Progress 09/15/03 to 09/14/08
Outputs
Progress Report Objectives (from AD-416) Research planned for 2007-2008 will include continued work on reducing losses and costs associated with outdoor storage of biomass, including work on different bale coverings and mega bale sizes. Work on direct harvest and low moisture ensiling will also be conducted, including investigations of a two-tier, two-pass cutting system as a means to create a high-value animal feed (top of plant) and lower-value biomass feedstock (bottom of plant). Design and fabrication of harvesting equipment capable of two-tier harvest in a single-pass will be done in 2007 with testing in 2008. ARS will provide salary and fringe benefits for a undergraduate research assistant for 12 months, and funds for supplies and other expenses associated with harvesting, processing, and storage of the biomass material. Approach (from AD-416) Switchgrass, reed canarygrass, and/or alfalfa will be harvested from replicated field plots using conventional mower-conditioner equipment. Harvest variables will include stage of maturity (various harvest dates) and cutting height. Yield, composition, and digestibility of the harvested material will be determined for each harvest treatment. Effect of harvest treatment on subsequent regrowth and quality will also be determined by carrying out the experiment over a second growing season. If weather permits (low snow cover), harvest dates will include late winter harvests, at which biomass reaches a desirable low moisture content. The harvested biomass will also be subjected to several storage methods, and their effects on nutrient retention in the harvested biomass and on the microbial populations thought to be important in forage preservation will be determined. Significant Activities that Support Special Target Populations Research on the harvesting of perennial forages was conducted by a collaborator at the University of Wisconsin-Madison (UW). Experimental plots (4 ha each) of switchgrass (SWG) and reed canarygrass (RCG), established at the UW Arlington Agricultural Research Station in 2004, have been used for harvesting and storage research over successive years 2004-2008. The most effective harvest strategy for both SWG and RCG was a single-cut system during late summer to early fall. SWG produced higher yields than RCG, as it had for the 3 previous years. Both crops dried more easily than alfalfa or other forage grasses. Wide-swath drying resulted in the shortest drying times and permitted baling at 20% moisture in a single day. An alternative harvest scheme, in which cutting of the crop was deferred until the following spring, resulted in drier material that could be baled immediately, but DM yields were reduced by 17% (SWG) or 26% (RCG). Density of both SWG and RCG bales was lower than for alfalfa or most forage grasses; this must be increased for economical shipping and handling purposes. SWG was more easily baled than was RCG, which tended to clog the baler throat. Baling efficiency was improved 46% by net wrapping versus baling with twine. Bales stored outdoors for 9 to 11 mos. had variable dry matter (DM) losses depending on baling method, with plastic film displaying the least loss (3.8%) and sisal twine the most (14.9%). Storage under cover reduced DM losses to 3% and resulted in more uniform biomass feedstock. Low-moisture anaerobic storage of round bales reduced DM losses even further, to 1.1%. The latter storage process could be used with direct-cut material without windrowing, field wilting, and bale handling, potentially reducing feedstock costs for biorefineries. Monitoring of the SCA was achieved through approximately bi-weekly telephone conversations and e-mails between ADODR and Cooperator, and by semiannual submission of reports by the Cooperator to the ADODR.
Impacts
(N/A)
Publications
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) Research planned for 2007-2008 will include continued work on reducing losses and costs associated with outdoor storage of biomass, including work on different bale coverings and mega bale sizes. Work on direct harvest and low moisture ensiling will also be conducted, including investigations of a two-tier, two-pass cutting system as a means to create a high-value animal feed (top of plant) and lower-value biomass feedstock (bottom of plant). Design and fabrication of harvesting equipment capable of two-tier harvest in a single-pass will be done in 2007 with testing in 2008. ARS will provide salary and fringe benefits for a undergraduate research assistant for 12 months, and funds for supplies and other expenses associated with harvesting, processing, and storage of the biomass material. Approach (from AD-416) Switchgrass, reed canarygrass, and/or alfalfa will be harvested from replicated field plots using conventional mower-conditioner equipment. Harvest variables will include stage of maturity (various harvest dates) and cutting height. Yield, composition, and digestibility of the harvested material will be determined for each harvest treatment. Effect of harvest treatment on subsequent regrowth and quality will also be determined by carrying out the experiment over a second growing season. If weather permits (low snow cover), harvest dates will include late winter harvests, at which biomass reaches a desirable low moisture content. The harvested biomass will also be subjected to several storage methods, and their effects on nutrient retention in the harvested biomass and on the microbial populations thought to be important in forage preservation will be determined. Significant Activities that Support Special Target Populations This report serves to document accomplishments under a Specific Cooperative Agreement (SCA) between ARS and the University of Wisconsin- Madison. Additional details of research can be found in the report of the parent project 3655-41000-004-00D: "Value-Added Products from Forages and Biomass Energy Crops." Research on the harvesting of perennial forages was conducted by Dr. Kevin Shinners, University of Wisconsin-Madison, who provided engineering expertise. Research conducted in 2006 concentrated on three areas: characterization of storage losses of dry biomass bales, quantifying the effects of initial moisture on the physical and chemical properties of biomass wrapped in a film tube and preserved by ensiling, and single-pass harvesting. In the first study, bales of reed canarygrass were formed in July 2006 using the following wrapping treatments: plastic twine, film wrap, net wrap and covered under a hay tarp. An indoor stored control treatment was also used. The bales were removed from storage in June 2007. Dry matter losses were under 4% for bales stored indoors and under the tarp, less than 6% for bales wrapped with film, less than 7% for bales wrapped with net wrap and almost 10% for bales wrapped with plastic twine. Loss of cellulose and hemicellulose ranged from 20 to 50% of the total dry matter loss. Moisture of all bales stored outdoors was highly variable, while bales stored indoors or under tarps had very uniform spatial distribution of moisture. The second study initiated in 2006 involved baling and wrapping switchgrass and reed canarygrass bales at roughly 60, 40 and 30% (w.b.) moisture. These bales were wrapped in a single film tube and were removed from storage in July 2007. The final study involved direct, single-pass harvest with a forage harvester. A direct-cut sickle head was modified to mount on a forage harvester and then three treatments were created: whole-crop, high-cut (mainly leaves) and low-cut (mainly stems). Both reed canarygrass and switchgrass were harvested in this fashion and all three treatments were preserved by ensiling in a bag silo. This material was removed from storage in July 2007. Fractional harvest of the high protein leaf from the high fiber stem can be accomplished by stripping the leaf from the stem, so an additional mechanism is being designed and evaluated to fractional harvest perennial grasses. Monitoring of the SCA was achieved through approximately biweekly telephone conversations and emails between ADODR and Cooperator, and by semiannual submission of reports by the Cooperator to the ADODR.
Impacts
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Progress 10/01/05 to 09/30/06
Outputs
Progress Report 4d Progress report. This report serves to document research conducted under a specific cooperative agreement between ARS and the University of Wisconsin-Madison to provide engineering expertise. Additional details of research can be found in the report of the parent project 3655-41000-004-00D: "Value- Added Products from Forages and Biomass Energy Crops." Research on the harvesting of perennial forages will be carried out by Dr. Kevin Shinners, Department of Biological Systems Engineering, University of Wisconsin- Madison. Bales were formed in July, August and October, 2005 using the following wrapping treatments: sisal twine, plastic twine, film wrap, and net wrap. These bales were stored outdoors for determination of storage characteristics. An indoor stored control treatment was used for comparison. A final treatment involved baling right after cutting and wrapping the bales in a tube of plastic film for preservation by anaerobic fermentation.
The bales were removed from storage in June 2006. Dry bales stored outdoors for 9 and 11 months averaged 3.4, 7.7, 8.3, and 14.9% DM loss for bales wrapped with plastic film, net wrap, plastic twine, and sisal twine, respectively. Bales stored indoors averaged 3.0% DM loss. Bales stored outdoors had variable moisture and spatially dependent quality. Considerable degradation occurred in the outer 50 mm of all bale wrap systems and also with any material in contact with the soil. Preservation by ensiling in a tube of plastic film produced average DM losses of 1.1%. Bio-refineries will require a product with uniform quality, moisture, and physical and chemical properties. The most uniform biomass feedstock was generated by storing indoors or ensiling in a tube of plastic film. Baling and then ensiling without field wilting was successful, indicating that a single-pass system could be developed to reduce harvesting and storage costs.
Impacts
(N/A)
Publications
- Shinners, K.J., Boettcher, G.C., Muck, R.E., Weimer, P.J., Casler, M.D. 2006. Drying, harvesting and storage characteristics of perennial grasses as biomass feedstocks. Proceedings of the Annual Meeting of the American Society of Agricultural and Biological Engineers International. Paper No. 061012. p. 1-19.
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Progress 10/01/04 to 09/30/05
Outputs
4d Progress report. This report serves to document research conducted under a specific cooperative agreement between ARS and the University of Wisconsin-Madison to provide engineering expertise. This project has been extended to 03/31/2006. Additional details of research can be found in the report of the parent project 3655-41000-004-00D: "Value-Added Products from Forages and Biomass Energy Crops." In Fall 2004, the reed canarygrass and switchgrass yielded 3.5 and 5.1 mg DM/ha, respectively. Reed canarygrass dried slightly faster than switchgrass because the former crop had lower yield. When dried in a swath, either crop dried to baling moisture by the afternoon of the second day. Half the reed canarygrass field was cut on July 14th, 2005, and another drying study was conducted. Growing conditions were quite dry and initial moisture at cutting was slightly less than 60% (weight basis). Under these conditions, crop dried in a swath or tedded dried to baling
moisture in a single day. The dried crop was round baled, and the following wrapping treatments were applied: sisal twine, plastic twine, net wrap, and net wrap with vapor barrier. These bales were stored outdoors for determination of storage characteristics. An indoor-stored control treatment was used for comparison. A final treatment involved baling right after cutting and wrapping the bales in a tube of plastic film for preservation by anaerobic fermentation. All bales will be stored until late fall when they will be removed for assessment of DM loss, moisture distribution, and chemical compositional change. Initial baseline samples from all bales were dried, ground, and then scanned in a NIRS sensor. Spectra were collected. Wet chemistry will be conducted on the samples so that an appropriate calibration can be built. Reed canarygrass yield was 6.3 mg DM/ha. A similar study will be undertaken in the fall of 2005 with the remainder of the reed canarygrass and the
switchgrass.
Impacts
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Progress 10/01/03 to 09/30/04
Outputs
4. What were the most significant accomplishments this past year? D. Progress Report: This report serves to document research conducted under a specific cooperative agreement between ARS and the University of Wisconsin-Madison to provide engineering expertise. Additional details of research can be found in the report of the parent project 3655-41000-004-00D: "Value- Added Products from Forages and Biomass Energy Crops." Research on the harvesting of perennial forages will be carried out by Dr. Kevin Shinners, University of Wisconsin-Madison. In this first year of the project, 10- acre stands of switchgrass and reed canarygrass were established at the University of Wisconsin Agricultural Research Station at Arlington, WI. These stands will be used to conduct research on the yield, fermentability, and persistence of each forage when cut at different heights at different maturities (including harvest after freezing in autumn).
Impacts
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Publications
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