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1、植物营养与肥料学报2010,16(6):1418-1425PlantNutritionandFertilizerScience黄土台塬不同土地利用方式下土壤碳组分的差异*刘梦云,常庆瑞,杨香云(西北农林科技大学资源环境学院,农业部黄土高原农业资源与环境修复重点开放实验室,陕西杨凌712100)摘要:为探讨土地利用方式对土壤碳固定的影响,以乔木、灌木、草和农田等不同植被类型,纯林和混交两种栽培模式的黄土台塬为对象,进行了土壤碳组分研究。结果表明,不同利用方式下林地和天然草地在0100cm土层总碳,
2、轻组、重组、可溶性有机碳以及轻组有机碳分配比例(LFOC/SOC)均不同程度高于耕地,而其有机无机复合度(HFOC/SOC)则低于耕地,灌木林地和天然草地这种趋势尤为突出;各种土地利用方式间,土壤总碳和HFOC/SOC在020cm差异显著,总碳在60100cm也差异明显,轻组、重组及可溶性有机碳在040cm,而无机碳则在40100cm差异明显;LFOC/SOC和DOC/SOC在各土层均存在一定差异。土壤总碳、有机碳以及各组分有机碳之间呈极显著正相关,而无机碳则与其呈负相关。轻组和可溶性有机
3、碳均与粗颗粒、易氧化有机碳以及2025mm团聚体有机碳的相关性高于与细颗粒、稳态有机碳和>2mm团聚体有机碳;而重组有机碳则与之相反。轻组有机碳较有机碳、总碳、重组以及可溶性有机碳能更敏感地反映利用方式之间的差异,可作为土壤质量变化的评价指标。关键词:黄土台塬;土地利用方式;总碳;无机碳;有机碳组分中图分类号:S152.4文献标识码:A文章编号:1008-505X(2010)06-1418-08Soilcarbonfractionsunderdifferentlandusetype
4、sinthetablelandsoftheLoessPlateau*LIUMengyun,CHANGQingrui,YANGXiangyun(KeyOpeningLaboratoryofAgricultureResourceandEnvironmentRenovationintheLoessPlateau,MinistryofAgriculture/CollegeofResourcesandEnvironment,NorthwestAgricultureandForestryUniversi
5、ty,Yangling,Shaanxi712100,China)Abstract:Effectsoflandusetypesonsoilorganiccarbon(SOC)sequestrationinthetablelandsoftheLoessPlateauwerestudiedinthispaper.Therewerefourvegetationtypescultivatedinpureandmixedplantingmodels,namelyarbor,shrub,grassandfar
6、mland.Soiltotalcarbon(STC),soilinorganiccarbon(SIC),densityoforganiccarbonanddissolvedorganiccarbonwereanalyzed.Theresultsshowedthatconcentrationsofsoiltotalcarbonin0-20cmand60-100cmweresignificantlydifferen,tandthelightfraction(LFC),heavyfraction(HFO
7、C)anddissolvedorganiccarbon(DOC)werein0-40cm,whilethesoilinorganiccarbonwasin40-100cm,LFOC/SOCandDOC/SOCweredifferentineachlayer,andHFOC/SOCwassignificantlydifferentin0-20cm.Soiltotalcarbon,lightfraction,heavyfraction,dissolvedorganiccarbonandLFOC/S
8、OCofforestlandandnaturalgrasslandwerehigherthanthoseoffarmland,whiletheirHFOC/SOCwerelowerthanthoseoffarmland,andthatofshrubforestlandandnaturalgrasslandshowedthistendencymuchmore.Underdifferentlandusesthereweresignificantpositivecorrelationsb