Using Soybeans
as an Alternate Forage
• Dr. Mike Hutjens
Dairy Extension Specialist
Jim Baltz
Instructional Design Specialist
University of Illinois at Urbana-Champaign
Learning Objectives
• After viewing this module you should be able to:
– Identify the stages of soybean growth
– Describe the key factors in harvesting soybeans as a
silage
– Evaluate the economics of using soybeans as a
forage
University of Illinois at Urbana-Champaign
Stages of Soybean Growth
• Growth staging: A growth stage for a field
begins when at least 50% of the plants have
reached or are beyond a certain stage and
stages may overlap.
– Vegetative stages
– Reproductive stages
University of Illinois at Urbana-Champaign
Soybean Parts
Trifoliate Leaf
Cotyledons
University of Illinois at Urbana-Champaign
Growing Point
Unifoliate Leaf
Reproductive Stages (WI and NC)
•
•
•
•
•
•
•
•
R1: Beginning bloom
R2: Full bloom
R3: Beginning pod development
R4: Full pod
R5: Beginning seed
R6: Full seed
R7: Beginning maturity
R8: Full Maturity
University of Illinois at Urbana-Champaign
Average number of days for each
reproductive stage
Stage
Abbreviation
R1-R2 to R3
Stage Title
Average Number
of Days
Begin bloom to begin pod
10
R3 to R4
Begin pod to full pod
9
R4 to R5
Full pod to begin seed
9
R5 to R6
Begin seed to full seed
15
R6 to R7
Full seed to begin maturity
18
R7 to R8
Begin maturity to full maturity
9
University of Illinois at Urbana-Champaign
adapted from Soybean Loss Instructions , National Crop Insurance Services (NCIS) #6302 Soybeans,91
Harvesting Soybean Silage
• Harvest soybeans at R3 stage, when one of the four top nodes
with a fully-developed leaf has a 3/16-inch-long pod.
• Wilt forage to 35% to 45% dry matter before ensiling depending
on storage unit.
• Chop at 3/8-inch theoretical length of cut (TLC).
• Add an inoculant (similar to an effective alfalfa/legume inoculant)
• Yields in drought year 1 to 2 tons/acre
University of Illinois at Urbana-Champaign
Soybean Silage by Dan Undersander, Kevin Jarvik, Tom Anderson, Nick Schneider, and Lee Milligan
Yield and quality of soybean forage as affected by
harvest maturity
University of Illinois at Urbana-Champaign
Modified from Soybeans for Hay or Silage by Dr. Dan Undersander
Forage quality of soybean silage not
mixed with other crops
University of Illinois at Urbana-Champaign
Soybean Silage by Dan Undersander, Kevin Jarvik, Tom Anderson, Nick Schneider, and Lee Milligan
Soybean Hay
• Harvested at R3 - when one of the top four nodes
with a fully developed leaf has a 3/16-inch long pod.
• Limit leaf loss by limiting number of times it’s
mechanically handled
• Dries slow (may require 2 to 3 days)
• Raking can lead to significant leaf loss
University of Illinois at Urbana-Champaign
Cautions before using soybeans as
a forage
• Check what herbicides and insecticides were
used to ensure no restrictions
• Contact a crop insurance agent before
harvesting for forage
University of Illinois at Urbana-Champaign
Economics of harvesting soybeans
• As forage, assume 1 ½ tons of dry matter
per acre valued at $200 a ton or $300 per
acre.
• As seed, $300 per acre / $15 per bushel, less
than 20 bushels may be the break point
• No harvesting charges were included with the
soybean seed
University of Illinois at Urbana-Champaign
In Summary
• Soybean forage may an alternative forage for
dairy and beef cattle
• Consider economics of each alternative
• Be aware of residue risks and treatments
• Soybean forage will be similar to other
legume forages, but not as palatable
University of Illinois at Urbana-Champaign
Check out our online dairy courses at
http://online.ansci.illinois.edu/
and Illini DairyNET at
http://www.livestocktrail.illinois.edu/dairynet/
Dr. Mike Hutjens
Dairy Extension Specialist
Jim Baltz
Instructional Design Specialist
University of Illinois at Urbana-Champaign