Effects Of Applying Bio-organic Fertilizer On Yield And Quality Of Flue-cured Tobacco And Soil Characteristics

Flue-cured tobacco is an important economic crop in China.The use of large amounts of fertilizers in planting has caused many problems,such as waste of resource,environmental pollution and the decline in yield and quality of flue-cured tobacco.Applying bio-organic fertilizer with moderately reducing chemical fertilizers usage is one of the important measures to improve the soil quality and the yield and quality of flue-cured tobacco.In this study,application of bio-organic fertilizer and reducing chemical fertilizers usage was performed.The field experiment with random block method was used to evaluate the effect on the yield,output value and chemical composition of flue-cured tobacco leaves.At the same time,soil biochemical properties,soil biochemical aspects,and high-throughput sequence of soil bacterial communities was obtained to explore the effects on soil physical and chemical properties,and microbial characteristics.The main findings are follows:(1)Effect on yield and quality of flue-cured tobaccoCompared with conventional fertilization,bio-organic fertilizer treatments with 0% and 10% fertilizer reduction increased the plant height at maturity period.These two treatments increased the yield of superior tobacco leaves by 19.2% and15.4%,middle tobacco leaves by 8.2% and 5.4%,total yield by 11.0% and 8.5%,output value by 11.9% and 9.8%,respectively.All the bio-organic fertilizer treatments increased the potassium content,reduced the chlorine content within a reasonable range,and increased the potassium chlorine ratio of tobacco leaves.Effect of bio-organic fertilizer treatment with 10% fertilizer reduction was the optimal.(2)Effect on physical and chemical properties of soilCompared with conventional fertilization treatment,bio-organic fertilizer treatments with 0% and 10% fertilizer reduction increased the content of the total nitrogen,alkali nitrogen and available phosphorus in each period.At the maturity stage,the soil available potassium content by the bio-organic fertilizer treatments was 19.9%~34.6% lower than that of the conventional fertilization treatment,and the difference was significant(P<0.05).The soil organic matter content was 22.7%~26.0% higher than the conventional fertilization treatment with significant difference(P < 0.05).(3)Effect on microbial characteristics of tobacco planting soilCompared with conventional fertilization treatment,all the bio-organic fertilizer treatments increased the number of soil culturable bacteria and actinomycetes by more than 29.1% and 20.9%,respectively;however,reduced the number of fungi by more than 23.6%.The soil enzyme activities of bio-organic fertilizer treatments with 0% and 10% fertilizer reduction were higher than that of conventional fertilization treatment.Moreover,all the bio-organic fertilizer treatments increased soil catalase activity,which increased by 14.0%~20.7% at the sapling period and 11.54%~19.35% at maturity period with significant difference(P<0.05).Compared with conventional fertilization treatment,all the bio-organic fertilizer treatments increased soil microbial biomass carbon content,which increased by 31.62~43.86mg/kg at the sapling period and 29.63~51.56mg/kg at maturity period.And they increased microbial biomass nitrogen content,which increased by 9.9%~22.7% at the sapling period and 10.2%~26.5% at maturity period.In addition to reducing the Chao1 and ACE index abundance of soil bacterial communities,all the bio-organic fertilizer treatments increased the bacterial communities richness.Simultaneously,the abundance of potential beneficial bacteria,such as Sphingomonas,Lysobacter and Nitrobacter;and the diversity of bacterial communities were increased,which was quite different from that of conventional fertilization treatment.The results of RDA analysis showed that soil available potassium content and catalase activity had the greatest correlation with soil bacterial communities.In summary,bio-organic fertilizer plus 10% fertilizer reduction can be as a formula for improving quality,yield and efficiency and reducing fertilizer in Jiange tobacco planting area.