Abstract
Biochar is widely used to improve soil physical properties and carbon sequestration.However,few studies focuse on the impact of maize stalk biochar on labile organic carbon(LOC)pool and the relationship between physical properties and LOC fractions.A field positioning experiment was performed in Mollisols region of Northeast China to evaluate the influence of maize stalk biochar on the spatial distribution and temporal changes of physical properties and LOC fractions.Maize stalk biochar treatments included C1(1.5 kg·hm-2),C2(3 kg·hm-2),C3(15 kg·hm-2),C4(30 kg·hm-2),and CK(0).The results showed that maize stalk biochar increased soil water contents(SWC)and soil porosity(SP),but reduced bulk density(BD).Maize stalk biochar reduced dissolved organic carbon(DOC)contents in the 0-20 cm soil layer,ranging from 0.25 g·kg-1 to 0.31 g·kg-1 in harvest period,while increased in the 20-40 cm soil layer.In addition,the application of biochar had a significant impact on the spatial distribution and temporal change of SWC,BD,SP,DOC,hot-water extractable carbon(HWC),acid hydrolyzed organic carbon(AHC I,II),and readily oxidized organic carbon(ROC).High amounts of maize stalk biochar up-regulated the contents of soil organic carbon SOC,HWC,AHC I,AHC II,and ROC.In addition,SWC and SP were the key physical factors to affect LOC fractions.In conclusions,maize stalk biochar could improve physical properties,and then influence LOC fractions,and maize stalk biochar could be used as an organic amendment for restoring degraded soils governed by their rates of addition.
NETL
NSTL
万方数据