1. Introduction
Soil plays a fundamental role in the functioning of the ecosystem; it is, therefore, critical to ensure the health of soil [
1]. However, the soil has been seriously polluted in many parts of the world, and recent estimates suggest that in some parts of China’s agricultural soil has been contaminated by heavy metals [
2]. According to the latest findings of the national survey on soil quality, 16.1% of all samples taken nationwide exceeded healthy levels of metal pollution, with 19.4% of samples taken from agricultural areas exceeding the standards, the main pollutants being Cd, Ni, Cu, As, Hg, Pb, DDT and PAHs [
3]. Over the last few decades, many surveys of this kind have been carried out in China, including in the North China Plain, the Pearl River Delta, the Yangtze River Basin, and South China. They have shown agricultural soil in China to be suffering from heavy metal pollution [
4].
Soil pollution not only affects the quality of the soil environment, but also poses a threat to food security, human health and ecological environments [
5]. Soil pollution has become a hot topic, with many pollution incidents reported by the media, such as high Cd levels being found in rice, and “contaminated land” [
6,
7]. Meanwhile, the itai-itai disease caused by Cd poisoning has already broken out among some villages in Hunan Province [
8]. It is an urgent requirement, therefore, to implement measures to reduce the risk of soil pollution.
In May 2016, the State Council of China issued the Action Plan for Prevention and Control of Soil Pollution (Soil Plan) to effectively control soil pollution and gradually improve soil quality. The Action Plan pledged to make about 90% of polluted arable land and over 90% of polluted sites safe for human use by 2020, with an increase to both over 95% by 2030 [
9]. Ten special measures have been drafted alongside the Soil Plan to ensure the fulfillment of these targets. A total of CNY 1.14 trillion is expected to be invested during the 5-year scheme (2016–2020).
The implementation of the Soil Plan requires a huge investment, which aims to improve China’s soil quality, but also promotes the development of soil pollution control-related sectors, boosting the macroeconomic system through the upstream and downstream supply chains [
10,
11]. Therefore, a scientific evaluation of the social and economic impact of the Soil Plan can assist industrial planners and environmental practitioners in scientific decision making. Meanwhile, during the Soil Plan, rising demands for products and services (such as power and steel) will inevitably lead to the use of more natural resources and generate pollutants, which poses environment issues [
12]. Therefore, the impact of the Soil Plan on the emission of pollutants should be scientifically evaluated.
The input-output model is a quantitative economic analysis method with which the technical and economic relationship between different sectors of the national economy, as well as each step of reproduction, can be scientifically analyzed against an input-output table [
12]. This model has been widely applied to analyze the impacts of large-scale infrastructure investment, the government economic stimulus plan, and environmental protection investments on the macroeconomy [
13,
14]. Economists have also used the model to analyze the effectiveness of environmental investments made in an attempt to fuel the economy [
15,
16,
17]. Additionally, resources and environmental input-output can also be simulated by inputting industrial pollution emissions and resource consumption data into the model, and evaluating the impact of environmental protection investment on resource consumption and emissions [
12].
In this study, a closed macro input-output model mapping the spillover and linkage effects of industrial and residential consumption was established to quantitatively evaluate the impacts of the Soil Plan on China’s economy. Meanwhile, the impact of the Soil Plan on employment within different sectors was also quantitatively simulated. In addition, an environmental input-output model was established to evaluate the impact of the Soil Plan on emissions.
4. Discussion
4.1. The Soil Plan’s Main Investments and Associated Economic Impacts
As shown in
Table 3, of the CNY 582.3 billion investment in Construction, most investment would be used to renovate tailing reservoirs, solid waste storage and landfill sites. As by-products of mining and mine-processing activities, tailings are a mixture of sand, fine-grained solid materials, water and significant quantities of heavy metals [
28]. Tailings are generally deposited in open-air tailing reservoirs without any treatment [
29]. It was estimated that China had more than 12,000 tailing reservoirs, occupying a large expanse of land across the nation [
30]. Tailing reservoirs are the main cause of acid mine drainage (AMD). AMD is easily produced after the oxidation of various sulfide minerals in tailings [
31]. Featuring low pH value and a high concentration of toxic metals, AMD can seriously contaminate the surrounding environment [
32]. Meanwhile, due to the aeolian transport of tailing sand, metal pollution can spill to soils of the adjacent agricultural and pasture land [
33]. Solid waste storage and landfill sites can also contaminate adjacent areas and cause serious damage [
34]. Therefore, efforts should be made to immediately reduce such environmental risks. A portion of the investment should also be used for isolating and retaining contaminated soil, preventing further expansion of polluted areas.
General equipment manufacturing would receive an investment of CNY 252.3 billion, for three main areas: purchase of general equipment in pollution prevention and control projects for tailing reservoirs, solid waste storage and landfill sites, and soil pollution rehabilitation projects. For soils of different pollution levels, different remediation strategies are laid out in the Soil Plan: for slightly contaminated soils, agronomy regulation and alternative planting can be used to ensure the soil’s continued use as well as food safety; for heavily contaminated soil, adjustment of plant structures, and returning farmland to forest or grassland was suggested to reduce the migration of pollutants into the food chain. The implementation of these strategies would generate new demands for seeds, saplings and grass, as well as planting and afforestation services. Therefore, a total of CNY 225.73 billion would be invested in Agriculture, forestry, animal husbandry and fishing and services.
The launch of environmental protection projects and construction of related equipment would increase the demand for steel products and, therefore, facilitate the development of ferrous metals, smelting and calendering. Meanwhile, environmental protection projects are likely to use large quantities of stones, cement and other construction materials, thereby contributing to the development of non-metallic mineral products. During the implementation of the Soil Plan, the development of the ferrous metal smelting and calendering and non-metallic mineral products would contribute a GDP growth of CNY 103.21 billion and CNY 93.70 billion, respectively. In addition, the development of other sectors would also be boosted by the upstream and downstream supply chains. The Soil Plan’s investments would also see the development of various other sectors, creating more jobs and a new basis for GDP growth. As a result of the Soil Plan’s investments, China’s GDP would grow by CNY 2.716 trillion and 2 million new jobs would be created over five years (2016–2020).
4.2. Potential Environmental Impact and Risk of the Soil Plan
The Soil Plan would increase the demand for products and services of various sectors, resulting in an increased consumption of resources and more emissions. Over the five years of its implementation, the Soil Plan would induce more atmospheric pollutants released into the environment, due to a huge consumption of power [
12]—especially taking into account China’s heavy reliance on thermal power. Meanwhile, ferrous metal smelting and calendering will lead to more atmospheric pollutants due to vast consumption of coal. During the Soil Plan, the power, heat production and supply, ferrous metal smelting and calendering would contribute new SO
2 emissions of 1.83 × 10
5 t and 1.16 × 10
5 t, and new NO
x emissions of 2.33 × 10
5 t and 1.18 × 10
5 t, respectively.
The Soil Plan will also lead to an increase in wastewater pollutants. The Agricultural sector accounted for 48.06% of total COD emissions, and 31.58% NH
3-N emissions. Nitrogenous fertilizers, livestock manure and other fertilizers used in the agricultural production process risk contaminating neighboring water bodies due to farmland runoff and sediment [
35,
36]. The Soil Plan will may consume more produce of Agriculture, forestry, animal husbandry, fishing and also likely to lead to higher emissions. The development of agriculture, meanwhile, is likely to result in greater demand for chemical products, such as fertilizers and pesticides; further promoting the development of chemical products. This will also lead to higher emissions according to the input-output model used in this research. During the Soil Plan, Agriculture, forestry, animal husbandry, fishing and service and Chemical products would contribute new COD emissions of 6.22 × 10
4 t and 1.16 × 10
4 t, and new NH
3-N emissions of 4.35 × 10
3 t and 1.92 × 10
3 t, respectively.
Greater demands for more products and services from various sectors, which are likely to accompany the Soil Plan, will lead to higher emissions. There are also similar examples in other fields. Previous research shows that the production of olives needs more than 90% of non-renewable energy requirements throughout the whole production chain [
37]. It may pose health threats to those residing in those areas. Therefore, more efforts should be made to promote technological advancements and industrial revamps for an accelerated circular economy, and clean production in key sectors [
38]. This may need greener supply chains to minimize negative environmental impact the Soil Plan [
39].
4.3. Limitation and Future Directions
In this study, a closed macro input-output model was used to simulate the economic impact of the Soil Plan’s investment. Our results were based on the following assumptions: (1) the Soil Plan’s investments would be solely used for the consumption of products, and that all projects undertaken during the Soil Plan would be implemented as originally planned; (2) industrial production technologies will remain unchanged between 2016 and 2020. The second assumption is a defect of the input-output model, as the simulation results will not reflect the impact of the technical advancements on future environmental protection activities. Therefore, it is recommended that the dynamic input-output model is used in future studies to improve prediction accuracy.
It is important that the Soil Plan is primarily used as a means of improving China’s soil environmental quality. Economic and environmental concerns, therefore, should not be the primary concern of investments. Furthermore, investment differs by region, as do the industrial structures of each individual province and city. Further study is needed to assess the economic and environmental impacts of investment in different regions. This would help provide appropriate policy recommendations for environmental protection in local regions.
5. Conclusions
The Soil Plan will play a significant role in the improvement of China’s soil quality and the development of the economy. During the implementation period (2016–2020), the Soil Plan is predicted to lead to a GDP growth of CNY 2.7 trillion, creating 2 million new jobs. In terms of GDP, those sectors most likely benefit from Soil Plan’s implementation include Construction, Agriculture, forestry, animal husbandry, fishing, Transportation and warehousing, Wholesale and retail, and Special-purpose equipment manufacturing. The Soil Plan will give a direct impetus to the development of relevant sectors, such as Construction and Debugging, environmental protection equipment manufacturing and comprehensive technical services. This will answer the demands of emerging environmental protection. However, with more demands for products and services within various sectors (such as the power, heat and chemical products), emissions of typical atmospheric and wastewater pollutants such as SO2, NOx, COD and NH3-N will also rise, with potentially serious environmental ramifications. Therefore, energy efficiency and pollution control must be improved across a range of sectors in order to reduce potential environmental impacts incurred by the Soil Plan.