中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
不同土地利用方式下黑土土壤微形态特征研究

文献类型:学位论文

作者张瑜
学位类别硕士
答辩日期2014
授予单位中国科学院研究生院
授予地点北京
导师张丹
关键词土壤微形态 黑土 土地利用 耕作年限
其他题名Studies of Soil Micromorphological Characters in different land-use type at Heilongjiang Province
学位专业土壤学
中文摘要黑土具有深厚的腐殖质层,是我国东北地区的主要耕作土壤,研究不同土地利用方式对黑土土壤微形态的影响,观察土壤的微结构变化,对土壤质量的评价有重要意义。本文以黑龙江省海伦市黑土土壤剖面为主要研究对象,从微形态角度并结合土壤理化性质分析对比不同土地利用方式(耕地、林地、草地、荒地)的黑土土壤微形态特征,探索土地利用对土壤微形态的影响及其规律,为研究土壤质量变化并解决土壤退化问题提供理论依据。 野外调查黑土土地利用方式,选择天然草甸黑土、油松林地、人工杨树林地、撂荒地、耕地(不同耕作年限)作为研究对象,采集样品,制作土壤薄片,在偏光显微镜下观察土壤微形态特征,包括土壤粗颗粒形态、土壤孔隙形态、土壤形成物、土壤有机物、土壤微垒结和土壤微结构,对其进行详细观察、分析和描述,并采集土壤微形态图像,用Image-Pro Plus 6.0图像处理软件定量分析土壤结构(包括粗颗粒的面积、周长、长径、短径、等圆直径、圆度,土壤孔隙的数量及大小)。同时,测定土壤的理化性质(包括土壤容重、含水量、机械组成、TOC、全氮、有效磷、速效钾)。对比分析数据,本文得出以下结论: 1、 不同土地利用方式下黑土土壤粗颗粒矿物组合基本一致,主要是石英和长石矿物,只偶尔发现有云母的残片。 2、 不同土地利用方式下的黑土土壤微垒结相似,由粗颗粒形成骨架,中间的空隙中部分填充了粘土矿物等细粒质的集合体,无填充的粗颗粒则相互支撑,为填集状垒结。黑土呈海绵状微结构,由大小不等的浑圆形或椭圆形团聚体组成,并含有许多腐殖质黑色絮凝物和颗粒物,团聚体被腐殖质膜包被,孔隙较多,结构疏松但不松散,土壤有良好的通气性和持水性。但是在耕作年限为50年的表土层其微结构致密紧实,为不规则棱块状。 3、 不同土地利用方式下黑土的土壤形成物相似,都主要是2:1型的粘土矿物,在B层和C层还有一些呈絮状凝团和斑状的铁锰新生体。土壤有机物的分布也相似,A层中以植物残体(大部分是植物根系)、腐殖质和蚯蚓排泄为主,B层中主要是一些腐殖质絮状物和颗粒物,C层基本无有机物。 4、 土地利用方式及耕作年限对黑土土壤粗颗粒的形态特征有显著影响:(1)草甸土和油松林地不受人类活动的影响,土壤颗粒保持原始状态,从A层到C层,土壤粗颗粒的面积、周长、长径、短径、等圆直径等特征值变小,且粒径在20~100μm的大颗粒物所占比例下降,而2~20μm的颗粒所占比例增大。(2)耕地由于耕作年限的不同,土壤粗颗粒形态特征也有显著不同。随着耕地耕作年限的延长,土壤粗颗粒的面积、周长、长径、短径、等圆直径等特征值增加,而20~100μm的颗粒物比例却下降。(3)耕地、林地、草地、撂荒地的粗颗粒大小排列顺序为油松林<2年耕地<人工杨树林地<10年耕地<草甸土<30年耕地<50年耕地<撂荒地。(4)耕地的土壤发生层粗颗粒变化与原始状态相似,但其中SA耕地和HL耕地的粗颗粒特征值,从A层到C层颗粒的面积、周长等值呈增大趋势,这可能是由于人类活动造成表土层土壤的扰动,破坏了土壤的结构,表土层碎屑物增多。 5、 不同土地利用方式对黑土土壤的孔隙结构有显著的影响:天然草甸黑土的土壤孔隙度很少且孔隙以管道状孔隙为主;油松林地的土壤孔隙分布均匀;耕作土壤的土壤孔隙度较大,且孔隙形状不规则,呈堆集性孔隙,孔隙度随着耕作年限的延长而降低;耕地退耕还林后,土壤孔隙度增大,且土壤孔隙结构较好,土壤的通气性好,耕地停止耕作撂荒后表土层的孔隙结构有所改善,孔隙度有所增加。 6、 不同土地利用方式对黑土土壤的理化性质有明显的影响:(1)油松林地和草甸土表土层粘粒含量较少,而深层土壤粘粒含量较高。耕地的粘粒含量随着作年限的增加而增加,尤其是表土层粘粒含量的增加最明显,且刚开始耕作的2~10年,土壤发生层从A层到C层,粘粒含量不断增加。但是当耕作30~50年后,土壤中的粘粒含量反而降低。退耕还林后的人工杨树林地和耕地停止耕作后的撂荒地的土壤发生层整体的粘粒含量较高。(2)耕作年限的延长导致土壤容重增大,而含水量降低。不同土地利用方式的土壤容重大小变化为草甸土<油松林地<人工杨树林地<耕地<撂荒地,而土壤含水量的大小变化为草甸土>油松林地>人工杨树林地>耕地>撂荒地。(3)同一土体土壤从A层到C层,随着土层深度的增加TOC含量逐渐降低。不同土地利用方式土壤有机碳含量的的变化为草甸土>油松林地>2年耕地>10年耕地>人工杨树林>30年耕地>50年耕地>撂荒地。
英文摘要Black soil is a main farming soil in northeast China because of its deep humus layer. It is a significant method to study the micromorphological features of black soil in different land-use type in order to estimate the quality of soil. Based on the research of the soil profile of black soil in Heilongjiang province and combined with the physicochemical property of soil, this paper researched the micromorphological features of different land-use black soil, such as cultivated land, forest land, grassland and wasteland. According to this research, we observed the soil microstructure to explore the effect of different land use on soil micromorphological and its regularity, and at the same time to offer the theoretical foundation to the evaluation of soil quality for solving the problem of soil degradation. According to investigating the land-use black soil on the field, we choosed natural meadow black soil, Chinese pine forestland, artificial poplar forest land, waste land, and cultivated land (different tillage years) as the research object, collected samples, and make soil slice. We put the soil slice under the polarized light microscope and observed the micromorphological features of soil, including shapes of soil coarse particles, shapes of void, soil pedpfeature, soil organic matter, soil plasmic fabric and soil microstructure, and at the same time collect the pictures of soil micromorphology. These pictures were analyzed and calculated by Image-Pro Plus 6.0 Image processing software to quantified the soil structure, including the coarse particle area, perimeter, length, width, diameter, roundness, the number and size of soil void. At the same time, we measured soil physical and chemical properties, including soil bulk density, water content, mechanical composition, TOC, total nitrogen, effective phosphorus, rapidly-available potassium). Analyzing the experimental data, we get the following conclusions: 1、The main mineral components of black soil coarse particles on the different land-use type are quartz and feldspar, and occasionally contained some pieces of mica. 2、The different land-use black soils have a similar plasmic fabric, called enaulic fabric. This plasmic fabric formed by the coarse particle skeleton, and void partly filled in the micromass aggregate, and if void is not filled by micromass, coarse particles support each other. The micro structure of black soil is like spongy, and consists of different size of round or oval aggregates and contains many black humic floc and particles. Aggregates are embraced by humus membrane and have a lot of voids, so the structure of soil is loose but not lax, and soil has good air and water permeability. However, the micro structure of the topsoil that had cultivated 50 years is compact structure and have little void. 3、The soil pedpfeature of black soil on different land use is mainly clay mineral (2:1 type), besides some flocculent and porphyritic Fe-Mn minerals exist in B and C layers. The distribution of soil organic matter in different land use is almost identical. The organic matter is plant residues (mostly plant roots), humus and earthworm excretion in A layer, and some humic floc and particles in B layer, and no organic matter in C layer. 4、Different land use and tillage years have a significant effect on morphological characteristics of black soil coarse particles: (1) Soil particles in the meadow soil and Chinese pine forestland affected slightly by human activities remain the original state. From A to C layer, of soil coarse particles,such as area, perimeter, length, width, diameter and so on, are decreased, and the proportion of coarse particles between 20 to 100 microns reduces but the proportion of coarse particles between 2 to 20 microns increases. (2) Micromorphological feature values of soil coarse particles of cultivated land, due to the different tillage years, are significantly different. Along with the extension of cultivated land, soil coarse particles f
语种中文
源URL[http://ir.imde.ac.cn/handle/131551/8028]  
专题成都山地灾害与环境研究所_山地表生过程与生态调控重点实验室
推荐引用方式
GB/T 7714
张瑜. 不同土地利用方式下黑土土壤微形态特征研究[D]. 北京. 中国科学院研究生院. 2014.

入库方式: OAI收割

来源:成都山地灾害与环境研究所

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