1. "In addition, the biochar is extremely effective in restoring soil fertility. Several overviews have presented evidence for the improvement of soil productivity by biochar"
2. "These results suggest that [biochar application] has the potential to improve soil productivity of upland rice production in Laos, but that the effect of [biochar] application is highly dependent on soil fertility and fertilizer management."
3. "It seems probable that [biochar] have been ubiquitous globally through history and that further examples will emerge in the future." [NOT PEER REVIEWED]
4. "Our results clearly demonstrated a synergistic positive effect of compost and biochar mixtures on soil organic-matter content, nutrients levels, and water-storage capacity of a sandy soil under field conditions."
5. "Research over the past decades has demonstrated the potential of biochar as a soil conditioner, improving fertility and nutrient-use efficiency, in addition to maximizing the productivity of crops, such as soybean and rice".
6. "The biochar amended soils retained more water at gravity drained equilibrium (up to 15%), had greater water retention at -1 and -5 bars soil water matric potential, (13 and 10% greater, respectively), larger specific surface areas (up to 18%), higher cation exchange capacities (up to 20%), and pH values (up to 1 pH unit) relative to the un-amended controls.The biochar amendments significantly increased total N (up to 7%), organic C (up to 69%), and Mehlich III extractable P. K, Mg and Ca but had no effect on Mehlich III extractable S. Cu, and Zn. The results indicate that biochar amendments have the potential to substantially improve the quality and fertility status of Midwestern agricultural soils."
7. "After 67 days and two leaching events, biochar additions to the Norfolk soil increased soil pH, soil organic carbon, Ca, K, Mn, and P and decreased exchangeable acidity, S, and Zn. These effects reﬂect the addition of elements and the higher sorption capacity of biochar for selective nutrients (especially Ca,
P, Zn, and Mn). Biochar additions to the Norfolk soil caused signiﬁcant fertility improvements."
8. You can find hundreds of more sources about biochar at: http://www.biochar-international.org/biblio
1. Lehmann J 2007 Bio-energy in the black. Frontiers in Ecology and the Environment 5, 381-387
2. Asai, H., Samson, et al. (2009). Biochar amendment techniques for upland rice production in northern Laos. Field Crops Res. 111, 81–84.
3. S. P. Sohi, E. Krull, E. Lopez-Capel, and R. Bol. "A Review of Biochar and Its Use and Function in Soil," Advances in Agronomy, volume 105, 65.
4. Jie, Liu et al., "Short-term effect of biochar and compost on soil fertility and water status of a Dystric Cambisol in NE Germany under field conditions," Journal of Plant Nutrition and Soil Science. Volume 175, Issue 5, pages 698–707, October, 2012
5. Fabiano, A et al., "Biochar: Agronomic and environmental potential in Brazilian savannah soils," Revista Brasileira de Engenharia Agrícola e Ambiental v.16, n.7, p.761–768, 2012.
6. Laird, D. A., et al., "Impact of biochar amendments on the quality of a typical Midwestern agricultural soil," Geoderma v. 158 p. 443-449, 2010.
7. Novak, J. M., et al.,"Impact of biochar amendment on fertility of a southeastern coastal plain soil," Soil Science, Volume 174(2), p.105-112, (2009)