The results showed doubling of crop yield in the highly degraded soils from about 3 to about 6 tons/ha maize grain yield (Kimetu et al., 2008). Kimetu J, Lehmann HJ, Ngoze S, Mugendi D, Kinyangi J, Riha S, Verchot L, Recha J and Pell A 2008 Reversibility of soil productivity decline with organic matter of differing quality along a degradation gradient.
Stability of biochar remaining in soil after 130 years was not affected by mean annual temperature, providing insight into the mechanism of biochar decomposition.
Cheng CH, Lehmann J, Thies JE, Burton SD and Engelhard MH 2006 Oxidation of black carbon by biotic and abiotic processes. Cheng CH, Lehmann J and Engelhard M 2008 Natural oxidation of black carbon in soils: changes in molecular form and surface charge along a climosequence. Cheng CH, Lehmann J, Thies JE and Burton S 2008 Stability of black carbon in soils across a climatic gradient.
It quantifies the emissions associated using a range of bioenergy crops such as miscanthus, switch grass, and corn, as well as crop residues of corn and wheat.
Results show that biochar applied to soil reduces greater amounts of greenhouse gas emissions than if the biochar were to be used to off-set fossil fuel.
Biochars were had greater adsorptive properties for cations through surface oxidation than through adsorption of organic matter.