Soybeans are being harvested in the heart of Manitoba’s traditional soybean belt, but as of Thursday, there were still fields a week or more away from the combine depending on the weather.
The variability underscores differences in maturity among varieties and seeding dates.
Dry, warm weather until now has helped ripen soybean crops across agricultural Manitoba, according to Manitoba Agriculture’s weekly crop reports.
Soybeans are fully mature at the R8 stage. That’s when 95 per cent of pods are brown and rattle when shaken.
At R8, depending on the weather, the crop is five to 10 days away from harvest.
Manitoba Agriculture’s website says to direct combine soybeans when the pods are dry and the seeds are hard.
Combining can be done when seed moisture is below 20 per cent, but soybeans must be stored at less than 14 per cent to avoid spoiling.
“Seed damage is high when soybean is harvested at less than 12 per cent moisture, and harvest losses can also be high under dry conditions.” the site says. “Four beans per square foot represents a harvest loss of 60 pounds per acre, so caution is advised. A floating cutterbar is ideal to minimize harvest losses. Careful adjustment of cylinder speed and concave clearance are needed to minimize cracking and splitting of seed.”
A small amount of green, puffy seeds in the harvested sample shouldn’t be a problem if the soybeans are dry. Most times the green seeds will dry and turn colour in storage, Lionel Kaskiw, a farm production advisor with Manitoba Agriculture, said during the CropTalk Westman webinar on Wednesday.
However, if soybeans containing green seeds are delivered directly from the combine to buyers farmers can expect to be docked, Kaskiw added.
Farmers who want to spray soybeans with glyphosate to kill green weeds and control perennial weeds should do so when soybeans have dropped 80 to 90 per cent of their leaves and pods are brown and dry, says the Sept. 7 issue of Manitoba Pulse and Soybean Growers’ Bean Report.
“Note that pre-harvest glyphosate will not speed up maturity,” the Bean Report says.
Farmers must also not harvest the crop earlier than the glyphosate label states and pay attention to the maximum residue levels.
— Allan Dawson is a reporter for the Manitoba Co-operator at Miami, Man. Follow him at @AllanReporter on Twitter.
Soybean harvest tips
- Monitor soybeans every other day once they begin to mature. Consult the Manitoba Pulse and Soybean Growers’ (MPSG) Soybean Maturity Guide to help time your harvest.
- Soybean fields are ready for harvest at less than 14 per cent seed moisture. However, try to avoid harvesting soybeans at less than 13 per cent moisture to prevent seed damage.
- Direct combine soybeans with a flex header at four miles per hour or less. Slower combine speeds (two to four mph) have shown significantly greater yields compared to faster travel speed (five mph), according to research conducted by the Prairie Agricultural Machinery Institute (PAMI). Using an air reel can also result in significantly greater yield, according to PAMI.
- Adjust the cylinder speed and concave clearance carefully to prevent seed cracking and splitting.
- Aim to lower the cutter bar within two inches of the ground to capture the lowest pods, preventing stubble losses.
Measure losses regularly during harvest to optimize combine settings and harvest practices.
Measuring harvest losses
MPSG has an app for calculating soybean losses harvest losses.
Eighty per cent of soybean harvest losses occur at the header. Understanding your losses and adjusting harvest practices accordingly can put more seed in the bin and more money in your pocket.
Soybean harvest losses can be easily calculated using the MPSG Bean App Harvest Loss Assessor.
This new app determines yield loss according to the number of seeds per square foot counted along the header or behind the combine, and estimated seed size.
Calculations are based on the rule that four seeds per square foot equals one bushel per acre of yield loss.
The app also provides pictures and definitions to account for the four types of header loss:
- Shatter: Seeds and pods shattered by the cutter bar.
- Stubble: Pods that remain attached to cut stubble.
- Lodged: Stalks that were lodged, rather than severed by the cutter bar.
- Loose: Stalks that were cut, but not delivered into the combine (similar to lodged).
— Information courtesy Manitoba Pulse and Soybean Growers from the MPSG Bean Report for Sept. 7, 2017.