By itself, phosphate rock is not soluble and so cannot provide phosphorus in an available form for plant use. Phosphorus fertilisers are produced by acidulating phosphate rock. Yara is currently involved in developing commercial-scale initiatives to develop this technology.īased on the two main end products, ammonium nitrate and urea, different fertiliser types are manufactured by mixing with ingredients such as phosphorus and potassium to form NPKs, dolomite to form CAN or by mixing urea and ammonium nitrate solution to make UAN. It is worth noting that the production of urea does not produce carbon dioxide as a by-product, but consumes carbon dioxide which is later released when the fertiliser is applied to crops, contributing to the fertiliser carbon footprint.Īmmonia can also be produced by using renewable energy sources such as hydroelectric, solar power or wind turbines, this is known as Green Ammonia. The second step in manufacturing nitrate fertiliser is to react ammonia with air to produce nitric acid which is then combined with ammonia to produce ammonium nitrate fertiliser.Īlternatively, ammonia can be combined with carbon dioxide from the first step to manufacture urea fertiliser. This step requires very high temperature and pressure and is known as the Haber-Bosch process.Īt this point, there is a choice, ammonia can be used to create either nitric acid or urea, or indeed the ammonia can be used for other industrial purposes. Natural gas is combined with nitrogen from the air to produce ammonia and as a by-product carbon dioxide is also produced. 80% of the gas is used as feedstock for fertiliser while 20% is used for heating the process and producing electricity. In several transformation steps, natural gas, essentially methane, is upgraded by combination with nitrogen from the air to form nitrogen fertiliser. Modern fertiliser plants produce nitrogen fertiliser from natural gas.