Microbial Carbonation – Alternative Technology to Composting

Many different technologies are available to optimise agricultural soil for harvesting greater yield. To rehabilitate the soil, artificial manure and organic fertilizers like compost, liquid ma-nure and fermentation residues are added; however, often organic fertilizers are biologically reactive or strongly mineralized with certain elements. New substrates called biochar, produced by pyrolysis or hydrothermal carbonation of organic material, may be added to the soil to increase the carbon content. High temperature and energy consumption is required in the manufacture of a biochar, which in turn affect its composition (PAH, dioxin). Furthermore, there is limited research carried out to date on the long-term behaviour of these biochars in soil. An alternative technology that may be utilized to improve agricultural soil is called microbial carbonation. The process is similar to open air composting; however, it is different in process control. In summary, the windrows are fixed and non-aerated and in contrast to conventional composting, the top of windrows are inoculated with selected strains of bacteria. The main aim of microbial carbonation and inoculation is in the humification of organic material. In comparison to normal composting, the soil resulting after the process of microbial carbonation has more organic elements and a reduced volume.