Trace element characterization for quality evaluation of compost from amended paddy straw inoculated with fungal consortium

Paddy straw was composted after amending with different nitrogen rich substrates of organic (farm yard manure, soybean trash, poultry manure) and inorganic (urea) origin. The amended substrates were also inoculated with a consortium of four mesophilic fungi (Aspergillus nidulans, ITCC2011, Trichoderma viride ITCC2211, Phanerochatae chrysosporium NCIM1073 and Aspergillus awamori F18) to hasten the process of decomposition and also to determine if the inoculation plays any role in the quality of the end product. Aerobically composted end product was characterized for extractable trace elements (Cr, Pb, Cu, Zn and Fe) along with other quality parameters, such as pH, EC, organic matter, total organic carbon, total Kjeldhal's nitrogen and C: N ratio. Though, level of most of the trace elements originated from different composts were found well within the prescribed limits for a standard compost, a slight increase in chromium was found in the compost prepared after amending with FYM and poultry, probably due to decrease in total mass of compost because of high degradation of organic matter. Inoculation with fungal consortium resulted in a substantial decrease in heavy metal contents in the composts.