Troubleshooting concerns associated with direct long cut vacuum grass silage
Direct long cut vacuum grass silage is a technique for forage preservation that is of increasing interest to grass based producers. A one-pass system requiring minimal investment in equipment or infrastructure and minimal manpower it is well-suited to small farms. Popularized in the farm press, there has been limited formal research investigating the process or resultant silage product. Farmers first formed a farmer research group in 2002 to evaluate the technique on their farms. They and several followers are now adopting and adapting the technique. Outstanding questions remain. The grass silage is unusual in its composition and apparently undergoes an atypical fermentation which may indicate an environment for growth of potentially toxic bacteria in the silage. This may be attributable to the use of vacuum rather than mechanical packing to eliminate air at ensiling or to the direct cut that results in higher moisture. Farmers have questions about the importance of the vacuum technique to the resultant silage. Consequently a trial is being conducted to address these questions.
Late in the 2006 season, second cut grass hay was harvested and used to form six (DLCVGS) silage piles with the assistance of a participating farmer. The piles were built at the NE Small Farm Institute site. Three replicates were formed. In each replicate one pile was subjected to a single vacuum for 20 minutes and the other pile to a double vacuum, for 30-35 minutes. Prior to harvest forage was sampled in the field (for analysis of grass-legume weed percentage). Chopped grass was also sampled from each pile prior to sealing and vacuuming(for analysis of nutritive value). After opening the silage from each pile will be analyzed for nutritive value and ensiling characteristics including aerobic and anaerobic bacteria. Soils from beneath the piles will be sampled after the piles are opened/removed to scan for possible exudates that may pose environmental problems. This data will be compared with baseline soil samples taken prior to the formation of the piles in August. Visual inspection of the two replicates in the field as well as the one replciate formed on tarmac/pavement indicated no seepage from the piles using this method.
Photos were taken and a field day planned for early 2007 when the piles will be opened. Resutls will be posted on the web.
By the end of 2006 approximately 20 farmers from around North America had inquired about the DLCVGS technique, primarily riding on the momentum of earlier work. The current trial was explained to each inquiring farmer. Once the field day is conducted and the report is released additional farmers will have access to the results of this project.
Between fifteen and fifty farmers will have better information when making decisions about DLCVGS.
An outline of the work to date is contained in the project summary, above. At the end of 2006, we had consulted with farmers, and began implementation of the study, building 3 replicates (2 piles each)of the grass silage in August with second cut forage. Data collection included sampling the forage before and after pile building for comparsion with the final sialge product; sampling soils beneath the piles in 2 replicates and observing the piles daily for seepage or leakage of silage exudates.
The project is on track resulting in better understanding of the risks associated with the technique.
Impacts and Contributions/Outcomes
This project continues the investigation of a promising technique for limited resource farmers, especially those interested in grass-based agriculture. Until the silage piles are opened and sampled we have no final data to report or use in the creation of recommendations for farmers. Interest in the technique and the results of this study, based on regular inquiries, is high. Information will be posted on the web when available.
Belchertown, MA 01007
Office Phone: 4133234531