Jane Qiu in Nature News: Researchers are warning that inappropriate management of phosphate fertilizer and animal manure in China has resulted in serious water pollution and substantial waste of phosphorus, a non-renewable inorganic chemical. Soils in many parts of the world are deficient in the chemical, which is required for plant growth. In its phosphate form, phosphorus is a vital part of the cell's genetic material, and is also found in adenosine triphosphate (ATP), the main energy carrier in cells.…Zhang Fusuo, a plant nutritionist at the China Agricultural University in Beijing, says China has 9% of the world's arable land and has to feed 21% of the world's population, yet its soils are not particularly fertile. An unpublished study by Zhang and colleagues, presented at the symposium, traced how the country has steadily boosted its use of phosphate over three decades.
In 1980, Zhang says, close to 80% of cropland in China contained less than 10 milligrams of phosphate available to plants per kilogram of soil — indicating a phosphate deficiency. Since then, the Chinese government has created a series of policies to encourage the production and use of phosphate fertilizer. But with phosphate use increasing at a rate of 5% per year, 85 million tonnes has accumulated in the soil. "The average phosphate content in the soil has nearly tripled and only a quarter of cropland is deficient in this nutrient now," says Zhang. "This has greatly increased crop production."
Such heavy fertilizer use has made China one of the biggest consumers of phosphate fertilizer. Last year, it used 11 million tonnes, or about 35% of global consumption, according to Zhang. With ever-increasing food demand, there is no sign that phosphate use in China will dwindle….
A longji rice terrace in Longsheng county, Guilin, China. Public domain photo by the suspiciously named Anna Frodesiak
No comments:
Post a Comment