Effect Of Biochar On Soil Physicochemical Property And Microbial Diversity In Different Soil Types

Application of biochar technology not only can dramatically reduce carbon dioxide and other greenhouse gas emission and achieve fixing carbon and reducing discharge, but also improve soil physiochemical property and biological character by applying biochar into soil. For this reason, applying biochar into soil received extensive attention. However, Viewpoints about the effect of biochar application are differs, this may be relate to the properties of the biochar, soil type and soil microbes. At present, relatively few studied on this subject. Therefore, this study discussed the effect of biochar application on soil physiochemical property and soil microbial diversity in four different types of soils （Albic soil, Fluvo-aquic soil, Grey desert soil and Brown soil）, and provide a reference for the application of biochar in agriculture. Main research results are as follows.1. Applying biochar could effectively increase the soil pH value in four different types of soil.40t·hm-2biochar treatment showed the highest pH value, followed by20t·hm-2biochar treatment, and treatment without biochar showed the lowest pH value. Significant difference between treatments were varied with different soil types and sampling periods. pH value of40t·hm-2biochar treatment increased0.17and0.35units, respectively, compared with20t·hm-2biochar treatment and without biochar treatment.20t·hm-2biochar treatment increased0.19units than without biochar treatment.2. Applying biochar could significantly increase soil organic matter, total carbon content and C/N.40t·hm-2biochar treatment was significantly higher than that without biochar treatment. Taking last sampling of autumn spinach for example, organic matter content of albic soil in40t·hm-2and20t·hm-2biochar treatment increased by11.9%and8.3%than control, respectively, fluvo-aquic soil increased by46.7%and26.2%, grey desert increased by11.6%and1.7%, and brown soil increased by33.8%and9.1%.3. There was no significant difference in available nitrogen content of soil between applying biochar treatment and without biochar treatment at the first sampling of spring spinach, but there was significant difference at the later sampling period. Available nigrogen content in40t-hm"2biochar treatment were increased by0.2～99.2%and0.6～127%, respectively, compared with20t-hm"2biochar treatment and without biochar treatment, and20t·hm-2biochar treatment increased by0.4%～42%than without biochar treatment. The total nitrogen content in40t·hm-2biochar treatment were increased by0.5～38.6%and0.7～23.2%, respectively, compared with20t·hm-2biochar treatment and without biochar treatment, and20t·hm-2biochar treatment increased by3.7%～24.7%than without biochar treatment.4.20t·hm-2and40t·hm-2biochar treatment increased available phosphorus and potassium content in different extent in four types of soil, while there were difference effects in soil total phosphorus and total potassium content. Albic soil applying20t·hm-2and40t·hm-2biochar treatments could increase exchangeable Na, Ca and Mg content, but reduce the content of effective zinc. Fluvo-aquic soil applying biochar treatments could improve soil exchangeable Ca, Mg and available zinc content, however, available Mn content decreased.5. Applying Biochar treatments increased the quantities of bacteria, actinomycetes, ammonifier, and nitrogen-fixing bacteria in four different types of soil. In the view of applying biochar proportion,40t·hm-2biochar treatment were higher than20t·hm-2biochar treatment. However, the fungi quantities in albic soil and fluvo-aquic soil decreased in applying biochar treatments, and this may be related to the soil type, soil nutrient content a well as microbial characteristics and so on. The microbial biomass carbons in applyin biochar treatments were higher than that of without biochar treatment in4types of soil, whil MBC of40t·hm-2biochar treatment was significantly higher than that of20t·hm-2biocha treatment.6. The AWCD, species richness index, evenness index, dominance index, and carboi utilization richness index in applying biochar treatments were lower than that of in withou adding biochar treatment in the initial stage of applying biochar in four different types of soil At the later stage of applying biochar treatment, the soil microbial AWCD and diversity inde: of the t·hm-2the biochar treatment were higher than that of20t·hm-2biochar treatmen and without adding biochar treatment, which could explain that the single carbon souro utilization and metabolic activity of soil microorganisms in the40t·hm-2biochar treatmen was higher than other treatments.7. Soil microbial available carbon sources in applying biochar treatment were highe than without biochar treatment in four types of soil. The Albic soil, gray desert soil and brow soil increased the utilization of other mixture carbon source, and Fluvo-aquic soil increase the utilization of amine carbon source. Comprehensive analysis the utilization characteristi of carbon source by microorganism in four different soil types, five kinds of available carbo: source presented in applying40t·hm-2biochar treatment:sugar had2kinds, amino acids ha2kinds, carboxylic acid had4kinds, polymer had3kinds, and other mixture had1kind. Fiv kinds of available carbon source presented in applying20t·hm-2biochar treatmet:sugar ha3kinds, amino acids had4kinds, carboxylic acid had4kinds, polymer had1kind, and othe mixture had1kind. Three kinds of characteristic carbon sources were used by witho applying biochar treatment:4kinds of sugar,2kinds of amino acids, and2kinds of polymers8. Soil microbial population structure diversity in applying biochar treatments wer improved in different extent in four types of soil. Microbial quality and population structure i the same kind of soil were differences with different biochar treatments and differer sampling periods. Furthermore, the effects of applying biochar on soil microbial populatio structure were differences in different types of soil.12specific single colonies were isolate from albic soil in applying biochar treatments, which were Bacillus pumilus, Bacillu megaterium, Paenibacillus glucanolyticus, Bacillus simplex, Chryseobacteriur gleum/indologenes, Rhizobium radiobacter, Cellulomonas hominis （CDC.A-3）, Arthrobactt histidinolovorans, Flavobacterium hydatis （26C）, Sphingobacterium multivorum, Penicilliu oxalicum Currie&Thom and Pseudomonas aeruginosa, respectively.6specific colonies wei separated from fluvo-aquic soil in applying biochar treatments, the similarity with the mo; similar strains in GenBank were99%～100%, and they were Chryseobacterium sp. WR Bacillus sp. DU26（2010）, Arthrobacter sp. CMJ2-1, Paenibacillus sp.9N4, Brevibacteriu, sp.210₁4and Bacillus sp. CMJ1-5, respectively. Analyzing relatively bright fluorescenc intensity and specificity bands in DGGE, there were6strains having100%similarity wil objective bands, uncultured bacteria were20strains, and culturable bacteria were38strain Total25specific bands were isolated from four types of soil,20bands of which were peculia to applying biochar treatments, which took up80%of all specific bands.