| In the human production and life,the quality of water environment,the quality of soil environment and the safety of agricultural products provided the guarantee of survival for people,which was extremely important.In this paper,water and soil environmental quality and agricultural product safety were evaluated in the main oasis area of Qiemo County in Xinjiang,China.The water quality and pollution degree of surface water and groundwater were analyzed by single factor evaluation method.The pollutant exceeding standard grade in the study area was evaluated by the pollution load index method.The potential ecological risk index method was used to describe the degree of pollution of heavy metals in sediments.SPSS software was used for cluster analysis of organic nutrition components in agricultural products,and the ability of agricultural products to absorb heavy metals was expressed by enrichment coefficient.Based on field investigation,the influence of soil and water quality on the safety of agricultural products in the research area was systematically elaborated and the comparative analysis with adjacent area was also discussed.The main results are as follows:(1)The environmental quality of surface water and groundwater was analyzed by selected representative related indicators.The results that the surface water quality in study area was poor and classⅢ and Ⅳ water account for 50.0%and 50.0%of the sampling points respectively.The mainl components that affect the surface water quality were F and Hg,the surface water was a slight pollution state.The groundwater quality in study area was extremely poor,class Ⅲ,Ⅳ and Ⅴ respectively accounts for 12.5%,12.5%and 75.0%of sampling point,and the main natural chemical components that affect the groundwater quality were TDS,Cl-and SO42-,the groundwater was a slight pollution state.(2)The average content of heavy metal elements in farmland soil in the main oasis area of Qiemo County was lower than the limit value of risk screening value and risk control value in Soil environmental quality:Risk control standard for soil contamination of agricultural land(GB15618-2018).The average contents of eight heavy metals were lower than soil background values of Xinjiang.(3)In the main oasis area of Qiemo County,the environmental quality of farmland soil was better,and the area of clean was larger.The area of slightly pollution was only 0.1%,which was mainly affected by As.The contents of beneficial elements Se was mainly deficient and edge,F was higher of the study area.It may be harmful to the health of the ecological environment and human health,and the lack of selenium-rich land has no development potential.(4)In the main oasis area of Qiemo County,the results of the ecological risk assessment of soil farmland showed that the single potential ecological risk degree of elements Cd and As were relatively high,and the ecological risk of other heavy metal elements was relatively low.Cd,As,Pb,Cr,Cu,Ni,Hg and Zn at all sample points were all of minor ecological risks.Therefore,there was a slight ecological risk of the farmland soil in the study area,and the probability of the problem of agricultural product safety was very small.(5)In the main oasis area of Qiemo County,the main characteristic fruit was jujube.Jujube in the study area has good absorption capacity of Cu in soil.The contents of inorganic toxicology indexes Pb,Cd,Hg and Cr in all the jujube samples were much lower than the allowable limit of the standard.And the overall safety of consumption was relatively high.(6)In the main oasis area of Qiemo County,the corn was the principal crops planted.The maize in the study area has good absorption capacity of Zn in soil.The contents of inorganic toxicology indexes Pb,Cd,Hg and As in all the maize samples were much lower than the allowable limit of the standard,while one point of As exceeded the allowable limit of the standard.All the elements of Pb,Cd,Hg and As in the maize samples were not exceeded the standard and far below the standard allowable limit,belong to the green foods. |
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