A great challenge to solve nitrogen pollution from intensive agriculture

The huge population and the small arable land area per person determine that intensive agriculture, which is characterized by high ratio of cultivated land to territory, high multiple cropping indices, and large input of agro-chemicals, is an inevitable choice for food security in China. Nitrogen use efficiency (NUE) of such an intensive agriculture is unlikely to reach the levels achieved in some developed countries because the NUE decreases with the increases in nitrogen application rate. While we should continue to struggling for higher NUE, we have to realize that nitrogen pollution from crop production could not be controlled by raising NUE alone under intensive agriculture. In order to protect our environment and sustain development, we have to face a challenge to solve nitrogen pollution under the condition of high nitrogen application rate. Research should be strengthened for the control of nitrogen pollution through establishment of theories, principles, technologies, and policies under the intensive agriculture.