The Preparation Of Phoenix Tree Catkin Biochar And The Application In Improving The Soil

Phoenix Tree Catkinis a substance with high content of phosphorus and potassium.In order to make use of the biomass resources effectively,the research chose thephoenix tree catkin as the raw material to prepare biochar by high temperature pyrolysis for improving the soil.Firstly,through the characterization and comparison of the properties of biochar at different pyrolysis temperatures,the optimum pyrolysis temperature can be selected.The soil incubation experiment was carried out by adding different proportions of biochar to the soil.One month later,the basic parameters of soil(PH,organic matter content,cation exchange capacity,available phosphorus and potassium content,enzymatic activity,etc.)were measured to evaluate the effect of biochar on the properties of the soil.The analysis of soil microbial diversity was conducted to analyze the soil structure changes and environmental factor correlation of soil samples before and after biochar incubation to explore the effect of biochar on soil microbes.A pot experiment was designed to explore the effects of biochar on crop growth by measuring the growth indicators and the nutrient uptake of the crops.The main findings of this study are as follows:(1)The phoenix tree catkin has the advantages of high P and K content(14.18±2.84 g/kg and 14.05±4.57 g/kg,respectively).According to the characterization and comparison of biochar at different temperatures,the content of P and K in biochar at 400 °C is the highest.Therefore,400°C was selected as the optimum pyrolysis temperature.(2)After the biochar was applied to the soil,the soil pH increased from 5.7 to 6.5-7.5,the organic matter content in soil increased by 109.2%,the cation exchange capacity increased by 485.6% and the available phosphorus and potassium content increased by 62.1% and 260.5% respectively when biochar dosage was 6%.The activity of urease and invertase in soil also increased.The application of biochar reduced the abundance and diversity of microorganisms in soil and changed the soil microbial community structure.The increase of the proportion of Firmicutes is beneficial to the degradation of organic matter in the soil,which can decompose macromolecules into small molecules which are easy to use.At the same time,the change of microbial community structure also affects the properties of soil.The genus in the soil which is closely related to the change of soil properties are uncultured_bacterium_f_Anaerolineaceae and Nocardioides.(3)The addition of biochar increased the germination rate,plant height,root length and root/shoot ratio of the crop and enhanced the nutrient absorption of the crop.The best effect was obtained when the dosage of biochar was 2%.The contents of P and K in crops increased,and the maximum increases of P and K in the stems were 22.2% and 10.8% compared with the control group,and the maximumincreasesof P and K in roots were 13.6% and 150.7% compared with the control group.