Soil microbial biomass is triggered into activity by trace amounts of substrate

Nobili, Maria De; Contin, Marco; Mondini, Claudio; Brookes, Philip C.

doi:10.1016/s0038-0717(01)00020-7

Cited by 424 publications

(202 citation statements)

References 14 publications

Supporting

Mentioning

187

Contrasting

Order By: Relevance

“…the long-term depletion of soil C and altered microbial community composition in Carney et al (2007)). Similarly inconsistent with our results is 'apparent priming', either through turnover of soil microbial biomass (Wu et al 1993), or a small increase in microbial mineralization of endo-cellular C reserves with no change in decomposition of soil organic matter (where microorganisms increase their metabolic activity following a trace C input in anticipation of a larger input in the near future; De Nobili et al 2001). These apparent priming mechanisms are not consistent with the large release of soilderived C from the mid-fertility soil (360 mg CO 2 -C g -1 soil), which was 120% greater than the original concentration of microbial C. Further evidence that priming measured in our study was not 'apparent' Fig.…”

Section: Priming Mechanismscontrasting

confidence: 99%

“…The rapid priming (the peak in primed-CO 2 occurred before the peak in sucrose derived-CO 2 ) due to microbial nutrient demand as indicated by our data is consistent with some studies of temperate soils (Zyakun and Dilly 2005;Blagodatskaya et al 2007;Nottingham et al 2009), but at odds with others that do not predict such rapid priming (Fontaine et al 2004) or an increased production of extracellular enzymes (De Nobili et al 2001). This suggests that different mechanisms may apply in different soils on different time scales.…”

Section: Priming Mechanismssupporting

confidence: 91%

See 1 more Smart Citation

Priming and microbial nutrient limitation in lowland tropical forest soils of contrasting fertility

et al. 2011

View full text Add to dashboard Cite

Section: Priming Mechanismscontrasting

confidence: 99%

Section: Priming Mechanismssupporting

confidence: 91%

Priming and microbial nutrient limitation in lowland tropical forest soils of contrasting fertility

et al. 2011

View full text Add to dashboard Cite

“…5, Tables 1 and 2). Organic management practices have been shown previously to increase the rate of soil processes without causing increases in microbial biomass [8,10,21,24,55,60]. Other studies have also similarly shown that when exposed to small additions of carbon substrate the rate of microbial processes can increase without a change in standing biomass [24,55].…”

Section: Discussionmentioning

confidence: 84%

Agricultural Management and Labile Carbon Additions Affect Soil Microbial Community Structure and Interact with Carbon and Nitrogen Cycling

2013

View full text Add to dashboard Cite

We investigated how conversion from conventional agriculture to organic management affected the structure and biogeochemical function of soil microbial communities. We hypothesized the following. (1) Changing agricultural management practices will alter soil microbial community structure driven by increasing microbial diversity in organic management. (2) Organically managed soil microbial communities will mineralize more N and will also mineralize more N in response to substrate addition than conventionally managed soil communities. (3) Microbial communities under organic management will be more efficient and respire less added C. Soils from organically and conventionally managed agroecosystems were incubated with and without glucose ( 13 C) additions at constant soil moisture. We extracted soil genomic DNA before and after incubation for TRFLP community fingerprinting of soil bacteria and fungi. We measured soil C and N pools before and after incubation, and we tracked total C respired and N mineralized at several points during the incubation. Twenty years of organic management altered soil bacterial and fungal community structure compared to continuous conventional management with the bacterial differences caused primarily by a large increase in diversity. Organically managed soils mineralized twice as much NO3 − as conventionally managed ones (44 vs. 23 μg N/g soil, respectively) and increased mineralization when labile C was added. There was no difference in respiration, but organically managed soils had larger pools of C suggesting greater efficiency in terms of respiration per unit soil C. These results indicate that the organic management induced a change in community composition resulting in a more diverse community with enhanced activity towards labile substrates and greater capacity to mineralize N.2

show abstract

“…Priming effects are changes in the turnover of organic matter caused by moderate treatment of the substrate e.g. microorganisms can use more refractory organic carbon after addition of labile organic matter (Hamer and Marschner, 2002) or they are activated by the added substrate, strongly increase their numbers and finally target more remaining refractory substrates if labile organic matter is completely consumed (De Nobili et al, 2001;Kuzyakov and Bol, 2006). For a review regarding priming effects see Kuzyakov et al (2000).…”

Section: Introductionmentioning

confidence: 99%

Variable effects of labile carbon on the carbon use of different microbial groups in black slate degradation

Seifert¹,

Trumbore²,

Xu³

et al. 2011

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Weathering of ancient organic matter contributes significantly to biogeochemical carbon cycles over geological times. The principle role of microorganisms in this process is well recognized. However, information is lacking on the contribution of individual groups of microorganisms and on the effect of labile carbon sources to the degradation process. Therefore, we investigated the contribution of fungi, Gram-positive and Gram-negative bacteria in the degradation process using a column experiment. Investigations were performed on low metamorphic black slates. All columns contained freshly crushed, sieved (0.63-2 mm), not autoclaved black slates. Two columns were inoculated with the lignite-degrading fungus Schizophyllum commune and received a culture medium containing 13 C labeled glucose, two columns received only this culture medium and two control columns received only water.The total mass balance was calculated from all carbon added to the slate and the CO 2 and DOC losses. Phospholipid fatty acids (PLFA) were extracted to investigate microbial communities. We used both the compound specific 14 C and 13 C signal of the PLFA to quantify carbon uptake from black slates and the glucose of the culture medium, respectively.The total carbon loss in these columns exceeded the amount of added carbon by approximately 60%, indicating that black slate carbon has been used. PLFA associated with Gram-positive bacteria dominated the indigenous community and took up 22% of carbon from black slate carbon, whereas PLFA of Gram-negative bacteria used only 8% of carbon from the slates. PLFA of Gram-negative bacteria and fungi were both mostly activated by the glucose addition. The added Schizophyllum did not establish well in the columns and was overgrown by the indigenous microbial community. Our results suggest that especially Gram-positive bacteria are able to live on and degrade black slate material. They also benefit from easy degradable carbon from the nutrient broth. In natural environments priming due to root exudates might consequently enhance weathering.

show abstract

Soil microbial biomass is triggered into activity by trace amounts of substrate

Cited by 424 publications

References 14 publications

Priming and microbial nutrient limitation in lowland tropical forest soils of contrasting fertility

Priming and microbial nutrient limitation in lowland tropical forest soils of contrasting fertility

Agricultural Management and Labile Carbon Additions Affect Soil Microbial Community Structure and Interact with Carbon and Nitrogen Cycling

Variable effects of labile carbon on the carbon use of different microbial groups in black slate degradation

Contact Info

Product

Resources

About