Department of Soil Science and Engineering, Faculty of Agriculture, Shahrekord University, P.O. Box 115, Shahrekord, Iran.
Ecotoxicology. 2021 Jan;30(1):17-30. doi: 10.1007/s10646-020-02286-1. Epub 2020 Oct 18.
Soil cadmium (Cd) pollution resulting from anthropogenic activities has become a major concern for microbial and biochemical functions that are critical for soil quality and ecosystem sustainability. Organic amendments can reduce Cd toxicity to the microbial community and enzymatic activity in Cd-polluted soils and thus would increase the ecological dose (ED) values. However, there has been less focus on the effect of organic amendments on microbial and biochemical responses to Cd toxicity in non-calcareous soils using the concept ED. The aim of this study was to assess the impact of compost application on microbial activity, microbial biomass, turnover rates of carbon and nitrogen, and enzymatic activities as the key ecological functions in a non-calcareous soil spiked with different Cd concentrations (0-200 mg kg). Results showed that soil amendment with compost decreased Cd availability by 48-76%, depending on the total soil Cd content. The application of compost reduced the negative influence of Cd eco-toxicity on most soil microbial and biochemical functions by 20-122%, depending on the Cd level and the assay itself. The ED values, derived from the sigmoidal dose-response and kinetic models, were 1.10- to 2.24-fold higher in the compost-amended soils than the unamended control soils at all Cd levels. In conclusion, the potential risks associated with high levels of Cd pollution can be alleviated for microbial and biochemical indicators of soil quality/health with application of 2500 kg ha compost as a cost-effective source of organic matter to non-calcareous soils. The findings would have some useful implications for organic matter-limited non-calcareous soils polluted with Cd.
人为活动导致的土壤镉 (Cd) 污染已成为影响微生物和生化功能的主要因素，这些功能对土壤质量和生态系统可持续性至关重要。有机改良剂可以降低 Cd 污染土壤中微生物群落和酶活性的毒性，从而提高生态剂量 (ED) 值。然而，在非钙质土壤中，使用 ED 概念，关于有机改良剂对微生物和生化对 Cd 毒性响应的影响的研究较少。本研究旨在评估堆肥施用于非钙质土壤中不同 Cd 浓度（0-200mgkg）时对微生物活性、微生物生物量、碳和氮周转率以及酶活性等关键生态功能的影响。结果表明，堆肥的施用使土壤中 Cd 的有效性降低了 48-76%，具体取决于土壤总 Cd 含量。堆肥的施用降低了 Cd 生态毒性对大多数土壤微生物和生化功能的负面影响，降低幅度为 20-122%，具体取决于 Cd 水平和测定本身。从 sigmoidal 剂量-反应和动力学模型得出的 ED 值在添加堆肥的土壤中比未添加堆肥的对照土壤高出 1.10-2.24 倍，在所有 Cd 水平下均如此。总之，对于非钙质土壤，在 Cd 污染水平较高的情况下，施用 2500kg ha 堆肥作为一种经济有效的有机质来源，可以缓解与土壤质量/健康相关的微生物和生化指标的潜在风险。这些发现对于受 Cd 污染的有机质有限的非钙质土壤具有一定的实际意义。
