四种生物炭对潮土土壤微生物群落结构的影响

为探究生物炭对土壤微生物群落结构的影响,以花生壳生物炭(PBC)、玉米秆生物炭(MBC)、杨木屑生物炭(ABC)和竹屑生物炭(BBC)为试验材料,每种生物炭分别以0、20.0、40.0、80.0、160.0 g·kg~(-1)的浓度添加到供试潮土中,经过45 d的室内培养后用磷脂脂肪酸(PLFAs)法分析土壤中微生物群落结构。研究结果表明:施用PBC、MBC和ABC对土壤总微生物总量、土壤细菌量有促进作用,但其增加幅度随生物炭浓度的升高呈现降低趋势,而添加BBC则会显著降低土壤微生物总量、土壤细菌量;PBC、MBC、ABC和BBC对土壤真菌细菌比有显著的促进作用;适量添加生物炭(20.0、40.0、80.0 g·kg~(-1))会增加真菌量,但大量(160 g·kg~(-1))添加PBC、BBC会显著降低真菌量。施入生物炭后,生物炭自身特殊理化性质和土壤理化性质如酸碱度、土壤电导率、比表面积、孔径等的变化是导致土壤微生物群落变化的主要原因;适量施加ABC、PBC相比于BBC、MBC更有利于潮土土壤微生物群落结构的发展。

The effect of four biochar on the structure of microbial communities in alluvial soil

This project was carried out in an effort to investigate how biochar affects soil microbial community structures using peanut shell biochar (PBC), maize straw biochar (MBC), aspen biochar (ABC)and bamboo biochar (BBC)applied as a soil amendment to alluvial soil. The amounts of biochar added for each treatment were 0, 20, 40, 80 g·kg^-1 and 160 g·kg^-1 respectively. After 45 days of incubation, we analyzed and classified microorganisms using the PLFA method and found that the total amount of microorganisms and bacteria increased, but there was a slowing trend in the growth rate, with the addition of PBC, MBC, and ABC. BBC reduced the total amount of microorganisms and bacteria in the soil. All biochar treatments increased the fungi-to-bacteria ratios. While fungi were proved to flourish with the addition of biochar at levels of 20, 40 g·kg^-1 and 80 g·kg^-1, excessive addition (160 g·kg^-1)of PBC and BBC significantly reduced the amount of fungi in the system. The main reasons for the change of the microorganism structures with biochar addition were the subsequent changes in the soil''s pH, EC, specific surface area and porosity, as well as some specific physicochemical properties of biochar. We concluded that as opposed to the addition of BBC and MBC, the addition of an appropriate amount of ABC and PBC could better promote the microbial communities in alluvial soil.