Experimental Study On Soil Improvement And Plant Selection For Ecological Regeneration In Drought Mining Area

Land reclamation and revegetation are the most fundamental way to solve theproblem of comprehensive ecological rehabilitation in abandoned drought mining area.Due to the dry climate and barren soil, it is generally difficult for plants to grow indrought mining area. Taking Datong Xinzhouyao Coal Mine Shantytowns as researcharea, this paper studied the method of improving the soil properties based onlaboratory experiments and selected several drought-resistant plants.The soil covering Shantytowns is the silt of loam and it has many characteristics,such as low organic matter content, infertility, alkalinity, poor texture. The soil’smineral constituents mainly contain quartz, feldspar sand and a small amount of clay.So the soil structure of Shantytowns is bad, and difficult to preserve moisture andfertility. We mixed those materials which the ratio was unimproved soil: organicfertilizer: rice husk: water retention agent in1000g:50g:5g:16g to improve the soilproperties, then the improved soil was weak alkaline.The soil grain size analysis andSEM microscopic analysis of improved soil showed that the fine clay contentincreased, the bonding material content between sand and silt increased, and hasformed the trend of the crumb structure. The soil texture was improved and waterretention ability was enhanced, and it belonged to sandy loam. All kinds of nutrientcontents of improved soil reached1.15~4.25times than the unimproved soil. Plantmorphology changes under drought stress showed that improved soil can play a betterrole in slowing affect by adverse effects on plant morphology than unimproved soil.So the soil improvement measure can be spread and used in the Shantytowns ofDatong Mining area.We chose nine plants, and used potted method under(with) drought stress andwater recovering treatment, then tested the related drought indexes, and adoptedsubordinate function value to comprehensively evaluate the nine plants droughtresistance. The results showed that:(1)On the20thday of drought stress, the order of comprehensive droughtresistance of the nine plants was: Sedum spectabile Boreau.(0.7700)>Buxus sinica.(0.7633)>Black Locust.(0.5683), Medicago sativa L.(0.5683)> Pinus tabulaeformisCarr.(0.5483)>Poa annuaL．(0.4867)>Wisteria sinensis (Sims)Sweet.(0.4400)>CaraganakorshinskiiKom.(0.4167)>Astragalus adsurgens Pall.(0.2383), among themSedum spectabile Boreau, Buxus sinica. were belonged toⅠlevel strong resistance,, Astragalus adsurgens Pall had Ⅴlevel not resistance and others were belonged to Ⅲlevel intermediate resistance.(2)After water recovering, the order of comprehensive drought resistance of thenine plants was: Sedum spectabile Boreau.(0.8633)>Buxus sinica.(0.7150)>Pinustabulaeformis Carr.(0.5162)>Black Locust.(0.4132)>Poa annuaL.(0.4058)>Astragalus adsurgens Pall.(0.3348)>Medicago sativa L.(0.2417)>CaraganakorshinskiiKom.(0.1880）>Wisteria sinensis (Sims）Sweet.(0).(3) According to the results of continuous drought stress and water recoveringtreatment, we can know that Buxus sinica.,Pinus tabulaeformis Carr. and Sedumspectabile Boreau. each has strong ability of drought resistance. Therefor, the threekinds plants can be provided as the plant selection of greening afforestation in aridand semi-arid regions of Datong.