microbial diversity analysis of selected agro-ecological sub-regions of west bengal
TRANSCRIPT
UNIVERSITY OF AGRICULTURAL SCIENCES,GKVKBANGALORE
DEPARTMENT OF AGRICULTURAL MICROBIOLOGY
ColloquiumDEBARSHI DASGUPTA
PALB-4137 M.Sc.(Agri.)
ADVISORY COMMITTEENAME & DESIGNATION
CHAIRPERSON Dr. G.P. Brahmaprakash Professor, Dept. of Agricultural Microbiology, UAS,GKVK, Bangalore-65.
MEMBER Dr.A. ManjunathProfessor, Dept. of Agricultural Microbiology, UAS,GKVK, Bangalore-65.
MEMBER Dr.B.C.MalleshaProfessor, Dept. of Agricultural Microbiology, UAS,GKVK, Bangalore-65.
MEMBER Dr.K.Chandrashekhara Professor of Entomology, AICRP on Chickpea, UAS,GKVK, Bangalore-65.
TENTATIVE TITLE OF THE RESEARCH PROGRAMME
“MICROBIAL DIVERSITY OF SELECTED AGRO-ECOLOGICAL SUB-REGIONS OF WEST BENGAL”
a) To enumerate the population of various agriculturally important microorganisms from various selected agro-ecological sub-regions of West Bengal.
b) Comparing the microbial biodiversity in different ecosystems of agro-ecological sub-regions of West Bengal.
RESEARCH OBJECTIVES
INTRODUCTION●Microbial biodiversity is responsible for functioning of all ecosystems, regulating soil dynamics, enhancing soil fertility and consequently soil health.
●This diversity(be it genetic or ecosystem or species) impact the above ground biotic interactions.
●Increase in microbial diversity and count have been known to enhance plant growth, nutrient mineralisation and stress resistance.
●Loss of microbial species and its effect on global ecosystem functioning need to be studied in depth.
●By analysing diversity according to conditions, we can have better idea as to how our environment affect microbes and vice-versa.
PURPOSE OF RESEARCH
In West Bengal soils, certain regions have been studied to investigate the impacts of bioclimates, soil depth, cropping systems, land use systems and management practices on the distribution of culturable microbial population.
But distribution of AIM’s have not been studied in details. The relationships of the soil chemical properties with the count have not been established.
Ganga-Eastern Plain is one of the most fertile regions in India. Eastern coastal Plain region is also significant region which is affected by salinity. Chhotanagpur plateau is a predominantly dry region. Microbial analysis can help us understand to a fair extent which microbes can survive better in the aforesaid AESR’s.
Diversity indices help in quantitative understanding of our data.
AESR 12.3:Chhotanagpur plateau and Garjat Hills,Hot dry sub-humid ESR with moderately deep to deep loamy red and lateritic soils,Medium AWC and LGP 150-180 days [J2Cd5]
AESR 15.1:Bengal basin and North Bihar plain,Hot moist sub-humid ESR with deep loamy to clayey alluvium – derived soils, Medium to high AWC and LGP 210 – 240 days [08Cm7]
AESR 18.5:Gangetic Delta,hot moist sub-humid to humid ESR with deep loamy to clayey Coastal and deltaic alluvium-derived soils,Medium AWC and LGP 240-270 days [S7Cm7]
BRIEF METHODOLOGY:
1. Sampling was done from at least two locations in every specified region within the mentioned AESRs.
2. From each plot, soil was taken at random, so that every point had equal chance to be selected.
3. However care was taken to include points near the centre of the plot and places near bunds ,or roads, to be avoided.
4. Individual samples were homogenised, composited, and treated as a single sample, in order to gain representative estimates.
5. Almost 500 g soil sample was taken from each area.6. Almost 400-500g soil was taken from each location.7. Time of sampling= Middle of June –end of July, 2015
PRETREATMENT AND STORAGE OF SAMPLES:
1.After soil sampling , samples were transferred in plastic bags.
2.The plastic bags were kept in a larger plastic bag , with wet cotton , to maintain the temperature around.
3.It is preferable that microbiological properties of soil are analysed without delay after sampling (ISO 10381-6,2009). This was a drawback issue in this case.
4.In this case, samples were stored at 2-4°C
5.Samples were hence transported from West Bengal.
ORGANISM MEDIUM
Total culturable Bacteria Soil extract Nutrient Agar
Total culturableFungi Martin’s Rose Bengal Agar
Total culturable Actinomycetes Kuster’s agar
Total culturable Rhizobium Yeast Extract Mannitol Agar
Total culturable Azotobacter Waksman No.77
Total culturable Azospirillum Dobereiner’s
Total culturable Phosphate solubilising microorganisms
Sperber’s
Total culturable Nitrifiers Peptone & Nitrosomonas & Nitrobacter broth- Extinction Dilution process
EXPERIMENTATION:•The experiments were carried out at the Department of Agricultural Microbiology, UAS, GKVK, Bengaluru.
•The following microorganisms were counted:Using standard serial dilution methods
STATISTICAL ANALYSIS:Data obtained from experiments were statistically analysed as per procedure outlined by Pearson & Lee(1902), using correlation studies between soil microbial population and soil chemical properties.
Shannon-Wiener Index:
Simpson’s Diversity Index:
Pi= Proportion abundance of i th species given byPi=ni/Ni=1,2,3,…….s.ni =no. of individuals of ith speciesN=known total number of individuals for all species in population
OBSERVATION R1(cfu/g) R2 (cfu/g) R3 (cfu/g) AVERAGE (cfu/g)Total Bacteria 21 x 104 32 x 104 28 x 104 2.7 x 105
Total Fungi 22 x 103 16 x 103 19 x 103 1.9 x 104
Total Actinomycetes 12 x 104 2 x 104 21 x 104 1.16 x 105
Total Rhizobium 3 x 102 4 x 102 1 x 103 5.67 x 102
Total Azotobacter 4 x 102 1 x 103 1 x 102 5 x 102
Total Azospirillum 104 104 103 7 x 103
Total Phosphate Solubilisers 6 x 102 11 x 102 2 x 102 6.33 x 102
Total Nitrifiers(i)NH4
+ Oxidisers 104 103 103 4 x 103
(ii)NO2- Oxidisers 102 102 102 102
N 4.05 x 105 individuals/g soil
pbac 0.660pfun 0.047pact 0.286
Shannon-Wiener Index 0.333Simpson’s Index 0.471
AESR 12.3 Sample 1Location : Jhargram
Crop: Arecanut
OBSERVATION R1(cfu/g) R2 (cfu/g) R3 (cfu/g) AVERAGE (cfu/g)Total Bacteria 27 x 104 15 x 104 11 x 104 1.76 x 105
Total Fungi 3 x 103 13 x 103 16 x 103 1.06 x 104
Total Actinomycetes 17 x 103 21 x 103 5 x 104 2.9 x 104
Total Rhizobium 3 x 102 4 x 102 3 x 102 3.33 x 102
Total Azotobacter 165 x 101 2 x 102 4 x 103 1.95 x 103
Total Azospirillum 103 102 102 4 x 102
Total Phosphate Solubilisers 3 x 102 4 x 102 1 x 103 5.67 x 102
Total Nitrifiers (i)NH4
+ Oxidisers 103 102 102 4 x 102
(ii)NO2- Oxidisers 102 102 102 102
N 2.156 x 105 individuals/g soil
pbac 0.816pfun 0.049pact 0.134
Shannon-Wiener Index 0.253Simpson’s Index 0.314
AESR 12.3 Sample : 2Location : Jhargram
Crop : Gamhar
OBSERVATION R1(cfu/g) R2 (cfu/g) R3 (cfu/g) AVERAGE (cfu/g)Total Bacteria 34 x 104 14 x 104 2 x 105 2.27 x 105
Total Fungi 12 x 103 17 x 103 3 x 104 1.97 x 104
Total Actinomycetes 16 x 103 2 x 104 18 x 103 1.8 x 104
Total Rhizobium 6 x 102 9 x 101 2 x 102 2.97 x 102
Total Azotobacter 2 x 103 2 x 102 8 x 102 1 x 103
Total Azospirillum 103 102 102 4 x 102
Total Phosphate Solubilisers 7 x 103 8 x 102 6 x 102 2.8 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 103 103 103 103
(ii)NO2- Oxidisers 102 103 102 4 x 102
N 2.647 x 105 individuals/g soilpbac 0.858pfun 0.074pact 0.068
Shannon-Wiener Index 0.219Simpson’s Index 0.254
AESR 12.3 Sample : 3Location : Jhargram
Crop : Guava
OBSERVATION R1(cfu/g) R2 (cfu/g) R3 (cfu/g) AVERAGE (cfu/g)Total Bacteria 19 x 104 20 x 104 20 x 104 1.96 x 105
Total Fungi 1 x 105 1 x 104 2 x 104 4.33 x 104
Total Actinomycetes 38 x 103 2 x 104 17 x 103 2.5 x 104
Total Rhizobium 2 x 102 5 x 102 3 x 102 3.33 x 102
Total Azotobacter 6 x 103 19 x 103 8 x 103 11 x 103
Total Azospirillum 104 104 103 7 x 103
Total Phosphate Solubilisers 8 x 102 2 x 103 15 x 102 1.43 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 102 103 102 4 x 102
(ii)NO2- Oxidisers 102 102 102 102
N 2.643 x 105 individuals/g soil
pbac 0.741pfun 0.163pact 0.095
Shannon-Wiener Index 0.321Simpson’s Index 0.415
AESR 12.3 Sample : 4Location : Bankura
Crop : Rice
OBSERVATION R1(cfu/g) R2 (cfu/g) R3 (cfu/g) AVERAGE (cfu/g)Total Bacteria 24 x 104 18 x 104 14 x 104 1.87 x 105
Total Fungi 4 x 104 19 x 103 20 x 103 2.63 x 104
Total Actinomycetes 2 x 104 1 x 104 1 x 104 1.33 x 104
Total Rhizobium 9 x 102 11 x 102 1 x 102 7 x 102
Total Azotobacter 5 x 103 8 x 103 26 x 102 5.2 x 103
Total Azospirillum 104 104 102 6.7 x 103
Total Phosphate Solubilisers 5 x 103 3 x 102 22 x 102 3.4 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 102 104 103 3.7 x 103
(ii)NO2- Oxidisers 102 102 102 102
N 2.266 x 105 individuals/g soilpbac 0.825pfun 0.116pact 0.059
Shannon-Wiener Index 0.249Simpson’s Index 0.302
AESR 12.3 Sample : 5Location : Khhatra
Crop: Rice
SAMPLE 1 SAMPLE 2 SAMPLE 3 SAMPLE 4 SAMPLE 50
1
2
3
4
5
6
5.435.24 5.35 5.29 5.27
4.284.02
4.29
4.644.42
5.06
4.464.25
4.44.12
Total Bacteria
Total Fungi
Total Acti-nomycetes
log
10 cf
u/g
soil
AESR 12.3
Total Bact.
Total Fungi
Total Actino.
Total Rhizo.
Total Azot.
Total Azos.
Total PSB
NH4+
Oxi.NO2
- Oxi.
Sand -0.49 0.82 -0.46 0.34 0.88 0.64 0.45 0.05 -0.41Silt 0.51 -0.81 0.44 -0.36 -0.87 -0.66 -0.44 -0.08 0.44Clay -0.96 0.08 -0.89 -0.02 0.38 -0.26 0.46 -0.37 -0.09Org.C 0.39 -0.86 0.41 -0.35 -0.88 -0.69 -0.47 -0.09 0.36
pH -0.90 0.33 -0.57 0.07 0.67 0.15 0.04 -0.30 -0.61Ca 0.44 -0.84 0.41 -0.36 -0.88 -0.68 -0.43 -0.08 0.43Mg 0.51 -0.79 0.47 -0.38 -0.86 -0.64 -0.47 -0.08 0.43Na 0.33 -0.85 0.38 -0.39 -0.84 -0.71 -0.52 -0.16 0.32K 0.317 -0.83 0.27 -0.47 -0.83 -0.79 -0.39 -0.22 0.49C.E.C. 0.46 -0.82 0.45 -0.36 -0.88 -0.66 -0.46 -0.07 0.40
Correlation coefficients of microbial population and soil physico-chemical properties under AESR 12.3
pbac for whole AESR 12.3 = 0.782
pfun for whole AESR 12.3 = 0.069
pact for whole AESR 12.3 = 0.149
Shannon-Wiener Index for whole AESR 12.3 = 0.286
Simpson’s Index for whole AESR 12.3 = 0.362
0.782
0.069
0.149
PROPORTION OF MICROBES IN AESR 12.3
Pbac
Pfun
Pact
OBSERVATION R1(cfu/g) R2(cfu/g) R3(cfu/g) AVERAGE(cfu/g)Total Bacteria 28 x 104 7 x 105 2 x 105 3.93 x 105
Total Fungi 25 x 103 3 x 104 2 x 104 2.5 x 104
Total Actinomycetes 4 x 104 3 x 104 41 x 103 3.7 x 104
Total Rhizobium 1 x 102 2 x 102 17 x 102 6.67 x 102
Total Azotobacter 7 x 103 1 x 104 2 x 103 6.33 x 103
Total Azospirillum 103 103 104 4 x 103
Total Phosphate Solubilisers 3 x 103 17 x 102 12 x 102 1.97 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 104 104 103 7 x 103
(ii)NO2- Oxidisers 102 102 102 102
N 4.55 x 105 individuals/g soil
pbac 0.864pfun 0.054pact 0.081
Shannon-Wiener Index 0.210Simpson’s Index 0.244
AESR 15.1 Sample : 1Location: Baichigram
Crop: Rice
OBSERVATION R1(cfu/g) R2(cfu/g) R3(cfu/g) AVERAGE(cfu/g)Total Bacteria 3 x 105 19 x 104 17 x 104 2.2 x 105
Total Fungi 25 x 103 16 x 103 3 x 104 2.36 x 104
Total Actinomycetes 15 x 104 2 x 105 1 x 105 1.5 x 105
Total Rhizobium 2 x 102 8 x 102 12 x 102 7.33 x 102
Total Azotobacter 5 x 103 37 x 102 16 x 102 3.43 x 103
Total Azospirillum 104 102 103 3.7 x 103
Total Phosphate Solubilisers 26 x 102 14 x 102 17 x 102 19 x 102
Total Nitrifiers (i)NH4
+ Oxidisers 103 103 103 103
(ii)NO2- Oxidisers 102 102 102 102
N 3.936 x 105 individuals/g soil
AESR 15.1 Sample : 2Location : Bardhhaman
Crop : Jute
pbac 0.559pfun 0.059pact 0.381
Shannon-Wiener Index 0.372Simpson’s Index 0.461
OBSERVATION R1(cfu/g) R2 (cfu/g) R3 (cfu/g) AVERAGE (cfu/g)Total Bacteria 3 x 105 21 x 104 18 x 104 2.3 x 105
Total Fungi 18 x 103 3 x 104 17 x 103 2.17 x 104
Total Actinomycetes 11 x 104 7 x 104 3 x 104 7 x 104
Total Rhizobium 7 x 102 12 x 102 3 x 102 7.33 x 102
Total Azotobacter 5 x 103 24 x 104 11 x 103 8.53 x 104
Total Azospirillum 102 102 103 4 x 102
Total Phosphate Solubilisers 22 x 102 1 x 103 7 x 103 3.4 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 102 102 102 102
(ii)NO2- Oxidisers 103 102 102 4* 102
N 3.217 x 105 individuals/g soil
pbac 0.715pfun 0.067pact 0.218
Shannon-Wiener Index 0.326Simpson’s Index 0.437
AESR 15.1 Sample : 3Location : Bardhhaman
Crop : Rice
OBSERVATION R1(cfu/g) R2 (cfu/g) R3 (cfu/g) AVERAGE (cfu/g)Total Bacteria 46 x 104 3 x 105 5 x 105 4.2 x 105
Total Fungi 6 x 104 2 x 104 8 x 103 2.93 x 104
Total Actinomycetes 3 x 104 11 x 103 5 x 103 1.53 x 104
Total Rhizobium 2 x 102 3 x 102 3 x 102 2.67 x 102
Total Azotobacter 4 x 102 11 x 101 1 x 102 2.03 x 102
Total Azospirillum 104 104 104 104
Total Phosphate Solubilisers 11 x 102 3 x 102 1 x 103 8 x 102
Total Nitrifiers (i)NH4
+ Oxidisers 103 103 102 7 x 102
(ii)NO2- Oxidisers 102 102 101 7 x 101
N 4.646 x 105 individuals/g soil
pbac 0.904pfun 0.063pact 0.033
Shannon-Wiener Index 0.163Simpson’s Index 0.178
AESR 15.1 Sample : 4Location : Maldah
Crop : Rice
OBSERVATION R1(cfu/g) R2 (cfu/g) R3 (cfu/g) AVERAGE (cfu/g)Total Bacteria 3 x 105 41 x 104 24 x 104 3.17 x 105
Total Fungi 22 x 103 7 x 104 2 x 104 3.73 x 104
Total Actinomycetes 9 x 103 11 x 103 5 x 103 8.3 x 103
Total Rhizobium 2 x 102 7 x 102 12 x 102 7 x 102
Total Azotobacter 4 x 103 7 x 102 9 x 102 1.87 x 103
Total Azospirillum 6 x 103 5 x 103 7 x 102 3.9 x 103
Total Phosphate Solubilisers 11 x 102 23 x 102 1 x 103 1.47 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 102 102 102 102
(ii)NO2- Oxidisers 102 102 101 7 x 101
N 3.626 x 105 individuals/g soil
pbac 0.874pfun 0.103pact 0.023
Shannon-Wiener Index 0.190Simpson’s Index 0.225
AESR 15.1 Sample : 5Location : Birbhum
Crop : Rice
SAMPLE 1 SAMPLE 2 SAMPLE 3 SAMPLE 4 SAMPLE 50
1
2
3
4
5
65.59
5.34 5.365.62 5.5
4.39 4.37 4.344.47 4.574.56
5.17
4.84
4.183.92
Total Bacteria
Total Fungi
Total Acti-nomycetes
log
10 c
fu/g
soil
AESR 15.1
Total Bact.
Total Fungi
Total Actino.
Total Rhizo.
Total Azot.
Total Azos.
Total PSB
NH4+
Oxi.NO2
- Oxi.
Sand -0.37 0.70 -0.31 0.41 0.00 -0.31 0.01 -0.58 -0.03Silt 0.19 -0.05 -0.49 -0.65 -0.52 0.75 -0.63 -0.23 -0.49Clay 0.12 0.51 0.72 0.29 0.50 -0.46 0.61 0.68 0.50Org.C 0.02 0.50 0.15 0.09 0.43 -0.26 -0.25 -0.34 0.38
pH -0.04 -0.58 0.09 0.29 -0.28 -0.11 0.22 0.49 0.15Ca -0.21 -0.32 0.63 0.72 0.47 -0.78 0.72 0.55 0.47Mg 0.01 0.01 0.51 0.50 0.48 -0.63 0.57 0.39 0.45Na 0.21 -0.46 0.35 0.32 -0.01 -0.28 0.28 0.95 0.01K 0.30 -0.40 0.45 0.24 0.14 -0.29 0.34 0.91 0.15C.E.C. -0.07 -0.41 0.70 0.55 0.51 -0.67 0.70 0.62 0.51
Correlation coefficients of microbial population and soil physico-chemical properties under AESR 15.1
pbac for whole AESR 15.1= 0.791
pfun for whole AESR 15.1= 0.069
pact for whole AESR 15.1 = 0.140
Shannon-Wiener Index for whole AESR 15.1 = 0.302
Simpson’s Index for whole AESR 15.1 = 0.350
0.791
0.069
0.14
PROPORTION OF MICROBES IN AESR 15.1
Pbac
Pfun
Pact
OBSERVATION R1(cfu/g) R2(cfu/g) R3(cfu/g) AVERAGE(cfu/g)Total Bacteria 23 x 104 3 x 105 31 x 104 2.8 x 105
Total Fungi 22 x 103 1 x 104 30 x 103 2.06 x 104
Total Actinomycetes 76 x 103 11 x 104 62 x 103 8.26 x 104
Total Rhizobium 16 x 102 2 x 103 1 x 102 1.23 x 103
Total Azotobacter 4 x 103 5 x 103 1 x 103 3.33 x 103
Total Azospirillum 103 103 104 4 x 103
Total Phosphate Solubilisers 12 x 102 2 x 103 14 x 102 1.53 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 102 104 104 6.7 x 103
(ii)NO2- Oxidisers 103 102 102 4 x 102
N 3.832 x 105 individuals/g soilpbac 0.731pfun 0.054pact 0.216
Shannon-Wiener Index 0.310Simpson’s Index 0.416
AESR 18.5 Sample : 1Location : Kakdwip
Crop : Cotton
OBSERVATION R1(cfu/g) R2(cfu/g) R3(cfu/g) AVERAGE(cfu/g)Total Bacteria 30 x 104 17 x 104 2 x 105 2.23 x 105
Total Fungi 3 x 104 12 x 103 16 x 103 1.93 x 104
Total Actinomycetes 6 x 104 4 x 103 3 x 103 2.23 x 104
Total Rhizobium 6 x 102 9 x 102 2 x 102 5.66 x 102
Total Azotobacter 15 x 102 2 x 103 1 x 103 1.5 x 103
Total Azospirillum 104 104 103 7 x 103
Total Phosphate Solubilisers 3 x 103 15 x 102 2 x 103 2.16 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 103 103 103 103
(ii)NO2- Oxidisers 102 102 103 4 x 102
N 2.646 x 105 individuals/g soil
pbac 0.842pfun 0.073pact 0.084
Shannon-Wiener Index 0.236Simpson’s Index 0.279
AESR 18.5 Sample : 2Location : Kakdwip
Crop : Tomato
OBSERVATION R1(cfu/g) R2(cfu/g) R3(cfu/g) AVERAGE(cfu/g)Total Bacteria 38 x 104 27 x 104 36 x 104 3.37 x 105
Total Fungi 2 x 104 22 x 103 19 x 103 2.03 x 104
Total Actinomycetes 5 x 104 4 x 103 5 x 103 1.97 x 104
Total Rhizobium 6 x 102 5 x 102 5 x 102 5.33 x 102
Total Azotobacter 9 x 102 13 x 102 15 x 102 1.23 x 103
Total Azospirillum 103 103 103 1 x 103
Total Phosphate Solubilisers 27 x 102 19 x 102 12 x 102 1.93 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 104 103 103 4 x 103
(ii)NO2- Oxidisers 103 103 102 7 x 102
N 3.77 x 105 individuals/g soil
pbac 0.894pfun 0.054pact 0.052
Shannon-Wiener Index 0.179Simpson’s Index 0.195
AESR 18.5 Sample : 3Location : Sagar Island
Crop : Rice
OBSERVATION R1(cfu/g) R2(cfu/g) R3(cfu/g) AVERAGE(cfu/g)Total Bacteria 25 x 104 20 x 104 17 x 104 2.07 x 105
Total Fungi 31 x 103 6 x 104 13 x 103 3.47 x 104
Total Actinomycetes 6 x 103 12 x 103 7 x 103 8.33 x 103
Total Rhizobium 3 x 102 2 x 102 3 x 102 2.67 x 102
Total Azotobacter 6 x 102 11 x 102 10 x 102 9 x 102
Total Azospirillum 102 103 103 7 x 102
Total Phosphate Solubilisers 23 x 102 34 x 102 17 x 102 2.47 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 102 102 103 4 x 102
(ii)NO2- Oxidisers 102 102 102 1 x 102
N 2.50 x 105 individuals/g soil
pbac 0.828pfun 0.139pact 0.033
Shannon-Wiener Index 0.236Simpson’s Index 0.294
AESR 18.5 Sample : 4Location : Sagar Island
Crop : Elephant foot yam
OBSERVATION R1(cfu/g) R2(cfu/g) R3(cfu/g) AVERAGE(cfu/g)Total Bacteria 4 x 105 31 x 104 29 x 104 3.33 x 105
Total Fungi 5 x 104 12 x 104 2 x 104 6.33 x 104
Total Actinomycetes 2 x 104 9 x 103 2 x 103 1.03 x 104
Total Rhizobium 3 x 103 1 x 103 3 x 103 2.33 x 103
Total Azotobacter 4 x 103 21 x 102 5 x 103 3.7 x 103
Total Azospirillum 103 103 104 4 x 103
Total Phosphate Solubilisers 2 x 103 1 x 103 17 x 102 1.57 x 103
Total Nitrifiers (i)NH4
+ Oxidisers 104 104 104 1 x 104
(ii)NO2- Oxidisers 104 103 103 4 x 103
N 4.066 x 105 individuals/g soil
pbac 0.818pfun 0.156pact 0.025
Shannon-Wiener Index 0.237Simpson’s Index 0.306
AESR 18.5 Sample : 5Location : Sagar Island
Crop : Chilli
SAMPLE 1 SAMPLE 2 SAMPLE 3 SAMPLE 4 SAMPLE 50
1
2
3
4
5
6
5.45 5.355.53
5.315.52
4.31 4.29 4.314.54
4.84.92
5.35
4.29
3.92 4.01
Total Bacteria
Total Fungi
Total Acti-nomycetes
log
10 c
fu/g
soil
AESR 18.5
Total Bact.
Total Fungi
Total Actino.
Total Rhizo.
Total Azot.
Total Azos.
Total PSB
NH4+
Oxi.NO2
-
Oxi.Sand -0.46 -0.75 0.69 -0.35 -0.03 0.60 -0.02 -0.34 -0.63Silt 0.48 0.78 -0.68 0.39 0.08 -0.57 -0.02 0.38 0.67Clay -0.05 -0.78 0.68 -0.40 -0.07 0.56 0.02 -0.38 -0.67Org.C 0.25 0.53 0.20 0.85 0.85 0.73 -0.67 0.70 0.71
pH 0.50 0.91 -0.26 0.93 0.74 0.25 -0.55 0.80 0.98Ca -0.12 -0.11 0.59 0.38 0.59 0.91 -0.49 0.28 0.09Mg 0.11 0.28 0.38 0.70 0.79 0.85 -0.64 0.56 0.48Na 0.45 0.83 -0.13 0.95 0.81 0.41 -0.62 0.80 0.94K 0.44 0.81 -0.09 0.95 0.82 0.45 -0.63 0.80 0.93C.E.C.
-0.21 -0.28 0.65 0.22 0.47 0.88 -0.40 0.14 -0.08
Correlation coefficients of microbial population and soil physico-chemical properties under AESR 18.5
pbac for whole AESR 18.5 = 0.776
pfun for whole AESR 18.5 = 0.117
pact for whole AESR 18.5 = 0.106
Shannon-Wiener Index for whole AESR 18.5= 0.297
Simpson’s Index for whole AESR 18.5 = 0.373
0.776
0.117
0.106
PROPORTION OF MICROBES IN AESR 18.5
Pbac
Pfun
Pact
AESR 12.3 AESR 15.1 AESR 18.50
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.3620.35
0.373
0.2860.302 0.297
SIMPSON'S INDEXSHANNON-WIENER INDEX
• When Shannon-Wiener index is considered, AESR 15.1 shows highest diversity and AESR 12.3 shows the lowest diversity.
• When Simpson’s index is considered, AESR 18.5 shows the highest diversity and AESR 15.1 shows the lowest diversity.
What does this imply???
Probable reasons:
Microbial diversity shows both spatial as well as temporal variation
June- July, 2015 was monsoon season in West Bengal. So surrounding environment might have played a determining role during this period.
• Prevalence of rich organic matter.• Actinomycetes are highly resilient organisms. • Washing effect• “Great Plate Count Anomaly”• Viable-but-not-culturable microorganisms.
• Jhargram experienced 280 mm rainfall in June, 2015 and 452 mm rainfall in July, 2015.
• Khhatra and Bankura experienced 128 mm of rainfall in June, 2015 and 467 mm rainfall in July, 2015. (AESR 12.3)
• Baichigram faced 335 mm rainfall in June, 2015 and 550 mm rainfall in July,
2015. • Bardhhaman experienced 443 mm rainfall in June, 2015 and 631 mm rainfall in
July, 2015.• Birbhum faced 521 mm rainfall in June, 2015 and 651 mm rainfall in July,
2015. • Maldah experienced 215 mm rainfall in the month of June, 2015 and 382 mm
rainfall throughout July, 2015. (AESR 15.1)
• Kakdwip and Sagar Island faced 261 mm rainfall in June, 2015 and 648 mm rainfall in July, 2015. (AESR 18.5) (IMD, 2015)
• Both the indices reflect biodiversity.
• However, Simpson’s index is more weighted on the dominant species compared to Shannon- Wiener index.
• Shannon-Wiener index is a better measure for species richness as well as evenness.
NOTABLE OBSERVATIONS:
• TC Rhizobium levels were highest in AESR 18.5, and lowest in AESR 12.3
• TC Azotobacter were higher in acidic soils. They thrived well in vegetable fields.
• In AESR 12.3 as well as AESR 15.1, Azospirillum was negatively correlated with the soil nutrient contents.
• Acidic pH might have curbed the population of phosphorus solubilisers.
• Nitrifiers were very positively correlated with soil calcium and potassium.
These results suggest that:
• There exists a great variation in the total populations of microbes and microbial diversity between the agro-ecological sub-regions,
and
• They determine the soil physico-chemical properties and vice-versa.
FUTURE LINE OF WORK
• rRNA and rDNA analysis.
• Metagenomics.
• Genomics, transcriptome analysis and proteome analysis.
• FAME analysis.
CONCLUSION
• There is a concerted need to protect biodiversity, including soil microbial diversity which is hugely responsible for the functioning of
our ecosystem and subsequent maintenance of life on Earth.
• Patterns of microbial diversity would reveal the agricultural prospects and potentials of a region.
• In order to properly implement “SUSTAINABLE” development and agriculture, we need to focus on enhancement of soil biodiversity.
