Studies On The Influences Of Biochar On Soil Functional Microorganisms

By pyrolysis under limited oxygen supply,biochar is converted from biomass feedstocks,such as straw, rice husks, etc. The porous structure and large surface area of biochar provide a suitable habitat for microorganisms when it is added to soil. It is very important for some soil functional microorganisms,such as phosphate-dissolving microorganism, potassium-releasing microorganism, azotobacter and so on. Because incorporation of biochar into soil may indirectly increases crop yields by promoting the growth and activity of soil functional microorganisms, biochar is gaining attention, for its broad application prospects in agriculture.The influences of straw biochar on the growth of 13 different soil microorganisms as well as its adsorption for microorganisms were studied, in which one strain was screened from soybean roots. In addition, the potassium-releasing strain Bacillus mucilaginosus 1.153 intensive studied, including the influence of four different types of biochars on the growth of it, the adsorption of it by different biochars, as well as the effect of different treated straw biochar on the growth of it.Experimental results showed that biochar could promote the growth of majority of the microorganisms, and it could also absorb some microorganisms. Different biochars had different effects on Bacillus mucilaginosus 1.153. Bamboo biochar and rice husk biochar could absorb more cells, and straw biochar could improve the growth and activity of the strain.After being washed by acid, alkali and organic solvent respectively, straw biochar could also promote the growth of the strain, but the effect was declined. Straw biochar could greatly slow the death rate of Bacillus mucilaginosus 1.153. After released from biochar, the growth of Bacillus mucilaginosus 1.153 was better than before, but it was not remarkable with continuous passage culture.