植物废弃物发酵基质对露天矿区排土场土壤改良研究

Study on the soil improvement of waste dump in open-pit mining areas using plant waste fermentation substrates

伴随着我国经济的高速发展,大量矿区资源被开采利用,尤其是开采过程中通过精矿筛选后剩余的大量岩石碎块和弃土弃渣形成的排土场,导致原有土地资源被占压和破坏。新形成的排土场土壤结构不完善、养分供应差,成为大量植物难以生长的废弃地区。研究围绕“山水林田湖草沙共治、人与自然和谐共生”的理念,利用矿区及周边的植物废弃物作为土壤基质,采用不同配比的植物废弃物对排土场土壤进行改良与提升。研究以高羊茅(Festuca arundinacea“卡纳瓦罗”)作为植物材料,比较原土、未发酵、未发酵∶原土=7∶3、发酵∶原土=7∶3和纯发酵共五种基质类型对草地观感质量、生长情况,以及土壤理化性质的影响,并运用TOPSIS法对各指标进行综合评价,选出最适合高羊茅生长的基质类型。结果表明:发酵∶原土=7∶3处理的基质对高羊茅观感质量存在显著的促进作用;发酵处理后的草地地上生物量和地下生物量均与原土处理无明显差异,但显著高于未发酵的两组处理;发酵处理后的两组基质表现出适宜草地生长的土壤干密度,提高了土壤通气性,且能够显著提高土壤中氮磷钾的养分供应。运用TOPSISI法综合评价可以看出,发酵∶原土=7∶3处理的综合质量评价最优,为0.82,远高于原土处理的0.49;而未发酵处理的综合质量评价最差,仅为0.38。因此,将植物废弃物发酵后与原土以7∶3的比例混合是一种较为合理的植物废弃物处理方式与混合比例,能够对矿区排土场土壤进行显著的改良与提升。

With China’s rapid economic growth,substantial mineral resources have been harnessed,especially the waste dump formed by the screening of concentrate during the mining process,resulting in the occupation and destruction of existing land resources.The newly formed waste dump has an imperfect soil structure and poor nutrient supply,resulting in an abandoned area where a large number of plants are difficult to grow.Guided by the philosophy of“integrated management of mountains,rivers,forests,fields,lakes,grasslands,and deserts,promoting harmonious coexistence between humans and nature”,the approach involves utilizing the plant waste in the original mining area and surrounding farmland as a soil substrate,employing various mixtures of plant waste to amend and enhance the soil in the waste dump.This study uses tall fescue(Festuca arundinacea“Cannavaro”)as plant materials.The effects of five substrate treatments(original soil,unfermented garden waste,unfermented garden waste∶original soil=7∶3,fermented garden waste∶original soil=7∶3 and fermented garden waste)on the turf quality,turf grass growth and soil physicochemical properties are compared.The most suitable substrate type for the growth of Festuca arundinacea is selected by TOPSIS comprehensive evaluation.The results show that the substrate of fermented garden waste∶original soil=7∶3 treatment has a certain promoting effect on the performance quality.The turf biomass of substrate after fermentation treatment has no significant difference with the original soil treatment,but it is significantly higher than that of the two treatments without fermentation.The two treatments of substrates after fermentation show the soil dry density suitable for turfgrass growth,which improves soil aeration and significantly increased the supply of nitrogen,phosphorus and potassium.The comprehensive quality index of fermented garden waste∶original soil=7∶3 treatment is the best,which is 0.82,higher than 0.49 of the original soil treatment.While the comprehensive quality evaluation of garden waste without fermentation treatment is the worst,which is only 0.38.Therefore,mixing the fermented garden waste and original soil according to the proportion of 7∶3 as the growth substrate for Festuca arundinacea is a reasonable plant waste treatment method and mixing ratio,which can significantly improve and enhance the disturbed soil in mining area’s waste dump.