不同种类生物炭对植烟土壤微生物及根茎病害发生的影响

Effects of different types of biochar on soil microorganism and rhizome diseases occurrence of flue-cured tobacco

采用田间试验研究了稻壳炭、木屑炭对烤烟根区土壤微生物、根茎病害发生以及烟叶产量的影响。结果表明,生物炭施用明显影响着烤烟根区土壤微生物数量及其对碳源的利用,进而影响着青枯病、黑胫病的发生情况和烟叶的产量、产值,但其效果因生物炭种类而异。木屑炭处理烤烟旺长期细菌和采烤前放线菌的数量明显比对照增加了11.7%和12.8%,而稻壳炭处理旺长和初烤时的真菌数量显著增加。植烟土壤中青枯菌和黑胫病菌的数量及其占微生物总量的百分比也以施用生物炭处理显著低于对照,而烤烟旺长期根区微生物对碳源的利用能力则相反;到烟叶采烤前,根区微生物对酚酸类和胺类的利用以生物炭处理相对最低;上述情况以木屑炭处理较稻壳炭处理更为明显。与对照相比,木屑炭处理青枯病的发病率和病情指数降低了24.3%和33.3%,黑胫病的发病率和病情指数降低了23.9%和14.9%,产量和产值增加了4.7%和21.1%;稻壳炭处理青枯病发病率和病情指数降低了18.1%和23.9%,黑胫病的发病率和病情指数降低了15.9%和6.0%,产量和产值增加了2.2%和12.0%。综合而言,施用生物炭能较好地改善土壤微生物状况及其对碳源的利用,减少青枯病和黑胫病的发生,增加烟叶的产量和产值;其中以木屑炭处理效果更佳。

A field experiment was carried out to study effects of rice husk biochar and wood biochar application respectively on rhizosphere microorganisms, rhizome diseases occurrence, and leaf yield of flue-cured tobacco. The application of biochar significantly affected the amount of rhizosphere microorganisms and the use of carbon sources of flue-cured tobacco. In turn, as well as the occurrences of granville wilt and tobacco black shank, also the yield and output value of tobacco leaf, which varied with the types of biochar. The treatment of wood biochar significantly increased the number of bacteria at vigorous growth stage and actinomycete at mature stage in flue-cured tobacco by 11.7% and 12.8% respectively, while the treatment of rice husk biochar significantly increased the number of fungus in both stages. Compared with the control, the application of biochar significantly reduced the number of Ralstonia solanacearm and Phytophthora parasitica var. nicotianac and the percentage to total microorganism. But rhizosphere microorganisms of flue-cured tobacco had the opposite effect on the carbon use ability in vigorous growing stage; before mature stage, phenolic acids and amines used by rhizosphere microorganisms were the lowest. The effect above, was more obvious in treatment of wood biochar than in treatment of rice husk biochar. Compared with control, the treatment of wood biochar decreased the incidence and disease index of granville wilt by 24.3% and 33.3%, and those of tobacco black shank decreased by 23.9% and 14.9%, while increased the output and output value by 4.7% and 21.1%. In rice husk biochar treatment, the incidence and disease index of granville wilt decreased by 18.1% and 23.9%, the incidence and disease index of tobacco black shank decreased by 15.9% and 6.0%, and the output and output value increased by 2.2% and 12.0%. In summary, the application of biochar can significantly impactive the situations of rhizosphere microorganisms of flue-cured tobacco and the utilization of different types of biochar, reducing the occurrence of granville wilt and black shank, and increasing the yield and output value of tobacco leaf. The effect of wood biochar is better.