
Processing Alfalfa and Soybeans--On the Spot
By Linda
McGraw January 7, 2000New products and increased markets
for alfalfa and soybeans are on the horizon for Midwest farmers in the next
century, thanks to the innovative research of
Agricultural Research Service and
University of Wisconsin scientists in
Madison. The petroleum industry has long fractionated crude oil into a variety of
products, each surpassing the original commodity in value. Now the same idea is
being shown to work for crops in a fieldside processing unit devised by ARS
agricultural engineer Richard G. Koegel at the
U.S. Dairy Forage Research Center. Until now, the process--called wet fractionation--was conducted in a central
processing facility. The drawback: Herbage, which contains about 80 percent
water, had to be transported from the field to the processing facility, and
waste liquid needed to be either dehydrated or transported back to the field as
liquid fertilizer. Last summer, Koegel assembled a group of machines in the first fieldside
demonstration of soybean herbage wet fractionation. For the most part,
commercially available machines were used, but Koegel modified a
hammermill--originally used for pulverizing grain by forcing it through
screens--to rupture the herbage without reducing fiber size. The work was
conducted under a Cooperative Research and Development Agreement (CRADA) with
industry. Demonstrating the feasibility of the concept was the first step toward
further development of a mobile field processor. Working like a combine, it cut
the crop and wet-fractionated it while juice was being processed in the field.
The energy cost for producing 6.4 tons of herbage and 3.5 tons of juice per
hour was about $0.76 per wet ton. Products from the fiber portion include cattle feed, chemical feedstocks,
mats for filtering pollutants from water, enzymes derived by growing fungi on
the fiber, and building materials. Products from the juice fraction include
food- and feed-grade protein concentrates, carotenoids, antioxidants and
industrially valuable enzymes. Scientific contact: Richard G. Koegel,
ARS U.S. Dairy Forage Research Center, Madison, Wis., phone (608) 264-5149, fax
(608) 264-5147, [email protected].
U.S. Department of Agriculture |