Effects of steam disinfestation on community structure, abundance and activity of heterotrophic, denitrifying and nitrifying bacteria in an organic farming soil

Steam treatment of surface soil: how does it affect water-soluble organic matter, C mineralization, and bacterial community composition?

“…Similar observation was obtained for the microbial activity. We have also shown in a previous study (Roux-Michollet et al 2008) that the abundance of culturable heterotrophic bacteria in the top 10 cm layer was resilient 27 days after the treatment. Finally, colonization dynamics is probably a long process which could explain that community composition was still different in the steamed soil compare with control, 10 days after the treatment, and dominated by r strategy populations according to the IGS length distribution among the bacterial phyla (Ranjard et al 2000).…”

“…Despite its widening use, the effects of steam disinfestation on soil functioning are poorly documented. The few published studies focused on weeds and phytopathogens viability to assess the treatment efficiency (van Loenen et al 2003) and also on diversity, biomass, and activity of soil microbial communi-ties (Khan et al 2010;Roux-Michollet et al 2008;Tanaka et al 2003). Nevertheless, heated vapor must affect the soil's physical, chemical, and biological properties, thus nutrient cycling.…”

“…Steamed and control soil microcosms were then incubated in controlled conditions for several days. Water-extractable components from the surface layer (0-2 cm), which has been shown to be the most affected by steam treatment (Roux-Michollet et al 2008), were obtained by a standard procedure, collected after filter sterilization, and analyzed by fluorescence and ATR-FTIR spectroscopy. In the same top layer, the impact of steaming on the soil bacterial community was assessed by (1) enumerating culturable heterotrophic bacteria, (2) measuring the soil respiration rate, and (3) characterizing the genetic structure of the eubacterial community.…”

Long‐term fertilization regimes change soil nitrification potential by impacting active autotrophic ammonia oxidizers and nitrite oxidizers as assessed by DNA stable isotope probing

“…The functional genes amoA and nxrA/nxrB, which encode the subunit A of ammonia monooxygenase and subunits A and B (nxrA and nxrB respectively) of nitrite oxidoreductase, respectively, are frequently used as genetic markers to explore the nitrification community. Nitrite oxidation has also been shown to be more sensitive than ammonia oxidation in disturbed soils (Gelfand and Yakir, 2008;Roux-Michollet et al, 2008), which highlights the crucial role of NOB in nitrification. In contrast, nitrite-oxidizing bacteria (NOB) have received little attention in this context.…”

Influencing Factors, Effects and Development Prospect of Soil Solarization

“…The main drawbacks of soil steaming are the cost, the required time and labor, and the undesired effects on microorganisms and the natural soil microflora, i.e. a biological vacuum, in particular, excessive and continuous high temperature has a detrimental effect on beneficial organisms such as nitrifying bacteria, rhizobia and mycorrhizae and microbial antagonists (Dawson and Johnson, 1965;Fenoglio et al, 2006;Roux-Michollet et al, 2008). In addition, dissolution of metal ions with prolonged heat exposure can lead to plant toxicity (Egli et al, 2006).…”