关键词: 生物炭, 生物炭, 重金属 生物有效性, 温室土壤 镉

Abstract: As people are paying more attention to healthy living, vegetables have become an essential part of the healthy diet of residents, and subsidies are of great significance in ensuring the supply of vegetables, maintaining vegetable price stability, protecting the interests of farmers, promoting food security and the development of modern agriculture and so on .Therefore, this paper used the data of 7 districts in Shanghai city in 2011-2015, using DEA and Malmquist index. The author found that the inefficiency of vegetable subsidy is caused by the technical inefficiency and the scale inefficiency, among which the inefficiency of scale is the main reason; And there is a mismatch between the size of subsidies and production scale; The average annual rate of Malmquist production was reduced by 13.5%, which was mainly due to the backward technology level and unreasonable scale subsidies. According to these results, it is suggested that the scale of subsidies should be adjusted reasonably according to the actual situation of vegetable industry development.