Global fertiliser use is likely to surpass 200 million tonnes in 2018, an increase of 25% compared to 2008 levels, the Food and Agriculture Organisation (FAO) reported this week. World demand for total fertiliser nutrients is estimated to grow at 1.8% per year from 2014 to 2018. In the coming years, fertiliser use will vary widely in the different regions of the world. Asia as a whole is the largest consumer and relies heavily on imports of all three major nutrients. Overall fertiliser use will grow fastests in Sub-Saharan Africa at 4.7% annually. Global use of nitrogen, by far the largest fertiliser base, is expected to rise 1.4% each year, with East and South Asia accounting for almost two thirds of nitrogen-based fertiliser use. Current nitrogen use in Sub-Saharan Africa is low and the region will only apply 340,000 additional tonnes of nitrogen in 2018 as compared to 2014, accounting for less than 5% of the projected global increase. Phosphate use in the world will increase by 2.2% and potash by 2.6%. According to FAO’s outlook report, applying fertiliser is only one way of replacing nitrogen that is removed from soils when crops are harvested. While the boost in nutrients provided by nitrogen fertilisers made possible the steep increase in agricultural production over the past century, the overuse of fertiliser in some countries has caused soil pollution in the form of nitrogen deposition and damaged water systems. The FAO stressed that the use of crop rotations, mulching and manure can also restore nitrogen to soils. Legumes such as soybeans, have microorganisms in their root systems that fix nitrogen from the air and make it available to plants, thus replacing mineral fertilisers or animal manure.