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| Distribution and environmental risk assessment of fertilizer application on farmland in the water source of the middle route of the South-to-North Water Transfer Project |
| Received:June 19, 2017 |
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| KeyWord:middle route of the South-to-North Water Transfer Project;fertilizer application level;temporal and spatial distribution;environmental risk assessment;water source area |
| Author Name | Affiliation | E-mail | | FANG Shan-qi | College of Agronomy, Northwest A & F University, Yangling 712100, China
The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100, China | | | YANG Jun | College of Agronomy, Northwest A & F University, Yangling 712100, China
The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100, China | | | QIANG Yan-fang | The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100, China
College of Forestry, Northwest A & F University, Yangling 712100, China | | | WANG Yan-dong | College of Agronomy, Northwest A & F University, Yangling 712100, China
The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100, China | | | XI Jian-chao | Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China | | | FENG Yong-zhong | College of Agronomy, Northwest A & F University, Yangling 712100, China
The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100, China | fengyz@nwsuaf.edu.cn | | YANG Gai-he | College of Agronomy, Northwest A & F University, Yangling 712100, China
The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100, China | | | REN Guang-xin | College of Agronomy, Northwest A & F University, Yangling 712100, China
The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100, China | |
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| Abstract: |
| To understand the temporal and spatial distribution of agricultural fertilizers and their potential threat to the ecological environment in the water source of the middle route of the South-to-North Water Diversion Project, the present study utilized the fertilizer pollution environmental risk assessment model to analyze and evaluate the spatiotemporal variation and environmental risk of chemical fertilizer application in the water source area. This model was based on field investigation and yearbook data of the fertilizer application amounts and cultivated land areas from 2002 to 2014 at the county level. The results showed that the intensity of chemical fertilizer application had been significantly excessive and increased from 2002 to 2014, with a net increase of 214.44 kg·hm-2 and an average annual growth rate of 3.03%. The intensity of fertilizer application was 2.74 times higher in the water source areas than in the safety standard fertilizer application of developed countries, which was 1.50 times the average value of fertilizer application in China and 2.47 times the intensity standard of fertilizer application in China's ecological county constructions. Additionally, the intensity of fertilizer application varied from region to region in the water source area. The total environmental risk index for cultivated land fertilizer application in the water source area increased year by year, increasing from 0.67 in 2002 to 0.74 in 2014, which was an increase of 10.45%. A medium risk level of fertilizer application was observed in the majority of areas. The areas under serious risk levels were Xixia, Chenggu, Hanbin, and Dengzhou, and the areas under safe levels were Shennongjia forest area, and Ningshan and Ziyang counties. The application of nitrogen fertilizer in the water source area was in the middle risk level, and the risk of phosphate fertilizer application was at a low risk level. Excessive intensity of chemical fertilizer application in the study area was caused by a wide range of sources, such as agricultural systems, different policies, technologies and ideas, and level of economic development. Planting patterns, fertilization techniques, and management methods were the direct causes of the overuse of fertilizers, whereas agricultural systems and policies were essential factors. The relevant government departments should take effective measures to control the application quantities of chemical fertilizers and improve fertilizer use efficiency, such as the implementation of agricultural intensive management, optimization of the planting structure, reinforcement of farmers' environmental awareness and agricultural knowledge education, improvement of farmers' scientific fertilization technology, and the popularization of soil testing and fertilizer recommendation. |
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