Weed seed survival in an agriculturally-based anaerobic digester

Weed seeds contaminating cattle feed can pass unaffected through the animal's digestive tract and may germinate when manure is returned to land as fertilizer. This investigation was undertaken to determine the effects of anaerobic fermentation of raw manure on the viability of Johnsongrass and Fall Panicum seeds which may be present in the waste. Dairy waste containing Johnsongrass and Fall Panicum seeds were subjected to batch and continuously-fed anaerobic fermentation processes in laboratory-scale digesters. The effect of influent solids concentration (4% and 6%) and retention time (15 days and 20 days) on seed viability was observed. The experiments were carried out in the mesophilic temperature range [35°C±1ºC]. Fall Panicum seeds were found to be less resistant to anaerobic digestion than Johnsongrass seeds. Greater seed destruction was achieved in 20-day digesters than in the 15-day digesters. The influent solids concentrations did not have significant effect on seed viability. By applying the Schafer-Chilcote seed population model, it was observed that the fermentation process was more effective in destroying non-dormant seeds than dormant seeds.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Agricultural Engineering

Department dc:contributor.department

Agricultural Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1983

Author dc:creator

• Jeyanayagam, Samuel S.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/76014

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/76014