Quality regulation pattern and consolidation time zone of county-level cultivated land based on multi agent collaboration

Cultivated land is one of the most important resources in modern agriculture. Quality regulation and time-sequence zoning have been also of great significance for the consolidation and construction of cultivated land resources, from the comprehensive perspective of the synergy of multiple subjects in the process of cultivated land use and protection. In this study, Quzhou County, an intensive agricultural region in the North China Plain, was taken as the study area. A diagnostic model of ecological niche obstacle factors was then applied to identify the obstacles to the quality of cultivated land. Combined with the main body, the regulation model was then constructed from the synergistic perspective of the main body and the object. The construction zones of cultivated land quality were divided, according to the spatial distribution. The specific application of the regulation model was explored in the different zones, in order to determine the time sequence of the consolidation. The results showed that: 1) The quality of cultivated land was dominated by the high and medium, which together accounted for 77.42% of the total. The average grade of cultivated land quality was 2.54 between high and medium quality. However the cultivated land quality locally showed a significant positive agglomeration. 2) There were different area characteristics at the different obstacle levels for each indicator of cultivated land quality. The main obstacle factors of cultivated land quality were the soil organic matter, groundwater depth, irrigation guarantee rate, soil cation exchange capacity, total nitrogen, available phosphorus, and soil profile constitution. 3) The roles of the different subjects (such as government, farmers, enterprises, universities, and village collectives) were determined in the different dimensions (such as growth condition, fertility status, production condition, water, and salt condition) from the perspectives of dominant, core, participatory, guiding, and linkage. The main obstacle factors were consolidated to improve the quality of cultivated land as the basic orientation. Then, the overall framework of the regulation model was comprehensively constructed from the aspects of control dimensions, indicators, measures, and subjects. 4) The quality of cultivated land was divided into four remediation sub-zones: priority, key, potential, and general consolidation zoning. The specific application of the regulation model was proposed in different consolidation sub-zones. Meanwhile, a time sequence was established to consolidate cultivated land quality for near-term construction in the priority zone, medium-term construction in the key zone, long-term construction in the potential zone, and long-term construction in the general zone. A regulation model can be expected to identify the time sequences of quality consolidation for the cultivated land at the county scale using the synergistic perspective of multiple subjects. The finding can provide a basic basis for constructing the quality regulation model and time sequences of cultivated land at different scales, such as the municipal and provincial levels.