Screening of Maize Cultivars with Phytoremediation Coupled with Agro-Production for Cd Pollution in Farmland Soil

Agricultural soil Cd (Cd) pollution threatens global food safety. Based on a meta-analysis of 55 global studies involving 464 maize cultivars, this research systematically elucidates the potential of maize for safe production and remediation in cadmium (Cd)-contaminated farmland. For low to moderately polluted fields, multiple cultivars with low grain Cd accumulation were identified, including 15 cultivars such as TieYan 919 and DanYu 508, which achieved over 90% lower grain Cd content than the legislative limits. DongDan 118 demonstrated simultaneous grain Cd reduction and yield increase, while XianYu 335 and ZhengDan 958 showed comprehensive performance in Cd reduction and yield stability. Maize genotype was identified as the decisive factor for grain Cd accumulation, soil pH was the key environmental factor regulating Cd translocation to grains, and field cultivation was conducive to the expression of low-accumulation traits. Accordingly, a “production coupled with remediation” technical pathway is proposed, centered on “low-accumulation cultivars as the core, soil pH regulation as the key, and field validation as the safeguard.” For heavily polluted fields, high-Cd-accumulating cultivars such as GuangTian-2 and JinZhuMi (pot cultivation) and HuaCaiNuo3 and QiuQing88 (field cultivation) were identified. Their remediation efficiency was driven by soil available Cd content, with significant local environmental influences, necessitating a remediation strategy guided by “cultivar selection as the core, soil management as the supplement, and local validation as the prerequisite.” This study provides a cultivar selection basis and agronomic regulation framework for the tiered management of Cd-contaminated farmland.