County-level changes in nitrogen budgets in agroecosystems against the background of rapid urbanization: A case study of Yixing Municipality in Eastern China’s Jiangsu Province
Abstract:Nitrogen budgets in agroecosystems in the year 1985, 2003 and 2008 were calculated for Yixing Municipality in Eastern China’s Jiangsu Province. Nitrogen surpluses on farmland was as high as 131.7 kg/hm2 in 1985, but had dropped sharply in recent years. By 2008, it had reached a well balanced nitrogen supply due to a remarkably lower input and the surplus was only a 5.0 kg/hm2. Reduced application of chemical fertilizers was the main explanation for the decreasing nitrogen input. Another major reason for the lower nitrogen input was the decreasing recycling of organic wastes in agriculture as the region became more and more urbanized. Reduced nitrogen surplus in farmlands favors the remediation of water pollution from non-point source. However, parts of discarded organic wastes are discharged into surface water without or with little treatment, posing new challenges to water quality management.
宁彤, 高超, 许有鹏. 快速城市化背景下县域尺度农田氮素平衡状况的演变
——以江苏省宜兴市为例
[J]. 中国环境科学, 2011, 31(4): 668-673.
NING Tong, GAO Chao, XU You-Peng. County-level changes in nitrogen budgets in agroecosystems against the background of rapid urbanization: A case study of Yixing Municipality in Eastern China’s Jiangsu Province. CHINA ENVIRONMENTAL SCIENCECE, 2011, 31(4): 668-673.