摘要
为全面认识南水北调中线水源地农业化肥施用的时空分布差异及对生态环境的潜在威胁,加强化肥施用风险管控,以南水北调中线水源地县级2002—2014年化肥施用量及耕地面积年鉴数据为基础,结合实地调查,运用化肥污染环境风险评价模型,对水源地化肥投入的时空变化分布特征和环境风险进行分析和评价。结果表明:2002—2014年水源地化肥施用明显过量且逐年增加,净增长214.44 kg·hm^(-2),年平均增长率为3.03%。水源地化肥施用强度是发达国家化肥施用安全标准上线的2.74倍,是全国化肥施用强度平均值的1.50倍,是我国生态县建设化肥施用负荷标准的2.47倍,且区域间存在差异。水源地整体化肥施用的风险指数呈逐年增加趋势,从2002年的0.67增至2014年的0.74,增幅为10.45%。多数地区化肥施用风险程度处于中等风险水平,其中西峡县、城固县、汉滨区和邓州市处于严重风险状态,宁陕县、神农架林区和紫阳县处于安全状态。水源地氮肥施用整体处于中等风险状态,磷肥施用风险整体处于低风险和尚安全状态。研究区化肥施用负荷过高是由体制、政策、技术、观念以及经济发展水平等多方面原因造成的,种植模式、施肥技术及管理方式是其直接原因,而农业体制和政策是其内在原因。相关部门应采取有效措施对化肥施用进行"控量增效"管理,如实行农业集约化经营,优化种植结构,加强农民环保意识和农技知识教育,提高农民科学施肥技术,普及推广配方施肥及测土施肥等。
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.
作者
房珊琪
杨珺
强艳芳
王彦东
席建超
冯永忠
杨改河
任广鑫
FANG Shan-qi;YANG Jun;QIANG Yan-fang;WANG Yan-dong;XI Jian-chao;FENG Yong-zhong;YANG Gai-he;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;College of Forestry, Northwest A＆F University, Yangling 712100, China;Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2018年第1期124-136,共13页
Journal of Agro-Environment Science
基金
科技基础性工作专项(2015FY110400-3)~~
关键词
南水北调中线工程
化肥施用负荷
时空特征
环境风险评价
水源地
middle route of the South-to-North Water Transfer Project
fertilizer application level
temporal and spatial distribution
environmental risk assessment
water source area
