土壤厌氧消毒技术、作用机理及其防治效果的影响因素

土壤厌氧消毒(anaerobic soil disinfestation,ASD)技术作为一种环境友好的非化学土壤消毒技术能有效防治真菌、细菌、线虫和杂草等引起的土传病害。该技术已在多个国家广泛应用并被证实可显著增加作物产量。ASD技术基本流程为向土壤中添加适量有机碳源、补充足够水分和用塑料薄膜覆膜密闭2～15周。ASD技术对土传病害防控的作用机理为有机碳源分解产生的挥发性有机物对土传病原菌有抑制作用,土壤理化指标的改变(如pH降低、有机质增加等)能提升土壤质量,从而提高作物抗逆能力,土壤厌氧条件促进土壤微生物群落结构及多样性的改变,通过生物竞争和结构重建改善土壤微生态环境,降低土传病害发生风险。ASD技术对土传病害的防治效果也因有机碳源类别、土壤理化性质及覆盖薄膜的不同而存在差异。因此,优化ASD技术试验条件、深入探索ASD技术作用机理、挖掘更多有灭菌活性的挥发性物质或有益生防菌是未来ASD技术的研究重点。同时,ASD技术与其他土壤消毒技术结合使用,有助于提高其防治效果,扩大应用范围。

Anaerobic soil disinfection technology, action mechanisms and influencing factors

Anaerobic soil disinfestation (ASD) technology, also known as biological disinfestation technology, is a non-chemical disinfestation technology which gained more attention through the years. Studies have shown that ASD can effectively control soil-borne diseases caused by soil-borne plant pathogens, nematodes, and weeds. Researchers adopted ASD as an alternative to replace chemical fumigants for pre-fumigation in many countries for soil disinfestation in various crops allowing yield increases. The main steps of ASD technologies include adding a certain amount of organic carbon source into the soil, irrigating enough water, and using a conventional agricultural plastic film to keep it airtight lasting for 2~15 weeks. The mechanisms of ASD-mediated pathogen control are not fully understood, and may include the release of volatile toxic organic products, the combination of biological and the metabolome shifts, lowered soil pH, and the release of metal ions. The efficacy of ASD on the pathogen, nematodes and weeds were affected by materials and conditions for ASD applications, including carbon sources, soil chemical and physical properties, and plastic tarp type. The research of ASD can focus on optimizing the ASD test conditions, stabilizing the disinfection effect, further exploring the mechanism of ASD, and discovering more volatile substances with sterilization activity or beneficial biocontrol bacteria in the future. The application of ASD technology in combination with other soil disinfection technologies will help improve its efficacy and expand its application scope.