A research report released last month has demonstrated that widespread nitrogen pollution in China could be prevented by more efficient use of fertilizers in farming, without compromising crop yields.
Researchers have found that average fertilizer use — around 600 kilograms per hectare – can be cut by 30 – 60 percent while maintaining the same yeilds by making use of organic manures and crop residues and rotating crops with nitrogen-producing leguminous plants.
While the high use of nitrogen fertilizers and double-cropping practices have seen the country achieve food self-sufficiency, it has also lead to massive environmental problems including the pollution of groundwater with nitrates, added to greenhouse gas emissions and other forms of air pollution – as well as harming the health of humans and ecosystems.
The study compared common fertilization techniques and optimum techniques in two of the most intensive double-cropping systems in China: rice/wheat in the Taihu region of east China and wheat/maize on the North China Plain.
Ju Xiaotang, a professor at the College of Resources and Environmental Sciences at the China Agricultural University in Beijing and lead author of the research, commented that he would like to see the government educate farmers to avoid over-fertilization and environmental degradation.
Zhang Shuqing, a researcher at the Institute of Agricultural Resources and Regional Planning at the Chinese Academy of Agricultural Sciences, said that farmers tend to use more fertilizer than necessary because they worry the crops will have insufficient nutrients.