1a.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.

1b.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.

3.Progress Report
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.