摘要
以四川成都经济区农业生态系统中的重金属Cd为对象,对其在土壤中的输入输出通量进行初步探索。综合各方面的因素,确定以大气干湿沉降、灌溉水、化肥为输入途径和农作物为输出途径进行研究。经过计算,经济区大气干湿沉降通量平均值为17.76g/hm2·a,灌溉水和化肥通量明显较低,三者对土壤Cd污染的贡献率分别为86%、10%和4%。对于6个不同的地区,三者比例略有差别,大气干湿沉降所占比例最高达94%,最低也达到了77%。Cd通过农作物收割输出的量相对较小。土壤Cd年净增量主要受大气干湿沉降的制约,因此大气环境质量应是重点监控的对象。以耕作土体为研究介质,经估算,当前的Cd年平均通量可引起土壤Cd的质量分数升高0.006mg/kg。
According to the flux of the heavy metal Cd in soils of the agroecosystem in the Chengdu economic region （CER）, Sichuan, the input and output fluxes of Cd in soils were studied. By integrating various factors, the authors took the atmospheric wet and dry deposition, irrigation water and fertilizer as Cd inputs and crops as Cd output for the study, The average atmospheric wet and dry deposition flux in the whole CER. is 17,76 g/hm^2.a, while the irrigation and fertilizer fluxes are much lower, They contribute 86, 10 and 4 % of Cd in soils respectively. Their proportions are somewhat different among six cities of the CER.： the contribution of the atmospheric wet and dry deposition is highest, ranging from 94 to 77%. The output flux of Cd through crop harvesting is relatively low. The annual net increment of Cd in soils is mainly controlled by atmospheric wet and dry deposition; therefore the quality of atmospheric environment should be the key monitoring target. It is estimated that the Cd content in soils of farmland may increase by 0.006 mg/kg due to the present average flux of cadmium.
出处
《地质通报》
CAS
CSCD
北大核心
2007年第7期869-877,共9页
Geological Bulletin of China
基金
中国地质调查局<四川省成都经济区农业生态地球化学评价>项目(编号:200314200016)资助
