Bio-waste treatment by composting processes is considered as a sustainable approach through which the carbon and nitrogen are restored and re-introduced into the soil as fertilizers. Live-stock operations generate large quantities of Bio-waste, including yard waste, animal bedding, animal manures, feed material, and urine, which are usually treated by composting processes. However, greenhouse gas emission, nutrient/metal leaching, and bad odor are major bottlenecks for live-stock bio-waste composting. Also, the fertilizer quality and soil applications are hampered because of the presence of antibiotics and pathogens, if the composting process is not well defined. Therefore, in-vessel composters or industrial composters are recommended for live-stock bio-waste treatment. However, the stability and fertilizer quality of compost related to the initial feed stock characteristics and operational conditions/strategies (i.e., the addition of bulking agent’s, waste pre-treatment, temperature regulations, special inoculum additions, and composter designs). However, moisture management is key for the successful operation of any bio-waste composting process, and is achieved through ash or biochar amendments or through co-composting. The addition of biochar, and a larger surface area, help to not only improve the moisture content, but also reduce the greenhouse gas emissions. Biochar addition also changes the microbial dynamics of the composting process and adsorbs heavy metals from the waste material/liquids, while acting as a catalyst for reducing the pathogen load. Even though the merits of biochar addition in the bio-waste composting process are very clear, there is much more that needs to be explained and understood.
With this background, the Special Issue, “Biochar and Greenhouse Gas Emissions during Livestock Bio-Waste Composting”, will cover the following topics (but not limited to), in order to provide the current state of art technology for improving the composting process: Centralized vs. decentralized composting processes and benefits; Carbon and nitrogen mass balance in open pit composting and in-vessel composting; Effective bulking agents for the composting of high-moisture bio-wastes; Role of biochar as a bulking agent and end product quality; Microbial community dynamics of compost process and pathogen reductions; Greenhouse gas emissions and capture from the composting process; Leaching of metals, organic volatiles, and toxic compounds from the composting process; Cost benefit analysis and energy substitutions; Future composting process at urban environments-pros and cons; Vermi-composting and bio-augmented composting processes; Compost quality and standard requirements for different types of compost.