Effects of Blended Sediment Application on Crop Growth and Heavy Metal Risk Assessment

The large‐scale dredging of lake sediments generates substantial sludge, presenting both environmental challenges and opportunities for agricultural reuse. This study evaluated the effects of blended sediment on crop growth and soil heavy metal safety using sediments from Gehu Lake, China. A field experiment employing a rice–wheat rotation compared three treatments: a control (CK, no sediment), raw sediment (Sed), and blended sediment (B‐Sed: 90% sediment, 5% compost, and 5% river sand), all applied at 60 t ha −1 . The blended sediment significantly enhanced crop performance: Wheat and rice yields increased by ∼26% and 52% compared with CK, without elevating grain sterility. Both sediment treatments improved soil quality, elevating soil organic matter (by 17% in Sed and 61% in B‐Sed), nutrient availability, and soil structure. Concentrations of heavy metals (Cd, Pb, As, Hg, Cu, Ni, Zn, and Cr) in soils and grains remained below China's national safety standards (GB 15618‐2018, GB 2762‐2022). Risk assessments confirmed low environmental ecological risk. A USEPA‐model‐based health risk assessment indicated that the total hazard index (THI) and total carcinogenic risk (TCR) for both adults and children were within acceptable limits, with the B‐Sed treatment posing the lowest risk. In conclusion, blended dredged sediment effectively enhanced soil fertility and crop yields in a rice–wheat enhance soil fertility and crop yields, supporting its sustainable reuse in agriculture.