Chemical fertilizer use in China has increased by 225 percent since 1980, according to a survey by the Soil and Fertilizer Institute of the Chinese Academy of Agricultural Sciences (CAAS). The yield increased 40 percent during this period. With a population of 1.3 billion, China uses more fertilizer than any other country accounting for about 30 percent of the world consumption. The current annual consumption of fertilizer in China is more than 54 million tonnes-including nitrogenous, phosphate, and potash fertilizers, of which 33 million tonnes are nitrogenous fertilizer. Nitrogen fertilizer usage is 191 kg per hectare, 151% of the French consumption, 159% of the German one, and 329% of the USA consumption. But in spite of this vast consumption, the Chinese grain yield is some 10-30 percent lower than in those countries.
In China’s largest grain production province, Jilin, some farmers use the fertilizer for the entire season, in the planting season itself. The yearly grain yield of the Jilin province has increased from 10 billion kg to 25 billion kg in the past 30 years, but the use of fertilizer increased much more, from some 0.5 million tonnes in 1984, to approximately 5 million tonnes in 2010.
Excess fertilizer usage is causing pollution as it gets into the air and water of China, it is fostering eutrophication in the water bodies resulting in an excessive growth of algae, increasing pests, lowering the quality of fruits and vegetables, and deteriorating the soil quality. Ammonia discharges cause air pollution; the nitrous oxide released is a major greenhouse gas, with nearly 300 times more global warming potential than carbon dioxide.
China, has as much arable land as India, but the arable lands rendered unusable are more than 40 percent of the total arable landmass, as a result of soil erosion, depletion, alkalinity, and acidification. The polluted cultivated lands are 10 million hectares and arable lands of poor quality with low yield are 67% of the cultivated lands. A recent survey on 10 provinces showed that the soil organic matter has been reduced in 35 percent, compared to that in the early 1990s.