氰氨化钙与秸秆还田协同处理对生菜土传病害防效及土壤质量的影响

 为明确氰氨化钙与秸秆还田协同处理对土传病菌的抑制效果以及对土壤微生物群落的恢复和土壤理化性质的影响,采用实时荧光定量PCR(Real-time quantitative PCR, qRT-PCR)、平板分离计数等方法测定土传病菌和微生物数量动态变化。生菜收获期测定植株农艺性状和产量,结合土壤理化性质开展土壤处理模式与土壤微生物互作相关分析。结果表明,氰氨化钙和玉米秸秆协同处理对生菜根腐病和生菜茎基腐病的防效分别达到56.81%和47.49%,且增产率(44.08%)较高,具有防病促生效果。氰氨化钙和玉米秸秆协同处理在消毒揭膜0 d微生物数量显著减少,定植期微生物数量逐渐恢复。此外,两种土壤处理均可提高土壤pH值,降低电导率含量。其中氰氨化钙和玉米秸秆协同处理可提高土壤有机质、有效磷和全氮含量。因此,氰氨化钙和玉米秸秆协同处理可抑制土传病菌增殖,增加生菜生物量,改善土壤理化性状,后期土壤微生物数量恢复且不会对微生物群落产生明显的扰动影响,对环境较安全。

Effect of calcium cyanamide and straw returning cooperative treatment on the control of lettuce soil-borne diseases and soil quality

In order to clarify the effect of the combined treatment of calcium cyanamide and straw returning on soil-borne pathogens, the restoration of soil microbial communities and the impact of soil's physical and chemical properties. Real-time quantitative PCR (qRT-PCR), plate separation and counting methods were used to determine the dynamic changes in the number of soil-borne pathogens and microorganisms. The agronomic characteristics and yield of lettuce were measured during the harvest period, and correlation analysis between soil treatment mode and soil microbial was carried out in combination with soil's physical and chemical properties. The results showed that the synergistic treatment of calcium cyanamide and corn stalks had 56.81% and 47.49% control effects on lettuce root rot and lettuce stem rot, respectively, and the yield increase rate (44.08%) was high, which has the benefit of disease prevention and growth promotion. The co-treatment of calcium cyanamide and corn stalks significantly reduced the number of microorganisms on day 0 after disinfection and unmasking, and the number of microorganisms gradually recovered during the colonization period. In addition, both soil treatments can increase soil pH and reduce electrical conductivity content. Among them, the coordinated treatment of calcium cyanamide and corn stalks can increase the content of soil organic matter, available phosphorus and total nitrogen. Therefore, the co-treatment of calcium cyanamide and corn stover can inhibit the proliferation of soil-borne pathogens, increase lettuce biomass, improve soil physical and chemical properties, and restore the number of soil microorganisms in later stages without significant disturbance to the microbial community, and is safer for the environment.