| The effect of different temperature and soil moisture conditions on the humus formationand transformation using indoor simulation test method from the dynamic perspective wasstudied in this paper.The transformation law with time was learned among the composing ofthe microbe,the amount of soil microbe biomass carbon (SMBC),the formation ofhumus,humin and their structure properties.Identified the important role of the microbe on theformation and transformation of the humus and humin's different components,discussed thechange law and transformation mechanism of the humin component at impact of differenttemperature and water conditions.All of the studies can provide the new information for thestudy of soil humin and Soil Biochemistry. the experimental results are as follows:(1) After the addition of corn stalk,the SMBC is the highest at low temperature andsubmerged conditions,but lowest at high temperature and low water content conditions atdifferent temperature and water content incubation.The SMBC at low temperature is908.1mg·kg-1,submerged is 805.5mg·kg-1,but high temperature and low water content are306.5and 507.7mg·kg-1,increased about 62%and 37%.(2) After corn stalks were added,the amount of SOC increased obviously, the SOC is11.03g·kg-1 before the corn stalks added,but is 23.31g·kg-1 after added.up to 52.7%.Under different culture conditions,high temperature can promote it decomposition andtransformation, 40℃Cis the most appropriate temperature to decomposition;Low water canpromote the SOC decomposition and transformation.40-55℃conditions are conducive to water-soluble substances (WSS) formation andaccumulation; 10-25℃conditions are conducive to the WSS decomposition andtransformation. 30% water content is beneficial to the formation and accumulation of WSS,and 90% water content is beneficial to the decomposition and transformation of WSS. Fromthe△logK value of WSS, we can see that 55℃culture condition makes its molecularstructure more simplification, 10℃conditions are conducive to the complexity of themolecular structure. Different moisture conditions, the 30% water content to the molecular structure simplified.Cultivation of different temperature conditions, the trend of absolute content of humicacid (HA) in the cultivation of high-temperature conditions declined, however, its proportionin the total carbon showed an increasing trend. The molecular structure of the HA is simplisticat different moisture conditions;Under different temperature conditions,the molecularstructure at 10-25℃condition is more simplification.The amount of FA is 0.15g·kg-1 increased to 1.48g·kg-1 after corn stalk added, the increaseratio is nearly 90%.30% water content cultivation is conducive to formation and accumulationof the FA; and submerged conditions are conducive to the decomposition and transformationof FA.From the△logK value of FA, room temperature conditions are conducive to themolecular structure simplistic of the FA,40C condition can complicate their molecularstructure;Under different moisture conditions,30% water content make for the molecularstructure simplification,submerged conditions are opposite.PQ is minimum at 40℃conditions with the whole process,but its blank ishighest,indicated that 40℃conductive to formation of the HA,But the corn stalkdecomposition process is contributed to the FA and HA conversion;Under different moistureconditions,PQ has the highest value at submerged conditions,Indicated that the higher watercontent,the more conductive to the formation of HA.(3) After added the corn stalk,the number of humin (HM) is significantly higher than CK,In different temperature conditions,55℃helped to the formation and accumulation of theHM,and 10℃would contribute to the HM decomposition and transformation;In differentmoisture conditions,30% water content conductive to the formation and accumulation of HM.Under different temperature conditions of the HMi,10-25℃can make for the HMiformation and accumulation;In different water content circumstances,Under the content of30% conditions,HMi has the fastest decomposition speed.From the△logK value ofHMi, 10-25℃conducive to the molecular structure simplification.Under different temperature conditions of HMc,40℃is the best temperature of the HMc tothe formation and accumulation and 55℃for HMc is beneficial to the decomposition andtransformation;Under different moisture conditions,90% water content conducive to theformation and accumulation of the HMc,and 30% water content can promote the HMcdecomposition and transformation.The impact on the HMc's△logK in different temperatureconditions. 10℃more conducive to the molecular structure simplification of the HMc,and 55℃conditions were conducive to molecular structure complex of the HMc;different moistureconditions,30% water content can make HMc molecular structure complex. HMr in different temperature conditions, 10℃conditions are conducive to the amount ofthe HMr accumulation,and 55℃conditions can promote the HMr decomposition andtransformation.In different Water content incubation,90% water content is beneficial to theformation and accumulation of HMr, and 30% water content promote the HMr decompositionand transformation.With the different temperature incubation of the I/C and (HMi+HMc)/HM,the I/C ratio lessthan 1 at 40℃culture conditions,and the (HMi+HMc)/HM ratio reach the highest,indicatedthat at this temperature promote the HMi decomposition and transformation,make for the(HMi+HMc)/HM increase,which is conducive to the formation of the soluble HM. Indifferent water content culture conditions, low water content is more conducive to make(HMi+HMc)/HM increase than high water content,which is conducive to the formation of thesoluble HM.(4) the HMi's comparison of C/H,it has the highest radio under high temperatureconditions,Noted that high temperature has the highest condensation and aromaticity, and theHMc's comparison of C/H and O/C,the ratio of the C/H is highest,but O/C is lowest undersubmerged conditions,indicated that HMc has the highest condensation and the lowestoxygen.Differential thermal analysis from the map,HA's molecular structure relatively simple atsubmerged conditions.Its more complex of the HA's molecular structure under normal culturethan other conditions,and HMc's molecular structure more complex than HMi.Submerged conditions make HA's aliphatic strong,and the strongest oxyenation,But hightemperature conditions reduced the HA's aliphatic hydrocarbon content,Joined with corn stalkcompared to the blank soil.HMi's aliphatic hydrocarbon content decrease,the lower degree ofoxidation and aromaticity.Flooding conditions are conducive to the aliphatic of HMi.25℃conditions conducive to the aliphatic of.HMc High moisture conditions are conducive to HMcaromatization.
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