Enhanced fertilization effect of a compost obtained from mixed herbs waste inoculated with novel strains of mesophilic bacteria

Mixed medicinal plant waste was composted with addition of novel bacterial strains belonging to the genera Streptomyces, Paenybacillus, Bacillus and Hymenobacter. The composting was followed by assessment of chemical and biological parameters including C/N ratio, loss of organic matter, phosphorous and potassium content as well as CO2 generation and dehydrogenase activity during 164 days. The selected mesophilic bacterial starters had a potential to significantly reduce the period of mixed herb waste decomposition, from about 6 months to about 2.5 months. Based on the seed germination index of four plants (Fagopirum esculentum, Thymus vulgaris, Cynara scolimus and Lavandula officinalis) the germination and radial root growth of the investigated plants was improved by the inoculated compost. The germination index of all tested species on the mature inoculated composts was in average 60% higher compared to the control compost. The research indicates that the mesophilic starter addition into the herbs waste can contribute to the speed of waste decomposition and lead to the improvement of biofertilization effect of the obtained compost.