Studies On The Role Of Microorganism In The Formation And Transformation Of Humus

Sixty-six species of microorganism were identified, and seventeen of them weredominate species. According to the result of identification, the role of microorganism in theformation and transformation of humus were researched in different incubate conditions. Theresults shown: there were no change of humus in different incubate conditions without anymicroorganisms in soil, it proved microorganisms play a very important role in the formationand transformation of humus. The factors of environment did not affect the result of formationand transformation of humus directly, but affect on the amounts of microorganisms and thereplace results of different species first, and then affect on the results of the formation andtransformation of humus by different microorganisms. The results shown:1,Cellulomonas fimi, Pseudomonas pseudoalaligenes, P.fluorescens var. I, Agrobacteriumradiobacter var.I, Streptomyces albus, S.chromfuscus, S.caeruleus, Bacillus subtilis,B.mycoides have function to accumulate the formation of FA.2,Nocardia rubropertincta, Nocardia convoluta, Aspergillus niger, Penicillium expansum,Phoma putaminum, P.nebulosa, Arthrobacter globiformis, Ar.citreus have function toaccumulate the transformation of FA.3,CeUulomonas fimi, Agrobacterium radiobacter var.I, Pseudomonas fluorescens var. I,Pseudomonas pseudoalaligenes, Streptomyces albus, S.caeruleus, S.chromfuscus, Bacillussubtilis have accumulated the formation of HA.4,B.mycoides, Nocardia rubropertincta, Phoma putaminum, P.nebulosa, Aspergillus niger,Penicillium expansum, Nocardia convoluta, Arthrobacter globiformis, A.citreus have functionto decompose the amounts of HA.5,When stalk of corn was input in soil, the amounts of microorganisms were stimulated andthe amounts of bacteria raise more quickly than the amounts of fungi, the rate of bacteria andfungi decline, it indicate that stalk of corn has a role to make fungi become dominate speciesin soil. Otherwise stalk of corn not only affect the species number of microorganisms, but alsohas a role to make soil organic substance to decompose raptly, and changed the humustransformation's feature, fungi play dominate role in humus transformation and became thedominate species in soil. 6,Temperature is one of the important environment factors to affect the amounts ofmicroorganisms, it affects on the amounts of fungi and bacteria essentially, but it seems dosenot affects the amounts of actinomycete. The research results also shown: temperature notonly changes the species number of microorganisms, but also change the replace results ofdifferent species. Higher temperature can lead to the species richness of microorganisms rise,and lead to HA decomposed, lower temperature have stimulate role to make HA accumulated,but different temperatures do not affect the amounts of FA changed.7,Besides temperature other environment factors such as soil moisture, the density of oxygenand carbon dioxide are also affect the amounts of microorganisms, but play a different role inthe species richness changed, the replace results of different species and the results offormation or transformation of humus. The research results shown: moisture in soil not onlychanged the species richness of microorganisms, but also changed the replace results ofdifferent species. When the moisture in soil is 30ï¼…, most of microorganisms play a dominaterole in the formation and transformation of HA, but when the moisture in soil is 15ï¼…, most ofmicroorganisms play a dominate role in the decompose of FA, in the dry and wet alternatelyincubate condition, most of microorganisms play a dominate role in the decompose of FA andHA at the same time. The density of oxygen not only changes the species richness ofmicroorganisms, but also changes the replace results of different species. Higher density ofoxygen can lead to the species number of microorganisms increase, and have stimulate role tomake HA and FA decomposed, lower density of oxygen have stimulate role to make HA andFA accumulated, but the accumulated amounts of HA and FA are not very obviously at theend when test was over (150 day). The density of 5ï¼…carbon dioxide does not change thereplace results of different species, speicies richness and the formation of HA and FA.