Construction of the new cognitive system for arable land resources from geospatial perspective

Arable land is a multiple complex system with food production as its core function and multiple functions such as living, ecology and culture, under the combined effect of natural resource elements and human activities. Currently, the spatial pattern and utilization of arable land in China are changing, showing five phenomena: "non-agricultural", "non-grain", "fragmentation", "marginalization" and "ecological degradation". Previous studies on cultivated land resources cognition emphasize the explicit use of arable land, and mainly focus on state assessment. To a certain extent, they ignore the explicit and implicit comprehensive use of arable land and their mutual feed mechanism with arable land ecosystem, which makes it difficult to quantitatively represent the "regional suitable arable land use intensity and pattern"; early warning "order parameters and their triggering mechanism and inflection point affecting regional arable land health"; trade-off the spatial pattern of arable land production, living and ecological function. The essence of arable land as a kind of resource is its "spatial availability". The unique geographic perspective of the interplay of elements, space and time provides a significant support for understanding the spatial patterns, spatial-temporal dynamic changes, impacts and driving factors of arable land resources. The development of theories and methods for the cognition of arable land resource from a geospatial perspective is the key to exploring a coupled synergistic path of arable land conservation and utilization. In this study, we explored the connotations of arable land resources, based on existing research on the quality and value of arable land resources, including analyzing the "element-function-value" cascade of the natural, livelihood, institutional and consciousness layers, combing the multi-scale, holistic, regional and dynamic characteristics. On this basis, we proposed a theoretical framework for the cognition of arable land resources, suggesting a comprehensive cognition of the pattern of arable land resources from three aspects of arable land resource utilization-noumenon attributes-benefit; developing a coupled utilization-noumenon attributes-benefit model of arable land resources process; and analyzing the influencing mechanism of cultural traditions and socio-economic development on the future demand for crop production. The theoretical basis for the cognition of arable land resources contains a series of theories such as resource carrying capacity, arable land quality, geographical trade-offs and synergies, geographical coupling and integration, and complex geosystems. These theories provide theoretical and methodological support for quantitatively describing the state of utilization, noumenon attributes and benefit of arable land resources, and clarifying the reciprocal effect among them. In particular, the theory of complex geographic systems provides a new way to recognize the evolution of cultivated land systems. Finally, the key technical system and challenges of the cognition of arable land resources have been discussed from four aspects, including space-air-ground integrated arable land resource perception, high-performance spatial-temporal data processing, spatial-temporal pattern and process analysis, and multi-scenario spatial simulation and optimization. China's 2023 “No. 1 central document” sets out goals in terms of strengthening arable land protection and use control, strengthening high-standard farmland construction, and promoting green agricultural development. The theoretical framework of comprehensive cognition of arable land resources proposed in this study can provide support for the realization of these goals in terms of optimizing the spatial pattern of arable land, delimiting the red line of arable land protection, warning the degradation of farmland ecosystem, analyzing the core short board factors of regional high-standard farmland construction, and evaluating the potential of regional arable land to reduce fertilizer (and pesticide) inputs and increase outputs. In the future work, empirical studies on the feed-back mechanism of arable land resources utilization, noumenon attributes and benefit under specific scenarios should be carried out in different regions and scales. Another important direction is to integrate dissipative structure, synergetic, self-organization, catastrophe theory and other complex system theories and methods to study the measurement method of "entropy" and "order" of arable land complex system; and explore the emergence process, order parameters and critical conditions of "entropy change" and "phase change" of macroscale arable land system by micro-scale utilization and its change.