Effect Of Bio-char On The Carbon Dioxide Emissions And Carbon Intercepted In Soil

Emission of CO₂resulting from agricultural soil is main pathway ofgreenhouse gas emission. The effective measure to reduce the CO₂content of theatmosphere are increasing the sequestration of soil carbon pool. Bio-char mightincrease the carbon capture ability and reduce CO₂emissions in soil because ofits special properties.Different contents of bio-char were added in two fertility soil. The changesof soil particles were observed by SEM and infrared spectrum. Aggregate contentdistribution and various types of organic matter content in the soil amended withbio-charcoal and control soil was studied to explore the impact of bio-char onsoil CO₂emission and carbon sequestration potential, The results showed that:（1） Impacts upon all types of soil organic matter that Bio-char addition tosoilBio-char addition to soil increased the soil organic carbon significantly, thesoil organic carbon increased by about5.5mg/g average the carbon contentincreased by1%; the soil organic carbon content gradually stabilized as theculture time passed by, and no apparent increase or to decrease of soil samples inthe different treatment.Bio-char addition to soil can contribute to the generation and accumulationof soil active organic matter. The soil active organic carbon increased by about0.36mg/g average the carbon content increased by1%; With the addition ofbio-char increased, the percentage of active organic carbon content in organiccarbon reduced significantly, as the culture time passed by, the active organiccarbon appeared to decrease, the stability of soil organic matter increasedsignificantly.Bio-char played a positive role on promoting the formation of soil humus, italso has potential impact on stabilized the soil carbon pool. Contents of humicsubstances, fulvic acid and humic acid increased compared with the control, as the culture time passed by, this trend was more obviously. Compared withcontrols, the total humus content increased by67.6%to146.4%8%of bio-charwere added.（2） Impacts upon the micro-environment characteristics that Bio-charaddition to soilBio-char promoted the formation of aggregates, particularly micro-aggregates which played an important role of soil carbon sequestration. Aftersamples cultured six months, compared with the control, the microaggregatecontent increased by12.36%to12.67%8%of bio-char were added. In addition,bio-char increased the Mean Weight Diameter （MWD） of aggregates, it enhancedthe stability of the soil structure.Bio-char increased inter-particle pore and specific surface area in soilmicro-environment, which boosted the accumulation of soil organic matter.Bio-char applied to promote the formation of minerals such as clay and organicmatter, thereby slowing the decomposition rate of organic matter.Bio-char can accelerate the formation of carbohydrate, esters, aromatics andother organic macromolecules, thus difficult to use by soil microbial. It can beconclude that bio-char had important effects on organic carbon intercepted in soil,and increasing the capacity of the soil carbon pool.In addition, based on the contrast test in group A and B samples, found thatthe effect on carbon intercepted by bio-char inputted to infertile soil was betterthan fertile soil.（3）Bio-char addition to soil reduced the soil CO₂emissions significantly,compared with the control, the soil CO₂emissions reduced about4.8-5.8%average the carbon content increased by1%, and the effect on carbon interceptedby bio-char inputted to infertile soil was better than fertile soil.It can be conclude that bio-char had important effects on organic carbonintercepted and then impact the release of CO₂in soil.