EGI OpenIR  > 研究系统  > 荒漠环境研究室
高矿化度水滴灌下沙漠公路防护林土壤性质变化特征研究
窦凯歌
学位类型硕士
导师雷加强
2015
学位授予单位中国科学院大学
学位授予地点北京
学位专业水土保持与荒漠化防治
关键词咸水滴灌 沙漠公路防护林地 土壤理化性质 分布特征 盐分
摘要塔里木沙漠公路防护林建设对土壤质地和养分状况具有显著的改善作用,同时,高矿化度水灌溉和盐生植物的生物积盐作用又将对土壤质量施加一定的负效应。本研究从田块尺度上分析了土壤质地、养分和盐分的空间分布特征及其受防护林结构的影响,并对公路沿线不同矿化度咸水灌溉下土壤盐分及离子分布特征进行了深入探讨。主要结论如下: (1)防护林建成前,土壤质地以砂粒为主,粘、粉粒含量极少,肥力水平低,盐分含量少,pH呈弱碱性。防护林建成后,土壤细粒物质增多,养分含量增加,盐渍化过程明显,盐结皮发育,碱度加剧。尤以0~10cm土层受防护林建设和咸水滴灌影响最为剧烈。随着土层深度的增加,细粒物质、养分和盐分含量逐渐降低并趋于稳定。 (2)土壤性质在空间内具有不同程度的变异性,粘粒、粉粒、砂粒、全磷、全钾和pH变异系数较小,含量相对稳定,有机质、全氮、速效磷、速效钾和电导率变异系数则较高。电导率和全氮在空间上呈条带状分布,其余指标多呈斑块状分布,受研究区地形影响,土壤质地、养分在南北方向均存在一个二阶趋势。 (3)在防护林体系的不同部位上土壤性质存在差异。土壤粒度中细粒物质含量落沙带高于固沙带高于阻沙带和流沙;全氮、电导率和pH在林下(固沙带、阻沙带)的含量高于林间落沙带和流沙;全钾受母质中矿质组分影响很大,因而含粘粒较多的落沙带全钾含量最高;除全氮和全钾外,其余养分含量均表现为固沙带>落沙带>阻沙带>流沙。 (4)灌溉用水是土壤盐分输入的主要途径,土壤积盐程度随灌溉水矿化度的增大而加剧,盐分表聚作用强烈,盐结皮高度发育;受灌溉水影响,灌溉后各离子含量相比流沙地都有不同程度的增加,离子组成从Cl-、Na+、HCO3-占明显优势变成以Cl-、Na+和SO42-为主;不同盐分离子化学性质不同,与土壤胶体的结合能力不同,盐分离子在随水向下淋洗的过程中存在分异性,在土壤剖面上的分布特征不同。
其他摘要The construction of Taklimakan desert highway shelterbelt improves soil texture and nutrient content significantly, at the same time, saline water irrigation and the biological salt accumulation of halophytes lead to some negative effects on soil quality. In this study, soil texture, nutrients and salinity’s spatial distribution characteristics and how they affected by shelterbelt structure were studied in field scale. The characteristics of soil salt and ions’ distribution under different mineralization degrees of saline water drip-irrigation along the road were discussed in detail. Main conclusions were as follows: (1)Before the shelterbelt was built, soil texture was dominated by sand, the contents of clay and silt were few, the content of soil fertility was low, the salt content was less, pH appeared weakly alkaline. By comparison, after the shelterbelt was built, there were increments in soil particulate matter, nutrient content, salinization processes, the salt crust development and aggravation of soil alkalinity. The effects of the sheltrebelt construction and saline water irrigation on 0~10cm soil layer were the severest.With the increase of soil depth, fine material, nutrient and salt content decreased and stabilized. (2)Soil properties exhibited different degrees of variability in the space. Coefficient variation of clay, silt, sand, TP, TK and pH were small, their content in the soil were relatively stable, while, coefficient variation of SOM, TN, AP, AK and EC were larger. EC and TN appeared a banded structure in space, other indexes mostly showed a patchy distribution. Affected by topography of the study area, soil texture and nutrient both appeared a second-order trend that in south-north direction. (3)Soil properties were different at different positions on the shelterbelt system. Soil particulate matter showed a regular that falling-sand belt more than fixation-sand belt and more than that of resistive-sand belt and quicksand; the content of TN, EC and pH in understory were higher than that in forest and quicksand; TK was affected greatly by the mineral composition of the parent material, thus, falling-sand belts contain more clay and its TK content was the highest; except for TN and TK, the rest of the nutrient content showed fixation-sand belt> falling-sand belt > resistive-sand belt> quicksand. (4)Irrigation water was the main way of soil salt input, soil salinity increased with increasing irrigation water salinity levels, salt ran into the surface soil intensely, soil crust highly developed; affected by the irrigation water, each ion content had different degrees of increase compared to quicksand, soil salinity composition was dominated from Cl-, Na+, HCO3- to Cl-, Na+ and SO42- after irrigation; different salt ions had different chemical properties, and their abilities to combine with soil colloids were different, so the process of salt ions leaching to subsoil existed heterogeneities, the distribution characteristics of different salt ions in soil profiles were different.
学科领域水土保持与荒漠化防治
语种中文
文献类型学位论文
条目标识符http://ir.xjlas.org/handle/365004/14644
专题研究系统_荒漠环境研究室
作者单位中科院新疆生态与地理研究所
推荐引用方式
GB/T 7714
窦凯歌. 高矿化度水滴灌下沙漠公路防护林土壤性质变化特征研究[D]. 北京. 中国科学院大学,2015.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[窦凯歌]的文章
百度学术
百度学术中相似的文章
[窦凯歌]的文章
必应学术
必应学术中相似的文章
[窦凯歌]的文章
相关权益政策
暂无数据
收藏/分享
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。