摘要
容重(ρ_b)是土壤最基本物理性质之一,是衡量土壤质量和生产力的重要指标,也是土壤碳氮贮量估算的重要参数。为探明黄土区不同土层ρ_b的分布特征并建立预测模型,在黄土区布设243个样点,获取0～10、10～20和20～40 cm土壤ρ_b及环境因子,采用经典统计学与地统计学方法,分析了不同土层ρ_b的空间变异特征,并利用逐步回归和传递函数方程对ρ_b的空间分布进行了模拟。结果表明:黄土区不同土层ρ_b均为中等程度变异,ρ_b随土层深度的增加而增大。不同土层农地ρ_b最大,其次为林地和草地。0～10、10～20和20～40 cm土壤ρ_b半方差函数最佳拟合模型分别为指数模型、指数模型和球状模型,变程为22～780km。粉粒含量、坡度、海拔、多年平均降水量、气温、干燥度和土地利用是影响区域尺度黄土区ρ_b空间分布的重要因素,基于相关因子建立的传递函数模型可以解释0～40cm深度ρ_b变异的38%～52%,且预测效果优于逐步回归方程,可用于田间条件下ρ_b空间分布特征的预测。
【Objective】Soil bulk density(ρ_b)is one of the most important soil physical properties and can be used to characterize soil quality and soil productivity and as a basic parameter to assess soil carbon and nitrogen storage.Furthermore,ρ_b has a significant effect on transport of soil water and solutes.However,large-scaled soil databases do not encompass muchρ_b data,owing to the time-and laborconsuming methods to acquire such data,especially the data of deep soil layers in the field.This study was conducted to(1)explore characteristics of regional spatial variation ofρ_b relative to soil layer across the loess area,(2)determine effects of soil texture,topography,climate and land use onρ_b and(3)compare the stepwise regression method with the pedotransfer function method in simulation of spatial variation ofρ_b.【Method】A total of 243 sampling sites were set based on a grid sampling scheme(40 km×40 km)in the loess area,andρ_b of the soils at the depth of 0~10,10~20 and 20~40 cm of the soil profile and relevant environmental variables,were collected separately,at each sampling site.Spatial variation ofρ_b was analyzed with the classical statistic method and geostatistical method,respectively.Stepwise regression equation and pedotransfer function equation was used to simulate spatial distribution of soilρ_b,separately.【Result】Results show thatρ_b varied moderately within a soil layer,and generally increased with soil depth in the profile loess area.ρ_b variability in the 0~40 cm soil layer was moderate according to the coefficient of variation.In general,cropland was the highest in meanρ_b,and followed by forestland and grassland.Semivariance of soilρ_b of the 0~10,10~20 and 20~40 cm soil layer can be best fitted by the exponential model,the exponential model and the spherical model,respectively.Soilρ_b of the 0~10 cm soil layer exhibited strong spatial dependence and those of the 10~20 and 20~40 cm soil layer did moderate ones.The optimal interval between sampling sites was 5.6~11.2,70.9~14
作者
于冬雪
贾小旭
黄来明
邵明安
王娇
YU Dongxue;JIA Xiaoxu;HUANG Laiming;SHAO Mingan;WANG Jiao(Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100190,China)
出处
《土壤学报》
CAS
CSCD
北大核心
2019年第1期55-64,共10页
Acta Pedologica Sinica
基金
国家自然科学基金项目(41501233
41530854)资助~~
关键词
黄土区
容重
空间变异
土地利用
传递函数
Loess area
Bulk density
Spatial variation
Land use
Pedotransfer function
