Agricultural nitrogen and phosphorus emissions to water and their mitigation options in the Haihe Basin, China

Overall, the plain areas accounted for around 80% of the total agricultural N and P emissions to water in 2012. The highest N and P emission intensities were 10 t N km-2 and 2 t P km-2, respectively. N and P emissions were significantly related to anthropogenic factors (such as the livestock density and cropland) in the plain areas; whereas in mountainous areas, both anthropogenic and natural factors (e.g., slope deviation and soil texture) significantly affected N and P emissions.

Our scenario analysis suggests that agricultural N and P emissions can be reduced by up to 45% and 77%, respectively for N and P in 2030, via improved agricultural and environmental policies, technologies and managements. The prohibition of direct animal manure discharge to the water system seems to be the most effective measure to mitigate the emissions. Our study provided a high-resolution agricultural N and P emissions to the water bodies of Haihe Basin and identified the most effective options to reduce these emissions in highly intensified agricultural areas.