黄土丘陵不同土地利用方式下土壤颗粒组成及其分形维数特征  

Soil Particle Composition and Its Fractal Dimension Characteristics of Different Land Uses in Loess Hilly Region

作　　者：杨婷[1] 景航[1] 姚旭[1] 董昌平 由政 薛萐[1,3] 

机构地区：[1]西北农林科技大学,陕西杨凌712100 [2]重庆市渝北区华蓥山林场,重庆401120 [3]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《水土保持研究》2016年第3期1-5,24,共6页Research of Soil and Water Conservation

基　　金：科技基础性工作专项(2014FY210100);国家科技支撑计划(2015BAC01B03);陕西省科学技术研究发展计划(2011KJXX36)

摘　　要：采用野外采样与室内分析方法，运用颗粒体积分形理论，研究了黄土丘陵区4种土地利用方式下的土壤颗粒组成及其剖面特征。结果表明，4种土地利用方式下的土壤理化性质差异显著，表层土壤除全磷外化学性质总体表现为天然林＞人工林＞草地＞坡耕地，容重坡耕地＞草地＞人工林＞天然林，50—100 cm土壤性质差异减小。土壤以粗粉粒为主，除粗沙粒外，土地利用对其余各粒级含量影响显著，层次性不明显，坡耕地和草地小粒级含量高于天然林和人工林。黏粒和粉粒含量与有机质、全氮极显著负相关，与容重极显著正相关；沙粒与有机质和容重极显著正相关，与容重呈极显著负相关。土壤颗粒组成分形维数为2.52-2.74，各层次坡耕地和草地之间没有显著差异，但显著高于人工林和天然林。随着土层加深坡耕地呈缓慢降低趋势，草地、人工林和天然林呈缓慢增加趋势。土壤分形维数与黏粒和粉粒和容重显著正相关，与砂粒、有机质、全氮显著负相关，与全磷无显著相关性。综上所述，黄土丘陵区不同土地利用方式下土壤颗粒组成差异较大，草地和林地相对于坡耕地大颗粒含量明显增多，小颗粒明显减少。Taking field sampling and laboratory analysis method,using the fractal theory of particle volume,we studied soil particles and their features in profiles of four kinds of land use modes in loess hilly-gully region.The results show that the four kinds of land use modes have significant different soil physical and chemical properties,surface soil chemical properties decrease in the order：natural forestplantationgrasslandfarmland except the total phosphorus,bulk densities decrease in the order：farmlandgrasslandplantationnatural forests,the difference of soil properties reduce in the layer of 50—100cm.Coarse silt is dominant in soil,in addition to the coarse sand grains,the land uses have significant effects on the contents of the rest fractions,the hierarchy is not obvious,small fraction contents of slope farmland and grassland are higher than those of natural forests and plantations.A significantly negative correlation between organic matter,total nitrogen and the contents of clay and silt was observed,bulk densities are extremely significantly positively correlated with the contents of clay and silt;sand content is extremely significantly positively correlated with organic matter and density,is very significantly negatively correlated with bulk density.Fractal dimension of soil particles was 2.52-2.74,there is no significant difference between the level of farmland and grassland,but significantly higher than plantations and natural forests.Fractal dimension reduces with the increase of soil depth in farmland,fractal dimensions of the grass,plantations and natural for-ests show a trend of slow increasey.Fractal dimension is significantly positively correlated with contents of clay and silt as well as bulk density,was significantly negatively correlated with contents of sand,organic matter,total nitrogen,there was no significant correlation with the total phosphorus.To sum up,the land uses of loess hilly-gully region have the greater influence on soil particle composition,compared with sloping farmland,the par

关 键 词：黄土丘陵区 土地利用方式 颗粒组成 分析维数 

分 类 号：S152.3[农业科学—土壤学]