## 2 Literature Review  
Through a summary of the domestic and foreign literature, it can be seen that the impact of agricultural film usage, pesticide usage and fertilizer input on agricultural development is mainly concentrated in three aspects. First, the use of agricultural film has promoted agricultural development. The large-scale use of white plastic film in agriculture has significantly increased productivity and brought about a double increase in agricultural output and benefits. This is referred to as the white revolution in the process of agricultural development [17]. Later, different scholars proved through experiments that agricultural film mulching increased crop yields [18; 19; 20] and has been successfully used in the majority of cash crops such as corn, cotton, rice, vegetables and fruits [21; 22; 23]. Changing the color of agricultural film from white to dark can cause plants to develop earlier and increase their yield [24; 25; 26]. The fogging of the agricultural film reduces the yield of crops; therefore, researchers have designed a variety of methods to produce anti-fog films [27] to ensure an increase in agricultural product output. Second, the use of agricultural film causes a series of harmful effects, and experts have adopted different solutions. Using a moderate amount of residual film (90-180 kg.hm\({}^{-2}\)) can promote the growth of seedling roots [28] but using a large amount of residual agricultural film will damage the agricultural environment and reduce crop yields [29; 30]. One solution is to replace the traditional cover film with a biodegradable much film [11; 31; 32; 33; 34]. Participating in agricultural technology training, social networks and information acquisition [35; 36] may increase farmers' willingness to participate in the treatment of residual film [37] and reduce the use of agricultural film. In addition, technological innovation [38; 39], environmental regulations [40] and industrial upgrading [41] can also reduce environmental pollution and promote green and sustainable development of agriculture. Third is the impact of fertilizer input and pesticide usage on agricultural development. [PERSON] and [PERSON] [42] used the principle of cost minimization to make an empirical analysis of the amount of fertilizer application during wheat production in Hebei, Henan and Shandong and found that increasing the output by increasing fertilizer input no longer achieves good results. However, different levels of phosphorus and potassium fertilizers are still overused [43]. Although the input of various fertilizers can increase wheat yield [22; 44; 45], it will also stimulate the emission of carbon dioxide in the soil [46] and cause environmental pollution. Wheat production in northern China is mostly dominated by insecticides, fungicides and herbicides, and the phenomenon of irrational use of drugs is common [47]. The safety and high yield of wheat can be achieved by popularizing the application of green drug reduction technology in the control of wheat diseases, insect pests and weeds [48]. In summary, the effects of agricultural film usage, pesticide usage and fertilizer input are a double-edged sword; they not only increase agricultural output but also pollute the soil environment and reduce agricultural output. Most of the abovementioned scholars studied the influence of agricultural film usage, pesticide usage and fertilizer input through experiments, which means that their research objects and scopes are a piece of land or a region of land [49; 50; 51]. The impact of agricultural film usage, pesticides usage and fertilizer input on regional agricultural development is rarely involved in the relevant literature. This paper has been supplemented and improved by two aspects. First, there are 31 provinces in mainland China. Due to missing data from Hainan, this study included almost every province data except for Hainan, which overcome the deviation in results that are caused by only using some regions to derive the national data and thus make the analysis results more robust.