Title: Thermophilic anaerobic digestion of cattle manure reduces seed viability for four weed species
Abstract: Anaerobic digestion of manure and other biowaste has been gaining public attention for producing biogas as a renewable energy. More digestate materials after harvesting biogas available will be used as biofertilizers, soil conditioners and amendments for land application. However, digestate is required to be free of weed seeds. The effect of anaerobic digestion on the survival of weed seeds has not been studied extensively. This study examined four weed seeds, wild oats (Avena fatua L.), wild buckwheat (Polygonum convolvulus L.), wild mustard (Sinapis arvensis (DC.) L.C.Wheeler) and volunteer canola (Brassica napus L.) that were placed in batch cultures with feedlot cattle manure at 55℃ for 7 and 24 hours. The results showed that after being subjected to anaerobic digestion for 7 hours, wild oats, volunteer canola and wild mustard had zero viability. Wild buckwheat had remaining viable seed after the 7 and 24 hour anaerobic digestion treatment as shown by the tetrazolium test. However, the remaining viable wild buckwheat seeds were considered to be incapable of normal growth and development.[Eckford R E, Newman J C, Li X, Watson P R. Thermophilic anaerobic digestion of cattle manure reduces seed viability for four weed species. Int J Agric & Biol Eng, 2012; 5(1): 71－75. DOI: 10.3965/j.ijabe.20120501.009]