The Soil Carbon Library Management Index And The Soil Enzyme Activity Of Coal Mine Under Different Vegetation Restoration Pattern

In the Loess Plateau, the climate is relatively dry, the terrain is broken, and the vegetation is severely damaged. The opened pit mining makes it more serious damage to the fragile ecological environment, and how to restore it has become more and more concerned. This study selects the of Heidaigou mine dump after 15 years under different vegetation patterns, soil organic carbon, soil labile organic carbon, soil carbon pool management index, soil enzyme activity and soil chemical properties to characterization of soil quality indicators was studied. The effect of different vegetation patterns on soil quality of soil and soil dump was evaluated from two aspects of soil chemistry and soil biology. The aim of this paper is to screen out the optimum pattern of vegetation restoration for soil drainage field, and to provide theoretical basis and technical support for vegetation restoration in the open pit coal mine. The results of this study are as follows:(Ⅰ) Four soil enzymes under different vegetation soil field are different. The activity of alkaline phosphatase in soil was 0-10 cm higher than that of 10-20 cm. Rows of alkaline phosphatase activity in soil field under different vegetation types for grassland > shrub > tree > abonded land. The activity of alkaline phosphatase in 0-20 cm soil layer was significantly higher than that in other vegetation types. Dump sucrase activity in 0-10 cm soil layer was significantly higher than that of 10-20 cm, consistent with grassland > shrub > tree > abonded land. 0-20 cm invertase activity in grassland was significantly higher than other vegetation types, even higher than the original landform. The activity of urease was basically presented as 10-20 cm larger than 0-10 cm. 0-10 cm soil invertase activity for arbor > shrub > grassland > abonded land; 10-20 cm arbor > shrub >grass land > abonded land. The urease activity of arbor 0-20 cm was significantly higher than that of other vegetation patterns. The catalase activity of different vegetation types on the soil of 10-20 cm was higher than that of 0-10 cm. Except for arbor, the difference was not significant between the different vegetation types, which indicated that the tree was the best vegetation to increase the catalase activity in the soil. The four kinds of soil enzyme activities were all larger than those of the newly constructed soil, which was lower than the original landform, which indicated that the different vegetation had a certain effect on soil enzyme activity(Ⅱ) Dump woodland including trees(Robinia pseudoacacia and Pinus tabulaeformis, Populus alba) and shrubs(Amorpha fruticosa, Caragana Korshinskii Kom, Hippophae rhamnoides) a total of six vegetation types was selected, the variation characteristics of the 0-100 cm soil organic carbon was analysised. The soil organic carbon content and organic carbon storage of different vegetation types are in accordance with the deepening of the depth of soil layer and the trend of decreasing. The gap between the 0-20 cm soil layer is relatively large, and the gap between 20-100 cm is very small. 0-100 cm soil layer forest SOC reserves improve 18.1%~42.4% than abandoned(17.52 t·hm-2). Among them, Amorpha fruticosa forest SOC reserves reached the highest 24.95 t·hm-2, significantly higher than other vegetation patterns. The average of SOC storage in the shrub land was 12.4% higher than that of the arbor wood. Consequently, different plantation restoration significantly improved the SOC level on the dump in 0~100 cm soil depth, especially for the topsoil. But there were still a big gap about SOC level between the wood restoration lands and the original land form. To improve the SOC on opencast coal mine dump, Robinia pseudoacacia can be selected as the main wood vegetation.(Ⅲ) The soil labile organic carbon content of 0-10 cm soil under different vegetation patterns was 2.45-4.66, 1.27-4.67, 1.31-2.68, 10-20 cm times, which indicated that the vegetation restoration was better than 10-20 cm in the 0-10 cm soil layer. 0-10 cm soil active organic carbon content for forest and grassland > grassland > arbor > shrub tree> shrub and arbor>abonded land. 10-20 cm forest and grassland > grassland > shrub and arbor >arbor > shrub > abonded land. Forest and grassland soil active organic carbon were significantly higher than those of other vegetation patterns, but the gap is very small between the two is not significant. Medium active soil organic carbon and carbon pool management index 10-20 cm higher than 0-10 cm, and high and low activity is inconsistent, but most of them are in line with the 10-20 cm higher than 0-10 cm. Thus it can be seen in the dump soil is moving in a positive direction. The effective rates of high, medium and low active organic carbon in different vegetation types were all significantly higher than that of 10-20 cm, which indicated that the effective rate of 0-10 cm was higher than that of 10-20 cm. The content of soil labile organic carbon and soil carbon pool management index under different vegetation patterns were all lower than that of the original landform, but all of which were significantly higher than those in the newly established soil. Therefore, vegetation restoration can increase soil active organic carbon content in soil, and it is helpful to restore the soil quality, especially in the best restoration of forest and grassland and grassland.(Ⅳ) Different vegetation restoration has different effects of the soil quality, abandoned land also has certain recovery soil fertility effection, this with different vegetation types of litter and root exudates, vegetation growth state is closely related to. The soil organic carbon storage of forest land was significantly positively correlated with the content of dry matter and organic carbon in the soil, which was in line with the linear equation y=1.27x+1.90 and y=1.25+0.0025 x. The relationship between soil moisture and soil organic carbon content was extremely significant positive correlation with y=0.21x-0.45, tree fine root biomass and SOC content conforms to the linear equation y=0.89+4.06x; shrub accord with linear equation y=1.35+1.53 x. Both were showed significantly positive correlation. The four kinds of enzyme activity of soil also showed significant positive correlation or negative correlation with soil chemical properties, and the activity of invertase was even higher than that of the original landform.