Phosphorus Flow Patterns in the Chaohu Watershed from 1978 to 2012
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- 作者：Songyan Jiang ; Zengwei Yuan
- 刊名：Environmental Science & Technology
- 出版年：2015
- 出版时间：December 15, 2015
- 年：2015
- 卷：49
- 期：24
- 页码：13973-13982
- 全文大小：597K
- ISSN：1520-5851
文摘
Understanding historical patterns of phosphorus (P) cycling is critical for sustainable P management and eutrophication mitigation in watersheds. This study built a bottom-up model using the substance flow analysis approach to quantify P cycling in the Chaohu watershed during 1978鈥?012. We found that P flows have been intensified, with a 5-fold increase of annual P inputs to sustain the expanding intensive agriculture. Annually, most P inputs (75%) were stored within the watershed, which caused accelerating buildup of legacy P in cultivated land (from 4.9 Gg to 6.5 脳 102 Gg), uncultivated land (from 2.1 Gg to 1.3 脳 102 Gg) and surface water (from 3.7 Gg to 2.6 脳 102 Gg) during 1978鈥?012. The main legacy P sources include fertilizer application for cultivated land, phosphogypsum abandonment for uncultivated land, respectively. The animal husbandry contributed about 63鈥?6% of total P inputs to surface water. The contribution of animal food-P increased greatly during 1978鈥?012, from 7% to 24% and from 1% to 8% for urban and rural residents, respectively. This work demonstrates principle for the buildup of legacy P at the watershed-scale, and advances the knowledge of sustainable P management, such as improving agricultural technologies to reduce fertilizer application.