of combine . Count all loose beans as well as the beans in loose and missed pods. Enter the number of beans per l O square feet in Table 2, line 1. If the total crop loss is less than 3 percent of the crop Figure 2. Use a plastic clothes line and four pins to form the rectangle. 1280 yield, keep on harvesting. You are doing a better than average job. If losses are greater than 3 percent, pinpoint the source of the losses to determine where adjustments are needed. Step two: preharvest loss. Determine the preharvest loss by placing the rectangular frame in standing beans. Count the loose beans on the ground and the beans in loose pods on the ground. Enter the number of beans per IO square feet in Table 2, line 2. Step 3: machine loss. Determine the machine loss by subtracting the preharvest loss from the total crop loss. Enter this number in Table 2, line 3. If the machine loss is 3 percent of the total crop yield, you are doing a better than average job and adjustments are not necessary. If the loss is greater than 3 percent, check the header losses . Step 4: header loss. Determine header losses by placing the rectangular frame across the swath harvested in front of the parked combine .. Place it over an area where there has been no discharge from the rear of the combine. Then, make bean counts as follows and enter the numbers in Table 2. Figure 4 shows header loss counts made in front of the combine . • Shatter loss. Count all loose beans on the ground and beans in loose pods on the ground . Enter the number of beans per l O square feet in line 4a. • Loose stalk loss. Count all the beans in pods attached to soybean stalks that were cut but not gathered into the machine. Enter the numberofbeans per 10 square feet in line 4b. • Lodged stalk loss. Count all the beans in pods attached to soybean stalks that were lodged and are still 'attached to the ground. Enter the number of beans per IO square feet in line 4c . • Stubble loss. Count all the beans in pods still attached to stubble . Enter the number of beans per IO square feet in line 4d. Obtain the total header loss by adding the losses for shatter, stubble, loose stalks and lodged stalk losses. Enter the total header loss in line 4. Step five: cylinder and separation loss. Determine cylinder and separation loss by subtracting the total header loss from the machine loss . Enter this difference in Table 2, line 5. Figure 3. Place the rectangular frame across the machine swath. --Table 2. Loss data table. Beans found in Number of beans Your bean loss Source of loss 10 sq. ft. area = to 1 bu./acre in bu./~~re .~,_ t-I. Total crop loss 40 2. Pre-harvest loss 40 3. Machine loss 40 4 . Gathering unit loss. Totals of: 40 a. Shatter 40 b. Loose stalk 40 c . Lodged stalk 40 d. Stubble 40 5. Cylinder and separation loss Tips for Keeping Combine Losses Low Your best guide for correct combine adjustment is your Operator's Manual. Remember that more than 80 percent of the machine loss usually occurs at the gathering unit. The following suggestions will help keep these losses to a minimum. Y' Make sure that knife sections, guards, wear plates and hold-down clips are in good condition and prop-erly adjusted. Y' Keep the seedbed level. Do not dig up soil around beans when cultivating. Y' Operate the cutterbar as close to the ground as possible at all times. A floating header unit or an automatic header control is nearly essential on self-propelled combine. Y' Use a ground speed of2 .8 to 3.0 miles per hour. To determine ground speed, count the number of 3-foot 1280 steps taken in 20 seconds while walking beside the combine. Divide this number by IO to get the ground speed in miles per hour. Y' Use a reel speed about 25 percent faster than ground ; speed. For 42-inch-diameter reels , use a reel speed of,l 11 revolutions per minute for each I mile per hour ground speed . Y' Reel axle should be 6 to 12 inches ahead of the cutterbar. Reel bats should leave beans just as they are cut. Reel depth should be just enough to control the beans. Y' A six-bat reel will give more uniform feeding than a four-bat reel. Y' Complete the harvest as quickly as possible after beans reach 15 percent moisture content. Y' A pick-up type reel with pick-up guards on the cutterbar is recommended when beans are lodged and tangled . TOTAL CROP LOSS (STEP 1) Figure 4. Header counts in steps 1, 2, and 4. HEADER LOSS (STEP 4) PREHARVEST LOSS (STEP 2) ■ Issued in furtherance of Cooperative Extension Work Acts of May 8 and June 30, 1914 in cooperation with the United States Department of Agriculture. Leonard C. Douglas, Director, Cooperative Extension Service, University of Missouri and Lincoln University, Columbia, Missouri 65211. ■ An equal opportunity institution. 1280 New 9/82/10M 

Measuring and reducing soybean harvesting losses

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Measuring and reducing soybean harvesting losses

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