Objective With the deepening understanding of sustainable land resource utilization, the ground substrate, as the foundational material layer supporting and nurturing natural resources, necessitates the development and application of a cultivated land suitability evaluation system that integrates key attributes of the surface substrate, to provide a scientific basis for the precise management and sustainable use of cultivated land resources.

Methods Fifteen indicators were selected from five dimensions: physical properties of the ground substrate, chemical properties of the ground substrate, topography, climate, and locational conditions. The Analytic Hierarchy Process (AHP) was used to determine the weights of each factor in the evaluation. The cultivated land suitability grades for the Ningbo area were calculated using a weighted summation method, and the evaluation results were subjected to spatial autocorrelation analysis using the local Moran’s I index.

Results The cultivated land suitability in Ningbo City exhibits a significant spatial differentiation pattern, characterized by higher suitability in the north and lower in the south, as well as higher suitability in plains and lower in mountainous areas. Specifically, the highly suitable areas account for 27.16%, concentrated in the northern and central plains of Ningbo; moderately suitable areas account for 19.43%, mainly located around urban areas and near piedmont plains; marginally suitable areas account for 35.07%, widely distributed in the lower−elevation regions on both sides of ridges in the low hills and mountainous areas of central and southern Ningbo; and unsuitable areas account for 18.34%, distributed in the higher−elevation regions of the low hills and mountainous areas in central and southern Ningbo. Spatial autocorrelation analysis further identified four significant types of spatial association for cultivated land suitability: positive correlation types—high−high (HH) and low−low (LL), and negative correlation types—high−low (HL) and low−high (LH).

Conclusions By systematically incorporating the attributes of the ground substrate into the evaluation system, the scientific rigor and relevance of cultivated land suitability evaluation have been enhanced. The evaluation results can provide direct reference for optimizing cultivated land layout, improving quality, and making protection decisions. It is recommended that future efforts combine dynamic monitoring data to promote the deeper application of this evaluation system in territorial spatial planning and ecological restoration.