Hydrothermal Biochar production : Effect on plant growth and Carbon oxidation

Biochar is a carbon-rich product resulting from pyrolysis or gasification of biomass under low oxygen concentration . Biochar application to agricultural soils has been proposed as a promising strategy for carbon (C) sequestration [1] and climate change mitigation. In recent years an alternative procedure called hydrothermal carbonization (HTC) has been developed to transform labile biomass into a more stable-end product (Hydrochar). HTC is a process of heating wet biomass with a suitable water content above 50 mass % at a temperature between 160 °C a nd 250 °C in a pressure vessel for several ours. A clear scientific definition of the products of hydrothermal carbonization does not exist even though hydrochar is similar to brown coal from a chemical point of view. Moreover, no information exists on the effects of the addition of hydrochar to plant and on its stability after addition into the soil. The aim of the present study was to quantify the effects of the incorporation of hydrochar into the soil on plant growth and C sequestration in the short term (one year)