April's Ag Advice by April Borders Harvest will be upon us soon but are you ready? Making sure that our machinery is in good operating condition is imperative for a successful harvest. The amount of time that it will take you to do some pre-harvest adjustments will pay off in the long run. Pre-harvest adjustments are vital when you look at today's economy. But what about during harvest? Do we ever stop to check our equipment to see what our harvesting losses are?
A sure way to up your harvest yield is to use a fast, easy method for measuring machine losses. Once the source and extent of loss is known, it is easy to make changes in machine adjustment and operating practices to keep losses to a minimum. Losses can be measured in 10 minutes or less. On average, four soybeans in a single square foot area will equal one bushel per acre loss.
So how do you go about calculating your harvest loss? First, you will need to construct a 10-square foot frame. This can be made of rope or plastic clothesline with small metal stakes (heavy wire or nails) at the corners to insert into the ground. The length of the frame should be the width of the combine header. Grab a note pad and pencil and you're ready to head to the field.
The accompanying table can be used to help you with your data collection.
When you are in the field combining, stop at least 300 feet in from the end of the field, in an area where the crop is typical of the entire field. Back the combine up about 15 feet. Place your rectangular frame across the swath harvested at the rear of the combine. Count all the beans in the frame and record the amount (column 1-A). Divide the number of beans counted by 40 and record the loss in bushels per acre (column1-B). This is your total crop loss. If loss is near 3 percent of yield, keep right on harvesting. If loss is greater, then proceed to pinpoint the sources of loss.
Determine pre-harvest loss by placing the rectangular frame in the standing crop in front of the combine. Count the loose beans on the ground and beans in pods lying loose on the ground. Record this number (column 2-A) and divide by 40 to get loss in bushels per acre. This number is your pre-harvest loss (enter in column 2-B).
Machine loss (column 3-B) is determined by subtracting the pre-harvest loss from the total crop loss. If machine loss is near 3 percent of yield or less, keep harvesting. If loss is more than 3 percent, then proceed to check gathering unit losses.
Gathering unit losses are determined by placing the rectangular frame in the space between the parked combine and the standing beans. Then proceed to make bean counts as follows.
1. Shatter loss � count all loss beans on the ground and beans in loose pods on the ground. Record this number (column 4 a-A) and divide by 40 and record bushels per acre loss (column 4 a-B).
2. Loose stalk loss � count all the beans in pods attached to soybean stalks that were cut but not gathered into machine. Record this number (column4 b-A), divide by 40 and record bushels per acre loss (column 4 b-B).
3. Lodged stalk loss � count all beans in pods attached to soybean stalks that were lodged and are still attached to the ground. Record this number (column 4 c-A), divide by 40 and record bushels per acre loss (column 4 c-B).
4. Stubble loss � count all beans in pods still attached to stubble. Record this number (column 4 d-A), divide by 40 and record bushels per acre loss (column 4 d-B).
Total gathering unit loss can now be obtained by adding the losses (in column B) for shatter, stubble, loose stalk and lodged stalk losses. (Record this number in column 4-B.) Cylinder and separation loss can now be determined by subtracting the gathering unit loss from the machine loss. (Enter this number in column5-B)
Compare your harvest loss levels to the desirable loss level based on 40 bushel per acre yield. Total crop loss – 1.3; Pre-harvest loss � 0.1; Machine loss � 1.2; Total gathering loss � 1.1; Shattering loss -0.4; Loose stalk loss � 0.2; Lodged stalk loss � 0.2; Stubble loss � 0.3; and Cylinder/Separation loss � 0.1. (Column C)
If your losses are greater than those listed you will want to look at making machinery adjustments and changing your operation practices so that you can obtain the least total loss possible. Repeating these loss checks in different parts of the field will greatly increase their accuracy.
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. Make sure that knife sections, guards, wear plates and hold-down clips are in good condition and properly adjusted. Operate the cutterbar as close to the ground as possible at all times.
For more information on measuring soybean harvest losses contact the Cooperative Extension Service at 677-7111.