The essential nutrients for healthy crop growth may affect the nanotechnology-based remediation of agricultural soils contaminated with cadmium (Cd). However, this hypothesis has not been thoroughly explored. This study investigated the Cd biotransformation and accumulation in wheat growing under a hydroponic system regulated by various nitrogen (N) and phosphate (P) fertilizers, after treatment with green-synthesized nano-zero-valent iron supported by diatomite (GnZVI@DE) composites. We found that the presence of urea–N and P with GnZVI@DE respectively inhibited Cd accumulation by 67.7% and 26.2% in wheat seedlings, alleviating further oxidative damage to wheat. This was because urea–N promoted the dispersion of GnZVI@DE particles that originated from increased steric hindrance. P induced the polyphosphate production on tea polyphenols covering GnZVI@DE, increasing Cd(II) adsorption and precipitation by 47.9% for lesser uptake by root surfaces. Conversely, nitrate-N and ammonium-N promoted Cd accumulation in wheat shoots by 86.0% and 26.3%. This was mainly attributed to reduced Cd immobilization by nanocomposites due to GnZVI@DE oxidation by nitrate and competitive adsorption by ammonium. Our study provides insights for developing a sustainable strategy for the remediation of Cd-contaminated soils and the healthy growth of wheat achieved by the synergistic force of nano-amendments combined with urea and phosphate fertilizers.

中文翻译：

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绿色合成的零价铁纳米复合材料结合不同肥料抑制小麦镉积累的协同作用


作物健康生长所必需的营养物质可能会影响对受镉 （Cd） 污染的农业土壤的基于纳米技术的修复。然而，这一假设尚未得到彻底的探讨。本研究研究了在各种氮 （N） 和磷酸盐 （P） 肥料调控的水培系统下，用硅藻土 （GnZVI@DE） 复合材料支撑的绿色合成纳米零价铁处理后生长的小麦的 Cd 生物转化和积累。我们发现尿素 N 和磷与 GnZVI@DE 的存在分别抑制了小麦幼苗 67.7% 和 26.2% 的 Cd 积累，进一步减轻了对小麦的氧化损伤。这是因为尿素-N 促进了由空间位阻增加引起的GnZVI@DE颗粒的分散。P 诱导覆盖 GnZVI@DE 的茶多酚产生多磷酸盐，使 Cd（II） 吸附和沉淀增加 47.9%，从而减少根表面的吸收。相反，硝态氮和铵态氮促进了小麦地上部 Cd 积累 86.0% 和 26.3%。这主要归因于由于硝酸盐的 GnZVI@DE 氧化和铵的竞争性吸附，纳米复合材料的 Cd 固定化减少。我们的研究为制定可持续策略提供见解，以修复受 Cd污染的土壤，并通过纳米改良剂与尿素和磷肥相结合的协同作用实现小麦的健康生长。