【作者】 吕世华； 曾祥忠； 张福锁； 王甲辰； 刘学军；

【Author】 Lu Shi-hua Zeng Xiang-zong Zhang Fu-suo Wang Jia-chen Liu Xue-jun( Institute of Soil and Fertilizer, Sichuan Academy of Agricultural Sciences, Chengdu 610066)( Department of Plant Nutrition, China Agricultural University, Beijing 100094 )

【机构】 四川省农业科学院土壤肥料研究所； 中国农业大学植物营养系；

【摘要】 对成都市周围11个区、市、县农村地下水硝酸盐含量进行了调查,并对2个农家院落的地下水定点观测,发现1999年3～4月所调查测定的168个样点中有12.5%的样点地下水硝酸盐含量超过最大允许量(50mgL-1),其中最高含量达240mgL-1,表明在该季节成都市农村地下水有硝酸盐污染,但污染程度不如我国北方地区严重。而定点观测却发现在成都地区地下水硝酸盐含量有剧烈的微域空间变化和时间变化,相距几米的样点地下水硝酸盐含量可差上百倍:水稻种植的中后期随排水晒田次数增加、灌水次数减少和地下水位的下降,地下水No3-含量明显增加,9月初有样点硝酸盐含量达到610 mg L-1,因此考虑地下水硝酸盐的时空变化特征,可认为成都市农村地下水硝酸盐污染将比本研究中3~4月份所调查的结果要严重得多。调查还表明,地下水硝酸盐含量与农田施氮量有关,但地理位置、土壤理化性状、地下水流向、流量以及灌溉和降水情况等均会影响地下水硝酸盐污染程度。施氮量高的地区地下水硝酸盐含量不一定高,而施氮量少的地区地下水硝酸盐污染却可能十分严重。更多还原

【Abstract】 SummaryAn investigation on nitrate content of groundwater in the countryside of 11 districts, cities and counties around Chengdu City, including a continuous observation of 3 fixed farmyard sites, was carried out in 1999. Among 168 groundwater samples investigated from March to April, 12.5% of it was polluted by nitrate according to the safe limit of nitrate proposed by WHO (50 mg L-1). The highest of it reached up to 240 mg L-1. But compared with the pollution in north region of China, this is not so serious. The location observation proved further that nitrate content of groundwater changed greatly with micro-space and time. For example, the difference of nitrate content of groundwater between two near sites with distance of several meters could reach up to one hundred times. Also, nitrate content of groundwater significantly increased with the increase of drainage times, the decrease of irrigation times and the decline of groundwater level in the later growing stages of paddy rice. Its peak content 610 mg L-1 occurred in early September. Therefore, if considering the space and time variation features of nitrate content of groundwater, we can conclude that nitrate pollution of groundwater in September in the countryside of Chengdu City is far more serious than that in March and April. In addition, nitrate content of groundwater is related to the amount of N applied. But, many other factors such as geographic position, soil physical-chemical properties, flow direction and speed of groundwater, irrigation and precipitation might affect the extent of nitrate pollution of groundwater. That was why nitrate content of groundwater was not always correlated alone with nitrogen application in local region.更多还原