Evolution of Farmland Soil Health Under Urbanization and Innovation of Low-Carbon Remediation Technologies: A Cross-Country Study

Abstract:

Urbanization-driven farmland conversion and pollution pose severe threats to soil health and food security. This study evaluated soil health indicators (physicochemical properties, microbial function, nutrient cycling) across 72 urban-peri-urban farmlands in 5 countries (USA, China, Spain, Japan, UK). A novel low-carbon remediation technology (biochar-biogas slurry co-application) was developed and validated. Results showed urban-peri-urban farmlands had 29% lower soil organic matter (SOM), 3.2-fold higher heavy metal (Cd, Cu) concentrations, and 41% lower microbial respiration than rural farmlands. The proposed technology increased SOM by 38%, reduced HM bioavailability by 65%, and cut carbon emissions by 42% compared to traditional chemical remediation. This study provides a low-carbon pathway for farmland soil health preservation amid urbanization.