Effect of microbiological inocula on chemical and physical properties and microbial community of cow manure compost

The effect of the microbiological inocula to efficiently decompose animal manures into mature compost was studied. In general, TOC, water contents and C/N ratio decreased during decomposition in two composts and those properties dropped faster in the microbiological inocula compost than the natural compost. The total nitrogen content and NO3−–N behaved in the opposite manner and those properties increased faster in the microbiological inocula compost than the natural compost. The pH and NH4+–N increased first, and then decreased in two composts. The microbiological inocula showed a more rapid rate of temperature elevation at the start of composting and prolonged the time of high-temperature process. The microbiological inocula were able to facilitate the microbial diversity of the compost. Based on germination assays, the microbiological inocula seems to be advantageous in reducing the maturation time of cow manure compost.

► In recent decades, increasing proportions of small, individual livestock farms have been replaced by large-scale, especially in China. A particular challenge that has arisen from this trend is the management of animal manure and waste water. Composting is increasingly considered a good way for recycling the surplus of manure as a stabilised and sanitised end product for agriculture, and much research work has been carried out in the last decade. Various chemical and biological parameters including pH, total organic carbon content (TOC), total nitrogen content, carbon to nitrogen (C/N) ratio, water soluble carbon have been established as indicators of compost stability. Microbes play key roles in these ecosystems and knowledge of microbial communities may suggest common composting mechanisms.
► The aims of this study were to assess the ability of the microbiological inocula to efficiently decompose animal manures into mature compost by monitoring the dynamics of a range of chemical and biological parameters. Experiments were conducted to identify and develop of microbiological inocula which would accelerate the composting process and enhance soil fertility on a sustainable basis in northeast of China. Our finding represents an important step towards the understanding of microbiological inocula and its function in the degradation process of compost.