effect of biochar on fungal communities in soil - rittmo · effect of biochar on fungal communities...
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Interactions plant - microorganisms in soil
Beneficial microorganisms
Non beneficial microorganisms
Positives effects • Plants nutrition • Resistance to abiotic stress • Resistance to biotic stress • Etc ....
Mycorhizes
Beneficial microorganisms
Interactions plant - microorganisms in soil
Non beneficial microorganisms
Negative effects: • Roots necrosis • Plants diseases • Etc...
Telluric fungi : Fusarium, Trichoderma, etc...
How biochar may affect the interaction between plant and
microorganisms in soil ?
State of the art Interactions biochar/microorganisms in soil
• In greenhouse studies, biochar added at 1.5 and 3.0% (wt/wt) to field soil caused proportional increases in root weights and linear reductions in the percentage of root lesions caused by Fusarium species.
• Addition of aromatic acids that are known allelopathic agents reduced AM colonization but the deleterious effects were not observed following the application of biochar at the higher rate.
Effect of Biochar Amendments on Mycorrhizal Associations and Fusarium Crown and Root Rot of Asparagus in Replant Soils (Elmer, et al. 2011)
Rhizoctonia solani suppression and plant growth promotion in cucumber as affected by biochar pyrolysis temperature, feedstock and concentration (Jaiswal et al. 2014)
• Influence of biochar produced from different feedstocks and at different production temperatures on its ability to suppress Rhizoctonia solani in cucumber
• At higher concentrations, biochar was ineffective or even increased the disease incidence and severity
EUC Eucalyptus wood GHW Greenhouse waste
State of the art Interactions biochar/microorganisms in soil
Biochar soil amendment increased bacterial but decreased fungal gene abundance with shifts in community structure in a slightly acid rice paddy from Southwest China (Chen et al. 2013)
Control Biochar 20 T/ha Biochar 40 T/ha
• Effect of biochar on gene copy number of fungal 18S rDNA significantly decreased by 35% and 46% under biochar at 20 and 40 T/ha respectively
State of the art Interactions biochar/microorganisms in soil
Interactions biochar/microorganisms in soil
Mechanisms by which biochar may affect these interactions are still unknown
Direct effect of biochar on microorganisms
Biochar effects on microorganisms in association with plants
Scientific research BioenNW
• Stimulation of plant defence regarding telluric phyto-pathogens
• Stimulation of plant growth and AM symbiosis
• Effect on soil diversity and biomass of fungal communities…
• Innovation : biochars from various origins
• Study of direct effect without plant
Methodology
Suppressive effect of biochars in vitro
Strirring 24h Biochars extracts
Suppressive effect of biochars in vitro
Microbial count
Non sterilized biochar extract
Sterilized biochar extract (filtration or thermic
treatment)
Effect of biochars on mycorrhizae germination
• Study of germination of 30 Funneliformis mosseae spores in a model substrate (sand) with biochar
-Number of spores -Number of germinated spores
% germination
Doses : • 5 T/ha • 10 T/ha • 20 T/ha
Results
Biochars
• Feedstock and production characteristics
Code Feedstocks Production
Scale
Pyrolysis
Temperature
PmW-BC Poultry manure and wood Pilot 500
D1-BC Digestate of corn and rye Pilot 500
D2-BC Digestate from a biogas plant Industrial 700
W1-BC Forestry Residues Industrial 650
W2-BC Forestry Residues Pilot 500
WC-BCX Vegetable and forestry wastes; refuse
compost
Pilot 500
D3-BC Digestate from a biogas plant Pilot 500
Pig-BC Pig manure Pilot 500
• % of inhibition in relation to the control (1-D1/Dt)
Suppressive effect of biochars in vitro
10 days of growth D1-BC D2-BC PmW-BC W1-BC
Rhizoctonia solani 58,13% 63,41% 67,89% 65,24%
Phytophtora sp. 62,20% 68,70% 69,51% 76,02%
Fusarium oxysporum 58,67% 71,11% 72,00% 68,67%
Pythium ultimum 49,17% 72,92% 73,75% 70,63%
10 days of growth W2-BC WC-BCX D3-BC Pig-BC
Rhizoctonia solani 41,38% 33,99% 44,83% 33,99%
Phytophtora sp. 29,76% 40,49% 41,46% 36,59%
Pythium ultimum 26,06% 34,46% 29,38% 22,60%
Suppressive effect of sterilized biochars in vitro
• Sterilized and non sterilized biochars extracts
• % of inhibition in relation to the control (1-D1/Dt)
NS = Non sterilized Fil = Filtrated (0,22 µm) Ther = Thermic treatment (121°C)
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
NS Fil Ther NS Fil Ther
W2-BC WC-BCX
Pythium ultimum (7 days of growth)
0%5%
10%15%20%25%30%35%40%45%
NS Fil Ther NS Fil Ther
W2-BC WC-BCX
Rhizoctonia solani (8 days of growth)
• Germination inhibition (biochar in model substrate : sand)
Effect of biochars on mycorrhizae germination
0
10
20
30
40
50
60
70
80
90
100
5T/ha
10T/ha
20T/ha
5T/ha
10T/ha
20T/ha
5T/ha
10T/ha
20T/ha
5T/ha
10T/ha
20T/ha
5T/ha
10T/ha
20T/ha
5T/ha
10T/ha
20T/ha
5T/ha
10T/ha
20T/ha
5T/ha
10T/ha
20T/ha
D1-BC D2-BC PmW-BC W1-BC W2-BC WC-BC D3-BC Pig-BC
% in
hib
itio
n o
f sp
ore
ge
rmin
atio
n /
co
ntr
ol
Ecotoxicity limit
Forestry residues Digestate /biogas plant Digestate /biogas plant
Industrial Industrial
Pilot
Pilot
Effect of biochars on mycorrhizae germination
• Chemical analysis
• Negative effect of biochar on spores mycorrhizae germination ETM ?
pH ?
Conductivity ?
Other molecules implicated on the suppressive effect on soil phytopathogen?
D1-BC D2-BC PmW-BC W1-BC W2-BC WC-BCX D3-BC Pig-BC
Unité
pH 10,59 10,74 10,99 9,66 9,1 11,9 11,4 11,9
Conductivit
y mS/m 2936 1103 850 58 40 304 537 3260
Cuivre mg/kg MS 93 92,7 164 13,2 14,7 48,3 96 894,2
Zinc mg/kg MS 413,8 494,1 971,5 177,8 215,9 222,1 360,3 1475,8
% inhibition
germination
5 T/ha 9,80 40,62 -1,22 4,59 90,30 53,82 33,19 58,27
10 T/ha 14,49 49,19 0,38 3,41 97,87 69,38 32,46 83,59
20 T/ha 93,44 32,34 34,71 36,87 98,81 82,10 87,01 100,00
Conclusions
Conclusions
• Biochar produced from different feedstock and at different production temperatures
Affect the soil born pathogen : suppressive effect on the growth of fugal phytopathogen
Effect related to chemical characteristics of biochar (fungicide molecule) but also to the presence of some microorganism on the biochar
Affect spore germination of mycorrhizae : the effective dose for toxic effect depend on the biochar
Thank you for your attention
Any question