生物炭对土壤微生物特性影响的研究进展

生物炭是在低氧条件下生物质经过热裂解得到的含碳丰富的产品,可提高土壤酸碱度,具有保水保肥及改善土壤微生物特性等功能。综述了生物炭对土壤微生物生物量、微生物群落结构及土壤酶活性的影响,多数研究表明:生物炭的碱性性质及多孔性质提供了适宜微生物生长的微环境,从而增加了土壤微生物生物量碳、微生物生物量氮等的含量; 生物炭含有的营养物质及多孔性质,促进了土壤中细菌及某些功能菌的生长,但同时生物炭中含有的重金属及多环芳烃等有毒物质对细菌生长存在抑制作用; 相比于土壤细菌,生物炭碳氮比(C/N)高、含大量难降解碳化合物,则有利于土壤真菌生长,并且生物炭具有的较大孔隙度,为真菌菌丝提供了附着位点; 生物炭对微生物的促进作用间接提高了土壤中脱氢酶、脲酶、β-葡萄糖苷酶等土壤酶活性。因此,未来应进一步探索生物炭与土壤微生物之间的相互作用机理,深入了解生物炭的土壤改良作用,深化对土壤微生物多样性的认识。
Biochar is a carbon-rich product by pyrolysis under low oxygen condition. Biochar occupy a huge advantage in soil improvement due to its effect on regulating soil pH, possessing and holding water/fertility capacity and ameliorating soil microbial property. This paper summarized soil microbial biomass, the behavior of soil microbial community structure and soil enzyme after applying biochar to the soil. The alkaline nature and porous nature of biochar provide suitable microenvironment for microbial growth resulting in increasing soil microbial biomass carbon and microbial biomass nitrogen. The nutrients and porous nature of biochar improve the bacterial and functional bacterial growth, however, heavy metal and polycyclic aromatic hydrocarbon in the biochar can inhibit bacterial growth. The high ratio of C and N and much of recalcitrant compound of biochar improve fungal growth rather than bacteria. Furthermore, a large number of pores provide attachment site for fungal hyphae, so biochar promotes the growth of fungus in the soil. Promotion of biochar to microorganism indirectly improves activity of dehydrogenase enzyme, urease and β-glucosidase and their like. Now study of the effects of biochar on the soil microbial property is scarce and future research should further explore mechanism between biochar and microorganism, to understand the improvement of biochar to soil and recognize soil microbial diversity