arbuscular mycorrhizal fungi kabir

33
Z. Kabir, Ph.D. Soil Health Specialist for CA, NV & PIA USDA-NRCS, Davis, CA Arbuscular Mycorrhizal Fungi (AMF) in Soil Health Paradigm

Upload: soil-and-water-conservation-society

Post on 13-Apr-2017

207 views

Category:

Environment


8 download

TRANSCRIPT

Page 1: Arbuscular mycorrhizal fungi   kabir

Z. Kabir, Ph.D.Soil Health Specialist for CA, NV & PIA

USDA-NRCS, Davis, CA

Arbuscular Mycorrhizal Fungi (AMF)in Soil Health Paradigm

Page 2: Arbuscular mycorrhizal fungi   kabir

Outline

• AMF and soil health functions• Impact of tillage practices on AMF• Effects of land fallow on AMF• Alternative to no-till practices on AMF• Combined effects of tillage & fallow on AMF• Cover crops in relation to AMF• Conclusions

Page 3: Arbuscular mycorrhizal fungi   kabir

Plant and Mycorrhizal Symbiotic Relationship

Carbohydrate

P & other nutrients

AMF

Page 4: Arbuscular mycorrhizal fungi   kabir

P Transport by AM Hyphae

Root Soil

PO4P depletion zone

2 mm 1 mm

Stele

AM hyphae

P uptake by AMF (adapted from Hayman, 1982)

Arbuscule& vesicle

100 mm

Page 5: Arbuscular mycorrhizal fungi   kabir

T-DNA Carrot Root and AMF

Photo:Kabir

Page 6: Arbuscular mycorrhizal fungi   kabir

Hypha

spore

Soil

Impact of AMF on Soil Stability

Kabir

Page 7: Arbuscular mycorrhizal fungi   kabir

Fall Tillage Spring Tillage

Tillage Practices

Page 8: Arbuscular mycorrhizal fungi   kabir

Seasonal Changes of AM Hyphae in Tillage Systems

Kabir et al.

Spring Disk Fall Plow

Apr Jun Aug Oct Apr

Page 9: Arbuscular mycorrhizal fungi   kabir

Seasonal and Vertical Distribution of AM Hyphae in NT and CT

0

100

200

300

400

500

600

700

1

2

3

4

05

1015

2025

Hyp

hal d

ensi

ty (c

m c

m-3

)

Growing

perio

d

Depth (cm)

NT

0

100

200

300

400

500

600

1

2

3

4

05

1015

2025

Hyp

hal d

ensi

ty (c

m c

m-3

)

Growing

perio

d

Depth (cm)

CT

Kabir, 2005

Page 10: Arbuscular mycorrhizal fungi   kabir

Influence of Tillage on AM Species

Scutellospora spp.

Boddington and Dodd found disappearance

Kabir et al. observed disappearance

G. aggregatum Glomus spp.

Sieverding observed 75%

G. scintillans

in plowed soil while 5% in NT

in CT

Page 11: Arbuscular mycorrhizal fungi   kabir

Tillage and Soil Aggregate Stability

Treatments Soil depth 0-5 cm 5-10 cm Grass 53.2a 42.2b NT 3 yr 37.7c 24.4de NT 2 yr 30.8cd 26.4de NT 1 yr 25.0de 24.8de CT 4yr 16.7f 20.8ef

Comparison of aggregate stability across treatments of no-till (NT) and conventional tillage (CT) corn at two soil depths.

Wright et al.

Page 12: Arbuscular mycorrhizal fungi   kabir

Intact AMF in No-till System

Page 13: Arbuscular mycorrhizal fungi   kabir

Williams et al. 2016

Soil Functional Zone Management

Page 14: Arbuscular mycorrhizal fungi   kabir

Spatial Distribution of AM Hyphae

Mid-row

Quarter-row

Row

Page 15: Arbuscular mycorrhizal fungi   kabir

Sandyloam soilA

ctiv

e hy

phal

leng

th (c

m c

m-3

)

50

100

150

200

250

300

Tota

l hyp

hal l

engt

h (c

m c

m-3

)

100

150

200

250

300

350

400CT RT NT

Clay soil

Row Quarter-row Mid-row Quarter-rowRow Mid-row1992 1993

Row Quarter-row Mid-row1992

Spatial Distribution of AM Hyphae in two Soils

Kabir et. al.Ag.Ecosys. & Environment

Page 16: Arbuscular mycorrhizal fungi   kabir

Fallow Soil Erosion

Land Fallowing

Page 17: Arbuscular mycorrhizal fungi   kabir

Harinikumar and Bagyaraj

40% reduction after one season of fallow

13% reduction when a non-AMF plant in rotation

In Australia, Thompson showed that mycorrhizal colonization, P, Zn uptake, yields of various crops are inversely related to the duration of the fallow. He called it a long-fallow disorder if fallow period is one year

Effect of Crop Rotation and Fallow on AMF

Page 18: Arbuscular mycorrhizal fungi   kabir

0 30 60 90Fallow Period (day)

Combined Effects of Tillage and Fallow

Kabir et al.Soil Biol. Biochem.

Page 19: Arbuscular mycorrhizal fungi   kabir

Cover Crops

Page 20: Arbuscular mycorrhizal fungi   kabir

AM fungi bridges Cover Crops to the Subsequent Crops

Cover crops die

AM hyphae

Page 21: Arbuscular mycorrhizal fungi   kabir

Cover crop plot

Fallow plot

Page 22: Arbuscular mycorrhizal fungi   kabir

Shoo

t P u

ptak

e (m

g)

0

1

2

3

4

5

6

20

40

60

80

100FallowOatsRyeRye & oats

Days after planting

Shoo

t dry

wei

ght (

g)

0.0

0.3

0.6

0.9

1.2

5.0

10.0

15.0

20.0

25.0

c

bb

a

c

b

a a

c

bab

a

c

b

a a

27 42

P uptake and dry weight in Cover Crops and Fallow Fields

Page 23: Arbuscular mycorrhizal fungi   kabir

Mycorrhizal and Non-mycorrhizal Cover Crops

BuckwheatOats Winter wheat

AM FungiNon-AM Fungi

Page 24: Arbuscular mycorrhizal fungi   kabir

Sweet Corn Root Colonized by Mycorrhizal Fungi

Days after planting10 20 30 40 50 60 70

Myc

orrh

izal

col

oniz

atio

n (%

)

0

20

40

60

80

100

Fallow Buckwheat Oats Winter wheat

*

*

*

*

*

*

Page 25: Arbuscular mycorrhizal fungi   kabir

Shoo

t P u

ptak

e (m

g)

0

5

10

15

20

25

FallowBuckwheatOatsWinter wheat

c cb

a

cc

b

a

Days after planting 14 31

Corn

sho

ot d

ry w

eigh

t (g)

0

1

2

3

4

c c ba

cc

b

a

Corn P uptake and Shoot Dry Weight

Page 26: Arbuscular mycorrhizal fungi   kabir

Suitable Crop Rotation

Corn following Soybean (Mycotrophic)

Corn following Canola(Non-mycotrophic)

Koide, BYU

Page 27: Arbuscular mycorrhizal fungi   kabir

Hyphal Length and Soil Aggregates in Cover Crops and Fallow Field

AM hyphal length (m g-1)

0 10 20 30 40 50 60

Wat

er s

tabl

e so

il ag

greg

ates

(%)

10

20

30

40

50

60

FallowRyeOatsRye + Oats

R2 = 0.39Hyphal length = 19.06 + 0.74 (%WSA)

P < 0.05

Kabir and KoidePlant and Soil

Page 28: Arbuscular mycorrhizal fungi   kabir

• Judicial manipulation of agronomic practices would benefit AMF survival and its benefits

• Minimal or no disturbance of soil improve AM fungal propagules and its diversity

• Mycotrophic plant in cropping systems throughout year would improve AM fungal survival and benefit to the soil and crops

Conclusions

Page 29: Arbuscular mycorrhizal fungi   kabir

Thank You

Page 30: Arbuscular mycorrhizal fungi   kabir

Ear Production of Corn in Different Cover Crops Treatments

Page 31: Arbuscular mycorrhizal fungi   kabir

Annual Plants P uptake

Plants take up-10-20 % applied P

AM fungi

Page 32: Arbuscular mycorrhizal fungi   kabir

AM Hyphae Produced Phosphatase

Koide & Kabir

Page 33: Arbuscular mycorrhizal fungi   kabir

Seasonal and vertical distribution of Spore in NT and CT

0

10

20

30

40

50

0

1

2

34

5

05

1015

2025Sp

ore

dens

ity (n

o. c

m-3

)

Growing

perio

d in N

T

Depth (cm)

Spor

e de

nsity

(no.

cm

-3)

0

10

20

30

40

50

0

1

2

34

5

05

1015

2025

Growin

g pe

riod

in C

T

Depth (cm)