Cadmium mitigation for safe Artemisia selengensis production in the Yangtze River Delta

Cadmium contamination of agricultural soils limits leafy vegetable production and threatens food safety. We investigated cadmium accumulation and mitigation strategies in luhao (Artemisia selengensis), a widely consumed leafy vegetable in the Yangtze River Delta, China. Analysis of 185 paired soil and plant samples from vegetable-dominated farmland in suburban Nanjing revealed mean cadmium concentrations of 0.28 mg kg−1 in soils and 66.1 μg kg−1 in edible tissues. Using crop-category-specific limits in GB2762-2022, 3.8% of crop samples exceeded the applicable Cd limit; for leafy vegetables, including luhao, the limit is 0.2 mg kg−1. Field experiments evaluated soil amendments combining lime, sulfide, and organic wastes. In acidic soils, these treatments reduced extractable cadmium by 22.1 to 25.0% and decreased cadmium in luhao shoots by 31.6 to 33.2%. Soil acidity and total soil cadmium were the primary drivers of uptake. Green and Kunming luhao accumulated less cadmium than red luhao in acidic soils, whereas differences diminished in neutral soils. Large-scale field validation across 200 hectares showed that lime and organic fertilizer reduced cadmium in luhao by 50.5% and increased yield by 51.5%. Integrating soil amendments with low-cadmium cultivars is an effective strategy for safe luhao production.