不同树种对黄河三角洲滨海盐碱地的土壤改良效应评价

发布时间：2018-03-10 06:11

本文选题：盐碱地　切入点：耐盐植物　出处：《山东农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：为了探讨黄河三角洲滨海盐碱地不同耐盐树种对土壤改良的效果,以林龄8年的柽柳(Tamarix chinensis)、杜梨(Pyrus betulifolia)、北沙柳(Salix psammophila)、白蜡(Fraxinus chinensis)人工林为研究对象,未造林空地为对照,采用野外取样和室内分析测定相结合的方法,对各样地的水盐运动规律及不同树种对土壤物理性质、化学性质和生物学指标的影响进行研究分析,并对土壤质量指标的相关性进行分析,运用主成分分析法对不同树种林地的土壤质量进行综合评价,以期为黄河三角洲滨海盐碱地绿化树种选择及可持续发展提供科学依据。研究结果表明,4种耐盐树种对黄河三角洲滨海盐碱地均具有一定的改良效果。主要研究内容和结果如下:1.在滨海盐碱地上利用耐盐植物造林,能在一定程度上影响土壤水盐动态变化,各样地土壤的水盐运动呈现一定的季节性和层次性。土壤表层盐分具有明显的表聚现象,以对照空地土壤表层盐分含量为最高,4种耐盐树种对土壤表层的降盐效果都较为显著。2.种植耐盐树种后,盐碱土壤的结构和物理性质有了一定的改善。各树种样地0-60cm土层平均土壤容重比对照空地降低了2.25%-7.08%,总孔隙度比对照样地升高了3.16%-10.63%。同时,各耐盐树种样地的土壤毛管孔隙度、非毛管孔隙度与田间持水量也有所增加。3.不同树种对盐碱土表层pH值具有明显的降低作用,其0-60cm土层平均pH值比对照空地降低了2.53%。各树种样地土壤平均有机质含量比对照空地提高了96.76%-276.39%,铵态氮、硝态氮、有效磷及速效钾等养分含量分别提高了76.47%、757.74%、32.76%、30.13%。不同树种对土壤阳离子交换性能及碱化度的影响效果各异,其碱化度大小依次为:柽柳(27.38%)杜梨(23.34%)对照(19.45%)白蜡(15.97%)北沙柳(13.34%)。4.通过不同树种样地土壤酶活性及微生物数量的测定,发现土壤酶活性随土层深度的增加逐渐降低,不同树种样地0-60cm土层平均磷酸酶、过氧化氢酶、脲酶、蔗糖酶活性比对照空地分别上升了47.09%、11.52%、41.07%、76.00%。而各树种样地土壤真菌、细菌和放线菌数量比对照空地分别高出6.33-42.96倍,3.57-55.53倍、0.67-3.56倍。可见种植耐盐植物后,土壤微生物性质和酶活性均有了改善。5.利用主成分分析法对不同树种样地土壤22项质量指标进行综合评价,其综合得分由大到小依次为:北沙柳(1.521)白蜡(1.234)杜梨(0.073)柽柳(-0.631)对照(-2.197)。说明北沙柳对盐碱地的改良效果最佳,其次是白蜡,再次是杜梨,柽柳的土壤改良效果相对较差。
[Abstract]:In order to study the effect of different salt tolerant tree species on soil improvement in the coastal saline and alkali land of the Yellow River Delta, the artificial forests of Tamarix chinensis, Pyrus betulifolia, Salix psammophila, Fraxinus chinensis, which are 8 years old, were used as study objects, and the unplanted land was used as control. By means of field sampling and indoor analysis, the effects of different tree species on soil physical properties, chemical properties and biological indexes were studied and analyzed. The correlation of soil quality indexes was analyzed, and the soil quality of different tree species woodland was evaluated by principal component analysis. In order to provide scientific basis for the selection and sustainable development of greening tree species in coastal saline and alkaline land of the Yellow River Delta, the results show that four salt-tolerant species have certain improvement effects on saline-alkali land of Yellow River Delta. The contents and results are as follows: 1.Afforestation with salt-tolerant plants on the coastal saline-alkali land, It can influence the dynamic change of soil water and salt to a certain extent, and the water and salt movement of various soil shows certain seasonality and stratification. The salt-reducing effect of four salt-tolerant tree species on the surface layer of soil was significant. 2. After planting the salt-tolerant tree species, the salt content in the surface layer of the soil was the highest. The soil structure and physical properties of saline-alkali soil have been improved to some extent. The average bulk density of soil in 0-60cm soil layer of each tree species plot has decreased 2.25-7.08 compared with that of the control field, and the total porosity has increased 3.16-10.63. meanwhile, the soil capillary porosity of each salt-tolerant tree species sample plot has been increased by 3.16-10.63. Non-capillary porosity and field water holding capacity also increased. 3. Different tree species had a significant effect on the decrease of surface pH value of saline-alkali soil. The average pH value of 0-60cm soil layer was 2.53 lower than that of the control field, and the average organic matter content of the soil in the sample plots was 96.76-276.39 higher than that in the control field. The contents of available phosphorus and available potassium increased 76.477.747.740.30.13.The effects of different tree species on soil cation exchange properties and alkalinity were different. The order of alkalinity was: Tamarix chinensis 27.38) Tu Li 23.34) the control was 19.45) and the white wax was 15.97) the soil enzyme activity and microbial quantity of different tree species were determined, and it was found that the soil enzyme activity decreased gradually with the increase of soil depth. The activities of phosphatase, catalase, urease and sucrase in 0-60 cm soil layer of different tree species were increased by 47.09 ~ 11.522 ~ 41.07cm and 76.00%, respectively, compared with that of the control field. The number of bacteria and actinomycetes were 6.33-42.96 times higher than that of the control field, respectively, 3.57-55.53 times and 0.67-3.56 times, respectively. The soil microbial properties and enzyme activities have been improved .5.The main component analysis was used to evaluate 22 soil quality indexes in different tree species plots. The comprehensive scores were as follows: Beishaliu (1.521) white wax (1.234) Tarix chinensis (0.073)) Tamarix chinensis (-0.631)) control (P < 0.05). The results showed that the effect of soil improvement on saline-alkali land was the best, followed by white wax, and the soil improvement effect of Tamarix was relatively poor.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S156.42

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