Determining the optimal time to harvest soybeans is one of the most important decisions a farmer makes each season. With soybean prices and profit margins as tight as ever, harvesting at the right moment maximizes yield, quality, and income.
Timing is everything when it comes to soybean harvest. Here are key tips on identifying when soybeans are mature and ready for harvest:
Monitor Pod Color and Leaf Drop
As soybeans near maturity, the leaves turn yellow and drop off, exposing the seed pods. Pods transition from green to brown or tan as they dry down. Once nearly all leaves have fallen and pods turn brown, start checking seed moisture and pod integrity. Pods should appear dry and brittle, cracking open to expose the beans. Avoid harvesting too early while pods are still pliable and green.
Check Seed Moisture
Seed moisture is the best indicator of soybean maturity. Mature soybeans need to be 13% moisture or less for safe storage. At 13-15% moisture, beans can be harvested and dried down with natural or artificial heat. Use a moisture tester to check multiple areas of the field. Soybeans are too wet if pods appear flexible and seeds are difficult to split. Ideal soybean harvest moisture is 13-13.5%.
Monitor Field Conditions
Look for other signs that soybeans are ready for harvest besides moisture. Stems should be dry and brittle not green. Pods should easily detach from stems when rubbed. Avoid harvesting after heavy rains or dew when moisture levels spike. Cool dry, breezy weather helps dry beans for harvest. Time harvest between rain events if possible.
Test Bean Quality
Slice open soybeans to assess their quality. Check that the inside is uniformly firm and the seed coat is tightly adhered. The hilum, or seed scar, should be closed with no visible cracking. Soft, shrunken, or wrinkled beans indicate over-maturity or damage, reducing quality grade. Harvest promptly once beans are fully mature to prevent losses.
Harvest Early Varieties First
When growing both early and late-maturing soybean varieties, prioritize harvest based on maturity timing. Earlier varieties dry down first and are more prone to shattering losses if harvest is delayed. Come back for later-maturing beans once initial varieties are harvested. Staggering maturity dates also spreads out workload.
Watch the Calendar
While weather-related maturity indicators are most critical keep average soybean maturity dates in mind for your region. Maturity dates help gauge if development is on schedule for the time of year. University crop calendars provide estimated soybean maturity timeframes for different zones.
Consider Re-Crop Plans
If double-cropping soybeans, timely harvest enables proper field preparation and planting of a second crop like winter wheat Harvest delays can reduce yields of subsequent crops in tight re-cropping windows. However, don’t rush soybean harvest if beans aren’t mature and dry enough yet
Monitor Crop Insurance Deadlines
Review crop insurance policies, which often stipulate harvest completion dates. Harvesting outside these dates can impact coverage. Time harvest to meet crop insurance deadlines if applicable.
Weigh Harvest Losses
Beginning too early when soybeans are still wet risks harvest losses and damaged beans. However, shatter and pod drop can accelerate as plants dry down, and late-season rains promote sprouting. Check yield monitors closely when harvesting and be prepared to adjust combine settings or harvest parameters to reduce field losses.
Consider Harvest Aids
Applying foliar treatments like glyphosate or paraquat just before maturity desiccates plants and quickens dry down for earlier harvest. These chemical harvest aids can help maximize yield if harvest is delayed due to weather. Always follow label directions.
Know When to Quit
Stop harvesting once seed moisture drops below 10% or damage and losses become excessive despite combine adjustments. At very low moistures, soybean seeds split and crack, rapidly downgrading quality. Halt harvest if adjusting machine settings still results in losses over 2%. Excessive harvest losses outweigh revenue gains.
Timing soybean harvest is ultimately a balancing act of yield, quality, and efficiency. Experience, frequent field monitoring, and recordkeeping help hone harvest decision-making. With careful planning and proactive adjustments, farmers can maximize their soybean return on investment this season.
Recommendations for a late soybean harvest
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Updated from an original article written by Mike Staton.
Overcome the challenges associated with a late soybean harvest.
Deep ruts created by harvesting soybeans in wet soil conditions. Photo by Mike Staton, MSU Extension.
It was reported by the National Agricultural Statistics Service of the United States Department of Agriculture that 45% of Michigan’s soybean crop was still in the field as of October. 29, 2023. It will be hard to harvest these fields because the next 6 to 10 days are expected to have normal to above-normal rainfall and temperatures below normal. The following recommendations from Michigan State University Extension will help producers overcome these challenges.
To keep the combine from making deep ruts like the ones in the picture, wait until the soil is dry or frozen enough to support it. If you do this, the ruts will fill with water and make it take longer to work in the field again. Soil compaction associated with wet harvest conditions can also reduce crop yields for several years. Adding tracks or flotation tires to the combine may help it float and grip better, and it may also help keep the soil from getting too compacted when it’s wet. Using the lowest air pressure recommended by the tire maker for the loaded combine is a good way to keep the soil from getting too compacted, no matter what kind of tires you have.
It is very important that the cutter bar is in great shape because the plants will be tough and hard to cut. All of the knife’s parts and guards should be tight and sharp, and all of the guards should be in the right place to get the best cutting results. The gap between the sickle and the hold downs should be about the thickness of a business card. Reducing your ground speed will also improve cutting and provide more uniform feeding into the combine. If the rows are 15 inches apart or more, harvesting at an angle to the rows should also help the plants grow better.
The moisture content of the seed will also be high. In theory, soybeans can be harvested when the seed moisture is below 20%. Moisture testers and yield monitors are usually accurate when measuring soybean moisture. But when soybeans are wet, Charles Hurburgh and Meaghan Andersen, both from Iowa State University Extension, say that you should compare at least three samples of your yield monitor or hand-held moisture meter to the meter used by the grain buyer. This is because the yield monitor or hand-held moisture meter tends to under-estimate the grain’s moisture content by one to two points.
Threshing and cleaning high moisture soybeans is challenging. Achieving uniform feeding and keeping the threshing cylinder/rotor full are the first steps to improving threshing. Draper heads and air-assisted reels will improve the uniformity of feeding. If threshing is not satisfactory, try reducing the concave clearance first. This may increase plugging problems at the cylinder/rotor if the straw is tough. If plugging is a problem or unacceptable threshing occurs, increase the speed of the cylinder or rotor. Make incremental adjustments and check threshing performance and grain quality after each adjustment. It can be tricky to find the right cylinder/rotor speed and concave clearance settings that get the job done without breaking or crushing too many beans.
I usually tell producers to look for gathering losses at the header because, in normal harvest conditions, 90% of all harvest losses happen at the header. This is still important to do as gathering losses will likely increase when harvest is delayed. But because the soybeans were picked so late, the tough stems and pods and soft seed will likely make threshing and cleaning losses worse, so keep an eye on your grain loss monitor.
The wet beans will need to be dried or aerated immediately after harvest. Please see the MSU Extension article on drying and storing wet soybeans for recommendations. If farmers want to bring wet soybeans directly to the elevator, they should find out how much moisture the elevator can handle before they bring the soybeans.
In the end, you should harvest what you can when you can because as the year ends, there is a greater chance that soybean quality will go down and field losses will rise. Some farmers might leave the beans in the field over the winter and pick them in the spring if the weather doesn’t get better. This is a risky practice. Wet, heavy snows can flatten the plants, making harvest very difficult. The risk of experiencing seed damage due to phomopsis is also increased with delayed harvest. The presence of phomopsis is confirmed if linear rows of black specks occur on the stem. If you see these signs and the pods are infected, damage to the seed can potentially occur. The good news is that soybeans are less likely to sprout in the pods when the pods are whole and not open.
Producers that consistently harvest soybeans in November should consider planting earlier maturing soybean varieties. Please see the MSU Extension article, “Should you plant earlier maturing soybean varieties?” for more information.
This article was produced by a partnership between MSU Extension and the Michigan Soybean Committee.
How does a farmer know when to harvest soybeans
FAQ
What month do you harvest soybeans?
How do you know when soybeans are ready to pick?
Why are soybeans harvested at night?
Do soybeans turn yellow when ready to harvest?
What time of day should you harvest soybeans?
Choosing the right time of day for harvesting can also contribute to moisture management. Typically, soybeans have lower moisture content in the afternoon compared to the early morning or evening. Harvesting during the drier part of the day can help minimize moisture-related issues and improve overall harvesting efficiency.
How do I determine the optimal time for soybean harvesting?
In summary, determining the optimal time for soybean harvesting requires considering various factors such as plant appearance, pod and seed characteristics, and moisture levels. Waiting for the right maturity level is important to maximize yield potential, maintain seed quality, and improve harvest efficiency.
Can I Harvest soybeans after a late-season rain?
It is generally advisable to harvest soybeans after a late-season rain, provided the fields have had enough time to dry out and the moisture level is within the acceptable range for harvesting. Rainfall can help improve soil moisture conditions, potentially increasing yields and reducing the risk of pod shattering during harvest.
What are the best conditions for harvesting soybeans?
The ideal conditions for harvesting soybeans are when the beans are dry and mature. The beans should be at least 16% moisture content and the pods should be yellow or brown. The soybeans should also be free of weeds and other debris. The best time to harvest soybeans is in the fall, when the weather is cool and dry.