RE: Did someone say research?23 Feb 2019 13:02
Old data but still interesting!
“trend of locating ammonia production capacity near natural gasfields and then shipping the product to the consumer increases the probability of additional production capacity installed in regions such as Central America, the Middle East, and South America. As a result, the United States is likely to become more import dependent in the future.”
“Figure 10 shows the trends in U.S. production, net imports, and apparent consumption from 1970 to 2002. Although apparent consumption of nitrogen varies from year to year in the United States, it has historically trended upward. Fertilizers, which remain the most important use for nitrogen, accounted for more than 85 percent of the total in 2002. The United States continues to supply its domestic crop needs and to provide food for export; increased crop production generally leads to increased use of fertilizer. In addition, as the land available for farming diminishes, farmers increase the density of the crops they grow to maintain or increase production. This intensive cropping removes nutrients from the soil at a faster rate, and as a result, a greater quantity of nutrients, which include nitrogen, needs to be replenished. With proper nitrogen application practices and other factors, such as crop rotation, pest management, and soil conservation, however, the quantity of nitrogen that needs to be added to the soil can be minimized.“
https://pubs.usgs.gov/of/2004/1290/2004-1290.pdf