Nitrogen cycle production, world

After the First World War, ammonia continued to be made by the Haber process, which was adopted in many countries, but the main outlet was in fertiliser production. World-wide production reached about 10 million tonnes per year in 1950, and is now nearly 100 million tonnes per year, of which 80 per cent is used to make nitrogenous fertilisers. The contribution that this makes to the nitrogen cycle (shown in figure 1.4) is very significant. 

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