fertilizer

China launched the decade with its first nationwide pollution census – the result of three years of data collection involving half a million staff. Agriculture, included for the first time in official statistics, was revealed as a major polluter, sending over 13 million tonnes of effluent from fertilizers and pesticides into waterways each year.
 
China is the world’s largest producer and consumer of synthetic nitrogen and phosphorus fertilizers, accounting for about a third of global manufacture and use. High application of fertilizers has implications for greenhouse gas emissions as well as water pollution. China’s last GHG census was in 2000.  Since then scientists have been actively trying to improve estimates and evidence to feed public debate and policy-making. A recent example is the journal paper Greenhouse gas emissions from nitrogen fertilizer use in China by Fredrich Kahrl, Yunju Li, Yufang Su, Timm Tennigkeit, Andreas Wilkes and Jianchu Xu.
 
Previous Chinese field studies have shown that farmers could reduce application of nitrogen fertilizers by 20-30% without loss of yield. If scaleable, Kahrl and colleagues estimate that farmers could save 7–10 MtN a year by 2020 by reducing fertilizer intensity, while maintaining harvests. The mitigation potential is impressive: GHG emission reductions of 100-310 MtCO₂e yr^-1, roughly equivalent to the mitigation potential of Indonesia’s entire power sector at the low end, or Africa’s at the high end. Read more »