Research Progress and Prospects of Non-Grain Use of Cultivated Land in Marginalized Contexts

Influenced by the rapid increase in labor costs and the decline in the comparative benefits of grain planting, the phenomenon of Non-Grain Use of Cultivated Land (NGUCL) in China has become increasingly prominent. Firstly, from the perspective of cultivated land marginalization, this study combines the theory of cultivated land marginalization, the theory of land rent, and the theory of farmers' behavior to jointly analyze the theoretical basis for the occurrence of NGUCL. Secondly, it systematically reviews the research progress regarding NGUCL, and finally presents prospects for future research. The study shows that: (1) At the level of theoretical analysis, the theory of cultivated land marginalization clarifies the core driving force and the realistic background of NGUCL. In the context of marginalization, the theory of land rent can explain the logic of choosing the location of NGUCL, and the theory of farmers' behavior can explain how differences in farmers' characteristics affect the occurrence of NGUCL. (2) The definition of NGUCL has been evolving and deepening, and at the present stage, the "food-crop ratio" is still the main indicator, but there are certain limitations in this way of measurement. (3) Under the constraints of production factors and policy incentives, the degree of NGUCL shows a fluctuating increase and is characterized by significant spatial differentiation. Among them, mountainous areas, food production and marketing zones, production and marketing balance zones, urban and peri-urban areas are among the areas in which NGUCL happens all the time. (4) While cultivated land marginalization is the main driving force of NGUCL, the occurrence of NGUCL is also affected by a combination of factors, such as natural endowment, which affects the appropriateness of cultivation, the characteristics of farmers, which affects the degree of farmers' demand for NGUCL, and national policies, which gradually slow down the process of NGUCL. (5) NGUCL has complex implications for ecosystems, food security and farmers' livelihoods. 6. The use control of cultivated land is the main measure in China to regulate NGUCL, but the sustainability of this measure is open to question. In the face of the rapid expansion of the cultivated land marginalization in China and the new requirements for the construction of a diversified food supply system, it is urgent to reconstruct the traditional cognition and research paradigm of NGUCL. In the future, we need to focus on the synergistic analysis of multi-stage, multi-scale and multi-subjects, and explore the evolution process, occurrence mechanism and governance mode of NGUCL.