Rediscovering the location of agricultural production: Spatial linkage of farmland use intensity and labor opportunity costs in Central China

Agricultural location theory was the earliest work to reveal the land use and agricultural layout of urban suburbs; however, there is an increasing difference between Dunn's theoretical model and modern agricultural layouts, and there is thus an urgent need to establish new theoretical relationships. In this work, we sought to reveal new patterns of modern suburban agricultural land use using remote sensing data and land economics knowledge. We used remote sensing data to obtain first-hand land-use information while considering the attractiveness of the urban center to labor, and we explored the impact of agricultural opportunity costs on agricultural land use. We found that agricultural land use in suburbs in Central China have four obvious layers: dominance of built-up areas, dominance of single cropping, dominance of double cropping, and dominance of triple cropping. From the perspective of planting patterns, with increasing distance from the city center, the proportion of single-cropping areas decreases from 60% to 20%, that of double-cropping areas increases from 20% to 70%, that of triple-cropping areas always remains below 10%, and the multiple-cropping index increases from 120% to 180%. From the perspective of land economics and considering labor cost, planting profits decrease with increasing distance from the city center. The increasing attractiveness of the urban center to migrant workers significantly weakens farmers' willingness to plant. From the perspective of the circle structure, before 2000, farmers' planting profits were higher than the opportunity costs in all regions; after 2000, farmers with arable land within a 40-km radius of the center may have been more inclined to choose farming, while those with land outside this 40-km radius may have been more inclined to work elsewhere. Under changing agricultural policies, farmers' planting profits increased to a historical high, but profits became negative in all regions after 2015, and the willingness of people to farm reached a historical low. With this work, we continue the development of the hierarchical structure model of The Location of Agricultural Production and summarize new laws of modern agricultural land use from the perspectives of remote sensing data and land economics, supplementing and enriching agricultural location theory.