Research On The Mechanism And Influence Of Biochar On Micro-ecological Environment Of Soil

Biochar is a carbon-rich solid material which produced from incompletecombustion of biomass and plays a more and more important role in environmentalscience. At present, it is advocated to product specifically for application for soil dueto the functions of long-term carbon sequestration and improving soil quality.However, the details of interactions of biochar, soil, microbes and roots of plant arestill far from being understood. The aim of this study was to assess the effect ofbiochar, bamboo charcoal (BC) and straw charcoal (SC) on soil quality and soilmicrobiology and initially determine structural and chemical changes of biocharincorporated into soil. The effects of studies were included:1. BC was extracted from soil by sieving-washing method after a period of timeand then was evaluated through microexamination of exterior and element analysis.2. A comparative field experiment to evaluate the effects of the combination ofbiochar and chemical fertilization on soil properties and microbial communitystructure. We tested these questions in field experiment by adding chemical fertilizerswith/without bamboo charcoal (BC)/straw charcoal (SC) for amending soil in orderto determine the effect of biochar addition on soil quality in comparison to traditionalfertilization practice and to discern the effect of biochar on soil microbial diversity.The following conclusions could be achieved after the analysis of experimentalresults.1. The pore structure of the bamboo charcoal was mainly micropore, and isaccouted for85.71%of the total number of holes.2. The results of scanning electron microscope-X-ray spectroscopy (SEM-EDS)showed that the elements of fresh and ageing biochar were mainly C. After two yearswhich BC applied into the soil, concentrations of C、K、Cl、Na decreased, O、P、Mg、Si、Fe、Al increased and the value of O/C increased by7%. The results of FTIRshowed that the biochar added into the soil appeared much more complicate absorption peak, and oxygen-containing functional group C=O, COOH. The results ofX-ray diffraction (XRD) indicated that the peaks of two kinds of bamboo charcoalswere hardly similar, part of peaks appeared narrow and sharp.3. Biochar is conducive to the improvement soil acidity. It also can increase theavailable nutrients and cation exchange capacity (CEC) significantly, Total soilnitrogen and potassium.4. Compared with the treatments of conventional fertilization, microbial biomasscarbon (MBC) of straw regular fertilization (SRF) had a largest increase, followed bystraw charcoal regular fertilization (SCRF) and bamboo charcoal regular fertilization(BCRF).5. PCR-DGGE results showed that more than20different electrophoreticbandsof each treatment can be isolated, which means paddy soil has rich diversity ofbacterial communities, and different fertilizer treatments showed a few stronginfluence on bacterial community. Most bands were shared by all seven samples andsignal intensity differed biochar fertilized treatments had more composite bandingpatterns, and higher microbial diversity. Shannon diversity indices calculated fromDGGE profiles indicated that the abundances of biochar treatments were higher thanthe abundances of other treatments, and was twice the abundance of CK. Study oncorrelation between soil nutrients and the diversity of soil microorganisms wasreceived and found that the diversity of soil microorganisms among the six treatmentswas closely related to the available nutrients and TOC of soil.