Effects Of Adding Biochar On Yield And Quality Of Flue-cured Tobacco And Soil Fertilizers In Two Kinds Of Typical Tobacco Planting Soils

In order to explore the influence of biochar on soil fertility in soil planted with tobacco and aroma content of tobacco,a field experiment was carried out in paddy soil and purple soil in Xiniu Town,Xinfeng County,Jiangxi Province in 2015.There were five treatments with different amounts of biochar(T1: 0 kg hm-2;T2: 450 kg hm-2;T3:900 kg hm-2;T4: 1350 kg hm-2;T5: 1800 kg hm-2).The main results were as follows: 1.Effects of biochar amount on pH and nutrients in paddy soil and purple soil The application of biochar could significantly improve the pH of paddy soil,but,the effect of biochar on pH of purple soil was not obvious.Adding biochar could promote the content of total nitrogen in paddy soil and purple soil,but the action time is different.Among them,Biochar had a significant effect on the total nitrogen content of paddy soil after growth peak period,but the application of biochar could increase the content of total nitrogen in the whole growth period of tobacco in purple soil.Adding biochar could improve the the content of alkali hydrolyzable nitrogen significantly.In paddy soil,the effect of higher biochar application(T5)on the content of alkali hydrolyzable nitrogen in the resettling growth stage was most obvious,but lower biocha(T2)was better in purple soil.The effect of biocha on available P was not obvious in paddy soil.In the purple soil,the content of available P in the treatment of lower biochar(T2)was significantly higher than that of other treatments at the growth stage of tobacco plants.The application of biochar could significantly increase the content of available potassium in paddy soil and purple soil,respectively by T5 and T2 treatments were the most significant,The maximum can be higher than the contrast 96.82% and 59.33%.The effects of biochar on the contents of Al,Ba,Cu,Fe,K,Mg,Na,P,Si,Ti and Zn in paddy soil were significantly enhanced,T4 treatment was the most obvious.In purple soil,the content of Cu and Zn is the highest in T2 treatment,which compared with the contrast respectively increased by 59.88% and 102.92%,the content of Ca increased with increasing application rate of biochar.But,adding biochar decreased the content of Ba and Ti in purple soil.2.Effects of biochar amount on enzyme activity in paddy soil and purple soilThe application of biochar could significantly improve the urease activity of paddy soil and purple soil in the whole tobacco plant growth period,The effect of T3 treatment was the most significant in paddy soil,compared to the contrast can be higher 28.27%~140.43%.In purple soil,the urease activity was increased most at 45 days after transplanting,among them,T2 and T3 treatment were higher than contrast 206.14% and 245.46% respectively.The influence of adding biochar into paddy soil on sucrase activity is to promote before.,and after transplanting 30 days and 60 days,T3 treatmentwas higher 68.63% and 22.03%than those of the contrast,other treatments showed inhibitory effect after the rosette stage.In purple soil,the influence of adding biochar on sucrase activity is inhibitory at rosette stage,following were promote.,and the T2 treatment was the highest in the whole growth period.The activity of cellulase in paddy soil was inhibited by the application of biochar in the whole process of tobacco plant growth,but the activity of cellulase in purple soil was increased by 0.38% ~ 94.99% compared with the contrast.3.Effects of biochar amount on carbon pool in paddy soil and purple soilThe influence of biochar on the total carbon,organic carbon and water-soluble carbon of paddy soil and purple soil showed a promoting effect.Compared with the contrast,the content of total carbon in the paddy soil and purple soil can increase 3.50%~33.13% and 10.18%~141.57% respectively.T3 and T2 had the most obvious effect on the content of soil organic carbon and water soluble carbon respectively in paddy soil and purple soil.The content of organic carbon was higher than the contrast 18.59% and 63.69% respectively.The content of water soluble carbon was higher than the contrast 122.07% and 70.74% respectively.C/ N content ratio of paddy soil increased with the increase of biochar application.In the purple soil,except for 30 days and 75 days after transplanting,biochar can increase the C/ N content ratio,T2 treatment increased most.T3 treatment had no significant difference with T1 treatment,other treatments showed inhibited effect on the content of easily oxidizable carbon and microbial biomass carbon in paddy soil.T2 treatment had the most significant promoting effect on the easily oxidizable carbon and microbial biomass carbon in purple soil,followed by T3 treatment.4.Effects of adding biochar on conventional chemical components of flue-cured tobacco.In paddy soil,adding biochar could increase the content of reducing sugar and total sugar in the middle and upper leaves of Flue-cured Tobacco.In purple soil,adding biochar could increase the proportion of reducing sugar in the middle and upper leaves.In paddy soil,the nicotine content of flue-cured tobacco leaves increased with the increase of biochar application rate,and the content of nicotine of flue-cured tobacco in purple soil was increased to a suitable range.The application of biochar in paddy soil could increase the content of potassium in flued-cured tobacco,at the moment,the content of chlorine was increased,but it was in the appropriate range,and the ratio of K/Cl was increased.The application of biochar could reduce the chlorine content of flue-cured tobacco in purple soil,and significantly increased the potassium content of upper leaves,and T3 and T4 had the most significant effect.5.Effects of adding biochar on neutral aroma components of flue-cured tobacco.In paddy soil,adding biochar can improve the content of cembranoids and chlorophyll degradation products in upper leaves of flue-cured tobacco,and the total amount of neutral aroma was highest in T3 treatment,which is 746.83?g/g.The content of neutral aroma in middle leaves in T4 and T5 treatments were higher than the contrast,respectively at 88.38 ?g/g and 280.16 ?g/g.In purple soil,The application of biochar could improve the content of Maillard reaction products,carrot pigment degradation products,Cembratriendiol degradation products,Chlorophyll degradation products,and reduce the content of Phenylalanine degradation products in upper leaves of flue-cured tobacco.With the increase of the amount of biochar,the total amount of neutral aroma in middle leaves was smaller.6.Effects of adding biochar on economic properties of flue-cured tobaccoThe application of biochar could increase the yield,output value and percentage of superior leaves of flue-cured tobacco in paddy soil and purple soil,T3 a nd T2 treatment had the most significant effect.The yields was lifted up in 52.94%,122.75% respectively as compared with that of the control,and output value was lifted up in 73.71%,108.85% respectively as compared with that of the control.The ratio of the medium class tobacco leaf was reduced,and the effect of proporti on of low grade tobacco leaf was closely related to the amount of biochar.To summarize,The application of biochar could improve soil fertility,improve the coordination of chemical components in tobacco leaf,increase the content of neutral aroma substances,and improve the quality and yield of Flue-cured tobacco.in paddy soil and purple soil.Taken together,adding biochar to paddy soil and purple soil can improve soil quality,yield and quality of flue-cured tobacco,particularly in conventional fertilization with biochar amount of 900 kg/hm~2 or 450 kg/hm~2.