不同粒径石灰岩弃渣客土改良效果分析

Amelioration effects of dress-soil on limestone spoil at different particle sizes

生态环境的保护与治理是目前世界关注和研究的重点,以石灰岩弃渣为研究对象,重点解决目前工程弃渣改良利用客土施用量大的难题。为了获取不同粒径区间弃渣混合客土改良的最优比例,试验选取北京房山石灰岩采石场弃渣,筛分成4种粒径区间,并按比例混合客土,撒播高羊茅种子,进行盆栽试验。通过测定不同配比弃渣的密度、孔隙度、毛管持水量和最大持水量,以及高羊茅植株的保存率、生长高度、生物量和根茎比,获取添加不同比例客土的改良效果和高羊茅生长状况。结果显示:客土改良石灰岩弃渣的影响体现需要一定的灌溉沉降过程,不同粒径弃渣土壤水分性质受客土添加量影响,相关性顺序为20~40 mm<10~20 mm<2 mm<2~10 mm,高羊茅在不同粒径弃渣生长受客土添加量的影响,其相关性影响顺序为2 mm<2~10 mm<10~20 mm<20~40 mm,客土最适添加比例为<2 mm和2~10 mm粒径弃渣添加40%,10~20和20~40 mm粒径弃渣添加60%。研究结果可为不同粒径石灰岩弃渣资源化利用及客土改良,提供理论和数据参考。

[ Background] The protection and restoration of the ecological environment has attracted the world＇ s attentions and became the focus of the research field. The researchers have been focusing on the improvement of the physical and chemical properties of mine spoil by using organic fertilizer, water retaining agent, garden waste, sludge, and other materials. However, the influences of different particle size and amount of spoil on soil moisture and plant growth have been ignored, thus we conducted this research to understand the amelioration effects of dress-soil at varied ratio on limestone spoil at different particle sizes. [ Methods] We chose limestone quarry spoil from Fangshan District of Beijing as research materials, and then sieved it into 20 -40 mm, 10 - 20 ram, 2 - 10 mm and 〈 2 mm. For simulating the particle size distribution of actual spoil, we used the spoil of above 4 particle sizes to create 12 kinds of spoil by combining them in varied ratios, and then mixed the dress-soil in the proportion of 0% , 20% , 40% , 60% , 80% and 100%. We selected the pot experiment, and sowed the Festuca elata 100 seeds in mixed spoil per pot, and measured the survival rate, height, biomass and root-shoot ratio in the following two years. For comparing the bulk density, porosity, capillary water holding capacity and maximum water holding capacity of the mixed spoil before and after the pot experiment, we took andtested the samples by ring knife method. The experiment data was processed by Excel2016 and SPSS19.0 software for Pearson correlation analysis. [ Results] The influence of dress-soil improvement of limestone spoil reflected certain irrigation sedimentation process, and adding and mixing dress-soil effectively improved spoil water holding capacity and subsequently improved the growth of tall fescue. The spoil water properties correlation order of different particle size by the amount of dress-soil addition was 20 - 40 mm 〈 10-20mm 〈 2mm 〈 2-10mm, and the correlation order of tall fescue growth was2mm 〈 2-10mm 〈 10-20mm 〈 20-40mm. The optimal dress-soil ratio for the spoil of 〈 2mmand2- 10 mm particle sizes was 40% , and was 60% for 10 - 20 mm and 20 - 40 mm particle size of spoil. Adding more than the optimal ratio of dress-soll caused little more amelioration effects of limestone spoil, and economic and ecological benefits were low. [ Conclusions] By this study we obtained the soil water properties and growth of tall rescue in different particle size limestone spoil mixed with dress-soil, the research methods and results may provide a reference for mine spoil utilization and ecological restoration. We should focus on the influence in the ameliorating process of different rock types, mineral composition, weathering degree and salt content in the further research on the improvement of mine waste rocks.