In recent years, as a way to achieve higher agricultural output while reducing the negative impact of agricultural production on the environment, agricultural sustainable intensification has attracted worldwide attention. Under the framework of "connotation definition-measuring method-influencing factor-implementation path", this paper systematically sorts out the main research results in the field of agricultural sustainable intensification. The results show that: (1) The connotation of agricultural sustainable intensification has not been clearly defined. It is widely believed that sustainable intensification has the characteristics of increasing production and reducing environmental damage, and is widely used in agricultural, biological and environmental sciences; (2) The measurement methods and indicators of agricultural sustainable intensification are diverse, and the measurement cases are mainly distributed in Europe, Asia, Africa and America; (3) The influencing factors of agricultural sustainable intensification can be roughly divided into four aspects: socio-economic factors, farmers’ own characteristics and natural factors, among which population pressure is the potential driving force for agricultural sustainable intensification; (4) The most obvious feature of agricultural sustainable intensification is the reduction of the yield gap. The strategy of implementing agricultural sustainable intensification can be attributed to the effective use of inputs and the adoption of sustainable practices and technologies. Therefore, the implementation path can be summarized as enhancing the effectiveness of external inputs to the agricultural system and optimizing the practice and technology mix within the crop production system. Finally, this paper concludes that research on connotation definition, influencing mechanism, different regional models, incentive mechanism for farmers, impact evaluation and system design of agricultural sustainable intensification should be strengthened in future.

In the context of China’s trial fallow policy; the heavy metal pollution of farmland is addressed via field surveys in Hunan Province, where the fallow policy has been implemented, and in Jiangxi Province, where it has not been implemented. We measured and analyzed willingness to accept (WTA) using the contingent valuation method (CVM). The conclusions of this study are as follows: (1) Farmer awareness of heavy metal pollution and pollution sources is higher in Jiangxi Province than in Hunan Province; (2) Ignoring the impact of other factors, the WTA of farmers is 902 (yuan /mu) in Jiangxi Province and 902.26 (yuan /mu) in Hunan Province. Considering the influence of the basic characteristics of the respondents using the parameter estimation method, the WTA of farmers is 839.34 (yuan/mu) in Jiangxi Province and 934.39 (yuan/mu) in Hunan Province. There is little difference in WTA between the two provinces, but both estimates are higher than the national compensation standards; (3) The factors that affect the WTA of farmers in Jiangxi Province are gender, education level, average annual income and per capita arable land. The factors that affect the WTA of farmers in Hunan Province are age, education level, family size, average annual income, per capita arable land area and farmer occupation; (4) At present, the means and methods of compensation for the implementation of the fallow policy are recognized by most farmers. The paper concludes with some policy suggestions based on above findings.

Implementing a land fallow policy is of great significance for ensuring China’s food security and promoting the improvement of the ecological environment. The implementation of a fallow project involves different stakeholders. Farmers are the main participants in the fallow project. The decision of farmers to practice fallow is the key factor for the successful development of the fallow project. Therefore, this study theoretically reveals the decision-making mechanism of farmers’ participation in cultivated land fallow by utilizing the hawk-dove evolutionary game theory among farmers and explains some challenges in the implementation of fallow in Guizhou Province. We drew the following conclusions: (1) The behavior of farmers will be affected by other farmers in the same situation, and the effects of mutual incentives and imitations between the groups of farmers are affected by their interests; (2) in the fallow project, the rate of choosing either fallow or unfallow depends on the ratio of fallow income to planting income. If the income of participating in fallow is higher, the demonstration effect of farmers participating in fallow is stronger, and the strategy of continued cultivation is adopted. The fewer unfallow farmers there are, the more consolidated the results of fallow will be; and (3) the government should protect the income of farmers after fallow as much as possible, implement flexible subsidy policies, and formulate corresponding policies to successfully consolidate the fallow results.