Research On The Implementing Body And The Remediation Scale Of Heavy Metal-contaminated Cultivated Land Remediation

The situation of heavy metal pollution in cultivated land is getting more and more serious,which severely restricts China’s food security.Many scholars have conducted a lot of explorations in terms of reducing pollution and safe use of cultivated land.However,there is less research on the implementation subject and implementation scale.Detailed investigation have been conducted since 2014 in the Chang-Zhu-Tan area,and various methods have been taken to repair,manage and safely use the contaminated farmland,which not only achieved good results,but also accumulated rich experience.In this process,the implementation subject is the key to ensuring the implementation effect,and large-scale remediation has become the current trend.Therefore,a systematic analysis of the development process of implementation subject from the aspects of type,quantity,and implementation scale,and promotion of the appropriate scale,play an important role in the remediation of heavy metals contaminated cultivated land.Firstly,on the basis of the empirical data from 2014 to 2020 in Chang-Zhu-Tan area,the development of the implementation subject was analyzed systematically,and a comprehensive understanding of the implementation subject was formed.Secondly,244 valid questionnaires was analyzed by the Data Envelopment Analysis method and Tobit model,moderate implementation scale of heavy metals contaminated cultivated land in Chang-Zhu-Tan area was calculated,and the factors of moderate implementation scale was discussed from individual characteristics and the implementation area’s basic characteristics.The preliminary results are as follows:(1)There are various types of implementation subjects for the restoration of heavy metals contaminated cultivated land in Chang-Zhu-Tan area.Among them,cooperative and enterprise have obvious advantages in terms of number and treatment scale,and will increasingly become the important forms.Other implementation subjects such as farmers,large households,and village groups are not as good as cooperatives and enterprises in terms of number and governance scale,and their effect is weakening gradually.(2)According to the results of DEA,the moderate implementation scale of cooperative is 33.33～40hm~2;the moderate implementation scale of enterprises is 233.33～246.67hm~2.In the future,an appropriate scale of remediation should be actively promoted,and the scale efficiency of the implementation subject should be greatly improved.(3)The main factors that affect the scale of cooperatives and enterprises are transportation convenience,annual technical training times,number of construction machinery.In addition,gender and experience have a certain impact on the head of cooperatives;the adequacy of labor force and the distance to the water source have a partial impact on the enterprises.The research on the implementation subject and its remediation scale is of great significance for ensuring the effect of remediation,as well as promoting the efficient development and sustainable development of the remediation of heavy metals contaminated cultivated land.Due to the limitation of the research area,only the Chang-Zhu-Tan area is explored,and the actual situation is more complicated,so for the areas with low concentration,cooperatives and enterprises can still be selected as the main subjects,but the scale can be adjusted appropriately according to the calculation results.