A greenhouse experiment aimed to assess the effects of poultry manure, sorghum, and clover residues (0 and 15 g kg⁻¹) on the zinc (Zn) bioavailable fraction in contaminated calcareous soil using two chemical assays, including diffusion gradient in thin-films (DGT) and diethylene triamine pentaacetic acid-triethanolamine (DTPA-TEA), and a bioassay with corn (Zea mase L.). The results showed that poultry manure, clover, and sorghum residues application increased dissolved organic carbon (DOC) by 53.6 and 36.1, and 9.2%, respectively, and decreased soil pH by 0.42, 0.26, and 0.06 units, respectively compared to unamended soil. These changes resulted in increases of Zn effective concentration (C_E) and DTPA-Zn, and plant Zn concentration as observed by the increase in exchangeable form of Zn. In the sorghum residues-amended soils, C_E-Zn decreased by 29.5% compared to other treatments. The best correlations between corn metal concentrations and soil metal bioavailability were obtained for C_E-Zn using the DGT technique, which also provided the best Zn bioavailability estimate. It is concluded that sorghum residues could be used to reduce the phytotoxicity risk of Zn in calcareous contaminated soil, and the DTPA method is the less robust indicator of Zn bioavailability than the DGT technique.

温室实验旨在评估家禽粪便、高粱和三叶草残留物（0 和 15 g kg ^-1）对受污染钙质土壤中锌 (Zn) 生物可利用部分的影响，使用两种化学分析方法，包括薄膜中的扩散梯度(DGT) 和二亚乙基三胺五乙酸-三乙醇胺 (DTPA-TEA)，以及玉米 ( Zea mase L.)的生物测定。结果表明，与未改良的土壤相比，家禽粪便、三叶草和高粱渣的施用分别增加了 53.6、36.1 和 9.2% 的溶解有机碳 (DOC)，并分别降低了 0.42、0.26 和 0.06 个单位的土壤 pH 值。这些变化导致 Zn 有效浓度（C _E) 和 DTPA-Zn，以及植物 Zn 浓度，如通过 Zn 可交换形式的增加所观察到的。在高粱渣改良土壤中，C _E -Zn 比其他处理降低了 29.5%。使用 DGT 技术获得了 C _E -Zn玉米金属浓度和土壤金属生物有效性之间的最佳相关性，这也提供了最佳 Zn 生物有效性估计值。得出的结论是，高粱残留物可用于降低钙质污染土壤中 Zn 的植物毒性风险，而 DTPA 方法对 Zn 生物有效性的影响不如 DGT 技术。