The circular economy: 9. Farming loses 70% of the manufactured fertiliser energy consumption
The science: There is much energy in digging up and transporting the basic raw materials to make fertilisers, especially phosphates and potash. We are running low on known phosphate reserves. One tonne of mineral Nitrate nutrient, from a modern comparatively efficient USA factory, takes 21,000 (yes, twenty one thousand) kWh of electricity to make it and it was mostly made by generating electricity by burning fossilised fuels to run and engine. When we get the Nitrogen onto the crop, rainfall and irrigation will lose maybe half.
The bad news: Modern food production has been built around mineral fertilisers. The concept of feeding 11 billion (if the UN estimate is right) using this technology is just not tenable.
The good news: Not only is it possible to produce good, safe food, better for human health, without mineral fertilisers, it is possible to lift yields by using composts made from urban wastes. The author has done it. With bio-assay over two decades.
Bill Butterworth Land Research Ltd 21 May 2016