Cadmium (Cd) can accumulate in vegetables and enter the food chain. The production of vegetables usually uses excessive amounts of fertilizers which bring environmental and health damages. The authors investigate the relationship between fertilization with nitrogen (N), phosphorus (P), and potassium (K) and the accumulation of Cd and nitrate in lettuce of the tropicalized variety “Gloriosa.” The experiment is under greenhouse conditions in a 2×2 factorial design, with the addition or not of 10 mg kg⁻¹ Cd to the soil, and the use of one and three times the recommended rate of N, P, and K for lettuce crop. The higher fertilization rate is related to the increase of Cd in the shoots. Gloriosa lettuce shows high Cd-accumulation capacity, especially in the shoots, evidencing great Cd-translocation. Fresh leaves reach up to 8 mg kg⁻¹ Cd, higher than permissible limits, but high Cd-tolerance and no visual symptoms of toxicity or reduction in biomass production. In plants grown with three times the recommended rates of N, nitrate concentrations are within the permissible limits for leafy vegetables. To avoid Cd-accumulation, besides monitoring soil Cd, it would be necessary to establish safe rates of fertilization for the cultivation of tropicalized lettuce varieties.

中文翻译：

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过度施肥模拟热带化莴苣中镉的积累

镉（Cd）可以在蔬菜中积累并进入食物链。蔬菜的生产通常使用过量的肥料，这会带来环境和健康损害。作者研究了施肥与氮 (N)、磷 (P) 和钾 (K) 与热带品种“Gloriosa”莴苣中镉和硝酸盐的积累之间的关系。实验在温室条件下采用 2×2 因子设计，添加或不添加 10 mg kg ^-1Cd 到土壤中，并使用 1 和 3 倍于生菜作物推荐的 N、P 和 K 含量。较高的施肥率与枝条中Cd的增加有关。Gloriosa 莴苣表现出很高的 Cd 积累能力，尤其是在芽中，证明了很大的 Cd 易位。鲜叶高达 8 mg kg ^-1 Cd，高于允许限值，但对 Cd 具有高耐受性，并且没有毒性或生物量产量减少的视觉症状。在以三倍推荐的氮含量种植的植物中，硝酸盐浓度在叶菜的允许限度内。为避免 Cd 积累，除了监测土壤 Cd 外，有必要为热带生菜品种的种植确定安全的施肥率。