1. Introduction
Land resources, one of the most important factors of natural resources, are an essential production and living element for people to survive and develop [
1,
2]. Among them, arable land, as the essence of land resources, is the basic element of agricultural production and the main source of food provision [
3,
4]. Therefore, the protection and utilization of arable land resources is of special significance to ensure food security, ecological safety, and sustainable use of resources [
5,
6,
7]. Previous studies reveal that about a quarter of the national poverty-stricken counties in China are subject to unfavorable constraints on land resources, mainly in terms of poor topographical conditions, poor arable land resources, scarcity and scattering, and serious degradation, which is not conducive to large-scale centralized operation and seriously affect the efficiency of agricultural production, thus affecting the livelihoods and incomes of the poor [
8,
9,
10]. The optimization and integration of arable land resources serve as an important platform and foundation for the socio-economic development of poverty-stricken areas and a basic livelihood guarantee for the population in poverty-stricken areas [
11,
12]. The efficient and sustainable use of arable land can effectively solve the food problem in poverty-stricken areas, promote regional agricultural development, and improve farmers’ living standards, which is of great significance to alleviating and eliminating regional poverty [
13].
In the previous phases of poverty eradication, people in poverty-stricken areas would pursue the quantity of arable land too much and adopt rough farming to earn their livings [
14], which led to the overuse of arable land and constantly reduced the resource and environmental carrying capacity of arable land in poverty-stricken areas, resulting in the deterioration of their ecological environment [
15]. For example, the massive application of chemical fertilizers, pesticides, and mulch to promote food production has increased the degree of exogenous environmental stresses such as soil erosion, pollution, soil salinization and soil sanding [
16,
17]. After the rough cultivation mentioned above, the original arable land is faced with the depletion of arable land and a decline in unit yields [
18], which in turn fails to satisfy the livelihoods of the poor. Therefore, they, in turn, will continue to opt for deforestation and clearing of new arable land [
19,
20], abandoning the former arable land, thus resulting in the uncontrolled expansion of the arable land. At the same time, the environmental problems facing the original arable land have not been dealt with appropriately [
21]. It leads to the continuous destruction of the ecological environment and puts poor areas into a vicious circle [
22].
China’s poverty eradication policy requires that ecological protection be given top priority and that new methods of ecological poverty alleviation be explored alongside economic development to eliminate poverty, which requires that ecological damage be eliminated in agricultural development in poverty-stricken areas [
23]. For instance, including the prohibition of new land reclamation for cultivation, the enhancement of complementary water resources and irrigation infrastructure, the dissemination of novel agricultural production technologies to increase crop yields per unit of arable land, the implementation of soil testing and tailored fertilizer application techniques to mitigate non-point source pollution and prevent soil compaction, ecological restoration of degraded cropland, and the reinforcement of arable land quality protection and enhancement [
24]. However, only a ban on new arable land reclamation to curb the uncontrolled expansion of arable land will likely affect people’s livelihood in poverty-stricken areas because their main income is from agricultural production [
25,
26,
27]. Therefore, current land and poverty alleviation research focuses more on compensation for fallowing and economic effects brought by land rectification and mostly concentrates on theoretical analysis and case summaries [
28]. There is a lack of research on the impact of China’s poverty eradication policies on arable land in poverty-stricken areas, especially in poverty-stricken mountainous areas. Moreover, the mechanism by which China’s poverty eradication policies affect arable land in poverty-stricken areas has not been elucidated.
Based on the above analysis, this study takes the poverty-stricken counties removed from poverty in the contiguous poverty area in Qinba Mountain in 2019 as the sample and the implementation of the poverty eradication policy in 2015 as the time point
1. The DID model is used to assess the changes in the amount of arable land in the poverty-stricken counties of the contiguous impoverished areas in the Qinba Mountains during the process of eliminating extreme poverty, and the mediating and moderating effect models are used to test the mechanisms of policy effects on arable land. The specific objectives of the study are as follows: (1) to verify whether the implementation of the poverty eradication policy has an impact on the change of arable land in the contiguous impoverished areas in the Qinba Mountains by using the DID model; (2) using a mediated effects model to test what factors influence the area of arable land; (3) to test whether the change of arable land areas effectively improves the ecological environment quality by using the regulating effect model.
2. Theoretical Mechanisms
Since the natural environment base of poverty-stricken areas is relatively poor compared with other areas, the poor arable land, poor quality endowment conditions, and spatial distribution show fragmentation characteristics. Thus the land productivity is relatively low, which is extremely unfavorable to the agricultural development of poor people [
29,
30]. So, the improvement of farming yield depends largely on the input of agricultural production materials such as chemical fertilizers, pesticides, and mulch. For example, the excessive and irrational use of fertilizers, pesticides and mulch can cause agricultural surface pollution and exacerbate the problem of declining arable land quality, thus creating a vicious cycle of increased reliance on fertilizers, pesticides and mulch for agricultural production inputs [
31,
32]. In addition, irrational irrigation methods, such as heavy irrigation the imbalance focus on the use of land rather than the maintenance of land are also important causes of increased arable land degradation [
33]. With the rapid degradation of arable land quality, the population in poverty-stricken areas will further deforest and clear new arable land to make a living. These phenomena are undoubtedly a vicious circle of environmental destruction and ecological resource sacrifice for poverty-stricken areas, which will cause huge externalities to biodiversity and climate change and harm sustainable development [
34,
35].
Existing research has also delved into the unregulated expansion and unsustainable utilization of arable land in impoverished regions from a supply and demand perspective [
36,
37,
38]. These research findings suggest that impoverished areas typically experience higher population growth rates. Agricultural households in these regions require a sufficient supply of food and income to meet the needs of their family members [
39]. Consequently, this increases the demand for arable land to enhance crop yields and land utilization [
40]. They may be deficient in modern agricultural technologies, efficient farming practices, and comprehensive infrastructure. This makes it more challenging for them to achieve high output and sustainable agricultural practices, rendering them unable to meet their subsistence requirements and exacerbating the demand for arable land [
41,
42]. However, the available arable land resources in impoverished regions are typically limited and beset with issues such as degradation, infertility, or fragmentation. As a result, farmers are compelled to rely on the finite land available for agricultural production, leading to overutilization and cultivation. Consequently, this results in a deterioration of soil quality, nutrient loss, and intensified soil erosion. This not only hinders the growth and yield of crops, resulting in unregulated expansion and unsustainable utilization of cropland but also engenders adverse effects on the ecological system’s health and the sustainable livelihoods of farmers [
43,
44].
China’s poverty eradication policy requires that ecological protection be given top priority and that new methods of ecological poverty alleviation be explored alongside economic development to eliminate poverty, which requires that poverty-stricken areas eliminate ecological damage in agricultural development. In the policy implementation process, local governments have undertaken various measures to alleviate or eliminate the prevailing conditions of cropland infertility, degradation, and unregulated expansion. For example, promote major projects to improve and restore arable land, including enhancing the renovation of low-and-medium-yielding fields or the construction of high-standard farmland according to local conditions, trying to increase the unit food production of arable land [
45,
46]. Advanced agricultural technologies such as efficient water-saving irrigation and rational fertilization have been introduced in arable land preparation and management. These can enhance crop yields on limited arable land and reduce the demand for new cropland expansion [
47].
Additionally, the adoption of advanced agricultural machinery and equipment has improved labor productivity, reducing the reliance on manual cultivation [
48,
49]. Furthermore, with the widespread dissemination of agricultural technology, farmers can increasingly rely on diversified agricultural production to meet various demands. This can lead to improved economic returns, livelihood satisfaction, and reduced demand for cropland, significantly mitigating the likelihood of unregulated cropland expansion in impoverished areas. Consequently, following the increase in per-unit grain production, farmers may emphasize land conservation and sustainability. They may implement measures to reduce soil erosion, unregulated expansion, and unsustainable land utilization, ensuring the land can maintain high productivity over the long term [
50,
51]. This shift can obviate the need for large-scale land expansion, enabling better management and conservation of existing land resources to ensure long-term agricultural sustainability.
In addition to implementing the aforementioned high-standard farmland measures, impoverished regions adopt various strategies for the governance of degraded and desertified cropland [
52,
53,
54]. These strategies include cropland retirement and the enhancement of windbreak and sand-fixation projects for desertified cropland, which facilitate ecological restoration and soil management. Degradation and desertification lead to a decline in land quality, severe water, and nutrient loss, rendering the land unsuitable for crop cultivation. Through afforestation, grassland restoration, and soil conservation, soil quality can be improved, enhancing moisture retention capacity and providing a more favorable growth environment for crops while concurrently restoring the ecological environment [
55,
56]. However, these measures may require allocating a portion of cropland for ecological restoration, reducing arable land area. For instance, the construction of terraces on sloping terrain, vegetation belts, and protective forest belts is undertaken to slow down water flow and prevent soil erosion. Rational irrigation management measures, such as drip irrigation and spray irrigation, can also be implemented to reduce water wastage and enhance irrigation efficiency [
57,
58]. Such actions serve the dual purpose of safeguarding and restoring the ecological environment while ensuring high-quality agricultural production.
Simultaneously, following the rehabilitation of degraded and desertified cropland, local governments promote adjustments to agricultural structures to reduce excessive land utilization. This may involve guiding farmers to diversify into other industries or altering crop planting patterns, such as promoting drought-resistant crops, crop rotation and fallow practices, and developing multi-story agroforestry [
59]. These measures not only secure income for the impoverished population but also reduce the overexploitation of cropland, safeguarding the ecological environment from degradation and mitigating instances of unregulated cropland expansion due to livelihood constraints. Adopting a multi-faceted approach that combines ecological restoration, sustainable agricultural practices, and agricultural structural adjustments ultimately promotes both environmental sustainability and the well-being of their communities [
60,
61].
Therefore, this paper proposed the following hypotheses:
H1. The poverty eradication policy will reduce the amount of arable land in poverty-stricken areas.
H2. The poverty eradication policy will mitigate the negative impact of reducing the amount of arable land in poverty-stricken areas by increasing the unit of food production.
H3. The poverty eradication policy will reduce the amount of arable land in poverty-stricken areas by improving the quality of the ecological environment.
5. Conclusions and Policy Recommendations
5.1. Conclusions
From the perspective of policy evaluation of the impact of poverty eradication policy on arable land in poverty-stricken areas, this paper adopts the DID model to study the impact of the policy on the amount of contiguous impoverished areas in the Qinba Mountains by a quasi-natural experiment of poverty eradication policy implementation, verifying the effects of the policy through robustness tests and controlling for potential endogeneity variables. As an international case of a more successful public policy focused on poverty eradication, this study summarizes the successful practice in China can provide a useful reference for poverty eradication actions in other countries and regions and lays a favorable foundation for achieving sustainable development.
This study reveals that policy implementation has led to a reduction in the cultivated land area in impoverished regions, and this reduction is attributed to improvements in yield per unit and environmental quality. Firstly, policies have raised yield per unit through the construction of high-standard farmland and the promotion of efficient agricultural technologies. This transformation has alleviated the reliance of impoverished populations in these areas on excessive new land reclamation to sustain their livelihoods. Secondly, policies encourage ecological restoration of degraded and saline-alkali soils, enhancing the environment while reducing cultivated land area. These dual measures have collectively contributed to the reduction in cultivated land area in impoverished regions without compromising production and the livelihood needs of the local population.
The findings of this study shed light on the pathways through which land management can simultaneously address the livelihood needs of impoverished populations and protect the ecological environment. It underscores the importance of well-designed policies safeguarding food security in impoverished areas while efficiently utilizing land resources for ecological conservation. In future policy formulation, it is crucial to consider the coordination of measures aimed at increasing crop yields and implementing land retirement for afforestation and grassland restoration, thereby maintaining a balance between livelihoods and ecological preservation. Additionally, it is imperative to strengthen the monitoring of land use dynamics in impoverished regions and conduct timely assessments of policy effectiveness.
5.2. Contributions and Limitations
5.2.1. Contributions
Although numerous studies have focused on China’s poverty alleviation policies, limited attention has been given to the impact of these policies on the reduction of cultivated land in impoverished areas. This paper addresses this gap by concentrating on the relationship between changes in cultivated land area and poverty alleviation policies. Secondly, this study contributes by elucidating the mechanisms through which poverty alleviation policies lead to a reduction in cultivated land. It clarifies how the simultaneous attainment of livelihood needs for impoverished populations and the protection of the ecological environment can be achieved through poverty eradication. This enrichment of the content and scope of poverty governance offers empirical evidence to policymakers, providing reference and insights for the sustainable development of impoverished regions. It facilitates the advancement of strategies for sustainable development.
5.2.2. Limitations
Despite the examination of the impact of China’s poverty alleviation policies on the reduction of cultivated land in impoverished areas, there are still aspects that have not been comprehensively investigated. For instance, policies such as social security, industry-targeted poverty alleviation, and employment-focused poverty alleviation may affect the study outcomes. In future research, it is imperative to consider these limitations and conduct in-depth investigations into the impact of other poverty alleviation strategies on the reduction of cultivated land in impoverished regions. By comprehensively assessing and comparing the effects of different factors, a more comprehensive evaluation of the efficacy of various poverty alleviation strategies can be conducted, thus providing valuable insights for the formulation of more effective poverty alleviation policies.
5.3. Policy Recommendations
The governance and conservation of cropland in poverty-stricken areas has been a governance problem in many countries and regions worldwide. Most of the cropland in poverty-stricken areas worldwide faces problems such as the vicious cycle of low production with high input-low output, land degradation and land salinization. It will indirectly encourage the population in poverty-stricken areas to destroy grasslands and woodlands and convert them into arable land for extensive agricultural production to earn a living, which is an extremely harmful and destructive act for the ecological environment. Therefore, in the future, it is necessary to improve the infrastructure in poverty-stricken areas, build high-quality farmland, and improve the soil to increase the unit yield of arable land to fundamentally stop the people in poverty-stricken areas from expanding cultivation for livelihood. Moreover, it is of great significance to increase the monitoring of arable land in poverty-stricken areas, and actively guide farmers to implement crop rotation and fallow initiatives to continuously restore the quality of arable land and provide opportunities for sustainable cultivation.