Did you know that during soybean harvest time, field losses can range from 5% to 12% of your total yield potential?
That's a significant hit to your bottom line. Unfortunately, over half of these losses typically come from header or threshing issues directly related to combine efficiency. In fact, numerous studies conducted over the past 40 years show that soybean harvesting losses can climb as high as 15% if not properly managed.
When it comes to soybean moisture, precision matters. Specifically, harvesting soybeans at 13% moisture content maximizes both yield and financial returns. However, if you delay harvest until your crop drops below 11% moisture, you significantly increase the risk of pod shattering and subsequent yield loss.
We understand these challenges firsthand. Consequently, we've put together this comprehensive guide to help you prevent unnecessary losses during your soybean harvest. From optimizing combine settings to controlling moisture levels, we'll cover the essential strategies that keep more soybeans in your bin and more profit in your pocket.
Proper combine setup is the foundation of a successful soybean harvest. Studies show that gathering units account for most soybean losses, often reaching up to 15% of total yield. With careful maintenance and operation, you can reduce these losses to a more acceptable 3%.
The cutterbar is your first defense against harvest losses. A well-maintained cutterbar requires attention to four critical components:
1. Sharp knife sections (particularly 3-inch coarse tooth sections for better residue flow)
2. Properly gapped knife hold-downs (within 1/32 inch of guards)
3. Aligned guards without bending
4. Correct knife register according to your operator's manual
Regarding reel adjustments, position is equally important as speed. For most conditions, set the reel axis 8-12 inches ahead of the cutterbar. Additionally, the reel tips should operate approximately 10-25% faster than your ground speed when crop stands normally. This prevents shattering while effectively guiding plants onto the platform.
For standing crops, set the reel to contact only the top third of plants. Furthermore, different header types require distinct reel settings—flex auger platforms need the reel "down and back" while flex draper headers work best with the reel positioned "up and out".
Fan speed serves as the key adjustment for cleaning. Start with the maximum recommended fan speed, then reduce it only enough to prevent blowing whole soybeans from the rear of the combine. As a practical tip, increase fan speed until all pod hulls leave the grain tank sample, then reduce by about 50 RPM.
For sieve settings, consider these adjustments:
· Run the bottom sieve wide open to maximize airflow
· Close the front portion of the top sieve (chaffer) until the grain tank shows 99% clean soybeans
· Adjust the rear portion of the top sieve to allow unthreshed pods to fall into the return auger
Properly set chaffer openings prevent grain from entering the returns system unnecessarily. Begin with the manufacturer's recommended settings—typically around 5/8 inch for the chaffer and 3/8 inch for the cleaning sieve.
Combine calibration represents a crucial step for keeping grain losses at acceptable levels. Research demonstrates that combine adjustments are required every two to three hours to optimize harvest efficiency. This might seem excessive, yet the potential savings justify the effort.
The header choice also impacts calibration needs. Draper headers typically outperform auger-fed platforms under varied conditions. They provide more uniform feeding, allowing you to start harvesting earlier in the day and continue later, ultimately increasing daily harvest capacity.
For flexible cutterbars with header height control, precise calibration prevents stubble loss. An extra inch of cutting height typically equates to about one bushel per acre in yield loss. Moreover, proper calibration helps you detect gathering losses versus machine losses, allowing for targeted adjustments.
To estimate field losses, try this measurement technique: drive backward about 10 feet and count soybeans on the ground in a 10-square-foot sampling area. Remember that four soybeans per square foot equals approximately one bushel per acre loss.
Moisture management stands as a critical factor for maximizing your soybean returns at harvest time. Getting this aspect right not only preserves yield but notably impacts your bottom line through weight retention and quality preservation.
The 13% moisture mark represents the sweet spot for soybean harvesting, serving as the industry standard for a reason. At this level, soybeans maintain optimal weight while minimizing mechanical damage during threshing. Since a standard bushel of soybeans weighs 60 pounds at 13% moisture, harvesting at this precise level maximizes your marketable yield.
Consider this financial reality: for every percentage point below 13% moisture, you're essentially giving away free weight. For instance, soybeans harvested at 11% moisture (89% dry matter) weigh approximately 58.65 pounds per bushel instead of 60 pounds. This translates to 1.35 pounds of lost water weight per bushel - weight you could have sold. At USD 8.50 per bushel with a 60-bushel yield, this seemingly small difference can cost you around USD 11.48 per acre.
Harvesting outside the optimal moisture range introduces substantial risks:
· Too dry (below 11%): Field losses increase dramatically as pods become brittle. Shatter losses rise significantly, especially if mature beans undergo multiple wetting and drying cycles. Splits and cracked seed coats become more common, inviting mold development and accelerating deterioration. Additionally, beans themselves become more susceptible to breakage during handling.
· Too wet (above 15%): Threshing becomes difficult above 18% moisture, leading to more crushed and damaged beans. Storage problems emerge quickly as wet beans deteriorate faster. Free fatty acid percentages increase more rapidly with higher moisture content, negatively affecting quality.
For long-term storage planning, soybeans at 13% moisture work well for winter storage. Nevertheless, if you intend to store through spring and summer, aim for 11% moisture to prevent mold growth and deterioration. As a useful comparison, soybeans at 11-12% moisture behave similarly to corn or wheat at 13.5-14.5% moisture in storage conditions.
Implementing soil moisture sensors represents one of the most effective strategies for optimizing your soybean harvest timing. These devices provide accurate, real-time data about field conditions, allowing for precise harvest planning. Despite their proven value, only about 30% of Mississippi farmers currently utilize this technology, compared to the 13% national adoption rate.
Field checking remains essential even with sensor technology. Before starting your harvest, physically examine pods for dryness. Remember that moisture content fluctuates throughout the day - soybeans typically dry out during daylight hours and reabsorb moisture overnight. This makes late morning often ideal for harvesting.
To maximize your harvest efficiency:
5. Begin harvesting at 14% moisture when 95% of pods show their mature tan color
6. Avoid harvesting during the driest afternoon hours to reduce shattering losses
7. If putting beans in drying bins, you can start harvesting at 16% moisture and aerate down to 13%
8. Verify your moisture tester's accuracy against your grain buyer's meter using multiple samples
Ultimately, the storage life of soybeans approximately doubles for each percentage point reduction in moisture content. This principle helps guide your decisions about harvest timing relative to your storage plans and market delivery schedule.
Field losses represent a major challenge for soybean growers, often amounting to 10% of potential yield and sometimes climbing as high as 15% to 20% due to careless harvest operations. Addressing these losses directly impacts your bottom line, making smart harvesting techniques worth your attention.
Gathering loss occurs when beans fail to enter the combine and accounts for approximately 80% of total harvest losses. This includes four distinct types:
9. Shatter loss - beans that fall from pods during cutting
10. Stubble loss - beans in pods attached to stubble below the cutter bar
11. Lodged stalk loss - beans in pods on uncut stalks that didn't enter the machine
12. Loose stalk loss - beans in pods on cut stalks that didn't reach the threshing unit
In contrast, machine losses occur inside the combine through incomplete threshing, separation, or cleaning. Although gathering losses far outweigh machine losses, both require attention for optimal harvest efficiency.
To accurately assess your soybean harvest losses, follow these steps:
First, create a measuring frame enclosing 10 square feet. The width should equal your combine header width. Walk through your field counting beans in several locations and divide by the total area measured. As a rule of thumb, four average-sized beans per square foot equals approximately one bushel per acre loss.
For a more thorough analysis, check three distinct areas: the standing crop (pre-harvest loss), behind the header (gathering loss), and behind the combine (total loss). The difference between total loss and the sum of pre-harvest plus gathering loss represents your machine loss.
Consider your harvest successful if total losses remain below 3% of yield – about 1.2 bushels per acre in a 40-bushel crop. Greater losses indicate adjustments are needed.
To minimize pod shatter and seed loss throughout harvest:
Maintain proper ground speed of 2.8-3.0 mph. Excessive speed causes beans to be stripped from stems and dropped. For rigid platforms, slower speeds are necessary compared to flex or row-crop headers.
Position the reel axle 6-12 inches ahead of the cutter bar and adjust reel speed to approximately 25% faster than ground speed. This ensures beans are cut cleanly without shattering.
Utilize daily moisture fluctuations by harvesting when pods retain some moisture. Begin earlier in the day when plant material remains damp from overnight dew. Complete harvest promptly after beans reach optimal moisture rather than waiting until all plants are completely dry.
Stagger field maturity by planting varieties with different relative maturities, allowing for a more extended harvest window and reducing the pressure to harvest everything simultaneously.
Smart farmers recognize that field conditions ultimately dictate soybean harvest timing. Careful planning based on these conditions can make the difference between maximum yields and substantial losses.
Green stem syndrome presents a common challenge, where soybean stems remain green even as pods mature normally. This condition slows harvest operations and creates issues with combine efficiency. Scout fields early to identify distribution patterns—widespread green stem often indicates weather factors or genetics.
Fields with heavy weed pressure require special attention, primarily because dry conditions can accelerate soybean dry-down while weeds remain green. Indeed, many Wisconsin farmers face weedy soybean fields due to reduced effectiveness of residual herbicides under drought conditions. This problematic combination can force harvesting overly dry soybeans in weed-infested fields.
The time of day dramatically impacts harvest success. Soybeans typically absorb morning dew, making plants sticky and less brittle. Consequently, harvesting during early morning hours often results in broken cutter bars or plants getting stuck around threshing drums.
Aim to begin harvesting when moisture content reaches 14-15%. Forthwith, consider harvesting when some leaves still remain on plants—beans may be drier than they appear. Altogether, avoid harvesting during late afternoons when beans are driest, as this increases shattering losses.
Wet soil conditions create substantial challenges. Whenever possible, wait until soil is dry enough to support equipment weight. Heavy machinery on saturated soil causes significant surface compaction, rutting, and deep subsoil compaction.
Field operations on wet soils can reduce yields by 10-20% in following seasons due to compaction damage. Generally, consider harvesting around the wettest areas first, returning to them afterward when conditions improve. For already rutted fields, postpone cosmetic tillage unless soil becomes sufficiently dry for proper fracturing.
After bringing soybeans from the field, proper storage becomes crucial for maintaining value and quality. Careful attention to post-harvest handling directly impacts your ultimate profitability.
Soybeans are fragile and require gentler drying than other grains. For commercial soybeans, limit drying temperature to 130°-140°F, whereas seed beans need even lower temperatures of 100°-110°F. Beyond temperature, relative humidity matters tremendously—maintain drying air above 40% relative humidity to prevent seed coat cracking. Remember that each 20°F temperature rise cuts relative humidity approximately in half.
For low-temperature bin drying, size heaters for no more than 20°F temperature rise and use an in-plenum humidistat to shut off the heater when relative humidity falls below 45%. Typically, drying requires 3-6 weeks with proper airflow.
Moisture content targets vary based on storage duration:
· Short-term winter storage: 13% moisture or less
· Storage through one planting season: 12% moisture or less
· Carryover seed storage: 10% moisture or less
Temperature control remains equally important as moisture. Aerate stored soybeans to maintain temperatures between 35-40°F in winter and 40-60°F in summer. This significantly reduces mold growth and insect activity. Once cooled, cover aerator and ductwork openings to prevent snow or moisture from entering.
Regular monitoring proves essential—check stored soybeans weekly during warm weather and every two weeks during cold periods. Use a 6-foot or 10-foot probe to collect samples from various depths, keeping samples separate to identify potential trouble spots.
Weed seeds pose significant challenges for soybean storage. When possible, avoid harvesting high-density weed patches entirely. Forthwith, adjust combine settings specifically to remove weed seeds during harvest.
Before storage, thoroughly clean bins, augers, legs, and transport vehicles. This prevents contamination from other grains, particularly corn, which some countries consider a noxious weed.
For cleaning during harvest, use compressed air to your advantage—it effectively removes seeds from equipment. Open trapdoors to clean grain augers and the tailings processor, plus unload the auger sump for thorough cleaning. Subsequently, destroying separated weed seeds prevents them from entering the soil seed bank.
Soybean harvesting presents numerous challenges that directly impact your bottom line. Throughout this guide, we've covered essential strategies to minimize losses and maximize profits during harvest season. Undoubtedly, the difference between a good and great harvest often comes down to attention to detail.
First and foremost, proper combine settings serve as your foundation for success. Sharp knife sections, correctly positioned reels, and calibrated headers can reduce gathering losses from 15% down to a more acceptable 3%. Additionally, moisture management stands as perhaps the most critical factor in preserving yield potential. Harvesting at 13% moisture maximizes both weight and quality while avoiding the financial penalties of harvesting too dry or the storage problems of harvesting too wet.
Field losses require vigilant monitoring. Remember that four soybeans per square foot equals approximately one bushel per acre in lost revenue. Therefore, regular field checks and adjustments to your harvesting approach based on actual conditions pay significant dividends.
Timing matters tremendously. Scouting for green stems, managing weed pressure, and selecting the right time of day for harvest all contribute to yield preservation. Similarly, waiting for appropriate soil conditions prevents compaction issues that could affect next year's crop.
After harvest, careful handling and storage extend your vigilance. Gentle drying techniques prevent seed coat cracking, while proper moisture and temperature management in bins safeguard your investment until market delivery.
We hope this comprehensive guide helps you capture more of your soybean crop's potential. By implementing these strategies, you can significantly reduce those 5-12% typical harvest losses and keep more profit where it belongs—in your pocket. The effort invested in optimizing your soybean harvest certainly yields returns far exceeding the time spent.