秸秆生物炭对土壤功能微生物生长及吸附的影响

摘要

生物炭具有多孔结构和较大的比表面积能够为许多土壤微生物的生长、繁殖提供有利的条件.生物炭通过促进土壤功能微生物的生长及活性,从而间接提高作物产量,在农业领域有着广阔的应用前景.为了研究秸秆生物炭对12种不同土壤功能微生物的影响,在培养基中添加0.6％的生物炭后,利用MTT法测定微生物生长曲线的变化,同时在一定浓度的菌悬液中加入0.6％的生物炭,室温振荡1h后,测定生物炭对微生物的吸附率.结果表明,秸秆生物炭对不同的细菌的生长影响不同,对于部分细菌存在明显生长促进作用,其中对胶质芽孢杆菌1.217的促进作用最明显,培养12h后其最大生长量可提高3.6倍;对于巨大芽孢杆菌1.217、 短小芽孢杆菌04306以及褐球固氮菌01077,加入生物炭培养14～20h后最大生长量可提高1.5倍左右;巨大芽胞杆菌01667加入生物炭培养12h后,其最大生长量也可提高1.3倍;而对于另外一部分细菌,生物炭对其生长基本没有影响或有较小的抑制作用.同时,生物炭水洗后,对不同细菌的影响与水洗前基本一致,对于巨大芽孢杆菌1.217、短小芽孢杆菌04306、绿色北里孢菌02567、苏云金芽孢杆菌04311、蜡状芽孢杆菌04289、巨大芽孢杆菌01667和短小芽孢杆菌01736,生物炭水洗前后对其生长影响差别不大.另外,秸秆生物炭对部分微生物具有一定的吸附作用,其中吸附效果最为明显的是蜡状芽胞杆菌4289和胶质芽胞杆菌1.153,吸附率分别为54.40％和48.10％.这些研究结果证明生物炭能够改变土壤功能微生物的生长状况,但是对于不同的微生物,生物炭的作用效果不同.%The porous structure and large surface area of biochar provide a suitable habitat for microorganisms when it is added to soil. Because incorporation of biochar into soil may indirectly increases crop yields by promoting the growth and activity of soil functional microorganisms, biochar is attracting attention for its broad application prospects in agriculture. In order to study the effects of straw biochar on 12 different soil microorganisms, the changes of microbial growth curves were determined by MTT method after adding 0.6％ biochar in the medium. At the same time, 0.6％ biochar was added to a certain concentration of bacterial suspensions, and the adsorption rate of biochar on microorganisms was measured after 1 hours shake at room temperature. Experimental results showed that straw biochar had different effects on the growth of different bacteria. Biochar could promote the growth of some bacteria, and its promoting effect on Bacillus megaterium 1.217 was the most obvious. After 12 hours, the maximum growth of Bacillus megaterium 1.217 increased by 3.6 times. The maximum growth of Bacillus megaterium 1.217, Bacillus pumilus 04306, and Azotobacter chroococcum 01077 increased by about 1.5 times after 14-20 hours when biochar was added, and after 12 hours, that of Bacillus megaterium 01667 increased by about 1.3 times too. While biochar had no influence or little inhibitory effects on the growth of the other bacteria. After water washing, the effects of biochar on the different bacteria were basically the same as before washing, and for Bacillus megaterium 1.217, Bacillus pumilus 04306, Kitasatospora viridis 02567, Bacillus thuringiensis 04311, Bacillus cereus 04289, Bacillus megaterium 01667 and Bacillus pumilus 01736, the influences of biochar before and after washing on them had no significant difference. Biochar could absorb some bacteria, and among them, it had most obvious adsorption effects on Bacillus cereus 04289 and Bacillus mucilaginosus 1.153. The adsorption rates were 54.40％ and 48.10％ respectively. These results showed that biochar could alter the growth of soil functional microorganisms. However, effects of biochar are different depending on the species of microorganisms.