老化生物炭理化性质及其对土壤和烤烟生长的影响OA

[Objective]The study investigated the alterations in physicochemical properties of aged biochar and evaluated its effects on dry matter accumulation,nitrogen,phosphorus and potassium content in tobacco,as well as fertilizer utilization and soil fertility after application into the soil,so as to provide a theoretical basis for the rational application of aged biochar in the cultivation of tobacco.[Method]Fresh bio-char(B0)was used to prepare water-washed aged biochar(B1),15％H2O2-aged biochar(B2)and 30％H2O2-aged biochar(B3).The physicochemical properties of biochar from different treatments were comparatively analyzed.Using Yunyan 87 tobacco as the test material,the prepared aged biochar was applied under the following treatments:non-biochar application(CK),fresh biochar application(TB0),water-washed aged biochar application(TB1),15％H2O2-oxidized aged biochar application(TB2),and 30％H2O2-oxidized aged biochar appli-cation(TB3).The effects of biochar application on dry matter accumulation,nitrogen,phosphorus and potassium content in tobacco plants,fertilizer utilization,and soil physicochemical properties were analyzed.[Result]After biochar aging,the pH and elemental carbon(C)and nitrogen(N)contents of biochar decreased,while the content of oxygen-containing functional groups increased.The fine particles produced on the surface of water-washed aged biochar filled the cracks of fresh biochar,and its surface was smoother compared with that of fresh bio-char,whereas the surface of oxidized biochar produced more fracture channels,and had more irregular particles compared with that of fresh biochar.In terms of rhizosphere soil,pH increased by 12.36％and 27.93％;alkali-hydrolyzable nitrogen increased by 12.20％and 10.87％in 15％H2O2 oxidized biochar and 30％H2O2 oxidized biochar treatments compared to CK.Organic matter,available phosphorus and available potassium decreased by 5.02％,20.20％and 4.25％under 15％H2O2 aging,and by 18.61％,12.74％and 16.73％under 30％H2O2 aging.Urease,acid phosphatase,catalase and sucrase activities decreased by 10.67％,8.36％,40.40％and 42.90％in 15％H2O2 oxidized biochar treatment compared with CK.As for the growth of tobacco,the total dry weight of tobacco increased by 34.40％,29.18％and 27.62％under washed aged biochar,15％H2O2 oxidized biochar and 30％H2O2 oxidized biochar treatments compared with CK respectively.The content of nitrogen,phosphorus and potassium,their accumulation and fertilizer utilization rate of aged biochar treatments were higher those of CK,and the differences were smaller than that of the treatment of applying fresh biochar.[Conclusion]After aging,the pore structure and oxygen-containing functional groups of biochar increased,and the pH,C and N content decreased.The application of aged biochar changed the agrochemical properties of the rhizosphere soil of baked cigarettes,weakened the related soil enzyme activities,and pro-moted the dry matter accumulation of the tobacco plant as well as the amount of nitrogen,phosphorus and potassium accumulation.