覆土厚度对复垦土壤团聚体稳定及有机碳贡献率的影响

Effects of Cover Thickness on Stability of Aggregates and Organic Carbon in Reclaimed Soil

为了探究覆土厚度对复垦土壤团聚体稳定及有机碳贡献率的影响,采用干筛法、湿筛法测定不同覆土厚度下土壤机械稳定性、水稳定性团聚体、团聚体有机碳分布,计算稳定性参数及有机碳贡献率,分析覆土厚度对其的影响。结果表明,在同一粒级下,随着覆土厚度的增加,团聚体有机碳含量呈先增加后减少的趋势。覆土0~20 cm的>0.25 mm水稳定性团聚体含量最大、土壤团聚体团粒指数最小,覆土为60~80 cm的土壤机械稳定性和水稳定性团聚体平均重量直径、几何平均直径、团聚体稳定率最大,团聚体破坏率最低,是研究区最适合微生物活动及土壤根系生长的覆土厚度,研究结果对煤矸石充填复垦土壤的合理利用及可持续发展具有重要意义。

In order to explore the effects of cover thickness on the stability of soil aggregates and the contribution rate of organic carbon,the mechanical stability of soil,the water stability aggregate and the organic carbon distribution of aggregates under different cover thicknesses were determined by dry sieve method and wet screen method,the stability parameters and organic carbon contribution rate were calculated,and the influence of cover thickness was analyzed.The results showed that under the same particle level,with the increase of the thickness of the cover,the average content of aggregate organic carbon showed a trend of increasing first and then decreasing.The>0.25 mm water stability aggregate content of 0-20 cm of the covered soil was the largest,the soil agglomerate particle index was the smallest,the average weight diameter,geometric average diameter and agglomerate stability of the soil mechanical stability and water stability aggregates with a soil cover of 60-80 cm are the largest,the agglomeration failure rate was the lowest,and it was the most suitable soil thickness for microbial activities and soil root growth in the study area,and the research results were of great significance for the rational utilization and sustainable development of the reclaimed soil filled with gangue.