INFLUENCE OF LONG-TERM ORGANICFARMING ON BANANA PLANTATION SOIL:FROM MICROBIAL ASPECT

Fo-Ting Shen Assistant Professor

Department of Soil and Environmental Sciences

National Chung Hsing University, Taichung, Taiwan

1

Introduction

¨ Organic farming, a promising agriculturalmanipulation which doesn’t rely on the utilization ofchemical fertilizer or chemical pesticide gains muchattention in the recent years.

¨ The benefits bring from organic farming include theimprovement of soil fertility, soil quality and foodsafety, which stand for a more sustainableagriculture.

2

Introduction

¨ Soil microorganisms play key roles in the nutrientcycling and transformation of soil organic matter.

¨ Regarding the biodiversity, microbial communitiesanalyses in terms of their population diversity andfunctional diversity, provide evidences of thebalance of organisms within ecosystems.

3

Does organic farming really increase thefunctional diversity of indigenous microorganisms?

Question4

Purpose

¨ Demonstrate the influence of long-term organic and conventional farming on soil microbial diversity

5

Farming systems

¨ Organic farming for 13 years (A)¨ Organic farming for 3 years (A1)¨ Conventional farming (G)

6

Parameter considerations

¨ Soil propertiesØ Water contentØ pH, ECØ Organic matter

¨ Bacterial numberØ HeterotrophsØ Nitrogen fixing bacteriaØ Phosphate solubilizing bacteria

¨ Carbon source utilizationØ Biolog GNØ Biolog GPØ Biolog Ecoplate

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A diluted soil suspension

8

9

10

11

After incubation

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Ci : the absorbance value of each response wellR : the absorbance value of control welln : total number of carbon sources

AWCD (Average well color development)

H index (Shannon-Wiener diversity index)

Pi : the ratio of the corrected absorbance value of each well to the sum of absorbance value of all wells

Functional diversity as revealed by calculating the richness, AWCD and H index

Richness = the number of utilized carbon sources13

Soil properties14

Aug-2011 Apr-2012Farming system

Water content

(%)

pH EC(μS/cm)

SOM(%)

Water content

(%)

pH EC(μS/cm)

SOM(%)

A 29.8 8.01 99.0 2.85 30.9 7.54 151.6 2.02A1 30.0 6.99 75.9 4.14 28.4 6.43 92.0 1.76G 25.9 6.58 88.5 2.27 23.8 5.19 127.9 1.77

A: 13-year organic farmingA1: 3-year organic farmingG: conventional farming

Viable number of indigenous bacteria15

Aug-2011 Apr-2012Farming system

Heterotrophs NFB1 PSB2 Heterotrophs NFB1 PSB2

colony forming unit (CFU) g-1 soilA 3.95x106 4.25x106 6.88x106 6.25x106 3.09x107 6.84x106

A1 4.68x106 7.25x106 7.73x106 4.99x106 4.54x107 9.55x106

G 2.08x106 5.19x106 2.28x106 3.73x106 2.81x107 3.70x106

1 NFB: nitrogen fixing bacteria2 PSB: phosphate solubilizing bacteria

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GN

Water α-Cyclodextrin Dextrin Glycogen Tween 40 Tween 80 N-Acetyl-D-Galactosamine

N-Acetyl-D-Glucosamine

Adonitol L-Arabinose D-Arabitol D-Cellobiose

i-Erythritol D-Frcutose L-Fucose D-galactose Gentiobiose α-D-glucose m-Inositol α-D-Lactose Lactulose Maltose D-Mannitol D-Mannose

D-Melibiose β-Methyl-D-Glucoside

D-Psicose D-Raffinose L-Rhamnose D-Sorbitol Sucrose D-Trehalose Turanose Xylitol Pyruvic AcidMethyl Ester

Succinic AcidMono-methyl

Ester

Acetic Acid Cis-AconiticAcid Citric Acid Formic Acid D-Galactonic

Acid LactoneD-Galacturonic

Acid D-Gluconic Acid D-GlucosaminicAcid

D-GlucuronicAcid

α-Hydroxybutyric

Acid

β-Hydroxybutyric

Acid

γ-Hydroxybutyric

Acidp-Hydroxy-Phenylacetic

AcidItaconic Acid α-Keto Butyric

Acidα-Ketoglutaric

Acidα-Ketovaleric

AcidD,L-Lactic Acid Malonic Acid Propionic Acid Quinic Acid D-Saccharic

AcidSebacic Acid Succinic Acid

BromosuccinicAcid

Succinamic Acid Glucuronamide L-Alaninamide D-Alanine L-Alanine L-Alanyl-glycine L-Asparagine L-Aspartic Acid L-Glutamic Acid Glycyl-L-Aspartic Acid

Glycyl-L-Glutamic Acid

L-Histidine Hydroxy-L-Proline

L-Leucine L-Ornithine L-Phenylalanine L-Proline L-PyroglutamicAcid

D-Serine L-Serine L-Threonine D,L-Carnitine γ-Amino ButyricAcid

Urocanic Acid Inosine Uridine Thymidine Phenyethyl-amine

Putrescine 2-Aminoethanol 2,3-Butanediol Glycerol D-L-α-GlycerolPhosphate

α-D-Glucose-1-Phosphate

D-Glucose-6-Phosphate

GP

Water α-Cyclodextrin β-Cyclodextrin Dextrin Glycogen Inulin Mannan Tween 40 Tween 80 N-Acetyl-D-Glucosamine

N-Acetyl-β-D-Mannosamine

Amygdalin

L-Arabinose D-Arabitol Arbutin D-Cellobiose D-Fructose L-Fucose D-galactose D-galacturonicAcid

Gentiobiose D-gluconic Acid α-D-glucose m-Inositol

α-D-Lactose Lactulose Maltose Maltotriose D-Mannitol D-Mannose D-Melezitose D-Melibiose α-Methyl-D-Galactoside

β-Methyl-D-Galactoside

3-MethylGlucose

α-Methyl-D-Glucoside

β-Methyl-D-Glucoside

α-Methyl-D-Mannoside

Palatinose D-Psicose D-Raffinose L-Rhamnose D-Ribose Salicin Sedoheptulosan D-Sorbitol Satchyose Sucrose

D-Tagatose D-Trehalose Turanose Xylitol D-Xylose Acetic Acidα-

HydroxybutyricAcid

β-Hydroxybutyric

Acid

γ-Hydroxybutyric

Acid

p-Hydroxy-Phenylacetic

Acid

α-KetoglutaricAcid

α-KetovalericAcid

Lactamide D-Lactic AcidMethyl Ester

L-Lactic Acid D-Malic Acid L-Malic Acid Pyruvic AcidMethyl Ester

Succinic AcidMono-methyl

EsterPropionic Acid Pyruvic Acid Succinamic Acid Succinic Acid N-Acetyl-L-

Glutamic Acid

L-Alaninamide D-Alanine L-Alanine L-Alanyl-Glycine

L-Asparagine L-Glutamic Acid Glycyl-L-Glutamic Acid

L-PyroglutamicAcid

L-Serine Putrescine 2,3-Butanediol Glycerol

Adenosine 2’-DeoxyAdenosine

Inosine Thymidine Uridine Adenosine-5’-Monophosphate

Thymidine-5’-Monophosphate

Uridine-5’-Monophosphate

D-Fructose-6-Phosphate

α-D-Glucose-1-Phosphate

D-Glucose-6-Phosphate

D-L-α-GlycerolPhosphate

ECO

Water β-Methyl-D-Glucoside

D-GalactonicAcid γ-Lactone

L-Arginine Water β-Methyl-D-Glucoside

D-GalactonicAcid γ-Lactone

L-Arginine Water β-Methyl-D-Glucoside

D-GalactonicAcid γ-Lactone

L-Arginine

Pyruvic AcidMethyl Ester

D-Xylose D-GalacturonicAcid

L-Asparagine Pyruvic AcidMethyl Ester

D-Xylose D-GalacturonicAcid

L-Asparagine Pyruvic AcidMethyl Ester

D-Xylose D-GalacturonicAcid

L-Asparagine

Tween 40 i-Erythritol 2-HydroxyBenzoic Acid

L-Phenylalanine Tween 40 i-Erythritol 2-HydroxyBenzoic Acid

L-Phenylalanine Tween 40 i-Erythritol 2-HydroxyBenzoic Acid

L-Phenylalanine

Tween 80 D-Mannitol 4-HydroxyBenzoic Acid

L-Serine Tween 80 D-Mannitol 4-HydroxyBenzoic Acid

L-Serine Tween 80 D-Mannitol 4-HydroxyBenzoic Acid

L-Serine

α-Cyclodextrin N-Acetyl-D-Glucosamine

γ-Hydroxybutyric

AcidL-Threonine α-Cyclodextrin N-Acetyl-D-

Glucosamine

γ-Hydroxybutyric

AcidL-Threonine α-Cyclodextrin N-Acetyl-D-

Glucosamine

γ-Hydroxybutyric

AcidL-Threonine

Glycogen D-GlucosaminicAcid

Itaconic Acid Glycyl-L-Glutamic Acid

Glycogen D-GlucosaminicAcid

Itaconic Acid Glycyl-L-Glutamic Acid

Glycogen D-GlucosaminicAcid

Itaconic Acid Glycyl-L-Glutamic Acid

D-Cellobiose Glucose-1-Phosphate

α-Keto ButyricAcid

Phenyethyl-amine

D-Cellobiose Glucose-1-Phosphate

α-Keto ButyricAcid

Phenyethyl-amine

D-Cellobiose Glucose-1-Phosphate

α-Keto ButyricAcid

Phenyethyl-amine

α-D-Lactose D-L-α-GlycerolPhosphate α-Malic Acid Putrescine α-D-Lactose D-L-α-Glycerol

Phosphate α-Malic Acid Putrescine α-D-Lactose D-L-α-GlycerolPhosphate α-Malic Acid Putrescine

Blue: both in GN and GP Brown: only in GN Dark green: only in GP Black: only in Ecoplate

17

Functional diversity- Biolog GN/GP microplate

GN

GP

Aug-2011

Functional diversity- Biolog GN/GP microplate

18

Aug-2011 Apr-2012Richness AWCD H index Richness AWCD H index

A 81 0.724 4.419 79 0.566 4.243A1 83 0.789 4.438 76 0.613 4.224G 78 0.659 4.324 60 0.390 4.090

GN

Aug-2011 Apr-2012Richness AWCD H index Richness AWCD H index

A 61 0.576 4.330 49 0.354 4.099A1 76 0.682 4.361 54 0.420 4.055G 47 0.449 4.225 31 0.227 4.074

GP

Functional diversity- Ecoplate19

0

5

10

15

20

25

30

35

0 50 100 150 200

Rich

ness

Time(hr)

A

A1

G

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

1.600

0 50 100 150 200

AW

CDTime(hr)

A

A1

G

Apr-2012 Sep-2012Richness AWCD H index Richness AWCD H index

A 27 0.619 3.119 25 0.664 3.145A1 27 0.646 3.121 28 0.740 3.249G 22 0.440 2.986 24 0.668 3.246

Carbon source analyses20

¨ Utilized in A and A1 but less used in G: succinamicacid, D-lactic acid methyl ester, inulin, uridine-5’-monophosphate, β-methyl-D-glucoside, glycyl-L-glutamic acid

¨ Less utilized carbon sources: 2,3-butanediol, formicacid, mannan, lactamide, thymidine-5’-monophosphate, sedoheptulosan, α-cyclodextrin, 2-hydroxy benzoic acid, α-ketobutyric acid

Conclusion

¨ Viable number of heterotrophs, nitrogen fixingbacteria and phosphate solubilizing bacteriaslightly increased after organic amendments.

¨ Higher richness, AWCD and H index which reflectedthe functional diversity were recorded in soils afterlong-term organic fertilization.

21

Conclusion

¨ Several kinds of carbon sources were only utilizedby bacteria presented in organic farmingsoils, which might serve as markers to trace uniquepopulations.

¨ The present study provided preliminary informationon the benefits of bacterial diversity gained fromorganic farming.

22

Prospection23

¨ Resolving the population diversity of soils underorganic and conventional farming systems

¨ Correlation between population diversity andfunctional diversity

¨ Correlation between microbial diversity and soilproperties, soil fertility and crop production

Acknowledgement

¨ Dr. Shih-Chao Chiang, Ms Chun-Mei Chang and MsMei-Jen Chen in Taiwan banana research institute

¨ Prof. Chiu-Chung Young in Department of Soil andEnvironmental Sciences, NCHU

¨ National Science Council¨ Ministry of Education

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Thanks for your kindly attention

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