| During the process of flue-cured tobacco production,environmental pollution was usually caused by the waste plastic film mulching cultivation at seedling stage.In order to remove plastic film contamination,wheat and corn straw were used as mulching materials in this experiment.Four experimental treatments were designed,T1:mulching with plastic film;T2:corn straw curtain covering;T3:maize straw curtain covering+microbial agent;T4:wheat straw mulching directly;T5:wheat straw mulching+microbial agents.The agronomic characteristics,yield quality,soil physical and chemical characteristics and microbial characteristics of flue-cured tobacco treated with different treatments were determined.The main results were as follows:(1)The growing period of flue-cured tobacco treated with straw mulching was extended for 7d.There were no significant differences in plant height,stem circumference and effective leaf number between T3 and T1 at the mature stage.Plant height in T5 was lower than that in T1,and all indexes tested in T2 and T4 were significantly lower than that in T1.The upper leaf area was 506.9 cm~2 in T1,and was 668.1 cm~2,which was the highest,in T3 during the topping period.The upper leaf area of T2 and T3 was significantly higher than that of T1 at mature stage.In all periods,only T3 did not show a significant difference compared with T1 treatment,and other treatments were significantly lower than T1.The T3 had the best anti-disease effect,and the incidence of anthrax,red star and black tibia was reduced by 11.7%,3.3%and 1.7%respectively compared with T1.(2)The physical and chemical properties of tobacco planting soil were tested,the results showed that the average surface temperature of T1 and T3 was 35.47?and31.56?respectively,which was 5.12?and 2.41?higher than that at 5 cm soil layer,indicating that straw mulching can reduce the temperature difference between day and night.The incidence of flowering diseases of T3 and T5 was 10.9%lower than that of T1.Straw mulching can increase the moisture content at 0-20cm soil layer.Inoculation of microbial agents could accelerate straw decomposition and significantly improve soil porosity.The maximum porosity of T3 was 46.67%,which was 4.06%higher than that of T1.The soil organic matter contents,total nitrogen,available potassium and available phosphorus were increased in T2-T5.(3)The number of soil bacteria,fungi and actinomycetes was tested,the results suggested that the microbial quantity reached the peak at the topping stage.All the indexes of T3 and T5 were significantly higher than T1,among which,fungi number of T3 was the highest,while the bacteria and actinomycetes number of T5 was the highest.Soil microbial biomass carbon and nitrogen in T3 and T5 were significantly higher than that of T1,and T3was the highest.All kinds of soil enzyme activities increased gradually,with the highest soil catalase activity and urease activity in T3 and the lowest in T1.Soil phosphatase activity and sucrase activity in T3 and T5 was higher than that of T2 and T4,respectively,while T1 had the lowest enzyme activity.Different straw mulching materials lead to different soil fungal community structure.Inoculation of functional microbial agents can significantly change the structure of soil fungal community and improve the diversity of soil fungal community.(4)The yield,output value and economic benefit of cured tobacco under different treatments were analyzed,the results revealed that the yield of tobacco leaves treated with T3 and T5 was significantly higher than that of T1.The average price between straw mulch treatments and T1 was re was not significant difference.The output value of T3 and T5was significantly higher than that of T1.Compared with T1,the content of total alkali and total nitrogen in the upper leaves of T3 and T5 increased,while the total potassium content was not significant.The content of chlorine in the lower leaves decreased significantly,and the content of total sugar increased to some extent.In general,the internal chemical composition of all treated tobacco leaves was within the content range of high-quality tobacco leaves. |
PDF Full Text Request