三种树种对赣南稀土尾矿土壤养分及微生物和酶活性的影响

发布时间：2018-07-06 18:34

本文选题：植被恢复 + 土壤养分　；参考：《江西农业大学》2015年硕士论文

【摘要】：由于赣南稀土矿山大面积无序开采,造成了灾难性的生态环境问题。课题组2012年来在赣南稀土尾矿采用构树(Broussonetia papyrifera,vent)、刺槐(Robinia pseudoacacia L.)、桉树(Eucalyptus)等树种进行造林,本研究主要从地下生态角度研究三种树种对稀土尾矿土壤微生物数量、土壤养分、土壤酶活性的影响,分析植被恢复效益,旨在为赣南稀土废弃矿生态修复树种的选择和应用提供数据材料和实践指导。主要结论如下:1、通过对赣南稀土尾矿土壤进行植被恢复,其土壤养分有了明显的改善。不同植被恢复土壤pH、有机质、全N、碱解N、全P、有效P、速效K均较对照地裸地有了显著地提高,并随土层深度的增加而降低,且其根际效应R/S值都大于1。桉树改善土壤养分状况的作用大于构树和刺槐,桉树一般对比其它树种都存在显著性差异。2、土壤微生物数量中以细菌数量最多,占土壤微生物总数的80%以上,真菌次之,放线菌数量最少只占0.43%左右。不同植被恢复土壤细菌、真菌、放线菌数量均表现为桉树构树刺槐裸地。不同植被恢复土壤中微生物数量变化趋势都表现为随着土层的加深,三大类微生物数量都趋于减少,0-20 cm根际土壤层明显高于20-40 cm根际土壤层。三种树种的根际效应值都大于1,三种树种均随土层深度的增加根际效应值减少。桉树土壤的细菌根际效应值最大,构树土壤的真菌和放线菌数量的根际效应值最大。3、不同恢复植被土壤酶活性较对照地裸地也有显著改善,桉树土壤酶活性总体较高。三种树种土壤酶均随土层深度的增加而降低,三种树种的土壤酶的根际效应都大于对照地裸地即1。4、土壤细菌与pH、有机质、全N、碱解N、磷酸酶成显著正相关(p0.05),与速效K成极显著正相关(p0.01);真菌与pH、有机质、全N、脲酶、磷酸酶成显著正相关(p0.05),与碱解N、速效K成极显著正相关(p0.01);放线菌与pH、有机质、全N、碱解N、脲酶、磷酸酶成显著正相关(p0.05),与速效K成极显著正相关(p0.01)。脲酶与pH、有机质、全N、碱解N成极显著正相关(p0.01),与速效钾成显著正相关(p0.05);过氧化氢酶与pH、有机质成显著正相关(p0.05);蔗糖酶与有机质、碱解N、速效K成显著正相关(p0.05),与pH、全N成极显著正相关(p0.01)。这说明土壤养分、土壤微生物数量、土壤酶是相互作用的,它们相互影响一同促进土壤养分循环。5、对三种树种土壤进行主成分分析,初步认为桉树是赣南稀土尾矿植被恢复最好的树种。
[Abstract]:Due to the disorderly mining of the rare earth mines in south Jiangxi Province, the ecological environment problem is disastrous. Since 2012, the three species of rare earth tailings in Gannan were planted with Broussonetia papyriferavent, Robinia pseudoacacia L., eucalyptus, etc. The effects of soil enzyme activity and vegetation restoration benefit were analyzed in order to provide data materials and practical guidance for the selection and application of tree species for ecological restoration of rare earth waste ore in southern Jiangxi. The main conclusions are as follows: 1. Through vegetation restoration of rare earth tailings soil in south Jiangxi, the soil nutrient has been improved obviously. The soil pH, organic matter, total N, alkali-hydrolyzed N, total P, available P, available K of different vegetation restoration soil were significantly higher than that of the control land, and decreased with the increase of soil depth, and the R- S value of rhizosphere effect was more than 1. The effect of eucalyptus on improving soil nutrient status was greater than that of Eucalyptus and Robinia pseudoacacia, and eucalyptus had significant difference compared with other tree species. The number of soil microbes was the most, accounting for more than 80% of the total number of soil microbes, followed by fungi. The number of actinomycetes was only about 0.43%. The number of bacteria, fungi and actinomycetes in different vegetation restoration soil were all bare land of Eucalyptus pseudoacacia (Robinia pseudoacacia). The change trend of microorganism quantity in different vegetation restoration soil was that with the deepening of soil layer, the number of three kinds of microbes tended to decrease in 0-20 cm rhizosphere soil layer than that in 20-40 cm rhizosphere soil layer. The rhizosphere effects of the three species were all greater than 1, and the three species decreased with the increase of soil depth. The rhizosphere effect value of eucalyptus soil was the largest, and the rhizosphere effect value of fungi and actinomycetes was the largest. The soil enzyme activity of different restoration vegetation was significantly improved than that of the control land, and the soil enzyme activity of eucalyptus soil was higher. Soil enzymes of three tree species decreased with the increase of soil depth. The rhizosphere effect of soil enzymes of three tree species was higher than that of bare land (1.4), soil bacteria, pH, organic matter, soil bacteria, and organic matter. Total N, alkaliolysis N, phosphatase were positively correlated with available K (p0.05), fungi were positively correlated with pH, organic matter, total N, urease, phosphatase (p0.05), and actinomycetes with pH, organic matter, urease, phosphatase (p0.05), actinomycetes with pH, organic matter (p0.01), actinomycetes with pH, organic matter. Total N, alkaliolysis N, urease and phosphatase were positively correlated (p0.05), and positively correlated with available K (p0.01). Urease was significantly positively correlated with pH, organic matter, total N and alkali-hydrolyzed N (p0.01), but positively correlated with available potassium (p0.05), catalase and pH, organic matter (p0.05), sucrase and organic matter (p0.05). There was a significant positive correlation between available K (p0.05) and pH and total N (p0.01). This shows that soil nutrients, soil microbial numbers and soil enzymes interact, and they interact with each other to promote soil nutrient cycling. 5. The principal component analysis of the soil of three tree species is carried out. It is considered that eucalyptus is the best species for vegetation restoration of rare earth tailings in south Jiangxi.
【学位授予单位】：江西农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S714

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