不同培养方式下生物炭对土壤微生物的影晌

发布时间：2018-05-05 11:41

本文选题：生物炭 + 培养试验　；参考：《沈阳农业大学》2016年硕士论文

【摘要】：大量研究表明,生物炭还田将对土壤微生物群落结构产生显著影响,进而促进土壤有机质的矿化、提高土壤肥力。生物炭丰富的孔隙结构被认为能够为土壤微生物的繁衍提供庇护所,但生物炭自身携带的碳源能够在多大程度上支撑微生物的生长尚不明确,在不同土壤类型中生物炭对微生物的影响亦缺乏横向比较。为此,本研究采用室内培养方法,以新鲜生物炭接种土壤菌悬液的方式,使用了BIOLOG、DGGE、Py-GC/MS等技术手段,研究了生物炭对土壤微生物生长的支撑能力：进一步丌展了土柱淋溶培养试验,以具有不同pH值的红壤土、风沙土和盐碱土为试材,通过历时13个月的27次淋溶,模拟研究了较长时间尺度上生物炭对土壤微生物的影响。主要研究结果如下：1.生物炭对土壤微生物群落结构影响巨大。生物炭处理中土壤微生物对典型碳源的利用能力(AWCD值)低于对照；随着培养时间的延长,生物炭处理中的土壤微生物群落结构有向土壤原始微生物群落结演替的趋势。2.生物炭可为微生物提供部分碳源,如2-甲基-3-戊醇等,但也有一些含碳物质会对微生物产生抑制,如2-乙基-1-己醇,苯并噻唑。碳源结构的差异可能是导致土壤微生物群落结构变化的原因之一。3.生物炭显著提高了红壤土、风沙土和盐碱土中的微生物量和微生物活性,但土壤微生物熵随着生物炭添加量的增加而减少。4.生物炭添加显著提高了红壤土、风沙土和盐碱土土壤有机碳含量、土壤微生物量碳和脱氢酶活力。到淋溶培养结束为止,三种土壤的微生物量碳平均提高了：红壤土36.7%,风沙土17.3%,盐碱土82.0%；三种土壤的脱氢酶活力平均提高了：红壤土26.4%,风沙土163.0%,盐碱土34.3%。添加生物炭有效减缓了土壤有机碳的损失,作用效果依次为：红壤土盐碱土风沙土。5.淋溶作用下,生物炭显著提高了红壤土pH值,平均提高了0.72个单位。风沙土和盐碱土的pH值在生物炭的作用下有所下降。总体而言,三种土壤在添加生物炭后pH值接近中性,可能是导致微生物量增加因素之一。综上所述,生物炭能够为土壤微生物的生长提供部分碳源,但数量有限,难以单独支撑微生物长期生长。在淋溶条件下,生物炭可显著促进土壤微生物的繁衍,其对土壤pH的影响可能是重要原因之一。生物炭对土壤碳源的吸附和固持及对土壤微生物的作用有待进一步研究。
[Abstract]:A large number of studies have shown that the return of biochar to the field will have a significant impact on the soil microbial community structure, thus promoting the mineralization of soil organic matter and improving soil fertility. The rich pore structure of biochar is thought to provide a safe haven for soil microbes, but the extent to which the carbon sources carried by biochar itself can support the growth of microbes is not clear. The effect of biochar on microorganism in different soil types is also lack of horizontal comparison. Therefore, in this study, the supporting ability of biochar to soil microbial growth was studied by means of biolog DGGEPy-GC- / MS and fresh biochar inoculated with soil bacteria suspension. The experiment of soil column leaching culture was carried out. The effects of biochar on soil microorganism in a long time scale were simulated with red loam, aeolian soil and saline-alkali soil with different pH values, and 27 leaching times for 13 months were used to study the effects of biochar on soil microorganism. The main results are as follows: 1. Biochar has great influence on soil microbial community structure. The soil microbial community structure in biochar treatment showed a tendency of succession to soil primitive microbial community with the prolongation of culture time, and the soil microbial utilization capacity and AWCD value were lower than that of the control, and the soil microbial community structure in biochar treatment had a tendency of succession to soil primitive microbial community with the prolongation of culture time. Biochar can provide some carbon sources for microbes, such as 2-methyl-3-pentanol, but some carbon-containing substances such as 2-ethyl-1-hexanol and benzothiazole can inhibit microorganisms. The difference of carbon source structure may be one of the reasons for the change of soil microbial community structure. Biochar significantly increased the microbial biomass and microbial activity in red loam, windy sandy soil and saline-alkali soil, but the soil microbial entropy decreased with the increase of biochar addition. The content of organic carbon, microbial biomass carbon and dehydrogenase activity in red loam, windy sandy soil and saline-alkali soil were significantly increased by adding biochar. Up to the end of leaching culture, the microbial biomass carbon of the three soils increased on average: red loam 36.7, wind-sand 17.3, saline-alkali 82.0.The dehydrogenase activity of the three soils increased on average: 26.4in red loam, 163.0in aeolian sand, 34.3d in saline-alkali soil. The loss of soil organic carbon was effectively reduced by adding biochar, and the effect was as follows: red loam, saline-alkali soil, wind-sand soil. Under leaching, biochar significantly increased pH value of red loam soil, with an average increase of 0.72 units. The pH value of wind-sand soil and saline-alkali soil decreased under the action of biochar. In general, the pH value of the three soils was close to neutral after the addition of biochar, which may be one of the factors leading to the increase of microbial biomass. In conclusion, biochar can provide some carbon source for the growth of soil microorganism, but the quantity is limited, it is difficult to support the long-term growth of microorganism alone. Under leaching conditions, biochar can significantly promote the proliferation of soil microbes, and its effect on soil pH may be one of the important reasons. The adsorption and sequestration of biochar to soil carbon source and the effect of biochar on soil microorganism should be further studied.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S154.3

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