The Effect Of Burying Different Winter Green Manure On The Character Of Planting Tobacco Soil And The Yield And Quality Of Flue-cured Tobacco

Tobacco is an important economic crop in China.Long term production practice shwed that continuous tobacco cropping lead to soil compact and soil fertility decline.Green manure has the effect of saving energy and reducing emissions and improving soil as organic fertilizer.In order to analyze the effect of burying smooth vetch(Ti treatment),burying ryegrass(T2 treatment)and burying milk vetch(T3 treatment)on the character of soil,the agronomic character,the yield and quality of flue-cured tobacco compared with abandoned field(CK treatment),this experiment was carried out based on K326 tobacco with randomized block design,which can improve the soil of tobacco growing areas,increase the yield of soil crops and farmers' income in planting tobacco areas,and lay a theoretical foundation for the sustainable management of soil in plantinging tobacco areas.The main results are as follows.1.Different green manure treatments had different effects on the characteristics of tobacco growing soils at different growth stages.Compared with the control,T3 treatment could improve the contents of available phosphorus,available potassium,exchangeable calcium and exchangeable magnesium in planting tobacco soil.As far as soil enzyme activity was concerned,Ti treatment was most beneficial to increase the activity of soil catalase and cellulase,and T2 treatment was the most beneficial to increase the activity of soil polyphenol oxidase,and T3 treatment was the most beneficial to increase the activity of soil invertase,urease and acid phosphatase.Compared with the control,the T1 and T2 treatments improved the bacterial Shannon index,Simpson index,Chao1 index and ACE index in the planting tobacco soil during the fast-growing and mature period,and T3 treatment improved the soil bacterial Shannon index,Simpson index,Chaol index and ACE index in the mature period.According to the composition of microbial flora,the average relative abundance of the dominant bacteria and fungi in the soil bacteria and fungi in the fast-growing and mature period of tobacco was changed by different green manures,and at phylum of soil bacteria,AD3,Acidobacteria,Gemmatimonadetes and Planctomy were improved by different green manure treatments.The average abundance of fungi including Basidiomycota and Chytridiomycota also increased by green manure treatments.2.Different green manure treatments improved tobacco growth and leaf development.Among different treatments The maximum leaf area of tobacco was improved by T1 treatment,and T3 treatment significantly increased the maximum leaf length,maximum leaf width and maximum leaf area in fasting-growing and dading period of tobacco.From the yield of flue-cured tobacco and the total biomass of tobacco plant,T1 treatment was beneficial to the accumulation of aboveground biomass,and T3 treatment was more beneficial to increase the accumulation of biomass in the underground part of the tobacco plant,but the differences in each treatment were not significant.3.Different green manure treatments had different effects on flue-cured tobacco quality.Compared with CK,T1 and T2 treatments significantly improved the ratio of sugar to nicotine and nitrogen to nicotine in B2F and nitrogen to nicotine in X2F and total potassium,ratio of sugar to nicotine,and ratio of nitrogen to nicotine in C3F,however,nicotine showed a significantly decreasing trend.In T3 treatment nicotine increased significantly in C3F and sugar decreased significantly both in B2F and X2F.