高寒露天矿区渣土基质粒度组成及养分特征

Granularity composition and nutrient characteristics of slag soil matrix in high-cold open-pit mining area

以青海省木里与江仓露天煤矿区渣土为研究对象,采集了矿区渣土样品20个,未受人为扰动和污染的沼泽草甸土壤样品17个作为背景值。通过测试分析矿区渣土和沼泽草甸土壤的粒径组成,发现两个矿区渣土粒级组成与沼泽草甸土壤相同,含量由高到低依次为粉粒-砂粒-黏粒,但是在组成比例上存在差异,沼泽草甸土壤粉粒的含量更为丰富。根据土壤质地分类标准,木里矿区的渣土归属于粉壤土,江仓矿区的渣土归属于粉壤土和壤土,以粉壤土为主,沼泽草甸土壤兼具粉壤土与壤土的特性。同时,对矿渣土的pH、有机碳、全钾、全磷、全氮、碱解氮、速效氮、有效磷、速效钾等指标进行统计分析,结果表明两个矿区的渣土pH值偏碱性且有机质含量低,全量养分与沼泽草甸土壤存在差异,其中全氮的含量远低于沼泽草甸土壤,全钾的含量略高于沼泽草甸土壤。速效养分中的速效氮含量非常贫瘠,有效磷与速效钾的平均含量均高于沼泽草甸土壤,尤其是速效钾更明显。相关性分析显示矿区渣土的黏粒与所有养分均呈正相关,粉粒、砂粒与养分关系逐渐减弱,因此在土壤修复和重构过程中不仅要关注渣土养分的变化,还应该改善渣土基质粒径的结构比例,加速土壤熟化,完善土壤-植物-微生物体系,构建适应高寒矿区植被生长的土壤。

Taking the muck from the Muli and Jiangcang open-pit mining areas in Qinghai Province as the research object,20 samples of muck from the mining area were collected,and 17 samples of marsh meadow soil without human disturbance and pollution were used as background values.Through testing and analyzing the particle size composition of the slag in the mining area and the soil in the marsh meadow,it was found that the composition of the slag in the two mining areas was the same as that of the swamp meadow soil,and the content was silt-sand-clay in descending order.There was different in the proportion of the composition,and the content of soil powder in the swamp meadow was more abundant.According to the soil texture classification standard,the slag soil in the Muli mining area belonged to silt loam,and the slag soil in the Jiangcang mining area belonged to silt loam and loam,mainly silt loam,and the swamp meadow soil had both the characteristics of silt loam and loam.At the same time,statistical analysis of the pH,organic carbon,total potassium,total phosphorus,total nitrogen,alkali hydrolyzable nitrogen,available nitrogen,available phosphorus,available potassium and other indicators of the slag soil showed that the pH value of the slag soil in the two mining areas was alkaline and the content of organic matter was low,and the total nutrients were different from the marsh meadow soil.The total nitrogen content was much lower than the marsh meadow soil,and the total potassium content was slightly higher than the marsh meadow soil.The content of available nitrogen in available nutrients was very poor,and the average content of available phosphorus and available potassium was higher than that of swamp meadow soil,especially available potassium was more obvious.Correlation analysis showed that the clay particles of the slag soil in the mining area were positively correlated with all nutrients,and the relationship between silt,sand and nutrients was gradually weakened.Therefore,in the process of soil remediation and reconstruction,attention should be paid not only to the nutrient changes of slag soil,but also to the structure ratio of the particle size of slag soil to accelerate soil maturation,improve the soil-plant-microbe system,and build a soil suitable for vegetation growth in alpine mining areas.