Spatial identification and tradeoff/synergy analysis of multiple agricultural land use system functions at grid scale in Henan Province

Multifunctional land use can greatly contribute to rural life and food security in the sustainable development of agriculture. It is very necessary to clarify the agricultural land use system under the concept of the "big food view" in China. The agricultural land use system can also cover the arable, forest, grassland, and water areas. Meanwhile, the quantification and spatial analysis of land function has been one of the most effective ways to explore land use systems and sustainability. However, only a few studies have been considered to integrate the agricultural land use systems for the evaluation of their multifunctionality. Particularly, multifunctional agricultural land can often include the intentional and unintentional provision of products and services that are related to the intended land use. Although the individual function of agricultural land is not as good as that of built-up land, the comprehensive advantage of the multifunctionality of agricultural land is very prominent. Moreover, there are some tradeoffs and synergies among them, where the multifunction of agricultural land use can be interwoven with each other. The research of agricultural land multifunctionality and their relationships can promote the balanced development of multiple land use functions, which is of great significance for optimizing land spatial patterns and promoting sustainable land use. Henan Province has been one of the main grain-producing areas of China, indicating a significant contribution to the national food security. Thus, it is a suitable area to explore the agricultural land use system. Taking the Henan Province as the research area, and the 1km grid as the research scale, this study aims to classify, evaluate, visualize, and analyze the multifunction of the agricultural land use system in 2020. The statistical and spatial analysis was also performed on the multi-source data. Besides, the tradeoff/synergy relationships were determined by the quantity and space among agricultural land functions. The results showed that the agricultural land use system included the five main functions: production, ecology, economy, society, and culture. Production functions demonstrate a spatial pattern of high in the east and low in the west. The overall structure of the ecological function was opposite to that of the production function. The generally high economic function was characterized by the high in the southeast, while the low in the central and north. The mean value of social function was higher than that of the central and western regions. The low mean value of cultural functions with high in the West and low in the East. The quantitative correlation of functional functions revealed that the synergistic relationships were found in the six groups of functional combinations, whereas, four groups shared the trade-offs. There was a strong tradeoff relationship between the production and economic function, and the medium was between the production and cultural function, but there was a relatively weak tradeoff relationship between the economic and cultural function. There was also a weak synergistic effect between the production and cultural function. Furthermore, the ten groups of the five main functions showed a distinct tradeoff/synergy relationship, in terms of the spatial correlation. The production, ecological, and cultural functions presented the trade-offs in most parts of the study area, accounting for 51.58% and 52.67% of the total area, respectively. There was a synergy between ecological and cultural functions in most regions of the study area, accounting for 46.54%. 36.71% of the grid shared a trade-off between economic and cultural functions. The agricultural land use system was closely related to several sustainable goals. The findings can provide a strong reference to understanding the agricultural land use systems and their sustainable use management.