Effect of Maize Straw Biochar on Bacterial Communities in Agricultural Soil

Biochar has become a popular soil amendment. However, its effect on soil microbial community is still unclear. In the present study, maize straw biochar was pyrolysed at 300°C, 450°C and 600°C, respectively, and then was added to agricultural soil at the ratio of 0.5%, 1% and 2%. Bacterial dynamics was analyzed in the pot experiments using denaturing gradient gel electrophoresis. The results indicated that the pyrolysis temperature has great impact on the elemental composition, pH and porous structures of biochar. Moreover, pyrolysis temperature was primary factor to drive the variation of bacterial community structure in biochar amended soil. In addition, the results suggested that biochar amendments on agricultural soil would decrease the bacterial diversity, and selectively promote growth of functional bacteria to become the dominant community, which could increase the bacterial community organization and improve the stability of bacteria to counteract effects of perturbation.