Characteristics of Zn flux in cultivated soil layer in karst and non-karst areas of Hengzhou,Guangxi
A comparative study was conducted to analyze the import and export pathways,as well as the annual input and output flux density of Zn in cultivated soil,in both karst and non-karst areas of Hengzhou,Guangxi.The results showed that the content of Zn in soil in karst area was significantly higher than that in non-karst area under the influence of the parent material.The input of soil Zn in both karst and non-karst areas was significantly affected by human activities,with atmospheric deposition being the primary input pathway.The average annual input flux densities were 494.15 and 484.99g/(hm2·a)in karst and non-karst areas,respectively.The main output pathway was through harvesting,with the annual output flux densities being 490.63 and 580.12g/(hm2·a)in karst and non-karst areas,respectively.The annual output flux density in non-karst area was slightly higher due to the influence of Fe-Mn nodulation and irrigation water.Overall,the annual input flux showed Zn accumulation.