牟定紫色土腐殖质的流失特征研究

发布时间：2018-03-13 18:18

  本文选题：腐殖质　切入点：降雨强度　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着公众的环保意识的增强和国家对环境的污染治理的重视,社会各界越来越关心和重视土壤侵蚀或水土流失的治理。由于紫色土抗蚀性弱,分布区域的地形的起伏大,又地处亚热带,若遇到比较强的降雨,紫色土极容易造成水土流失,因而导致土壤养分的流失,土壤肥力的下降,和生产力的下降,严重地影响了当地人民的生产和生活。本研究在系统的总结国内外的相关研究资料的基础上,以牟定飒马场6种植被覆盖下(桉树林、针阔混交林、灌丛、暖温性针叶林、落叶阔叶林、果园)的紫色土为研究对象,研究了 6种植被覆盖下紫色土的理化性质(包括pH值、总P、有效P、总N、有效N、有机质)和腐殖质组分(包括胡敏酸、富里酸、胡敏素)剖面分布特征。以果园土壤为例,选择3种不同降雨强度,在室内进行土柱模拟试验,研究腐殖质碳量在水中的溶出特征,以及不同的降雨强度和不同的土壤深度对土壤腐殖质碳量流失的影响。研究结果如下:(1)将土壤的剖面分为枯枝落叶层、0-10、10-20、20-30cm四个层次,按这个层次分别采集土样,研究6种植被覆盖下紫色土的理化性质和腐殖质的剖面分布特征。结果表明:枯枝落叶层的总P、有效P、总N、有效N、有机质的质量和腐殖质(HS-C)、胡敏素(HM-C)、胡敏酸(HA-C)、富里酸(FA-C)的碳量显著高于其它层。随着土壤深度的增加,而总P、有效P、总N、有效N、有机质、HS-C、HM-C、HA-C、FA-C的含量减小。不同的植被覆盖方式下的牟定紫色土的土壤腐殖质的碳量有显著的差异。腐殖质的平均碳量由低到高依次为:桉树林果园针阔混交林暖温性针叶林灌丛落叶阔叶林。腐殖质、胡敏素、胡敏酸、富里酸两两相互之间均存在极显著正相关关系(p0.01)。同时,腐殖质、胡敏素、胡敏酸和富里酸与土壤有机质、总P、有效P、总N、有效N均存在显著正相关关系(p0.05)。(2)将降雨强度设置为0.5mm·min~(-1)、1mm·min~(-1)、2mm·min~(-1),研究不同的降雨条件下果园的土壤侵蚀对腐殖质的溶出的影响。结果表明:3种降雨强度下的开始漏液的时间分别是499、338、176 min;总历时分别为1639、1378、1088 min。每采集水样 100 mL,在降雨强度为 0.5 mm·min~(-1)、1 mm·min~(-1)、2 mm·min~(-1)下需要的时间分别是30、20、7 min,因此侵蚀液相对应的产流速率分别为3.33、5、14.29 mL·min~(-1)。说明降雨的强度越大,采样的时间越少,侵蚀液相对应的产流速率越快。在不同的降雨强度下,总有机碳、富里酸、胡敏酸碳量表现出来的溶出规律大体上是一致的,均呈现出先增大后降低的变化趋势,而且随着降雨强度的增大,它们相应的溶出浓度也增大。当降雨强度为0.5 mm·min~(-1)时,总有机碳、富里酸、胡敏酸碳量最大的溶出浓度分别是33.22±1.97、22.98±0.17、6.78±0.17mg·L-1。降雨强度为1mm·min~(-1)时,总有机碳、富里酸、胡敏酸碳量最大的溶出浓度分别是 68.89±1.13、22.98±0.19、8.52±0.23 mg·L-1。降雨强度为2mm·min~(-1)时,总有机碳、富里酸、胡敏酸碳量最大的溶出浓度分别是82.42±0.76、37.64±0.19、9.39±0.23mg·L-1。富里酸碳量在水中的溶出浓度大体上比腐殖胡敏酸大,这是因为富里酸在水中的移动性比胡敏酸大。在研究区,不同降雨强度、不同土壤深度下的腐殖质流失程度存在一定差异。降雨强度为2 mm·min~(-1)时,总有机碳、富里酸、胡敏酸的碳量减少率的范围分别是40.7～45.8%、33.1～38.4%和54.7～59.2%,流失程度相对最剧烈。降雨强度为1mm.min~(-1)时,三者的碳量减少率的范围分别是26.8～31.3%、23.4～27.3%和39.7～43.3%,流失程度相对次之。在降雨强度为0.5 mm·min~(-1)时,三者的碳量减少率的范围分别是11.3～14.2%、10.3～12.3%和11.9～16.2%,流失程度相对最弱。腐殖质碳量的流失程度在土壤深度为0-10 cm层时最严重,在土壤深度为10-20 cm层时次之,在土壤深度为20-30 cm层时相对最弱。因此总有机碳、富里酸和胡敏酸碳量的减少率随降雨强度的增加而显著增加,随土壤深度的增加而减小。(3)以果园土壤为例,研究其不同深度土壤团聚体的分布,寻求耕作土壤结构的抗侵蚀特征。果园紫色土的分形维数范围在2.11～2.48之间,其中团聚体0-10、10-20、20-30 cm的分形维数分别是2.48、2.26、2.1 1。团聚体的分形维数随着土壤深度的增加而降低,说明土壤结构随土壤深度的增加,其稳定性越好。干筛0-10、10-20、20-30 cm的平均重量直径(MWD)值分别是3.28±0.08、4.96±0.05、5.47±0.13mm,湿筛0-10、10-20、20-30cm的MWD值分别是2.38±0.07、2.47±0.05、2.7±0.11mm,湿筛团聚体的MWD值明显低于干筛团聚体的MWD值,说明相对于干筛团聚体的MWD值来说,土壤结构的稳定性的状况更应该用湿筛团聚体的MWD值来反映。而无论是干筛还是湿筛情况下的MWD值表现出随着土壤深度的增加而增大的现象,说明土壤的稳定性随土壤深度的增加越稳定。(4)水土流失的调控措施:对于林地来说,保留地表植被和加大植被覆盖度及合理利用空间布局是控制土壤侵蚀、养分径流损失的行之有效的方法。间种绿肥、尽量保持土壤疏松和要开好排沟渠及合理使用有机肥等都可以提高果园的腐殖质含量。
[Abstract]:In recent years, with the pollution of the environment of the public awareness of environmental protection and national attention from all sectors of society, more and more concern and attention for controlling soil erosion or soil erosion. Because the purple soil erosion resistance is weak, the distribution area of terrain, and is located in the subtropical zone, if encountered strong rainfall, purple the soil is likely to lead to soil erosion, resulting in the loss of soil nutrients, soil fertility decline, and decreased productivity, seriously affected the local people's production and life. The research based on summarizing the domestic relevant information system abroad. In 6 vegetation cover race Monding SA (under the Eucalyptus trees, coniferous forest, shrub, warm temperate coniferous forest, deciduous broad-leaved forest, orchard) in purple soil as the research object, studied the physicochemical properties of the 6 vegetation cover of purple soil (including pH value, total P, available P, total N, available N, organic matter) And humus (including Hu Min acid, fulvic acid, Hu Minsu) in orchard soil profile distribution characteristics. For example, a choice of 3 different rainfall intensity, soil column experiments indoors, the amount of carbon in humus on the dissolution characteristics of the water, and the effects of different rainfall intensities and different depth of soil erosion the soil humus carbon content. The results are as follows: (1) the soil profile is divided into the litter layer, four layers of 0-10,10-20,20-30cm, according to the level of soil samples were collected. The profile distribution of physicochemical properties and humic matter of 6 vegetation coverage in purple soil. The results showed that the total P branches the litter available P, total N, available N, organic matter and humus quality (HS-C), Hu Minsu (HM-C), Hu Min acid (HA-C), fulvic acid (FA-C) the carbon content was significantly higher than that of other layers. With the increase of soil depth, and total P, available P, total N. Available N, organic matter, HS-C HM-C, HA-C, FA-C, reduce the content of soil humus carbon content. Different vegetation under Monding purple soil had significant difference. The average amount of humus carbon from low to high as follows: Eucalyptus forest orchard coniferous forest and warm coniferous forest shrub deciduous broad-leaved forest. Humic matter, Hu the main, Hu Min acid, fulvic acid between 22 was significantly correlated (P0.01). At the same time, Hu Minsu, humus, humic acid and fulvic acid and soil organic matter, total P, available P, total N, there were significant positive correlation between N (P0.05) (2). The rainfall intensity is set to 0.5mm min~ (-1), 1mm min~ (-1), 2mm min~ (-1), study the different rainfall conditions of orchard soil erosion on humus dissolution effect. The results showed that 3 kinds of rainfall intensity to leakage time was 499338176 min in total; duration was 163913781088 min. per collection 姘存牱 100 mL,鍦ㄩ檷闆ㄥ己搴︿负 0.5 mm路min~(-1),1 mm路min~(-1),2 mm路min~(-1)涓嬮渶瑕佺殑鏃堕棿鍒嗗埆鏄，

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