School of Life Science, Sun Yat-sen University, Guangzhou 510275, China.
J Environ Sci (China). 2010;22(2):184-91. doi: 10.1016/s1001-0742(09)60091-7.
Non-point source water pollution generated by agricultural production is considered a major environmental issue in the Three Gorges Reservoir Area (TGRA) of China. The Annualised Agricultural Non-Point Source Pollution (AnnAGNPS) model was selected to assess the impact of the application of various management treats, including seven crops, five fertilizer levels and three-group management practice scenarios, on water quality from Heigou River Watershed in TGRA. The scenario subsets include conservation tillage practice (CTP), conservation reserve program (CRP) and conversion of cropland into forestland program (CCFP). Results indicated that tea can not be replaced by other crops because comparatively tea resulted in a higher sediment yield. CTP with no-tillage was more effective to reduce sediment yield, but could increased nutrient loss. CRP reduced sediment yield significantly, but slightly benefited on nutrient loss. CCFP reduced not only sediment yield but also the nutrient loss significantly. The conversion of cropland with a slope greater than 10 degrees into forestland was found to be the best scenario as the sediment yield export is less than 5 tons/ha and nutrient loss is within the permissible limit.
农业生产导致的非点源水污染被认为是中国三峡库区（TGRA）的一个主要环境问题。本研究选择了周年农业非点源污染（AnnAGNPS）模型来评估各种管理措施（包括七种作物、五种肥料水平和三组管理实践情景）对 TGRA 黑沟河流域水质的影响。情景子集包括保护性耕作实践（CTP）、保护储备计划（CRP）和耕地退耕还林还草计划（CCFP）。结果表明，由于茶叶的产沙量相对较高，因此不能用其他作物替代茶叶。免耕的 CTP 更有效地减少了泥沙产沙量，但会增加养分流失。CRP 显著减少了泥沙产沙量，但对养分流失的影响较小。CCFP 不仅减少了泥沙产沙量，而且显著减少了养分流失。研究发现，将坡度大于 10 度的耕地退耕还林还草是最佳情景，因为其泥沙输出量小于 5 吨/公顷，养分流失在允许范围内。
