| This paper based on the investigation of plant species of the iron mine wasteland in Wu'an and relevant literature review,as well as the analysis of physical and chemical properties of the soil in the original iron mine wasteland,then three combinations of the covered plants about ecological restoration(the combination of leguminous grasses,only legumes,grass and shrubs,respectively)and three types of the soil improvement program(the soil substrate 1:the soil from original iron mine wasteland;the soil substrate 2:the soil from original iron mine wasteland add 20%rural soil;the soil substrate 3:the soil from original iron mine wasteland add 20%rural soil and microbial fertilizer about15kg/667m~2)were determined.When the harvest,the plant growth index,the pH value,organic matter,total nitrogen,total phosphorus of soil and total potassium were measured.According to the soil nutrient index,and the subordinate function was used to evaluated the soil fertility,and then the effects of different plant combination patterns and soil improvement substrates on the growth of covering green plants and soil fertility in the mine wasteland were analyzed.Finally,based on plant species diversity,plant combination pattern and the soil improvement matrix types in the planting area,the restoration effect of mine wasteland was evaluated.The paper obtained the following main conclusions:(1)Through the field investigation,there are 12 families,27 genera and 32 species of native plants in the iron mine wasteland and the surrounding aeras of Wu'an,amount which gramineae and willows were the most with 6 species each,followed by 5 species of leguminosae and 4 species of compositae.(2)Through the growth and ecological index of each plant in the plant configuration and combination,under the same soil matrix type,the optimum efficiency for covering the abandoned mine land is the combination of legume and gramineous grass;The second is the combination of leguminous herbs;The last is grass and shrub.Under the same combination,the optimum efficiency for improving abandoned mine land is matrix 3,secondly is matrix 2,the last is matrix 1.(3)By the analysis of the content of organic matter,total nitrogen,ammonium nitrogen,nitrate nitrogen,available phosphorus,available potassium under different culture substrates of three types of vegetation allocation pattern,the result showed that the content of soil factors were plant combination of leguminous and gramineous grasses>plant combination of leguminous herbs>plant combination of grass and shrub under the same soil substrates.But the result showed that the content of soil factors were former abandoned land with rural soil and microbial fertilizer>former abandoned land with rural soil>former abandoned land under the same plant combination pattern.The combination of leguminous and gramineous plants has a good effect on the improvement of soil fertility in mining wasteland.It is better than the combination of leguminous plants and grass irrigation.The effect is also the best in the improved substrate with microbial fertilizer.(4)From the perspective of species diversity,there were some differences in biological parameters of different vegetation combinations under the different cultural substrates.With the increase of the variety of soil substance,the index of plant diversity was improved.The highest of diversity indicator was the soil substance of microbial fertilizer,and the index of plant species diversity showed the plant combination of leguminosae and Gramineae>the plant combination of Leguminosae>the plant combination of grass and shrub.(5)From the actual production and economic cost analysis,it is concluded that leguminous and gramineous combinations are easier to implement as the best choice.From the perspective of different soil improvement substrates,substrate 3 has the best effect,but substrate 2 has different effects.There is no obvious difference in the measurement index.Considering the matrix 2 from an economic perspective is more worthy of practical promotion. |
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