Effects Of Biochar Addition On Soil Organic Carbon Minerazation And Soil Aggregate Composition And Organic Carbon Distribution

Biochar refers to the highly aromatic substance,it is made from straw waste under complete or partial exclusion of oxygen and as a way to reduce greenhouse gases emissions,soil organic matter influences the formation of soil aggregate,soil aggregate affects the stability of soil organic carbon.Taking the normal soil which applys biochar three years ago as the object of study,the particle size fractions(PSFs)of soils were obtained using physical dispersion procedure,soil organic carbon mineralization was monitored under laboratory incubation,?13C and FTIR were used in order to study the mechanism of carbon sequestration by biochar applying.The main findings are as follow:1.The mineralization rate of soil organic carbon reached maximum on the first day of incubation and decreased rapidly then tended to stable afterwards.Throughout the 28 days of incubation biochar reduced cumulative mineralization of soil organic carbon.Applying biochar significantly increased the contents of soil microbial biomass compared with the treatments without biochar(CK).The rasults also indicated that biochar decreased metabolic quotients,microbial quotients,Q10 andC0 compared with CK.2.Biochar can increase the content of soil>20?m aggregates.The contents of soil organic carbon in>2?m aggregates were increased with biochar application.The rasults indicated that biochar had the benefits in improving the soil structure.3.Biochar had significantly affected the distribution of soil organic carbon.The results indicates that biochar was mainly enriched in>20?m soil aggregates,while also increased the relative content of aromatic carbon,increasing the ratio of hydrophobic C/hydrophilic C,reducing the relative content of polysaccharides in>20?m soil aggregates.The more active soil carbon often concentrated in larger aggregates,which means biochar may affect the composition of organic carbon in larger aggregates.