Location: Subtropical Plant Pathology ResearchTitle: Influence of carbon source amendment on effectiveness of anaerobic soil disinfestation Author
|Eichler Inwood, Sarah|
Submitted to: ASHS Centennial Conference
Publication Type: Abstract Only
Publication Acceptance Date: 7/10/2013
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: Anaerobic soil disinfestation (ASD; also termed biological soil disinfestation or soil reductive sterilization) is a non-chemical soil disinfestation process which includes 1) soil incorporation of a labile carbon (C) source, 2) mulching with a polyethylene film to limit gas exchange, and 3) drip irrigation to saturation of the topsoil or bedded area. A number of mechanisms contribute to control of pathogen, nematode, and weeds during ASD treatment, although not all have been well-characterized to date. These mechanisms include the formation of organic acids and volatile compounds during anaerobic decomposition of the added C source, as well as biocontrol by microorganisms favored by ASD treatment and changes in soil chemical constituents under anaerobic conditions. In Tennessee, USA, growth chamber, greenhouse, and field studies have been conducted to evaluate and optimize the ASD procedure for regional production systems and to evaluate pest, soil, and crop responses to differing C source rates and properties. Growth chamber studies conducted at the soil temperatures typical to spring soil treatment in this region (15 to 25°C), suggest that C amendment rates may need to be as high as 4 mg C g-1 soil to reduce inoculum of Fusarium oxysporum. With lower rates of C source amendment, effectiveness of ASD for increasing mortality of inoculum of F. oxysporum, Sclerotium rolfsii and Meloidogyne incognita has been inconsistent, likely influenced by differences in soil temperature and biochemical constituents of specific amendments. Studies to determine optimal rates of C amendment and C:N ratio of soil amendments for consistent ASD treatment are ongoing.