Abstract:Farmland soil is the foundation of national food security, and the management and protection of soil health is crucial to achieve sustainable development goals. Based on the theory of functional soil management, selected evaluation indicators for the five functions of primary productivity, provision and cycling of nutrients, provision of functional and intrinsic biodiversity, water purification and regulation, and carbon sequestration and regulation, by identifying paddy land, irrigated land and dry land for different soils. The relationship between the supply and demand of functions was identified, a soil function supply and demand discriminant matrix was constructed, and the heavy metal pollution threat factors were overlied, the farmland soil health was evaluated, and the spatial mapping of evaluation indicator—soil function/threat—soil health was realized. A study on the applicability of the evaluation method was carried out in Wen County, Henan Province. The results showed that the spatial pattern of the supply and demand of the five soil functions in Wen County basically showed a trend of gradually increasing from south to north, with Qingfengling as the boundary, the supply and demand of soil functions in the central and northern regions were in surplus, while the supply and demand in the southern region were in an imbalanced state. Staggered distribution of soil health grades, the sub-health area accounted for the largest proportion, accounting for 44.4%. Healthy soil was scattered in Huangzhuang Town, Fantian Town, Wude Town, and Xiangyun Town. Soil texture, soil structure, soil nutrients, soil biological activity and heavy metal pollution threat were the main factors for the spatial differentiation of soil health. This research can enrich the soil health evaluation method system theoretically, and promote the sustainable utilization and management of farmland resources in practice.
