宁夏汝箕沟露天煤矿排土场渣土植生基质改良效果分析

The Effect of Improving Slag Vegetative Substrate at the Dump of Open-pit Coal Mine in Rujigou,Ningxia,China

露天煤矿开采活动在推动经济与社会发展进步的同时,会因扰动表土而对周边环境造成不可逆的破坏。因此,开展矿山生态修复工作迫在眉睫。植被覆盖是矿山生态修复工作中的重要一环,适宜的土壤结构与养分条件是植物正常生长发育的基础。本研究选取排土场渣土、沙子、腐殖酸、磷酸二铵与尿素作为改良材料,调节渣土的结构与肥力,将渣土改良为适宜植物生长的植生基质,通过对比不同处理下植生基质的理化性质与紫花苜蓿生长效果,筛选出适宜当地植物生长的植生基质配比,对汝箕沟大峰露天煤矿排土场渣土进行改良。研究表明,提高施肥水平可以提升植生基质养分含量,增大pH值,但高施肥水平下紫花苜蓿生长效果不佳;以沙改土可以较好改良渣土的结构问题,对其的肥力也会有一定程度的调节作用;适量添加腐殖酸可以熟化渣土,使植生基质的化学特性更加稳定。从而得出大峰露天煤矿排土场渣土最优植生基质配比为渣土:沙子:腐殖酸(18:1:1)。本研究筛选出了大峰露天煤矿排土场渣土改良的最优植生基质配比,为该地区的渣土改良方法提供了参考,有助于缓解该地区的土壤资源短缺问题,同时为土源区的生态环境保护提供了帮助,也为矿山生态修复中的渣土资源化利用提供了新的思路。

While promoting economic and social development of China,open-pit coal mining will also cause irreversible harm to the surrounding environment due to disturbing the topsoil.Therefore,eco-logical restoration measures are urgently required.Vegetation cover is an important part of mine ecological restoration work.Suitable soil structure and nutrient conditions are the basis of normal plant growth and develop-ment.In this study,the slag,sand,humic acid,diammonium phosphate(DAP)and urea were selected as the im-proved materials to adjust the structure and fertility of the slag and improve the slag into a suitable vegetative sub-strate for plant growth.From among various configurations of the vegetative substrate,the most suitable substrate for plant growth was filtered by comparing the physical and chemical properties and their effects on Alfalfa growth under different treatments.The results showed that the application of fertilizers could increase the nutrient content of the vegetative substrate and increase the pH,but the growth of Alfalfa was not optimal under the high fertilization treatment.The addition of sand could mitigate the structural problems of slag,and sand also showed a certain de-gree of regulation on fertility.Moreover,the addition of appropriate amounts of humic acid can enhance slag mat-uration and stabilize the chemical properties of the vegetative substrate.According to the results,the most optimal slag-sand-humic acid ratio for the vegetative substrate of the dump site of the Dafeng Open-pit Coal Mine is 18:1:1.The findings are expected to offer a reference for the improvement method of slag in this area,which alleviates the shortage of soil resources.It provides support for ecological environmental protection in soil source area,and also offers a new idea for the resource utilization of slag in the ecological restoration.