Source: UNIV OF WISCONSIN submitted to
HARVEST-FRACTIONATION OF ALFALFA
 
PROJECT DIRECTOR: Shinners, K.
 
PERFORMING ORGANIZATION
BIOLOGICAL SYSTEMS ENGINEERING
UNIV OF WISCONSIN
MADISON,WI 53706
 
NON TECHNICAL SUMMARY: High quality alfalfa leaves are co-mingled with low value stems at harvest, reducing the overall value of the crop. The purpose of the project is to add value to alfalfa by separating the high and low quality fractions at harvest.
 
OBJECTIVES: The objectives of this project are to develop a single-day alfalfa harvesting scheme which yields two crop streams: high-value leaves and low-value stems. The leaves can be used as ruminant animal feed or processed to value-added products like protein supplements. The stems can be used as ruminant roughage or can be converted to energy through hydrolysis and fermentation.
 
APPROACH: Harvest-fractionation of alfalfa is a novel harvesting appraoch that utlizes a stripping rotor to remove the leaf fraction from the standing stem. The leaves can be direct ensiled for use as a high-protein animal feed while the stem fraction can be cut, wilted, and harvested for a high-fiber roughage for ruminants; or either fraction could be processed into value-added products. Harvest-fractionation will be investigated as a single-day alfalfa harvesting system that will allow dairy producers to more optimally balance rations and as a system to enhance value-added processes such as juice protein extraction or bio-energy production. Research will be made into (1) fractional yield and nutrient composition of alfalfa fractionated at harvest, (2) techniques to direct ensile the leaf fraction, (3) the effects of feeding re-constituted alfalfa to dairy animals, (4) modeling the economic potential through use of the Integrate Farm System Model (IFSM), and (5) improvements the system can bring to value-added processes such as juice protein extraction.
 
CRIS NUMBER: 0204657 SUBFILE: CRIS
PROJECT NUMBER: WIS04971 SPONSOR AGENCY: NIFA
PROJECT TYPE: HATCH PROJECT STATUS: TERMINATED MULTI-STATE PROJECT NUMBER: (N/A)
START DATE: Oct 1, 2005 TERMINATION DATE: Sep 30, 2008

GRANT PROGRAM: (N/A)
GRANT PROGRAM AREA: (N/A)

CLASSIFICATION
Knowledge Area (KA)Subject (S)Science (F)Objective (G)Percent
205164020202.225%
402164020202.175%

CLASSIFICATION HEADINGS
KA402 - Engineering Systems and Equipment
KA205 - Plant Management Systems
S1640 - Alfalfa
F2020 - Engineering
G2.2 - Increase Efficiency of Production and Marketing Systems
G2.1 - Expand Domestic Market Opportunities


RESEARCH EFFORT CATEGORIES
BASIC (N/A)%
APPLIED 50%
DEVELOPMENTAL 50%

KEYWORDS: alfalfa; harvesting; fractionation; leaves; stems; value added; ensiling; silage; harvesting equipment; equipment development; process development; feed; protein supplements; energy sources; roughage; fermentation; hydrolysis

PROGRESS: Jan 1, 2007 TO Dec 31, 2007
OUTPUTS: Harvest-fractionation of alfalfa involved stripping the leaves from the stem at the time of harvest using a tined rotor that was modified from a snap bean stripping rotor. The amount of leaf tissue stripped from the stem is dependent upon the penetration depth of the stripping rotor and the tine to tip speed ratio. A biomass-type alfalfa, which was bred to be harvested twice per year and stand taller with fewer tendencies to lodge at later maturity stages, was established in 2006. Although the alfalfa established quite well it did not come close to meeting expectations. In 2007, the crop lodged extensively early in its maturity cycle and lost biomass after lodging. Stripping took place on July 12th, 2007, so the crop was quite rank and 100% lodged. However, it was quite easy to strip leaves from this material, and the moisture of the stripped fraction was 66%, so direct ensiling after stripping was possible. Chemical compositional analysis will be carried out on the two fractions to determine the animal feed and biomass feedstock potential of the leaf and stem fractions, respectively. The stripped stems were cut and then dried to baling moisture and baled in round bales with three different types of wrap: twine, net and film wrap. Although the bales are still stored outdoors, it has been observed that the bales wrapped in twine are suffering from extensive storage degradation because the absence of leaves has prevented a adequate thatch from forming on the rind of the bale and water is more easily penetrating the bale during precipitation. Bales wrapped with net or film are appearing to fair much better during storage. Harvest fractionation was also used on switchgrass and reed canarygrass, two highly promising biomass feedstocks. The stripping process was successful on these two crops as well. A new stripping mechanism is under design and fabrication. The new configuration will strip the upper plant parts with a tined rotor while simultaneously cutting the stem fraction. In previous incarnations, the self-propelled stripping machine would run down the stripped stems because there was no stem cutting mechanism. An added cutting step following stripping would increase costs and reduce yield of the run over stems. The new mechanism will have a tined rotor that is fully adjustable for position and speed. Below and behind the rotor will be a disk cutterbar that will cut the stripped stems and place them in a windrow on the ground. The stripped fraction will be captured by an auger, gathered into a feedroll assembly and then chopped and transported into a trailing wagon. The entire unit will mount on a self-propelled forage harvester, which will serve as the power unit and also provide the size-reduction and transport functions. PARTICIPANTS: Principal Investigator - Kevin J. Shinners Graduate Student - Jeff Duncan Collaborators - Paul Weimer (USDA-ARS) and Mike Casler (USDA-ARS) TARGET AUDIENCES: Target audiences for this work include policy makers and economic modelers from federal agencies working on biomass feedstock related issues (e.g. DOE and USDA), agricultural machinery manufacturers (e.g. John Deere, CNH Global), dairy nutritionists, and alfalfa growers and breeders. PROJECT MODIFICATIONS: There were no major changes to the approach on this project during 2007.

IMPACT: 2007-01-01 TO 2007-12-31 What is proposed is a novel harvest-fractionation process to strip alfalfa leaves from the stem as the first harvest step. The stripped leaves could be used for any number of products including, but not limited to, a high-protein ruminant feed preserved by direct ensiling or value-added products processed off-farm. The stem fraction could be simultaneously cut at leaf harvest and allowed to field wilt, serving as an on-farm roughage source or as a feedstock for value-added products processed off-farm, particularly fermented to ethanol. Harvest fractionation has the following advantages: (1) the high-value leaf fraction is removed immediately at harvest so yield is high and weather related losses are low, (2) fractionation takes place at harvest so no further processing steps or equipment is needed, (3) capital costs of the fractionation equipment is low, (4) fractionation takes place on the farm so only the desired fractions need leave the farm, thereby reducing transport costs, and (5) leaves and stems can be recombined to optimally meet ruminant nutritional requirements when high and low value forage fractions are separated. The outcomes of this research will allow an economic assessment of the viability of harvest fractionation as harvesting scheme to produce not only a high-value animal feed, but also a high-fiber feedstock for ethanol production.

PUBLICATION INFORMATION: 2007-01-01 TO 2007-12-31
Shinners, K.J., B.N. Binversie, M. E. Herzmann, and M.F. Digman. 2007. Harvest fractionation of alfalfa. Transactions of the ASAE. 50(3):713-718.

PROJECT CONTACT INFORMATION
NAME: Shinners, K.
PHONE: 608-263-0756
FAX: 608-262-1228