【作者】 颜德宏；

【导师】 何腾兵；

【作者基本信息】 贵州大学 ， 环境科学， 2009， 硕士

【摘要】 本文主要以贵州喀斯特生态环境下发育的石灰性水稻土为研究对象,以石灰性旱作土壤作为参比对象,采集了相应的水稻土和旱地土样,采用野外调查与室内分析相结合的方法应用环境科学和土壤学的相关原理,探讨了贵州喀斯特生态环境下发育的石灰性水稻土的发生特征与生态环境之间的关系,为研究喀斯特生态环境对石灰性水稻土发生特征的影响以及石灰性水稻土的分类提供依据。主要得到一下结论:(1)石灰性水稻土剖面层次间存在碳酸钙的聚集,可分为犁底层聚集型和底层聚集型。石灰性水稻土表层的碳酸钙含量比起源土壤(旱地)的要低,而剖面平均含量也低于旱地土壤,表明水耕熟化过程引起了碳酸钙的淋溶损失。供试石灰性水稻土剖面中碳酸钙的含量变化在3.91～91.86g/kg之间,水稻土剖面的平均含量在7.56～53.97 g/kg之间。碳酸钙含量可以作为喀斯特生态环境下石灰性水稻土的发生特征及分类指标之一。(2)石灰性水稻土剖面中的质地变化具有一定规律性,同一剖面中,粘粒一般呈现底层淀积,而相应的起源土壤中存在B层淀积,而粘粒、粉粒和砂粒的分布范围比起源土壤的要大:从剖面的平均粉粘比来看,水稻土的平均粉粘比低于相应的起源土壤。说明水稻土在水耕熟化作用下粘粒的生成及其在剖面上的淋溶与淀积作用明显。潴育型石灰性水稻土中,W层和C层的粘粒含量明显高于A层,一般在25～65%之间,质地比较粘重,一般质地为粘土类。粘粒含量及其在剖面上的移动状况既反映了石灰性水稻土的发生特征,又可以作为喀斯特生态环境的石灰性水稻土分类的辅助指标。(3)有机质在石灰性水稻土上部土层的积累作用和各种形态铁在剖面中的淋溶与淀积现象反映了石灰性水稻土的发生过程。采用A/C值或C/A值能直接反映土壤物质在土壤剖面中的分异程度。在水稻土中有机质与各种形态铁的含量之间存在着一定的相关性,与起源土壤旱地相比,有机质以及各种形态铁在石灰性水稻土剖面层次上的分异程度更加明显,石灰性水稻土耕作层的有机质含量高于相应的旱地耕作层。供试石灰性水稻土的铁活化度A/C值一般变化在1.60～7.50,铁络合度A/C值为2.00～20.00,铁晶胶率C/A值为2.00～15.00。A/C值或C/A值能够直接反映水稻土的发生特征,可以作为喀斯特生态环境的石灰性水稻土的分类指标之一。(4)供试石灰性水稻土的有效硅含量与pH值和粘粒含量之间呈极显著的正相关关系,有效硅含量在石灰性水稻土剖面上的分布状况与粘粒的分布状况基本一致,且根据二者与有效硅相关系数比较,pH对有效硅的影响更大,表明有效硅含量在水稻土剖面上的变化也是石灰性水稻土的发生特征之一。(5)贵州喀斯特生态环境条件对石灰性水稻土剖面中物质的迁移与转化、淋溶与淀积等发生过程具有一定的影响。海拔高度影响有机质在剖面上的分异程度(A/C值),其A/C值呈现低海拔地区＞中海拔地区＞高海拔地区的趋势,即海拔高度与有机质A/C值之间呈显著的负相关关系(r=-0.617,n=15);而海拔高度与络合铁含量以及络合度A/C值之间则呈极显著负相关关系(r=-0.677,n=15和r=-0.729,n=15)。年均温影响石灰性水稻土中有机质的积累和铁的淋淀,年均温与水稻土有机质A/C值存在一定的正相关性(r=0.404,n=15);年均温与络合铁含量和络合度A/C值之间达到显著相关关系(r=0.540,n=15和r=0.655,n=15)。年均降水量对石灰性水稻土发生特征指标的影响不明显。更多还原

【Abstract】 This article mainly takes calcareous paddy soil and calcareous upland soil as the research object,which grow under karst ecological environment in Guizhou.The corresponding soil samples of the paddy soil and the upland soil have been collected, based on the field investigation and indoor analysis,and related principle of environmental science and soil science,to discuss the relations between occurrence characteristic and ecological environment of calcareous paddy soil,in order to provide the oretical basis for studying the influence which karst ecological environment brings upon the occurrence characteristic of paddy soil,as well as to provide the basis for classifying the calcareous paddy soil in Guizhou karst area.As a whole mainly obtains following conclusions:(1) Calcareous paddy soil has the accumulation of calcium carbonate in the soil profile horizons,the accumulation is divided into the plough pan accumulation and the bottom accumulation.The results show that,the accumulation of calcium carbonate in the surface layer of hydromorphic was lower than origin soil(the dry cropland),and equilibrium content in soil profile was also lower than the dry cropland’s.The result showed that water mold soil-ripening lead to lixiviation loss of calcium carbonate.The accumulation of the calcium carbonate in experimental calcareous paddy soil mostly was between 3.91 and 91.86 g/kg,and the average contents of calcareous paddy soil in the soil profile horizons was from 7.56 to 53.97, which were one of the classified assistant and occurrence characteristic indexes of calcareous paddy soil under karst ecological environment.(2) Texture’s change of calcareous paddy soil follows the following regularity,in the sole profile,the clay usually presents the bottom deposition,but there is illuvated in the illuvial horizon in the corresponding origin soil,the distribution range of the clay,the silt and the sand are lower than the origin soil,which showed that the generation of soil clay under water mold soil-ripening and leaching and illuviation action were obvious.The clay content in W layer and C layer obviously was more than the surface layer,which was between 25%and 65%,heavy texture,clay loam, just like clay type.The clay content and moving situation on profile for one thing reflected the occurrence characteristic of paddy soil,for another was the classified assistant index of Calcareous paddy soil under karst ecological environment.(3) In calcareous paddy soil profile horizons,accumulation effect of organic matter,leaching and deposition process of various shape of iron showed the soil occurrence process.The A/C value or C/A value of soil index can directly display differential degree of soil material in soil.The organic matter has correlation with contents of various shape of iron in the paddy soil,compared with the arid land of origin soil,the differential degree of organic matter and various shape of iron in soil profile horizons was more significantly than the arid land,accumulation of organic matter in the surface layer of calcareous paddy soil was also higher significantly than the arid land.In experimental calcareous paddy soil,the A/C value of activation grade was generally between 1.60 and 7.50;The A/C value of complexation grade was generally between 2.00 and 20.00;The A/C value of iron colloid crystal grade was between 2.00 and 15.00.The A/C or C/A value of Index for Various Series in paddy soil was able to reflect the occurrence characteristic directly,which was one of the mainly classified indexes of calcareous paddy soil under karst ecological environment.(4) In experimental calcareous paddy soil,There was very significant positive correlation between Distribution of Available Silicon in soil profile horizons and pH value of soil,content of soil clay,along with leaching and deposition of clay,content of Available Silicon also change.Which showed that variation on paddy soil profile was also one of the occurrence characteristic indexes of calcareous paddy soil under karst ecological environment.(5) Under karst ecological environment in Guizhou plateau area,there is certain relationship between migration and transformation of material,leaching and deposition and ecological environment in calcareous paddy soil.The results show that: There was significant negative correlation(r=-0.617,n=15)between differentiation (A/C value) of organic matter in soil profile horizons and altitude,its A/C value presents that:low elevation area＞middle elevation area＞high elevation area.In addition,There was very significant positive correlation(r=-0.677,n=15 and r=-0.729,n=15)between altitude and content of Chelated iron,A/C value of complex grade.Annual temperature influenced the accumulation of organic substance,leaching loss and particles deposited.There is certain positive correlation(r=0.404,n=15)between annual temperature of different area and A/C value or C/A value of every index in paddy soil profile,among them there was significant correlation(r=0.540,n=15 and r=0.655,n=15) between A/C value of Chelated iron, complex grade and annual temperature.But because the controlling factor of water and human in paddy soil are dominant,which makes correlation not obvious between annual precipitation and differentiation degree of every index.更多还原