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Production Update
Total U. S. soybean production is predicted to be a record 2.9 billion bushel crop, up 7 percent from last year. Record soybean acreage plus a forecast yield of 40.6 bushels (the second highest on record) are to account for the large harvest. Very favorable growing conditions have occurred over most of the Mid-West and the crop is ahead in maturity. Unfortunately, Virginia producers have not been so lucky. Yields are forecast to only average 22 bu/A, very similar to last year. Only the southeastern portion of the state will likely experience average or above average yields. Northeast Virginia seems to be the most devastated by the drought.
Demand for the soybean crop is of course being affected by the Asian economic crisis, but is still reasonably high. Demand picked up slightly due to lower prices, but ending stock predictions increased due to the predicted increase in production. Ending stocks are predicted to reach 485 million bushels, the largest since 1985/86 stocks of 536 million bushels. Using Dr. David Kenyon's price-stocks graph below, one can see why U. S. soybean prices are being forecast at $4.65 to 5.35 per bushel, the lowest price since 1986-87. . Still, the ending stocks-to-use ratio is only 18.4%, lower than the 28.5% level in 1985/86.
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Late-season is a good time to trouble-shoot the soybean crop for disease, nematodes, soil compactions, etc. Stem and root rot diseases began showing foliar symptoms during September. Likewise, problems with nematodes and soil compaction begin revealing themselves. It would be wise to walk the fields regularly and note these problems. Although it may be too late to do anything about the problem this year, it can dramatically affect future years' crops. If disease or plant problems are suspected, take soil and/or tissue samples and take them to the nearest Cooperative Extension office or diagnostic lab.
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Fall is the best time to sample for fertility and nematodes. Below are some guidelines.
Sampling for Nematodes: Samples should be taken in September while the population is at its peak. Samples taken after harvest will not be as reliable due to the nematode population decline. Composite 20 1-inch diameter soil cores taken in a systematic zig-zag pattern over a 5-acre area. For larger fields with similar soil type and cropping history, select 2 to 5 random, representative 4 to 5 acre sections for field and follow the above procedures. Insert the sampling tube at a slight angle under the plant to a depth of 8 to 10 inches. This will insure that soil and roots are included in the sample. Thoroughly mix the soil from all cores and place in plastic or plastic-lined bags. Nematodes in the sample must arrive alive to be properly identified. Keep the samples in cool storage (refrigerator) until ready to ship. Do not store the samples for more than 2 days. Samples can be analyzed at Virginia Tech's Plant Disease Clinic and Nematode Assay Lab. Forms for preditive nematode assay can be found at County Extension offices.
Fertility Sampling: Soil fertility samples have been traditionally taken during the fall of the year after crops have been harvested, but they can be taken anytime during the year. Take a sample for each different soil type and for land that will be managed differently from the rest of the field. Take around 20 soil cores per sample at a depth of approximately 8 inches, again walking a systemic zig-zag pattern through the field. Thoroughly mix all cores together in a plastic pail before filling the soil sample box. Samples can be sent to the Virginia Cooperative Extension Service Soil Testing Lab or another private laboratory.
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Harvest is rapidly approaching and some harvest tips may need reviewing. Generally, it is recommended that soybean harvest begin as soon as the moisture content drops below 15% if drying facilities are available to avoid excessive field losses. If delaying harvest until moisture drops below 13%, one should begin harvest as quickly as possible. Successive wetting and drying of soybeans after seed moisture has reached 13% increases the likelihood of shattering and related pre-harvest losses.
Harvest losses can be divided into 4 basic categories: pre-harvest losses, cutter bar (header) losses, cylinder (rotor or threshing) losses, and splitting (straw walker) losses. Although it is not possible to achieve zero harvest losses, they can be minimized with careful adjustments. During the course of the day, as conditions change, it may be necessary to make careful adjustments to the combine to keep each type of loss to a minimum. Determining combine losses as one starts the operation and as conditions change can prevent yield reductions due to harvest losses. Four soybean seed per square foot equal 1 bu/A yield loss. Harvest losses can be estimated using the following steps.
| Header Width (feet) | Frame Length (inches) |
|---|---|
| 10 | 12 |
| 12 | 10 |
| 14 | 8.6 |
| 16 | 7.5 |
| 20 | 6.0 |
| 24 | 5.0 |
| 30* | 4.0 |
*For large headers, use 20 sq. ft. area. Adjust frame length and calculations accordingly.
b. Loose Stalk Loss Ð Count all beans in pods still attached to soybean stalks that were cut but not gathered into the machine, divide by 40.
c. Lodged Stalk Loss Ð Count all beans in pods still attached to soybean stalks that are lodged and still attached to the ground, divide by 40.
d. Stubble Loss Ð Count all beans in pods attached to the stubble, divide by forty.
| Source of Loss | Beans in 10 ft2 | Your Loss (bu/A) | Aceptable Loss (bu/A) | |
| 1. Total | _____________ | /40* = | _____________ | 1.2 |
| 2. Pre-Harvest | _____________ | /40* = | _____________ | 0.1 |
| 3. Machine (Line1 - Line 2) | _____________ | /40* = | _____________ | 1.1 |
| 4. Gathering Unit (Lines 4a +4b+4c+4d - Line 2) | _____________ | /40* = | _____________ | 1.0 |
| a. Shatter | _____________ | /40* = | _____________ | 0.3 |
| b. Loose Stalk | _____________ | /40* = | _____________ | 0.2 |
| c. Lodged Stalk | _____________ | /40* = | _____________ | 0.2 |
| d. Stubble | _____________ | /40* = | _____________ | 0.3 |
| 5. Cylinder and Separator Loss (Line 3 - Line 4) | _____________ | /40* = | _____________ | 0.1 |
*Number of soybean seed in 10 ft2 to equal 1 bu/A loss (2,904 seeds/pound).
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Virginia Soybean Yield Contest
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Soybean Update & Production Guide on the Web
All issues of Soybean Update and the Soybean Production Guide can now be found on my World Wide Web site: http://www.vaes.vt.edu/tidewater/faculty/holshouser/holshouser.html. I am currently in the process of building a comprehensive Web page in which various soybean information can be accessed. Stay tuned.
Sincerely,
David L. Holshouser
Extension Soybean Specialist
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