# Can Biochar Improve the Sustainability of Animal Production?
## 7 Conclusions/Future Work  
There is a great amount of research dedicated to biochar applications in agriculture in general, with growing interest in connecting biochar uses to animal agriculture. The current review examined some of the most recent literature on the use of biochar at various stages of animal production to support sustainability goals. Biochar was demonstrated to be effective in capturing a variety of organic and inorganic compounds in manure. These attributes showed a uniformly positive impact on manure storage and treatment with a less positive impact for inclusion in feed or during land application.  
Future work should address the potential for biochar modifications, such as steam activation or acid/base modification, to enhance affinity for a wider range of emissions or to optimize the adsorption of a particular contaminant. There continue to be gaps in knowledge regarding the biochar net impact on various aspects of animal agriculture. For instance, biochar incorporation in feed was shown to have a mixed effect on feed efficiency, emissions, and nutrient absorption. There is a need for the complete reporting of the biochar parent material, production conditions, and modifications to better assist in understanding the modes of action in the gut.  
Furthermore, there appears to be an age-related impact of biochar as a feed ingredient that needs to be closely examined. None of the studies investigating biochar use in feed assessed its impacts on manure characteristics during storage or after land application. Similarly, biochar use in emission mitigation during composting showed mixed results. The variability in the biochar characteristics, composting feedstock, and composting process arrangement all contributed to the inconsistent performance observed with biochar addition.  
For acceptance in animal production, there also needs to be more work done on determining the optimal dosages, form (powder vs. non-powder), and feedstock type for different applications (in-house, lagoon storage, feed, etc.). There are numerous variables at play in biochar production that would benefit from more consistent and complete reporting of biochar properties (the surface-area, particle-size, and pore-size distribution; surface functional groups; etc.). At this point, the net impacts of biochar addition in animal production are less clear due to the gaps in systematic evaluations of the roles of biochar across the production cycle. In a multi-stage system with complex mechanisms, it is important to understand the net effects of biochar addition on the productivity and net impacts of animal production.  
Conceptualization, C.G. and M.S.; Literature investigation, C.G., M.S., P.K., J.G. and S.S.; writing--original draft preparation, C.G.; writing--review and editing, C.G., M.S., P.K., J.G. and S.S.; supervision, C.G. and M.S.; project administration, C.G. and M.S.; funding acquisition, M.S., P.K., J.G. and S.S. All authors have read and agreed to the published version of the manuscript.  
This review was supported through funding from NC Department of Agriculture and Consumer Services, Bioenergy Research Initiative (NCDA&CS BRI), grant no. 21-61-4003, \"Miscanthus Biochar Potential as Broiler Litter Amendment\".  
The authors declare no conflict of interest.