Only a small amount of fertilizer usage in the US is waste based. In 2015 13M tons of nitrogen based synthetic fertilizer was used, on top of that 4M tons each

Only a small amount of fertilizer usage in the US is waste based. In 2015 13M tons of nitrogen based synthetic fertilizer was used, on top of that 4M tons each of phosphate and potash fertilizer. For waste based fertilizer compost, dried manure and sewage total 600K tons. That doesn't even take into account that the raw weights aren't directly comparable. https://www.ers.usda.gov/data-products/fertilizer-use-and-price.aspx https://www.ers.usda.gov/data-products/fertilizer-use-and-pr...