| The heavy metal content of cultivated soil is related to crop growth and food production,which further affects food safety and human health.By carrying out the evaluation of heavy metal pollution in cultivated soil and dividing the safe use area of cultivated land on this basis,it is possible to rationally arrange agricultural planting according to the soil safety status of cultivated land,ensure the safety of agricultural food and promote the healthy development of agricultural economy.In the "Opinions of the Central Committee of the Communist Party of China and the State Council on Implementing the Rural Revitalization Strategy" issued by the State Council in2018,it was mentioned that it is necessary to "promote the prevention and control of heavy metal contaminated arable land,and carry out the pilot application of soil pollution control and remediation technology",which shows that the problem of heavy metal pollution in cultivated soil has been It has aroused great concern from the party and the state.Tailai County is located in the southwest of Heilongjiang Province and is affiliated to Qiqihar City.As a national commodity grain production base county,agriculture plays an important role in the county's economic development.In this study,Tailai County was used as the research area,and the content and spatial distribution of heavy metals(As,Pb,Hg,Cr,Cd,Cu,Ni,Zn)in the cultivated land of Tailai County were studied by using geostatistical methods.The analysis was carried out,and the soil background value of Tailai County was used as the evaluation standard.From the perspective of the pollution of single heavy metal elements,the effect of high concentration pollutants on the soil environment,the ecological effects of heavy metals,environmental effects and toxic effects,the single index method was selected.,Nemero comprehensive pollution index method and potential ecological hazard index method three evaluation methods,comprehensive evaluation of heavy metal pollution status of cultivated land in Tailai County,and on this basis,the classification of safety grades in Tailai County cultivated land,respectively The rational use strategy of different grades provides a basis for the safe use of cultivated land in Tailai County.The main conclusions of this paper are as follows:(1)The spatial distribution of heavy metals in the cultivated soil layer of Tailai County is similar to the spatial distribution pattern of heavy metals in deep soil,and the content is slightly different.The spatial distribution of heavy metals in the tillage layer and the spatial distribution ofheavy metals in the deep soil were higher in the middle,followed by the middle-western content,and lower in the northeast and southeast.The content of heavy metal elements in the tillage layer except for the average value of As and Pb is slightly lower than that of the deep layer.The average content of other heavy metal elements(Hg,Cr,Cd,Cu,Ni,Zn)is higher than that of the deep layer,reaching the average of the deep content of 1.54,1.27,respectively.1.26,1.22,1.18,1.05 times,indicating that there is a slight difference in heavy metal content between the tillage layer and the deep soil.(2)The evaluation results of heavy metal pollution in the surface soil of cultivated land in Tailai County showed that the surface soil environment of cultivated land showed light pollution as a whole.The soil background value of Tailai County was used as the evaluation standard.The evaluation results of single index method indicated that the heavy metals in cultivated land in Tailai County were mainly lightly polluted,but there were a few heavy pollutions in heavy metals Hg and Cd.The evaluation results of Nemero comprehensive pollution index method It indicates that the number of samples with light pollution and above ranks in Tailai County accounts for85.88% of the total sample size.The soil of cultivated land in Tailai County is mainly light pollution,but there is a certain degree of medium pollution and heavy pollution;the evaluation result of potential ecological hazard index method It indicates that the soil of cultivated land in Tailai County is mainly caused by slight ecological damage,but there is about 1/4 of medium ecological damage.(3)According to the results of the single index method,the Nemero comprehensive pollution index method and the potential ecological hazard index method,the ranking results are classified by the principle of permutation and combination,and the GIS technology is used to extract the various grades.The results show that the safe utilization area and basic The safety utilization area accounts for a small proportion,mainly distributed in the small area of the northeast and southeast of the study area;the low-risk monitoring area is widely distributed in the study area,and the medium-risk early warning area is mainly distributed in the middle,and there is no high-risk restricted area.In the safe use area and basic safe use area,the soil should be given excellent advantages to create characteristic agricultural products and promote regional agricultural economic development;comprehensive monitoring should be carried out in low-risk monitoring areas,low-accumulation crops should be planted or crop rotation should be carried out;The district should carry out soil pollution control to ensure the safety of agricultural production and food health. |
PDF Full Text Request