Effect Of Straw Biochar On Soil Physicochemical Properties And Microbial Diversity

Due to the improvement of the soil by biochar,the application of biochar on agriculture has attracted a great deal of attention.Biochar can not only sequester carbon,increase soil fertility and quality,but also absorb organic and heavy metal pollutants.Furthermore,Biochar can affect microbial metabolism directly or indirectly by changing the environment in which the soil microorganisms grow.It can change the structure of microbial communities and affect microbial diversity.In this experiment,0 g/kg,20 g/kg,40 g/kg,80 g/kg,and 160 g/kg concentration water-soluble components were added to the soil to explore the influence of different doses of biochar on soil physicochemical and microbial diversity.In the meantime,the organic-soluble and non-extractable components of straw biochar were added to the soil to explore the effects of different components of biochar on soil physicochemical properties and microbial diversity.The main results are as follows:(1)Adding different concentrations of biochar water extract to the soil can effectively increase soil available P,effective K content and soil conductivity,and their content increased with increasing concentration of biochar.For the slightly alkaline purple soil,the application of straw biochar water extract has no significant effect on soil pH and CEC.There was also no significant difference in soil organic matter,total nitrogen and alkali-hydrolyzed nitrogen in the short-term culture of soil with biochar water extract.(2)Under short-term culture,with the increase of concentration of biochar water extract,the bacterial abundance and diversity showed a trend of increasing first and then decreasing as a whole,and reaching the maximum at 80 g/kg,followed by 160 g/kg;The abundance and diversity of fungi showed a trend of decreasing,but the downward trend has slightly increased at 160 g/kg.(3)The water-soluble components of biochar increase the available phosphorus and available potassium in the soil and increase the electrical conductivity.The organic soluble components have a certain degree of gain in the available phosphorus content.Nonextractable components increase the nutrients,including available phosphorus and effective potassium,organic matter and total nitrogen content.The results of this study show that the neutral straw biochar reduces the pH of the slightly alkaline purple soil.(4)Straw biochar promoted the bacterial diversity of the soil,which was mainly caused by the water-soluble components and non-extractable components of biochar,while the organic extractable components of biochar significantly inhibited the bacterial richness.