New biochar research Julie Major, PhD Independent consultant Soil Science and Biochar julie.major.ca@gmail.com
Biochar as a habitat for microbes • Greater amounts of culturable rhizosphere and bulk substrate microbes with biochar (Graber et al. 2010)
• Trichoderma spp. and root-associated yeast not detected in unamended substrate and increased by 2-3 orders of magnitude in biochar-amended substrate (Graber et al. 2010) • 16 of the 20 microbial isolates from biocharamended treatments corresponded to plant growth promoting and/or biocontrol agents (Graber et al. 2010)
Improved disease resistance • Biochar reduced the severity of Fusarium root rot in asparagus plants also inoculated with arbuscular mycorrhizal fungi (Matsubara 2002) • Systemic resistance to gray mold (caused by Botrytis cinerea) and powdery mildew (caused by Leveillula taurica) on pepper and tomato, and to a mite pest (Polyphagotarsonemus latus Banks) improved with biochar (Elad et al. 2010) • Hormesis???
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Mycorrhizae • Biochar applied in bands in a dryland wheat field encouraged mycorrhizal root colonization of the crop in the year after application, and residual effects were also observed 2 years later (Solaiman et al. 2010) • No improvements in the colonization of roots of the leguminous tree Leucaena leucocephala by AMF with biochar made from the same species, in pot studies (Habte and Antal, 2010)
Earthworms • Red worms killed by high rates of poultry litter biochar, unharmed by high rates of pine chip biochar (Liesch et al. 2010) • Tropical worm found to prefer biochar-amended soil, ingests it for purposes other than obtaining nutrients (Topoliantz and Ponge, 2005) • In QC study, in general more worms in biocharamended soil
Other uses for biochar • Golf courses: – Reduce nutrient leaching (Brockhoff et al. 2010 but not Slavens et al 2010)
– More dense, better looking turf (Slavens et al. 2010) – Better moisture retention (Brockhoff et al. 2010)
Other uses for biochar • Bulking agent in compost: – Total nitrogen losses over 42 days of composting sewage sludge reduced by 64% by adding 9% biochar to the sludge as opposed to a control not receiving biochar (Hua et al., 2009)
– also over 42 days adding 20% of biochar to poultry litter reduced ammonia emissions by 64% (Steiner et al. 2010)
Other uses for biochar • Bulking agent in compost – maximum temperatures of the compost were reached faster when biochar was applied (Steiner et al., 2010)
– degree of humification of the resulting compost was greater (Dias et al. 2009)
Green roofs • leachate from trays filled with biocharamended medium contained 79% less nitrate, 43% less phosphate, 42% less total phosphorus and 72% less total organic carbon • 4% more water retention (Beck et al. 2011)
Feed supplement • growth rate was 20% greater, and final animal weight was 5% greater when goats fed tannin-rich Acacia sp. fodder were also fed less than 1 g bamboo charcoal per kg animal weight per day (Van et al. 2006) • Less odour • Delivery to soil
Land reclamation/remedation
Jones et al. (2010)
Used for wood vinegar • • • • •
Wood preservative (Velmurugan et al., 2009) Enhances seed germination (Mu et al., 2003) Termiticide (Yatagai et al., 2002) Inhibit pathogenic fungi (Wang et al., 2005) wood vinegar significantly and linearly improved the weight gain in piglets, as well as the digestibility of dry matter, crude protein and gross energy in their feed (Choi et al., 2009)