Study On The Effect Of Biochar-Based Fertilizer On The China Rose Growth And Soil Nutrients

With the rapid development of modern society,the demand for food and resources has further expanded,and declining soil fertility is an obstacle factor limiting agricultural production.Biochar-based fertilizer with biochar as carrier can effectively adsorb nutrients,delay nutrient release and reduce nutrient leaching losses,which can significantly contribute to the improvement of soil quality and crop growth and yield.In this study,three kinds of straw biochar were prepared from corn straw,wheat straw and broad bean straw as raw materials at a carbonization temperature of 500℃.Three kinds of straw biochar were modified by H₃PO₄,KOH,KH₂PO₄ and KMn O₄to screen the H₃PO₄-modified corn straw biochar.The structure and surface morphology were characterized by infrared spectroscopy（FTIR）and scanning electron microscopy（SEM）,and the effects of different modified concentrations,initial p H,and dosing amounts on the adsorption of K+by biochar,and the adsorption mechanism was explored by combining isothermal adsorption model and adsorption kinetic model.The application potential of raw charcoal-based fertilizer on the China rose growth and soil improvement of investigated through potting trials.The main conclusions obtained are as follows:（1）H₃PO₄-modified corn straw biochar showed the best adsorption effect on K⁺with an adsorption amount of 20.0g·kg^-1.（2）The adsorption effect of H3PO4-modified corn straw biochar on K⁺was KB-40%>KB-50%>KB-30%>KB-20%.（3）The adsorption kinetic model showed that the R² of the adsorption model correlation coefficient KB-40%was 0.984,and the adsorption process of KB-40%on K⁺was more consistent with the Langmuir equation,which had an R² value of 0.990.（4）SEM at 4000x can more clearly see the existence of multiple voids on the surface,KB-40%surface pores are relatively increased and smooth.FTIR at 1595cm-1,1090cm-1peak shape changes,there is a broader strong absorption peak.（5）Application of biochar-based fertilizer significantly increased the chlorophyll content,plant height,crown width and fresh-cut flower yield of China rose.The leaf chlorophyll content of T5 treatment was the highest,59.1;the height of China rose plant in T5 treatment increased the most,reaching 59.97cm,81.17%higher than CK treatment,and the improvement effect was T5>T2>T4>T3>T1>CK;the crown width of China rose plant in T5 treatment increased 9.33cm compared with CK treatment.（6）Soil application of modified biochar-based fertilizer to increase soil p H and carbon to nitrogen ratio,increase soil organic matter and soil total potassium content.The p H of T5treatment increased by 6.58%compared to the control,the carbon to nitrogen ratio was44.79:1,the soil organic matter increased by 1.52 times compared to CK,and the soil potassium content of T5 treatment reached the highest level of 4.97 g·kg^-1.