Co-Innovation Center for Sustainable Forestry in Southern China, Jiangsu Province Key Laboratory of Soil and Water Conservation and Ecological Restoration, Nanjing Forestry University, 159 Longpan Road, Nanjing, Jiangsu 210037, China.
Earth and Environmental Science Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Sci Total Environ. 2021 Mar 20;761:143215. doi: 10.1016/j.scitotenv.2020.143215. Epub 2020 Oct 27.
There has been a rapid increase in abandoned mines across China, Consequently, external-soil spray seeding technologies have emerged as a common method for their remediation. However, slope soils are typically unstable and easily collapsed and the nutrients absorbed by plants are insufficient, which complicate ecological restoration. For this study, we added mineral-solubilizing microbes and a water retaining agent to an external-soil spray seeding substrate in Lespedeza bicolor pots. We investigated the soil nutrients, soil enzyme activities, root growth parameters, root tensile properties, and root-reinforced soil shear strengths. The results revealed that the addition of microbes enhanced soil nutrients, soil enzyme activities, and the content of lignin and hemicellulose, which promoted root growth. Further, the addition of a water retaining agent promoted Lespedeza bicolor root growth but decreased the root tensile strength and force. Shear stress under the microbe treatment was more robust than without it. Finally, root growth was correlated with soil nutrients and enzyme activities, whereas the root tensile force and strength were correlated with lignin and cellulose. Our results suggested that the addition of mineral-solubilizing microbes had the capacity to enhance the quality of soils to facilitate the growth of plants. These results provide a new and viable strategy for the ecological restoration of abandon mine sites.
中国废弃矿山数量迅速增加，因此，外源土壤喷雾播种技术已成为其修复的常用方法。然而，边坡土壤通常不稳定，容易坍塌，且植物吸收的养分不足，这使得生态恢复变得复杂。在这项研究中，我们在胡枝子盆栽中添加了溶磷微生物和保水剂到外源土壤喷雾播种基质中。我们研究了土壤养分、土壤酶活性、根系生长参数、根系拉伸特性和根增强土壤抗剪强度。结果表明，添加微生物可以增强土壤养分、土壤酶活性和木质素及半纤维素的含量，从而促进根系生长。此外，保水剂的添加促进了胡枝子的根系生长，但降低了根系拉伸强度和力。有微生物处理的剪切应力比没有微生物处理的更稳定。最后，根系生长与土壤养分和酶活性相关，而根系拉伸力和强度与木质素和纤维素相关。我们的结果表明，添加溶磷微生物可以提高土壤质量，促进植物生长。这些结果为废弃矿山的生态恢复提供了一种新的可行策略。
