Currently, newer journal research is focused on how to make sustainable fertilizer production more economically feasible, such as the development of methods to recover phosphorus without significant additional financial, energy, or process costs. Overall, sustainable fertilizer production is likely to rely on a combination of improvements in the sustainable industrial production of ammonia and the use and processing of wastes for fertilizer use. As seen with ethanol production 375 , the indirect costs and carbon emission derived from waste conversion to fertilizers can be significant, and systems that reduce the transportation and energy costs and land-use changes of waste conversion to fertilizers are likely to be important. Unlike ethanol, however, waste conversion to fertilizers should reduce the environmental costs of fertilizer use by limiting the emission of nutrients into the environment and thus reducing eutrophication. Regulatory and resource economic incentives for improving profitable viability of newer, more integrated, and multipurpose recovery technologies, suggests patenting trends in these technologies and in use of recovered nutrient products will continue to rise. Research on sustainable fertilizer development and the scale up to commercial viability will continue to support crop nutrition, increasing the capacity of the global food system while making progress on managing greenhouse gas emissions and improving the management of wastes for a more sustainable, circular economy. Improving the sustainability of fertilizer production using improved ammonia production and waste reuse can also improve the robustness of fertilizer production while allowing the world to feed more people.