Charcoal as a micro-habitat for VA mycorrhizal fungi, and its practical implication

341

Agriculture, Ecosystems and Environment, 29 (1989) 341-344 Elsevier Science Publishers B.V., Amsterdam Printed in Czechoslovakla

C h a r c o a l a s a M i c r o - h a b S t a t f o r VA M y c o r r h i z a l F u n g i , and i t s P r a c t i c a l Implication Nasanori Saito Tohoku N a t i o n a l A g r i c u l t u r a l Experiment S t a t i o n , Norioka, I w a t e , 020-01, J a p a n

ABSTP~CT A stimulating recently

in

effect

Japan.

of

In

charcoal

order

on

to

i n d i g e n o u s VAN f u n g i was

evaluate

this

effect

condRtions0 soybean was grown i n a humus r i c h Ando s o i l application

of

charcoal.

The

stimulating

effect

of

found

under

field

with or w i t h o u t charcoal

on

the

i n f e c t i o n o f soybean by t h e i n d i g e n o u s VAN fun&l was confirmed u n d e r t h e s e conditions.

This e f f e c t was found o n l y b e f o r e the f l o w e r i n g s t a g e and w i t h

low r a t e s of P f e r t i l i z e r .

INTBODUCTION Recently

Ogawa

et

al.

(1983)

found

that

infection

of

soybean

by

i n d i g e n o u s VAN f u n g i was s t i m u l a t e d when c~harcoal was a p p l i e d to the s o i l . They a s c r i b e d t h i s

effect

of c h a r c o a l

to

its

( p o r o u s and a l k a l i n e ) ,

which a r e p r e f e r a b l e

they

charcoal

suggested

that

contains

s a p r o p h y t e s so thaC VAN f u n g i s e n s i t i v e e a s i l y grow i n c h a r c o a l p a r t i c l e s the a p p l i c a t i o n

growth

f o r VAN f u n g i . no

substrate

may make i t

practical

available

for

This i m p l i e s t h a t

p o s s i b l e to promote crop

of VAN f u n g x .

e x p e r i m e n t s were conducted i n o r d e r to c o n f i r m t h i s to e x p l , ~ c i t s

Furthermore.

t o c o m p e t i t i o n from s a p r o p h y t e s can

(Ogawa & Yamabe 1986).

of c h a r c o a l t o s o i l

growth by s t i m u l a t i n g _ t h e

physico-chemicaI properties

~o~ c h i s

reason,

field

e f f e c t of c h a r c o a l and

i m p l i c a t i o n under f i e l d c o n d i t i o n s .

342

MATERIALS AND METHODS A site

at

the

Experiment S t a t i o n , soil

is

experimental

farm

of

Tohoku

a humus r i c h Ando s g i l .

2),

application

soybean

of c h a r c o a l

various fertilizer levels

in

exp.

Agricultural

M o r i o k a - c i t y , J a p a n , was used f o r t h e e x p e r i m e n t s . Soybean grown i n t h i s

w e l l - i n f e c t e d by t h e i n d i g e n o u s VAM f u n g i . (experiment

National

was

grown

in

this

(1500 g/m 2 i n exp.

The p l a n t s

were

is usually

I n 1985 ( e x p e r i m e n t 1) and 1986

t r e a t m e n t s (3 f e r t i l i z e r 2).

field

The

field

with

or

without

1, 500 gtm2 i n exp. l e v e l s i n exp.

successively

the

2) u n d e r

!, 4 fertilizer

uprv~tedo

and

their

growth, n o d u l a t i o n , P c o n t e n t and i n f e c t i o n by VAM f u n g i were examined. RESULTS Experiment 1

A stimulating

f u n g i was found a t f o u r

effect

of

charcoal

leaf-unfolding stage

on t h e

infection

(47 days a f t e r

of VAM

s o w i n g ) , VAM

i n f e c t i o n was s t i m u l a t e d by c h a r c o a l , b u t p l a n t growth and n o d u l a t i o n were not.

F i g . 1 shows t h e r e l a t i o n s h i p

between the d e g r e e of i n f e c t i o n and t h e

leaf P content.

Although a s l i g h t

application

found a week b e f o r e

was

enhancement of p l a n t krowth by c h a r c o a l f l o w e r i n g (70 d a y s ) ,

no e f f e c t

was

found a f t e r w a r d s . gxperiment 2 practical

The second e x p e r i m e n t was conducted i n o r d e r

i m p l i c a t i o n of c h a r c o a l a p p l i c a t i o n .

of f e r t i l i z e r

In t h i s experiment the r a t e

a p p l i e d was w i t h i n t h e range recommended t o f a r m e r s ,

r a t e of c h a r c o a l was reduced b e c a u s e of ~ t s high c o s t ,

of c h a r c o a l on i n f e c t i o n

r a t e s of P f e r t i l i z e r

and t h e

The enhancement o f

p l a n t growth by c h a r c o a l was found o n l y b e f o r e f l o w e r i n g . effect

to e x p l o r e t h e

The s t i m u l a t i n g

was found o n l y b e f o r e f l o w e r i n g when low

were a p p l i e d . DISCUSSION

The p r e s e n t s t u d y c o n f i r m e d t h e s t i m u l a t i n g e f f e c t

of c h a r c o a l on t h e

i n d i g e n o u s VAM f u n g i u n d e r f i e l d

conditions.

I t was o b s e r v e d t h a t

spores

hyphae

attached

of

particles

VAM f u n g i which

were

and

their

collected

su~,gested by Ogawa e t a l .

from

were

the

soil

after

to

the

many

charcoal

harvesting.

As

( 1 9 8 6 ) , c h a r c o a l was a good m i c r o - h a b i t a t f o r VAM

363

_

(%)

~rcoal

40

O O c-

20

O

cD cD L_

--cha~ 0.1 0.2 0.3(%) Leaf P content I

c~

P~g. I.

Relationship

between

I

I

infection by

indigenous

VAN

fungi

and

P

content in the leaves (Exp. ~. 41 days after sowing). fungi

in

the

properties

soil.

of charcoal,

t o be e f f e c t i v e volcanic

tuff

Expanded

clay,

inoculated fungal indicate implies suitable

From t h e

which

with

that,

to

soil

used was

mycelium

gave

as

of

the

(1988)

al.

a

similar

substrate

reported

(Deh~e

view

physico-chemical

other than charcoal

Ni~hzo e t

the

was

VAN f u n g i , and

of

porous m a t e r i a l s

f o r VAN f u n g i . applied

spores

point

and

to

in

contain

Backhaus,

found t h a t effect

porous m a t e r i e l s

carriers

such

as

charcoal

f o r VAH f u n g i i n o c u l a n t

on

hydroponic high

1986).

i n g e n e r a l , VAN f u n g i p r e f e r porous m a t e r i a l s .

that

are expected

lucerne.

cultures

levels

of

These

result~

the

This f u r t h e r

and expanded c l a y

(Baltraschat,

a porous

can

be

1987; S a i t o e t a I . ,

1988). However, t h e a p p l i c a t i o n

considered to conditions.

o f c h a r c o a l f o r i m p r o v i n g c r o p p e r f o r m a n c e was

be impractical,

at

least under

The s o i l used was r e l a t i v e l y

the present experimental

so p o r o u s t h a t

it

might o b s c u r e

544

the effect

of applied charcoal.

the efficacy

of charcoal

In o r d e r t o a p p l y c h a r c o a l

in relation

as well as to the soil properties

to the nature

in practice.

of indigenous V~ fungi

s h o u l d be c l a r i f i e d . REFERENCES

BALTRUSCHAT. H,: E v a l u a t i o n o f t h e s u i t a b i l i t y material

f o r YAM s p o r e s i n f i e l d

61: 163-169,

o f expanded c l a y a s c a r r i e r

inoculation

o f m a i z e , Angew. B o t a n i k . ,

1987.

DEHNE, H.W., BACKitAUS, G . F . : The use o f VAM f u n g i i n p l a n t p r o d u c t i o n . Pfl~ranh..

93(4): 415-424,

Z.

1986.

NISHIO, M., OKANO, M.. ¥~IAMOTO. T . :

Development o f e f f e c t i v e

t e c h n o l o g y u s i n g VA m y c o r r h i z a ~ B u l l . Green Energy Programme Group I I No. 19, 113-123, Min. A ~ r i c . F o r . F i s h . , OGAWA, M. YAMABE, ¥ . . SUGIURA, G . : E f f e c t s

Japan,

1988.

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3rd ~ n t . Mycol. Cong.,

1983. OGAWA, M.,

¥PhlbBE, ¥ . :

Effects

f o r m a t i o n of s o y b e a n s . 108-133, Min. ~ r i c . SAITO, M., ~d~A0, S . ,

Bull.

of charcoal

on VA m y c o r r h i z a e

and n o d u l e

Green Energy Programme Group I I °

For. Fish.,

Japan,

No. 8,

1986.

ICHIKI, H . : Development of e f f e c t i v e

technology using

e

VA m y c o r r h i z a ,

B u l l . Green Energy Programme Group I I ,

Min. A g r i c . F o r . F i s h , J a p a n ,

No. 19,

124-138,

1988.

Salto, H., 1989: Charcoal as a micro-habltat for VA m¥corrhlzal fungi and its practical implication. Agric. Ecosystems Environ., 29: 341-344.