Since wheat season has come upon us early this year, there has been much discussion about double cropping soybeans into the wheat stubble, looking for a little added revenue to the farm this season.

Challenges

  • Residue control – we must ensure that residue from the wheat is controlled.  Baling the straw seems to be the best bet when double cropping, but all straw or chaff remaining in the field must be spread uniformly.
  • Moisture – this season especially may be a challenge.  With the lack of rain in the month of June, there is some pretty dry dirt out there and cracks down to China.  A good shot of rain seems to be the best bet just prior to or after planting.
  • Efficient Planting – with the shortened growing season you need to be proactive in getting the soybeans planted. Have the baler in the field, get the bales removed and have the drill ready to roll.  Time is of the essence.

Selecting Soybean Maturity, Planting Rate and Row Spacing

  • Research in Ontario and south of the border has shown that selecting a standard maturity for your area or decreasing the maturity by no more than 150 CHU has the best potential yield ability.

  • Planting rates should be increased to 250,000 seeds per acre. There is less time for soybeans to gain height to pod, therefore the higher plant density gives you a better probability of higher yield and efficient harvesting.

Timely Planting

  • This season gives us a great opportunity to attempt a Double Crop Plan on our wheat stubble.  A study in Ontario shows that soybeans planted on July 10 will give you a 60% yield potential. Every day after that yield potential decreases.
  • It is important to get soybeans planted as soon as possible and attempt to put them into moisture if moisture is present within 2 inches.  It is not recommended to plant deeper than 2 inches; plant and pray for rain.

Budget

  • Seed Cost per acre – approx. $74.00
  • Herbicide cost – approx. $18.00
  • Total cost minus Equipment and Fuel – $92.00
  • Revenue 30 bu X $13.30 = $399.00

Nutrient Removal

Please remember that you are removing more nutrients than you planned at the beginning of the season.  You must also budget for more fertilizer to be applied in the fall when the crop is harvested.  To understand what you need to replace take your final yield and multiply by 0.86 for phosphorous and 1.4 for potash.  For example, a 30 bushel soybean crop would remove 26 lbs of phosphorous and 42lbs of potash.  You must add this to the removal of your wheat crop when returning nutrients to the soil in the fall. 

See the example below:

Wheat Crop 90 Bushel/Acre

P removal = 54lbs actual P

K removal = 32.4lbs actual K

Soybean Crop 30 Bushel/Acre

P removal = 26lbs actual P

K removal = 42lbs actual K

Total removal

P removal = 80lbs actual P

K removal = 74.4lbs actual K

Conclusion

If you ever wanted to attempt double cropping, this may be the year to do it. Give it some great thought and build a budget. If it works for you, contact your local Maizex Representative and they will help you plan it out.

Chuck Belanger, Maizex Seeds Territory Manager, Southwest Kent and North Essex Counties
Twitter: @sprayman63 

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