| In order to explore the effects of biochar-based fertilizer on soil microbial diversity and flue-cured tobacco growth in different types of tobacco-growing soils,field experiments were conducted to investigate the effects of different biochar-based fertilizer application rates on tobacco growth and development,soil physical and chemical properties and quality of flue-cured tobacco leaves in different types of tobacco-growing soils.Biolog-ECO method was used to analyze the characteristics of soil microbial diversity.No biochar-based fertilizer(CK),0.9 t/hm2(T1),1.5 t/hm2(T2)and 1.8 t/hm2(T3)were applied.The main results are as follows:1.The application of biochar-based fertilizer could significantly improve the growth index of flue-cured tobacco in dark brown soil,cinnamon soil and paddy soil,and the treatment of T2(1.5 t/hm2)was the best.Compared with the control,the plant height,stem circumference,node spacing and aboveground dry weight of flue-cured tobacco increased by 30.67%,5.70%,9.76%and 11.13%respectively.The number of effective leaves increased with the increase of application rate;the growth indexes of flue-cured tobacco in cinnamon soil treated with T1(0.9 t/hm 2)and T2(1.5 t/hm2)were significantly higher than those in control,while the growth indexes of Flue-cured Tobacco under T3(1.8 t/hm2)treatment showed a downward trend compared with control;after applying biochar-based fertilizer to paddy soil,except the number of effective leaves and stem circumference,the plant height of T1 and T2 treatments were higher than that of control.The maximum leaf area,pitch,aboveground dry weight and root dry weight were all increased compared with the control,while the T3 treatment showed a different degree of reduction compared with the control.On the whole,the growth of tobacco plants in the three types of soils increased first and then decreased with the increase of biochar-based fertilizer application.2.The physical and chemical properties of dark brown soil,cinnamon soil and paddy soil are greatly affected by biochar-based fertilizer,and the regularity is similar.Compared with the control,biochar-based fertilizer decreased the pH of dark brown soil and increased the pH of cinnamon soil and paddy soil,which could neutralize soil acidity and alkalinity,especially for acidic soil.The soil microbial biomass C/N was improved,and the soil microbial biomass C/N was increased in all types of soils.Except cinnamon soil,the microbial biomass C and N in other types of soils showed an increasing trend3.The results showed that the content of alkali-hydrolyzed nitrogen in dark brown soil,cinnamon soil and paddy soil increased first and then decreased with the increase of application rate.The best performance was in T2 treatment,which increased 15.82%,23.56%and 12.73%respectively compared with the control.The available phosphorus increased with the increase of application rate in dark brown soil,while in cinnamon soil and paddy soil,the content of available phosphorus increased first.The regularity of decreasing after increasing;available potassium increased,but there were great differences among different types of soil.4.Biocharcoal-based fertilizer can increase the AWCD value of soil microorganisms in dark brown soil,cinnamon soil and paddy soil with the increase of incubation time.At the same time,biocharcoal-based fertilizer can significantly improve the utilization efficiency of Soil Microbial Amino acids,polymers,carbohydrates and carboxylic acids.Principal component analysis shows that biocharcoal-based fertilizer can significantly change dark brown soil,cinnamon soil and paddy soil.The microbial community structure of paddy soil,in which T2 treatment scored higher in principal component analysis and was more discrete than CK treatment,showed that the utilization characteristics of soil microbial carbon sources in T2 and CK were quite different.5.The results showed that biocharcoal-based fertilizer could enhance the chemical composition of flue-cured tobacco in all types of soils,and the contents of total sugar,reducing sugar,total nitrogen,nicotine,potassium and chlorine in T2 treatment were within the suitable range of chemical composition of Flue-cured tobacco.In addition,biocharcoal-based fertilizer could increase the nicotine-alkali ratio,Sugar-alkali ratio and potassium-chlorine ratio of dark Brown soil,cinnamon soil and paddy soil after flue-curing.Basically,it showed a trend of increasing first and then decreasing with application. |
