Late season, The Bean Report

The Bean Report – August 30, 2023

AUGUST 30, 2023

Crop Update

  • Soybeans range from R6.5 to R8 (full maturity) with most crops at R7 (mid-maturity). Short-season soybeans in Western Manitoba are further advanced.
  • Field pea harvest is on-going. Pea yields range from 30 to 90 bu/ac, depending on region.
    • Peas are ready for harvest when overall seed moisture is 18 to 20%. The maximum safe storage moisture for peas is 16%. Aeration in the bin is typically used to reach this safe storage moisture. Peas usually sweat after going in the bin, so monitor for moisture build-up or spoilage post-harvest.
    • Pea Desiccation and Harvest Guide →
    • Maintaining Pea Seed Quality →
  • Dry beans range from R8.5 (mid-maturity) to R9 (full maturity). Some fields have already been undercut, while straight-cut harvest is expected to start this week.
    • Stems bleached by white mold are easy to spot in the field right now. Break stems open to look for hard, black sclerotia bodies to confirm the presence of white mould.
    • If desiccating, target the R9 (full maturity) stage when 80% of leaves have dropped and 80% of pods had changed to their mature colour in the greenest areas of the field. Seeds in the youngest pods will have lost their green colour when split in half. Dry Bean Desiccation and Harvest Guide →
    • The maximum safe storage moisture for dry beans is 16%. Seed moisture below 16% increases the risk of cracked seed coats and split beans. Seed moisture above 18% increases the risk of heating and spoilage. Moisture will fluctuate throughout the day and should be monitored. Handle edible beans as little and as gently as possible.
    • Harvesting Tips to Improve Dry Bean Quality →
  • Faba beans range from R7 (mid-maturity) to R8 (full maturity).
  • Post-Harvest and Long-Term Storage of Soybeans and Pulses →
Soybeans at mid-maturity near Minto on Aug. 21, 2023.
Pod and Stem Blight (black dots) on a soybean stem near maturity.
Yellow pea harvest near Notre Dame on Aug. 16, 2023.
Black beans (Blackstrap) post-desiccation near Deloraine, MB on Aug. 22, 2023.
Navy beans (T9905) at mid-maturity near Glenboro on Aug. 24, 2023 scheduled to be undercut the following day.

Dry Bean Harvest

Dry beans may be harvested by undercutting and windrowing, swathing or straight cutting. Undercutting is typical for row-cropped beans and vine-type varieties that pod low to the ground. Straight cutting or swathing is more common for solid-seeded beans and bush-type varieties with higher pods. Straight cutting also requires flat soil that has not been inter-row cultivated.

Dry beans are ready for harvest when:

  • All leaves have dropped
  • All pods have changed colour
  • 75% of pods are dry and the remaining pods may be flexible and yellow with seeds that have fully changed colour (R9 stage)
  • Seed moisture is 16-18%

Harvesting Tips to Improve Dry Bean Quality:

Tips to reduce soil and smearing:

  • Screen kits at the header and under the feeder house will help eliminate soil.
  • Windrowing beans that have been undercut will help remove any soil clinging to the roots.
  • Increasing fan speed can help if the soil is dry.
  • For soft, puffy immature beans, smearing can occur when the moisture combines with the soil entering the combine. Waiting until these beans dry down further in the field is one option, but if you can keep these beans from earth tagging, they will dry down normally in the bin.
  • Using a conveyor mounted on the combine to unload can also help reduce smearing.

Tips to reduce splits and cracks:

  • Reduce cylinder speed. Starting speeds range from 300 to 600 rpm depending on bean type and harvest conditions. Reduce speed in 100 rpm intervals until you see a noticeable difference in cracks.
  • If this doesn’t work, try closing your concave to thresh beans out quicker. A more open concave will allow beans to flow further into the threshing system, interacting with the rotor and cracking beans.
  • Install a wide-wire concave. This allows beans to flow through the concave faster.
  • More material entering the combine through larger windrows or a wider cutting width will also help cushion beans.
  • Harvest when plants are dry so pods open more easily as they move through the cylinder and concave. Harvesting damp plant material may not open as quickly, resulting in more cracks and splits.

Soybean Harvest

  • Soybeans are ready for harvest once seed moisture is <14%, around 5-10 days after R8 (full maturity) has been reached. At R8, 95% of pods are brown, all leaves have dropped and seeds rattle within pods.
  • Soybeans can be combined when seed moisture is below 20%, but seed must be stored at <14%. Avoid harvesting at <12% seed moisture to prevent cracking and splitting.
  • Soybeans may be direct harvested (straight cut) or swathed. Direct harvesting is the preferred method. If swathed, combine shortly after to avoid quality loss. Soybeans are easily damaged by rain if left in the swath.
  • Keep harvest speed below 5 mph to minimize header losses. Measure losses regularly during harvest to optimize your combine settings.
  • If soybean seed moisture is <11%, harvest when humidity is high to reduce shatter loss and mechanical damage.
  • Reducing Soybean Harvest Losses →

Fall Rye Ahead of Next Year’s Dry Beans and Soybeans

  • Properly managed, fall rye as a cover crop ahead of dry beans and soybeans can protect soil from erosion and minimize weed pressure while maintaining  yield potential.
    • Dry beans are planted late in spring, resulting in a long window of bare soil from the time when snow melts in the spring to when the crop goes in the ground.
  • Rye termination must be carefully timed in the spring to maintain yield potential during plant establishment under dry conditions.
    • Under relatively dry conditions from 2018 to 2020 at Carrington, ND pinto bean yields following a fall rye cover crop were statistically similar to the check when the rye was terminated with glyphosate 17-36 days before planting. Find the quick summary of Dr. Greg Endres, NDSU’s research on fall rye preceding soybeans and dry beans. Or, read the more detailed summary of managing rye as a cover crop.
    • Recent MB research evaluated termination timing of the fall rye cover crop in the spring. In this experiment, soybean yield was not different among the control, plots terminated 14 days before planting, terminated 4 days before planting or terminated 1 day after planting. To conserve moisture, terminate the rye earlier in the spring, to use more moisture, let it grow longer.
Fall Rye on May 5, 2023.

Balancing P and K Nutrient Budgets

  • The P and K removed with harvested soybean and pulse seed is high and there is a limited crop capacity to tolerate seed-placed fertilizers.
  • Early harvest allows time for a large addition of P and/or K fertilizer or manure in the fall.
  • For example, in a soybean-canola-wheat rotation (yielding 40, 50 and 60 bu/ac, respectively) over thee years we would require approximately 140 lbs P2O5/ac to match the P removed. You could apply 100 lbs P2O5/ac in the fall, reserving an application of 20 lbs P2O5/ac as starter fertilizer for both the canola and wheat crops, which are more likely to respond to seed-placed P fertilizer than soybeans.
    • This one-time P application should be incorporated, or banded, to reduce nutrient losses due to surface run off. This fertilization strategy would maintain soil fertility over the course of the rotation, saving time and cart space during seeding.