application of mithserlich methods-1942

7/25/2019 Application of Mithserlich Methods-1942

1/64

L

h

i5i

ft*

THE A P P L I CA T I ON

0?

MI TSCHERLI CHS

GROWTH LAWAND POT METHOD OF

S OI L

T ES T I NG

TO

NUTRI T I ONAL STUDI ES

WTH

RASPBERR I ES

AND OATS

b y

Br u c e An d e r s o n Di c k s o n

A

T h e s i s

s u b mi t t e d i n

P a r t i a l F u l f i l m e n t of

T h e

Re q u i r e me n t s

f o r t heDe g r e eof

MASTER

OE S CI E NCE I N AGRI CUL TURE

i n t he

De p a r t me n t

o f

HORTI CUL TURE

T h e U n i v e r s i t y of

A p r i l ,

B r i t i s h

1 ? 4 2

Co l u mb i a


2/64

Tab l e o f Co nt e nt s

Ack nowl edgment s

2

I n t r o d u c t i o n . . . . . . . . . . . . . 3

Re v i e w o f t h e M i t s c h e r l i c h g r o wt h l a w' 4

P a r t I An Expe r i men t w i t h Cu t h b e r t R a s p b e r r i e s

I n t r o d u c t i o n . . . . . . . . . . . . . . . . . . . 12

Ex pe r i me nt a l

M a t e r i a l s and c o n t r o l o f c o n d i t i o n s 13

P l a n o f

e x pe r i me nt

14

Ha r v e s t

met hods 16

Met hods o f a n a l y s i s 16

R e s u l t s

o f t h e

r a s p b e r r y

e x pe r i me nt

T h e

d r y

we i gh t

da t a

. . . 17

T h e

max i mum

p o s s i b l e

y i e l d . . . . 18

T h e p r o p o r t i o n a l i t y c o n s t a n t . . . . . . . . 19

T h e f e r t i l i t y o f t h e s a nd- p ea t mi x t u r e . . . . 20

C a l c u l a t i o n o f t h e

y i e l d s f o r

a

t r u e

l o g a r i t h m i c

c u r v e

. . . . . . . . . 21

R e s u l t s o f r a s p b e r r y a n a l y s i s . 24

C o n c l u s i o n s

o n t h e

r a s p b e r r y

e x pe r i me n t 27

P a r t

I I An Ex p e r i me n t

w i t h Oat s

I n t r o d u c t i o n 30


3/64

Ex pe r i me nt a l

. . . 31

Ap pa r a t u s ,

s o i l s a mp l e s ,

mi x i ng p r o c e d u r e ,

p l a n t ma t e r i a l , wa t e r i ng c o n t r o l o f c o n d i t i o n s . 3 1

F e ed i ng p l a n and s t oek s o l u t i o n s 33

Ha r v e s t

met hods . . . . . . . . . 35

Met hods o f a n a l y s i s 36

R e s u l t s

o f t h e o a t

ex pe r i me nt

D r y we i g h t

da t a

36

The

max i mum p o s s i b l e y i e l d . 40

The p r o p o r t i o n a l i t y

c o ns t a nt 41

S o i l n i t r o g e n . . . . . . . . . . . . . . . . 42

C a l c u l a t i o n s

o f t h e

y i e l d s

f o r

a

t r u e


c u r v e

. 42

R e s u l t s o f c h e mi c a l

s o i l

t e s t s . . . . . . . . . . 45

R e s u l t s o f p l a n t a n a l y s i s . . . . . . . . . . . . 47

Co nc l u s i o ns

on t h e o a t

e x pe r i me n t

. . 52

Gene r a l

c o n c l u s i o n s

on t h e

a p p l i c a t i o n

o f t h e

M i t s c h e r l i c h met hod t o r a s p b e r r i e s and

oa t s

. . . . . . 57

B i b l i o g r a p h y

. 61


4/64

( 2 )

Ac knowl edgement s

The

w r i t e r t ak es gr e a t p l e as u r e

i n

a c k n o wl e dgi n g

t he a s s i s t a n c e

o f Dr .

G. H. Har r i s , As s o c i a t e Pr o f e s s o r

o f t h e De pa r t me nt o f H o r t i c u l t u r e , U n i v e r s i t y o f

B r i t i s h Co l u mb i a , i n t h e a d mi n i s t r a t i o n o f t h e e x p e r i

ment a l

wor k o f t h e

r a s p b er r y ex pe r i ment ,

t h e

c h emi c a l

a n a l y s i s , a nd t h e p r e pa r a t i o no f t h e manus c r i p t .

Ack nowl edgemen t s a r e

a l s o e x t e nded

t o Mr . J , J . Woods *

Su pe r i n t e nde nt o f t h e Do mi n i o n Expe r i men t S t a t i o n ,

Sa an i c h t o n,

B. C. , who

g ene r o us l y p r o v i d ed

t h e

equ i p -

ment ,

m a t e r i a l s ,

and t i me f o r t h e o a t e x pe r i me nt , and

h e l p f u l l y c r i t i c i z e d

t h e ma nus c r i p t . Thank s a r e t e nd

e r e d t o Mr . T. H. Ans t e y, g r a du at e i np l a n t n u t r i t i o n ,

f o r

p r o o f - r e a d i n g

t h e

manus c r i p t ,

a nd t o

Mi s s K at h l e en

Woods f o r h e r

v e r y

e x c e l l e n t

t y p i n g .


5/64

THEAPPLI CATI ON OPM TSCHERLI CHSGROWTH LAWAND POT METHOD OP

SOI L TESTI NG TO

NUTRI TI ONAL

STUDI ES

WTH

RASPBERRI ES AND

OATS

I n t r o d u c t i o n

The i mpo r t a nc e of d et e r mi n i ng t h ema nu r i a l r e qu i r e me nt s

o f

s o i l s andt hei n t e r p r e t a t i o n of t h es e d e t e r mi na t i o ns i n

t e r ms

of pr o b ab l e p l a n t

y i e l d s ,

hasl o ng b e en r e c ogn i z e dby

a g r i c u l t u r i s t s . Ame t hod wh i c h pu r po r t s t of or m a newapp

r o a c h

t o

t h i s

pr ob l em andwh i c h hasen j oyed c o ns i d e r a b l e

p o p u l a r i t y i n Eu r o pe f o r t h e p as t t h i r t y ye a r s , hasb e e n p r o

po s edby

E.

A. M i t s c h e r l i c h ( 8) of K on i gs b e r g , Ger many.

Al t h ou gh M i t s c h e r l i c h pu b l i s h e d h i s

f i r s t

pape r s onh i s p l a n t

met hod of s o i l t e s t i n g i n 1909, t h ey r e c i e v ed l i t t l e a t t e n

t i o n i n t h e E n g l i s h l anguage p u b l i c a t i o n s

u n t i l

1932

when

St e wa r t , of

t he

I mpe r i a l Bu r eau of S o i l Sc i e n c e , pu b l i s h e da

l i t e r a t u r e r e v i e w of t hes u b j e c t ( 13) . Si n c e t h en , h o we ve r ,

Capo ( 4) , Har t ung ( 5) , Mac y ( 6) , Mag i s t ad ( 7) ,

and

Wi l l c o x9

( 1 5 ) , a l l

of No r t h Ame r i c a , h a vemade c o n t r i b u t i o n s on t he

M i t s c h e r l i c h me t h o d.

The

M i t s c h e r l i c h

me t h od f o r

s o i l f e r t i l i t y

i n v e s t i g a

t i o n s i s e s s e n t i a l l y

t he

s t udy of

t he

t r e n dof t h e y i e l d s

f r o m

a s e r i e s of

p l a n t s

gr own t o

ma t u r i t y

u n d e r a

s ys t e ma t i c

s cheme of f e r t i l i z a t i o n . M i t s c h e r l i c h i ssoc o nv i nc e d of

t he

v a l i d i t y of h i s me t hod

t h a t he c l a i ms , and

o f f e r s

p r o o f ( 9) ,

t h a t

he

has

d e r i v e da g e ne r a l

y i e l d l aw

wh i c h i s amenab l e

t o ma t h ema t i c a l t r e at me nt . He

a l s o

c l a i ms t h a t when

s p e c i a l l y


6/64

de s i gne d ex pe r i me nt s a r e c o ns i de r e d i n t h e

l i g h t

o f h i s

y i e l d l a w , a q u a n t i t a t i v e r e l a t i o n s h i p b e t ween

s o i l

f e r t i l i t y

a n d p l a n t y i e l d ma y b e

f o u n d .

Re c ogn i z i ng t h e

i mpo t e nc e

o f

t h e s e

c l a i ms , i t wa s d e

c i d e d t o t e s t t h e

v a l i d i t y

o f t h e M i t s c h e r l i c h

met hod

a n d t o

a s c e r t a i n ,

t h er e by, whe t h e r

a n a p p l i c a t i o n o f i t wo u l d b e o f

v al u e i n s u pp l i me n t i ng t h e r a p i d c h e mi c a l met hods ( 1 0 ) . ( 1 2 )

o f e s t i ma t i n g

s o i l

f e r t i l i t y

n o w i n

po pu l a r

u s e i n

B r i t i s h

Co l u mb i a . I t wa s d ec i de d a l s o t o i n v e s t i g a t e whe t h e r t h e

u s e o f t h e M i t s c h e r l i c h met hod w i t h d i f f e r e n t a g r i c u l t u r a l

p l a n t

t ype s wo ul d s ugge s t

a n i mpr o v e d

t e c h ni que

f o r p l a n t

n u t r i t i o n

ex pe r i me nt s .

W t h t h i s

p u r p o s e

i n

v i e w,

t wo

e xpe r i me nt s

wer e

u nd e r

t a k en . T h e

f i r s t ,

d u r i n g t h e summer o f 1 9 4 0 , wa s a n

e x pe r

i ment

i n t h e n i t r o g e n n u t r i t i o n o f Cu t h b er t r a s p b e r r i e s , a n d

t h e s e c o n d , d u r i n g t h e

s e a s o n

o f 1941- 1942, wa s a n ex pe r i me nt

w i t h o a t s , wher e t h e met hod wa s u s e d i n c o n j u n c t i o n w i t h t h e

r a p i d c h e mi c a l

s o i l

t e s t me t h o ds .

Re v i e w o f t h e M i t s c h e r l i c h

Gr owt h

L a w

Many o f t h e e a r l y wo r k e r s i n t h e f i e l d o f p l a n t n u t r i

t i o n s u c h a s L e i b i g , H e l l r e i g a l , a n d Wagne r , began e x p e r i me n

t a t i o n b y

s t u d y i n g

t h e e f f e c t o f v a r y i n g t h e a p p l i c a t i o n o f

a s i n g l e n u t r i e n t f r o m a n ampl e l e v e l down t o a z e r o a p p l i c

a t i o n , a t t h e

same

t i me

k e ep i ng

a l l

o t h e r

known

g r o wt h

f a c t o r s a t a n ampl e

l e v e l . Al t h ou gh

some o f t h e s e me n o b -


7/64

t a i n e d e x c e l l e n t r e s u l t s ( 9 ) , t he

f u l l ma t h e ma t i c a l

p o s s i b

i l i t i e s

of t h e i r

y i e l d

c u r v e s wer enotp o i n t e d out u n t i l

M i t s c h e r l i c h r e c o g n i z e d t he s i m i l a r i t y i n t he

s hape

of t h es e

gr o wt h c u r v e s and p o s t u l a t e d t h a t i f t hee x pe r i me nt s wer e

done

unde r

s p e c i f i e d c o n d i t i o n s , a g e n e r a l

e qua t i o n

c o u l d be

w r i t t e n

wh i c h

wou l d

app l y

t o a l l of

t hem.


s t u d i e d t h e s e gr o wt h c u r v e s , as w e l l as

t h os e

o b t a i n e d

f r om

h i s

own

e x pe r i me nt s ,

and

c o nc l u de d

t h a t

t he

y i e l d

was a

l o g a r i t h m i c f u n c t i o n

of a g r o wt h

f a c t o r ,

when

t h a t f a c t o r

wa s i n c r e a s e d i n u n i t

I nc r e me nt s f r om

z e r o , a l l o t h e r g r o wt h

f a c t o r s b e i n g * s u p p l i e d at an

ampl e

l e v e l ( 9 ) .

E x p r e s s e d

I n

s ymb o l s ,

h i s r e l a t i o n i s r e p r e s e nt e dby,

wh i c h

s t a t e s

b r i e f l y

t h a t t heI n c r e me nt of y i e l d , dy, o b t a i n

e d peru n i t i n c r e me nt ofgr o wt h f a c t o r , dx, i s p r o p o r t i o n a l

t o t hedec r ement

f r o m

t he maxi mum ( i . e . p r o p o r t i o n a l t o t he

d i f f e r e n c e b e t ween t he

y i e l d

o b t a i n e d , y, and t he maxi mum

p o s s i b l e

y i e l d of the

s e r i e s ,

A) .

I n

o r d e r t oe qu at e

t h e s e q u a n t i t i e s ,

t he

r i g h t

hand

s i d e i s m u l t i p l i e dby the

needed nu me r a l , wh i c h

may be

known

a s a p r o p o r t i o n a l i t y c o n s t a n t , or e f f e c t f a c t o r , c.

( I )

When i n t e g r a t e d and t r ans f o r me d t h i s e qua t i o n bec omes

l o g ( A- y)

= l o gA - c. x

-

( I D


8/64

o r , s o l v i n g f o r y:

y = A ( l - 1CT

C X

) - - - - - ( HI )

Th i s

i s

a

g en e r a l e qu at i o n wh i c h

has

a l r e a dy

b e e n

f i t t e d

t o

many

n a t u r a l phenomena. St ewa r t ( 13) p o i n t s

put

t h a t

t h i s

l o g a r i t h mi c e qua t i o n i s

i d e n t i c a l

w i t h t heequa t i o n a p p l i e d

t o t hev e l o c i t yof r e a c t i o n of a monomo l ec u l a r c h emi c a l

change atc o n s t a nt t e mpe r a t u r e , s uc h as t he de c ompos i t i on . o f

h yd r o ge n

pe r o x i de i n

aqueous

s o l u t i o n .

I t

i s

a l s o

i d e n t i c a l

w i t h t h a t a p p l i e d

t o t he

r a t e

of

r a d i o - a c t i v e d i s i n t e g r a t i o n

o f me t a l s .

Under some c i r c ums t an c es , i t hasb e e n f o u n d

d i f f i c u l t

t o d et e r mi ne t he maxi mump o s s i b l e y i e l d , A, of t he s e r i e s

e x p e r i me n t a l l y . I tc a n , h oweve r , be c a l c u l a t e d by s i mu l t a n

e ous l y

s o l v i n g t h r e e e qua t i o ns .

I n

o r de r

t o do t h i s , t he

i nc r e me nt s ofgr o wt h f a c t o r

must

be d e l i b e r a t e l y c h o s e nso

t h a t x g- X3=

x^- Xg.

The r e s u l t i n g y i e l d s may t h e nbe

a p p l i e d t o t het h r e e equa t i ons of the f o r m ( I I ) , wh i c h may

t a k e t her e ar r ange d f or mof

a

To)

2

-

( y - . )

( yQ .

( i v )

&

~ 2( y2) - ( y l ) - ( y

3

)

wher ey , yg, and y

3

ar e t hey i e l d s ob t a i ne d f r om f e r t i l i z e r

t r e at me nt s x- ^ Xg, and x^r e s p e c t i v e l y .

Thus ,

h av i ng o b t a i ne d t hee x pe r i me nt a l y i e l d d at a , t he

most pr o b ab l e va l u e f o r t he maxi mumy i e l d may be c a l c u l a t e d

and u s e d i ns u b s equent c a l c u l a t i o n s .


9/64

I n

t h e

f o r e go i ng e qua t i o ns ,

t h e

symbol

x

r e pr e s e nt s

t h e

amount o f t h e

gr o wt h f a c t o r

added t o t h e

s o i l .

One

t r e a t

ment i n t h e

s e r i e s ,

howeve r ,

r e c i e v e s

none o f t h e

gr owt h

f a c t o r i nq u e s t i o n , s o t h at I f a y i e l d i s o b t a i ne d a t a l l i n

t h a t

t r e a t ment , i t

i s t h e

r e s u l t

o f t h e amount o f t h e

gr owt h

f a c t o r

o r i g i n a l l y

p r e s e n t

i n t h e

s o i l .

The amount o f

gr owt h

f a c t o r i s

d es i gna t e d

b y t h e symbol b . As a

r e s u l t

o f

i t s

p r e s e n c e

i n a l l o f t h e

po t s

t h e

who l e

g r o wt h

c u r v e

i s

d i s

p l a c e d upwar ds by a g i v e n amount . T h e r e f o r e , i no r d er t o

c o mpl e t e

t h e

mean i ng

o f

equa t i o n ( I I ) ,

t h e

t o t a l

amount o f

t he gr o wt h f a c t o r p r e s e nt

i n t h e

s o i l

i s

r e pr e s en t e d

b y,

x + b . The

equa t i o n

now becomes

l o g( A- y) = l ogA - c ( x +b ) ( y )

Si nc e b o t h

b and c

a r e ,

as

y e t ,

unknown

q u a n t i t i e s

i n

t h i s

e qu at i o n,

t wo

s uc h e qu at i o ns

mus t b e

s o l v ed s i mu l t a ne ou s l y,

t he

c ondensed f o r m o f wh i c hi s

l o g ( A - y - j ) -

l og( A- yg)

c

= ( VI )

x

2

- x

x

The

s o l u t i o n

o f

e qua t i o n ( VI ) pr o vi de s

u s

wi t h

a number

c a l l e d a p r o p o r t i o n a l i t y c o n s t a n t , c , wh i c h makes i t p o s s i b l e

t o i n t e r p r e t M i t s c h e r l i c h ' s

y i e l d l a w a s a

wo r k a b l e e qua t i o n .


goes f u r t h e r t h an

t h i s ,

h oweve r ,

and shows

t h a t

t h i s

n umber i s c h a r a c t e r i s t i c o f t h e

s l o pe

o f t h e y i e l d

c u r v e

and

t h a t

t h i s numb er i s

a l ways

t h e

same

f o r a

g i v en

gr o wt h f a c t o r , r e ga r d l e s s

o f t h e

p l a nt

u s e d ,

p r o v i d e d

he


10/64

- 8 -

u s e s t he

s ame

s i z e of p o t , t he

same we i gh t

of s o i l , and t he

same u n i t s

of

meas ur ement i n a l l

of

t h e

ex pe r i me nt s . He,

t h e r e f o r e , g i v e s t h i s p r o p o r t i o n a l i t y c o ns t a nt s p e c i a l s i g

n i f i c a n c e by c a l l i n g i t an e f f e c t f a c t o r of

t h e

gr o wt h

f a c t o r ( 9 ) .

When

t h e

p r o p o r t i o n a l i t y c o ns t an t , c,

i s

f o un d by s o l v

i n g equa t i o n ( V I ) ,

t h e n

e qua t i o n ( V)

may be

s o l v e d f o r

b,

t h e

amount

of

g r o wt h

f a c t o r o r i g i n a l l y

p r e s e nt

i n

t he

s o i l .

When r e a r r a n g e d e qua t i o n ( V) b e c ome s

l o gA - l o g ( A- y

Q

)

b =

_ _ _ _ _ _ _ _ _

. ( VI I )

c

wher e

y

0

i s t h e

y i e l d

ob t a i ne d

when

t he

s o i l

r e c e i v e d

a l l

of

t h e g r o wt h f a c t o r s e x c e p t t he onec o n c e r n ed

i n

t he s e r i e s .

Hav i ng,

ob t a i ne d

a l l of t heI n f o r ma t i o n r e q u i r e d f o r

e qua t i o n ( V ) ,

t he

c a l c u l a t i o n p r o c e d u r e

may be

r e ve r s e d

and

t h e y i e l d s , y,

wh i c h

t h e o r e t i c a l l y

s hou l d

have been

ob t a i n ed

i n

t he

e x pe r i me nt ,

may be

c a l c u l a t e d . Th i s i s done p u r e l y

a s a c h e c k on

t h e

y i e l d l a w , t h a t i s , t o see howc l o s e l yt he

y i e l d

c u r v e

ob t a i ne d r e s e mb l e s

a

t r u e l o g a r i t h mi c

c u r v eof

t h e

same s l o p e

( s ame p r o p o r t i o n a l i t y

c o n s t a n t , ) . -

Co nd uc t i n g

n u t r i t i o n ex pe r i me nt s i n t h i s q u a n t i t a t i v e

manner

n o t o n l y

a f f o r d s us a

means

of e v a l u a t i n g s o i l f e r t

i l i t y

i n

t e r ms

of

a c t u a l

we i gh t

of

g r o wt h

f a c t o r s ,

but

i t

a l s o a f f o r d s us a

means

of e v a l u a t i n g i t

i n

t e r ms of p l a n t


11/64

y i e l d .

Thus ,

when t hey i e l d

i s p l o t t e d

as pe r c e n t of t he

maxi mum t he

amoun t

ofg r o wt h f a c t o r r e q u i r e d f o r a50

y i e l d can q u i c k l y he de t e r mi n ed . M i t s c h e r l i c h ' s l aws t a t e s

t h a t t he i n c r e a s e i n g r o wt h peru n i t of f a c t o r i s p r o p o r

t i o n a l t o t hedec r emen t f r om t h e maxi mum P rom t h i S j i t

f o l l o w s t h a t i f t heamoun t of

f e r t i l i z e r

r e q u i r e d f o r a

50

y i e l d i s d ou b l e d, i t

w i l l

g i v e an i n c r e a s e of

50

of t he

d ec r e me nt ,

t h a t i s , 50$ of

50 = 25 ,

and t he

y i e l d

f r om

t he

do ub l e d amount

w i l l be75 of t he maxi mum

Ba ul e ( 2)

has

pr o po s e d

t h a t

t he

amoun t

of each

n u t r i e n t r e q u i r e d f o r

a

5 0

y i e l d

be

d e s i g n a t e d

as a

f o o d u n i t

(now known as t he

Ba ul e u n i t ) . F ur t h e r mo r e ,

i t

hasb e e n f o u n d

t h a t

when

h a l f

t h e maxi mumy i e l d i s o b t a i n e d i n one of s u c h a s e r i e s , t he

amount

ofgr o wt h f a c t o r p r e s e n t i s one t e n t h as h i g h as i t

i s

f o r t he maxi mum Thus , a l t h ough f o u r Ba ul e u n i t s

w i l l


p r o du c e a

93. 75$

y i e l d ' , i t

w i l l

t a k e more t h an

t w i c e as much ( 10Ba ul e u n i t s ) t o r a i s e i t t o

100

t

p r o v i d

i n g t o x i c c o n d i t i o n s ar e notr e ac h e d f o r t hep l a n t s p e c i e s

b e i n g

u s e d .

M i t s c h e r l i c h ' s

y i e l d

l aw and

Baul e' s p r o p o s a l f o r

f o o d u n i t e v a l u a t i o n

of

n u t r i e n t s

ar e

d i a g r a ma t i c a l l y

r e p r e s e n t e d i nF i g u r e 1.

I n

e x pe r i me nt s wh i c h

I l l u s t r a t e t h i s

g r o wt h

l a w , i t

has

b e e n

g e n e r a l l y

f o und

( 1 5 ) t h a t ,

i n

s and

or

s o i l s

of l ow

phos

ph at e f i x i n g power , t he maxi mumy i e l d

i s o b t a i n e d

when t he


12/64

F i g u r e 1. Di a gr a ma t i e Re pr e s e n t a t i o n o f M i t s c h e r l i c h ' s

Y i e l d Law and

Bau l e ' s

f o o d

u n i t s

o f

Gr owt h

F ac t o r .


13/64

- 11-

t h r e e

ma i n

f a c t o r s

a r e

pr e s e n t

I n t h e r a t i o 5 : l j 2

( U: P2G5: K2O)

Thus

when t h e

p h os p h at e

and t h e

po t a s h

a r e a t t h e i r max i mum

v al ue s f o r gr owt h

and

n i t r o ge n i s v a r i e d upwar ds

I n

u n i t

I nc r e me nt s f r o m z e r o ,

t h e

g r e a t e s t

y i e l d

i s

o b t a i ne d

wher e

t h e n i t r o g e n i s

5

t i mes h i gh e r t h an

t h e p h os p h at e a nd2\

t i mes h i gh e r t han

t h e

po t a s h .

The s ame r e l a t i o n h a s b een

f o und

when t h e

o t h e r gr owt h f a c t o r s

a r e

v a r i e d

i n

t u r n .

The

d e t a i l s

o f t h e


t e c hn i que f o r

I l l u s t r a t

i n g

t h i s l a w a r e

g i v e n i n h i s

own book

( 8) .

' The mos t d e t a i l

ed

E n g l i s h

l anguage ac coun t

o f t h e

pr o c edu r e

I s

t h a t g j v en

b y St e wa r t ( 13) . v


14/64

- 1 2 -

P a r t I

A N

EXPERI MENT

WTHCUTHBBRT

RASPBERRI ES


F o r s e v e r a l ye ar s n o w o n e o f t h e ma j o r pr o b l e ms o f t h e

E r a s e r V a l l e y o f B r i t i s h Co l u mb i a h a s

b e e n

t h a t c o nc e r n ed

w i t h t h e d i f f i c u l t i e s me t i n r a s p b e r r y g r o wi n g. Many d i f f

e r e n t

phases

o f t h e

pr o b l em

h ave been

s t u d i e d b y t h e

pe r s o n n e l

o f t h e

B r i t i s h

Co l u mb i a Ra s p b er r y Commi t t ee ( 1 4 ) .

T h e

i mpo r t a nc e

o f n i t r o g e n

f e r t i l i z e r s

i s g e n e r a l l y

r e c o g n i z e d b y t h i s body. A c c o r d i n g t o Woods ( 1 4 ) , r e s u l t s

f r o m

b o t h t h e

Ex pe r i me nt a l

F a r m a t A g a s s i z a n d t h e p l o t s a t

H a t z i c , show t h a t o n l y

n i t r o ge nou s

f e r t i l i z e r s a r e o f v a l u e ,

a l t h ough

h e c o u l d f i n d n o c o n s i s t a n t c o r r e l a t i o n

b e t ween

t h e

a n a l y s i s o f s o i l s f r om good a n d

p o o r

p l a n t a t i o n s .

H a r r i s ( 1 4 ) h a s s t r e s s e d wa t e r a s b e i n g o f pr i me i mpo r t a nc e

a n d h a s

shown

good r e s u l t s w i t h n i t r o g e n a n d

ph o s p h at e s

a s

n u t r i t i o n a l

f a c t o r s i n t h e r a s p b e r r y pr o b l e m. T h e n i t r o g e n

n u t r i t i o n

o f t h e r a s p b e r r y p l a n t , t h e r e f o r e , h a s

b e e n

a n d

s t i l l

i s a n

i mpo r t a nt

p a r t o f t h e r a s p b e r r y d e c l i n e pr o b l e m,

a n d t h e

a ut h o r

f e l t t h a t t h e q u a n t i t a t i v e

met hods

o r i g i n a t e d

b y M i t s c h e r l i c h s h o u l d b e

t r i e d

a s a ne w a p p r o a c h .

Ch emi c a l a n a l y s i s o f t h e p l a n t m a t e r i a l wa s c a r r i e d o u t

f o r t h e

p u r p o s e

o f f i n d i n g o u t

whe t he r

o r n o t t h e pe r c e n t a ge

c ompos i t i o n

a n d t h e t o t a l n u t r i e n t c o n t e nt

wer e

i n a n y wa y


15/64

- 13-

c o r r e l a t e d wi t h t h e

s o i l n u t r i e n t l e v e l

and t h e o b t a i ne d

y i e l d .

i

Ex pe r i me nt a l

M a t e r i a l s and

Co n t r o l

o f

Co nd i t i o n s

Twe nt y- f i v e t e n I nc h c l a y po t s wer e t h or ough l y washed

and

d r i e d .

The

i n t e r i o r s

o f t h es e po t s wer e t h e n h e at e d b y

i n v e r t i n g ove r

an

e l e c t r i c h o t p l a t e

and

t h o r o ugh l y c o at e d

( i n s i d e

o nl y ) wi t h me l t ed

p a r a f f i n

( Pa r a wa x ) .

The

po t s

wer e

f i l l e d

wi t h a mi x t u r e o f washed

sand

and f r e s h l y powder ed

peat o f l o w

f e r t i l i t y

va l u e . Th i s mi x t u r e was

50- 50

b y

vo l ume

( appr o x i ma t e l y 6100 gr ams d r y

sand

and 400 gr ams d r i e d

peat pe r p o t ) . F r om t h e appar en t

s p e c i f i c

g r a v i t y o f t h i s

mi x t u r e ,

t h e a c r e we i gh t t o a de pt h o f s i x i nc h e s was d e t e r

mi ned

as 3, 764, 000p ou nd s .

Twe nt y- f i v e Cu t h be r t r a s pb e r r y s uc k e r s wer e

s e l e c t e d

on

t he b a s i s o f u n i f o r mi t yo f

s i z e

f r o m 300 o r

mor e

t a k e n f r o m

t he

U n i v e r s i t y

f i e l d

p l o t s . V a r i a t i o n s i n v i g o r and g r o wt h

power wer e p r e s en t n e v e r - t h e - l e s s and u l t i m a t e l y caused

c o n s i d e r a b l e

e r r o r i n t h e ex pe r i me nt .

The r o o t s o f t h e p l a n t s wer e was he d

f r e e

o f

s o i l

and

t h e y wer e t h en t r a n s p l a n t e dt o t h e po t s on May 18, 1940.

The n u t r i e n t s o l u t i o n s wer e a dmi n i s t e r e d and t h e e x pe r i me nt

was

c o nt i nu e d du r i n g

t h e

summer

mont hs

u n t i l

Oc t obe r

11, 1940.

The e x p er i me nt was s e t up i n a l a t h - h ous e s ou t h o f t h e


16/64

- 1 4 -

U h i v e r s i t y gr e e nh o u s e , p a r t i a l

shade b e i n g g i v e n b y f o u r -

i n c h p l a n k s

spaced

f o u r i n c h e s a p a r t , s i x f e e t abovet h e

s u r f a c e

o f t h e

p o t s .

At

t i me s

o f

heavy r a i n f a l l

a

canvas

was

s p r e a d ove r

t h e t o p o f t h e

l a t h - h o u s e

t o

p r e v e n t

t h e

f l o o d i n g

o f t h e p o t s and t h e

c on s equent

o v e r f l o w i n g o f t h e

d r a i n a g e

p a n s .

D i s e a s e

a nd

p e s t c o n t r o l s wer e

made

w i t h l i me s u l p h u r

a n d n i c o t i n e s p r a y s .

Th e

r a s p b e r r y s a w - f l y

s u c c e e d e d

i n

c a u s i n g s m a l l i n j u r i e s t o t h e l e a v e s b e f o r e t h e y wer e

s a t i s

f a c t o r i l y c o n t r o l l e d .

P l a n o f Ex pe r i me nt

T h e s e r i e s

o f

r a s p b e r r i e s

wer e

s u p p l i e d w i t h ampl e

amount s

o f

a l l n u t r i e n t s i n c l u d i n g

wa t e r , e x c ep t

n i t r o g e n ,

wh i c h was v a r i e d

downwar d

f r om an ampl e l e v e l t o a d e f i n i t e l y

d e f i c i e n t l e v e l .

T h e ampl e l e v e l

was

d e r i v e d f r o m Bau l e ' s f o o d u n i t e v a l

u a t i o n

o f

n u t r i e n t s ( 1 5 ) .

F o r

examp l e ,

when 225

pounds

o f

n i t r o g e n a r e a v a i l a b l e t o a n a c r e o f a c r o p , I t w i l l mak e a

50

y i e l d .

Thus , 4 u n i t s o r 900 pounds n i t r o g e n p e r a c r e

w i l l

g i v e

a t h e o r e t i c a l

y i e l d

o f

94

I n a f i e l d t r i a l . The

e f f i c i e n c y

o f t h e

f e r t i l i z e r , h oweve r ,

i s

i n c r e a s e d

( o n a n

a r e a b a s i s ) when i t i s c o n f i n e d t o a p o t . T h e r e f o r e , 2

Ba ul e u n i t s o f n i t r o g e n ( 550pounds p e r a c r e ) wer e u s e d a s a n

ampl e

l e v e l .

The s ame

l e v e l

was

u s e d

f o r

t h e

po t a s h

b u t t h e

ph o s ph at e a p p l i c a t i o n

was

d e r i v e d

on a 6

Ba ul e u n i t b a s i s

I n


17/64

- 1 5 -

o r d e r t o t a k e c a r e o f p o s s i b l e f i x a t i o n i n i n s o l u b l e

f o r ms .

I n t h i s e x pe r i me n t t h e n i t r o g e n wa s t h e o n l y v a r i a b l e ,

b e i n g s u p p l i e d a t s i x d i f f e r e n t

l e v e l s .

( 1 ) 0 . 1 2 gm N p e r p o t

( 2 ) 0 . 3 3

( 3 ) 0 . 5 4

( 4 ) 0 . 6 7

( 5 ) 1 . 3 4

( 6 ) 2 . 0 1

These v a l u e s wer e c h o s e n s u c h t h a t ( 2 ) - ( 1 ) = ( 3 ) - ( 2 )

a n d ( 5 ) - ( 4 ) = ( 6 ) - ( 5 | . i n o r d e r t h a t t h e

y i e l d

v a l u e s o b t a i n

e d

wo u l d

b e a p p l i c a b l e t o e q u a t i o n ( I V ) wh i c h i s

2 ( y

f

) - (

y i

) - ( y

3

)

wher e A i s . t h e c a l c u l a t e dmaxi mump o s s i b l e y i e l d a n d

y - j _ ,

y

2

,

a n d y

3

a r e t h e y i e l d s o b t a i n e d e i t h e r

f r o m t r e at me nt s

( 1 ) ,

( 2 ) ,

a n d ( 3 ) o r ( 4 ) , ( 5 ) , a n d ( 6 ) , r e s p e c t i v e l y , e x pr e s s e d

i n

gr ams

d r y

we i gh t .

T h e P g 0

5

wa s s u p p l i e d i n t h e

same amount

t o a l l t h e

p o t s , name l y 1 . 0 3 gm p e r p o t ( 1 . 7 1 gm

mo no c al c i u m

ph os ph at e ) .

T h e K

2

0 wa s s u p p l i e d i n a s i m i l a r manner a t 0 . 8 1 5 gm p e r

p o t ( 1 . 6 2 gm po t a s s i um s u l p h a t e ) . T h e

mi n o r

e l e me nt s wer e

s u p p l i e d t o

e a c h

p o t a s f o l l o w s ^


18/64

- 16-

MgS0

4

400 mg

M SO

100 mg

CuS0

4

20 mg

F eS04 50 mg

H

3

B0

3

4 mg

The e x pe r i me n t was k e p t

w e l l

mo i s t e ne d t h r o ugh o ut t h e

gr owt h p e r i o d .

The

d r a i n age wa t e r

was

r e t u r n e d

c a r e f u l l y t o

i t s

r e s p e c t i v e

p o t a t

eac h wa t e r i n g

s o

t h a t

no

n u t r i e n t s

wer e

l o s t f r o m

t h e

s y s t e m.

The

e x pe r i me n t

was done I n q u a d r u p l i c a t e . The

s i n g l e

c h e c k

p o t

r e c e i v e d

no

f e r t i l i z e r

a t

a l l .

Ha r v e s t

Met hods

The

l owe r l e av e s wh i c h

showed s i g n s o f

d r o pp i ng

o f f

d u r i n g t h e e x pe r i me n t wer e h a r v e s t e d f r om t i me t o t i me and

wer e k e p t i n

l a b e l e d

b a g s . On Oc t obe r 11, t h e

r e s t

o f t h e

l e av es

wer e

s t r i p p e d o f f .

The canes we r e c u t up i n t o s m a l l

p i e c e s . The r o o t s we r e s o

t h i c k l y ma t t e d

t h a t

i t

was

f o u nd

d i f f i c u l t

t o

wash

t h e m

c omp l e t e l y f r e e

o f

s and .

Mos t o f i t

shook

f r e e

h o we v e r ,

when

t h e

r o o t s

we r e d r y . The

m a t e r i a l

was d r i e d t o a c o n s t a nt we i gh t a t 75- 80* 0. Bo t h t o p we i gh t s

and

r o o t

we i gh t s wer e o b t a i n e d.

Met hods o f A n a l y s i s

The

d r i e d p l a n t m a t e r i a l f r om ea c h

p o t

( r o o t s , s t e ms ,

and l e a v e s )

was

gr ound

t o a

c o a r s e

me a l I n a

meat g r i n d e r .

The n i t r o g e n

a n a l y s i s

was r u n i n t r i p l i c a t e and t wo gr am


19/64

- 1 7 -

s amp l es wer e u s e d I n

o r d e r

t omi n i mi z e t he

s a mp l i n g e r r o r .

The K j e l d a h l met hodwas u s e d ( 1 ) . Ash s o l u t i o n s wer emade

o n

f i v e g r am s ampl e s . The ph o s p h at e

d e t e r m i n a t i o n s

wer e

made on t he ash s o l u t i o n u s i n g Ts c h opp ' s me t h od as mo d i f i e d

f o r use

w i t h

t h eB. D H

N e s s l e r i z e r c o l o r d i s c s ( 3 ) .

The

po t a s h

i n t he ash s o l u t i o nwas d et e r mi ne dby t he S h e r r i l l

c e n t r i f u g e me t h od ( 11) .

R e s u l t s

of the

Ra s pb e r r y

E xpe r i me nt

The

Dr y

We i gh t Dat a

The y i e l d s o b t a i n e d i n t hee x pe r i me n t ar e

s hown

i n

Tab l e 1. The

f i g u r e s

ar e t hed r y

we i gh t

of t h e wh ol e

p l a n t

( r o o t s ,

s t e ms ,

and l e a v e s ) .

The g e n e r a l t r e n d of i n c r e a s e i n

y i e l d

w i t h I n c r e a s ei n

n i t r o g e n

l e v e l was

e v i d e n t

i n

s p i t e

of t he

r a t h e r l a r g e

de

v i a t i o n and l a c k of c o n f o r mi t y w i t h a t r u e l o g a r i t h mi c

c u r v e _ ( F i g u r e

2 ) .

S i n c e

t h ep h os p h at e andpo t a s h wer e

s u p p l i e d at 1. 03 and 0. 815 gmper pot r e s p e c t i v e l y , i t w i l l

a l s o

be

s e e n

f r o m

t he

t a b l e t h a t

t h e

y i e l d

c o n t i n u e d

t o I n

c r e a s e u n t i l t he n i t r o g e n was t w i c e as h i g h as t h e

p h os p h at e

o r p o t a s h .

By f a r t h e mo s t s a t i s f a c t o r y g r o wt hwas o b t a i n e d i n t he

h i g h n i t r o g e n t r e a t me n t ,

wher e t hec anes wer e

n e a r l y

s i x

f e e t

t a l l ,

5/ 8

i n c h e s t h i c k

at

t h eb a s e

and

s u p p o r t e d l a r g e

h e a l t h y l e a v e s .

The l ow end of t he

s e r i e s

showed

d e f i n i t e


20/64

- 1 8 -

n i t r o g e n s t a r v a t i o n s ympt oms o f s m a l l y e l l o w l e a v e s and v e r y

s p i n d l y

c a n e s . I t w i l l a l s o b e n ot e d f r om

Tab l e

1 t h a t ,

a l t h o u g h

t h e

c h e c k p l a n t

was

d e f i n i t e l y

s ma l l e r

t h a n

t h a t

o f

t h e l o w e s t n i t r o g e n a p p l i c a t i o n , i t

made s u f f i c i e n t

g r o wt h

t o i n d i c a t e t h e

pr e s e nc e

o f a s m a l l amount o f n i t r o g e n i n

t h e s a nd- pea t mi x t u r e .

Tab l e 1. T o t a l Dr y

We i ght

o f Ra s pb e r r y P l a n t s R e s u l t i n g

f r o m N i t r o g e n S u p p l i e d a t D i f f e r e n t L e v e l s

N i t r o g e n A p p l i c - Dr y

We i ght

o f P l a n t s

a t i o n s p e r p o t

( gm)

R e p l i c a t i o n s

Aver age

Check

.__

36. 4

0. 12 30. 6 93. 0

36. 2

71. 2 57. 8

0. 33

120. 0

1 0 3 . 6

1 0 4 . 9

103. 4

1 0 7 . 9

0. 54 . 1 2 7 . 1

90. 7 105. 8

1 1 9 . 1 110. 7

0. 67

1 2 8 . 3

63. 4

1 0 9 . 6 1 6 7 . 5 117. 2

1. 34

126. 2

1 3 8 . 3

1 5 7 . 9

134. 8 1 3 9 . 3

2. 01 156. 7 204. 6

1 9 1 . 3

204. 6

1 8 9 . 3

TheMaxi mumP o s s i b l e

Y i e l d

The

mar k ed

v a r i a t i o n i n t h i s e x pe r i me nt , as s h own i n

Tab l e 1, mak es t h e u s e o f c a l c u l a t i o n s r a t h e r h a z a r d o u s .

Howev er ,

s i n c e

t h e

g e n e r a l t r e n d

i s

p r e s e n t , c e r t a i n

o f t h e

v a l u e s o b t a i n e d

may be u s e d a s t h e

b a s i s

o f

app r o x i ma t e


21/64

- 19-

c a l c u l a t i o n s . The y i e l d s wh i c h b e s t s u i t t he l o g a r i t h i c

c u r v e ar e 71. 2 gm 103. 4. gm and 127. 1. gm These y i e l d s

wer e

ob t a i ne d

f r om

p o t s s u pp l i e d wi t h n i t r o g e nat 0. 12 gm

0. 33 gm and 0. 54 gmr e s p e c t i v e l y . App l yi n g t h i s i n f o r ma

t i o n t o t he equ at i on?

( 103. 4)

2

- ( 71. 2) ( 127. 1)

A = = 193. 2. :gm

2( 103. 4)

-

( 71. 2)

-

( 127. 1)

Th i s c a l c u l a t e d va l u e f o r

t he maxi mum

y i e l d i s o n l y f o u r

gr ams

h i gh e r t h an t hea v er age of t heh i gh e s t y i e l d s ob t a i ne d

i n t heex pe r i me nt . When one c ons i de r s t hei nh e r e nt v a r i a

t i o n i n t her a s p be r r y s u c k e r s , even i f c a r e f u l l y s e l e c t e d ,

t h es e v a l u es ar e i nf a i r

a gr e eme nt .

The

P r o p o r t i o n a l i t y

Co ns t a nt , c

I t i s d e s i r a b l enow t o

c o mpar e , t h e

o b t a i ne d

y i e l d

c ur ve wi t h a t r u e l o ga r i t h mi c c u r v e , i n o r de r t o es t i ma t e

t he c o n f o r mi t y of t hee xpe r i ment t o t heM i t s c h e r l i c h

y i e l d

l aw. Si nc e

t he maxi mum

y i e l d ,

A, and t he mni mum

y i e l d ,

y

Q

,

( y i e l d

f r o m t hec h e c k po t ) ar ea l r e ad y de t e r mi ned f o r t he

t r u e

c u r v e , i t r e ma i n s t o f i n d wh i c h one of t he p o s s i b l e


c u r ve s t h a t c o u l d

f i t

b e t ween t h es e po i n t s , b es t

s u i t s

t hes hape of t heo b t a i n ed c u r v e . That I s t o say , i t

r e ma i n s

t od et e r mi ne t hes l o pe of t hec u r ve

be t ween

t he

maxi mumand t he mi ni mum. As a l r e ady po i n t e d o u t , t h i s s l o pe

i s

d et e r mi ne d by t hep r o p o r t i o n a l i t y c o ns t a nt of t he


22/64

- 20-

M i t s c h e r l i c h y i e l d r e l a t i o n and t h i s i s f o und b y s o l v i n g

e aua t l o n ( VI ) . Owi ng t o t h e gr e a t v a r i a t i o n i n t h e y i e l d s

o b t a i ne d, e a c h s e t o f v al u es a p p l i e d t o t h e equa t i o n r e s u l t

ed i n a d i f f e r e n t v al u e f o r t h e p r o p o r t i o n a l i t y c o ns t an t .

Th i s r e nde r e d t h e u s e o f e qua t i o n ( VI ) u n s a t i s f a c t o r y . I n

o r d e r t o a v o i d t h i s d i f f i c u l t y , a s e r i e s o f c a l c u l a t i o n s

wer e

c a r r i e d

o u t o n a

gr o up

o f number s be t ween 0, 5 and 1, 0

u n t i l

i t

was

f ound t h a t

a

p r o p o r t i o n a l i t y

c o ns t a nt

o f 0. 74

r e s u l t e d i n a c u r v e t h a t c l o s e l y a ppr o x i ma t e d t h e c u r v e o f

t h e o b t a i ne d y i e l d s ( F i gu r e2 ) .

The F e r t i l i t y o f t h e Sand- pea t Mi x t u r e

Be f o r e pr o c ee di n g wi t h t h e c a l c u l a t i o n s f o r t h et h eo r e t

i c a l

y i e l d s i n d i c a t e d

b y t h e

t r u e

l o g a r i t h mi c

c u r v e ,

i t i s

n e c e s s a r y t o f i n d t h e i n i t i a l n i t r o ge n c on t e nt o f t h e sand-

peat mi x t u r e . Th i s c a n b e de t e r mi ne d b y s o l v i n g f o r b i n

e qua t i o n ( V I I ) .

l ogA - l o g ( A- y

Q

)

Eq ua t i o n ( VI I ) i s b =

The da t a a r e , A = 193. 2 gm ( t h e

maxi mum

y i e l d )

y

Q

= 36. 4 gm ( t h e y i e l d wher e no n i t r o g e n

was added)

c = 0. 74 . (

t h e

p r o p o r t i o n a l i t y

c o n s t a n t )

S u b s t i t u t i n g ,

i :

l o g( 193. 2)

-

l o g( 193. 2

- 36. 4)

b =

0. 74


23/64

- 21-

b = 0. 12 gm n i t r og e n per po t

Th i s i s t he

amount

of n i t r o ge n t h a t was

o r i g i n a l l y

p r e s e n t

i n t he s a nd - pe at mi x t u r e as dt e r mi n ed by t h e


met hod o f

s o i l

t e s t i n g .

C a l c u l a t i o n o f t h e Y i e l d s f o r a

Tr u e

Loga r i t h mi c

Cur ve

Hav i ng ob t a i n e d t h e above i n f o r ma t i o n , t h e t h e o r e t i c a l

y i e l d s

I n di c a t e d by t he t r u e l o ga r i t h mi c c ur ve

wh i c h

has t he

same

s l ope ( c = 0. 74) as t he ob t a i ned c ur ve , may now be c a l

c u l a t e d and p l o t t e d i n o r d e r t o s ee how c l o s e l y t he e x pe r i

ment

c on f o r ms t o t h e M i t s c h e r l i c h y i e l d l aw.

Eq ua t i o n ( V)

wh i c h

i n c l u d e s t he v a l ue f o r b i s

u s e d .

l o g( A- y) = l o gA - c ( x + b )

F o r e xamp l e , when A = 193. 2, c = 0. 74, b = 0. 12, x = 0. 12 and

y i s t h e y i e l d wh i c h s h ou l d no r ma l l y h ave r e s u l t e d

f r o m i t ,

t h e n

l o g( 193. 2 - y) = l o g l 93. 2 - 0. 74( 0. 12+ 0. 12)

y = 67. 0 gm

I n

t h i s manner , a l l o f t he y i e l d s wh i c h


s h ou l d h ave been o b t a i ne d f r om t he

s e v en

t r e at me nt s

wer e

c a l c u l a t e d . The r e s u l t s a r e t a b u l a t e d i n Tab l e 2, and a r e

ex pr e s s ed b o t h i n gr ams d r y ma t t e r and i n pe r c e n t o f t h e

maxi mum

y i e l d

( 193. 2

gm) .


24/64

- 2 2 -

T a b l e 2. Compar i s on o f O b t a i n e d Y i e l d s and T h e o r e t i c a l

Y i e l d s

o f

Ra s pb e r r y P l a n t s

N i t r o g e n

A p p l i e d

Gr ams Dr yWe i gh t

P e r c e n t Max i mum

p e r

p o t

( gm)

C a l c u l a t e d

Y i e l d s

O b t a i n e d

Y i e l d s

C a l c u l a t e d

Y i e l d s

O b t a i n e d

Y i e l d s

Check

3 5 . 3

3 6 . 6

1 8 . 3

1 8 . 8

0. 12

6 7 . 0 5 7 . 8 3 4 . 7 2 9 . 9

0. 33

1 0 3 . 4

1 0 7 . 9

5 3 . 5

5 5 . 8

0. 54

1 3 0 . 4

1 1 0 . 7

6 7 . 5

5 7 . 3

0. 67 1 4 2 . 9

1 1 7 . 2 7 4 . 0

6 0 . 7

1. 34 1 7 7 . 1

1 3 9 . 3

9 1 . 7

7 2 . 1

2. 01

1 8 8 . 1 1 8 9 . 3

97. 4

9 8 . 0

Fr om

T a b l e

2, a nd

p a r t i c u l a r l y

f r o m

F i g u r e 2 wh i c h

c o n t a i n s

t h i s

d a t a , i t i s c l e a r t h a t t h e o b t a i n e d

y i e l d

c u r v e f o l l o w s t h e g e n e r a l i n c r e a s e e x p e c t e d i n a

M i t s c h e r l i c h t r i a l , b u t i t o b v i o u s l y d e v i a t e s f r o m t h e


c u r v e

i n

t h r e e : o f e t h e s e v en t r e a t me n t s . A c c o r d

i n g t o F i g u r e 2, a50 y i e l d o f r a s p b e r r y p l a n t : was o b t a i n e d

when t h e n i t r o g e n

l e v e l

was 0. 4 gm p e r po t ( 0. 06 gm pe r

k i l o g r a m o f s o i l ) .

I n

F i g u r e 2, t h e

y i e l d

d a t a e x p r e s s e d as p e r c e n t o f t h e

maxi mum

y i e l d

i s

p l o t t e d a g a i n s t

t h e

t o t a l

s o i l

n i t r o g e n ,

( x + b )

o f

e a c h t r e a t me n t .


25/64

- 23-

too

7 i t a / S o i l N i t r o j e n , x +

b ) ,

j r a m s

F i g u r e 2, The E f f e c t o f V a r y i n g N i t r o g e n L e v e l s on t h e

T o t a l

Dr y

Wei ght

o f Ra s pb e r r y P l a n t s Compar ed w i t h a

Tr ue

L o g a r i t h mi c

Cur ve


26/64

- 2 4 -

R e s u l t s o f

Ra s pb e r r y

A n a l y s i s

T h e r e s u l t s o f t h e a n a l y s i s a r eex pr e s s e d b ot h as t o t a l

c o nt e nt

p e r r a s p b e r r y p l a n t and as

pe r c e nt a ge c o mpo s i t i o n

i n

Tab l e s

3 and 4, r e s p e c t i v e l y . The

t o t a l

c o nt e nt p e r p l a n t

i s a l s o r e pr e s en t e d g r a p h i c a l l y

i n

F i g u r e

3.

Tab l e

5.

T o t a l N u t r i e n t

Con t en t p e r

Ra s pb e r r y P l a n t .

( eac h

f i g u r e

i s an

a ver age

o f

f o u r r e p l i c a t e s )

N i t r o g e n

Tr e at me nt

( gm)

N i t r o g e n

( N ) ( gm)

Ph o s p h at e

{P2O5)

( gm)

Po t a s h

( K

2

0 )

( gm)

Check

0. 232 0. 117

0. 238

0. 12

0. 438

0. 214

0. 565

0. 33

0. 860

0. 417

0. 934

0. 54

0. 895

0 . 4 1 5

0. 947

0. 67

0. 944

0 . 4 6 1

1 . 022

1. 34

1. 116

0 . 5 4 1

1. 224

2 . 0 1

1. 752

0. 774

1 . 5 6 5

T h e t o t a l a b s o r p t i o n c u r v e s f o l l o w

t h e

s hape

o f t h e

y i e l d c u r v e

v e r y c l o s e l y ( F i g u r e 3 ) . T h i s was no t o n l y

t r u e f o r n i t r o g e n b u t was a l s o t r u e f o r p h os p h at e and

p ot a s h

a s w e l l . That i s ,

as t h e

n i t r o g e n a p p l i c a t i o n s

wer e

v a r i e d

downwar d

t o a d e f i c i e n t

l e v e l

n o t o n l y t h e y i e l d s and t h e i r


27/64

- 2 5 -

F l g u r e 5 . T h e E f f e c t o f I n c r e a s i n g N i t r o g e n L e v e l o n t h e

T o t a l

N u t r i e n t A b s o r p t i o n I n Ra s pb e r r y P l a n t s


28/64

- 26-

n i t r o g e n c o n t e n t s , b u t a l s o t h e i r

p h os p h at e

and p o t a s h c o n

t e n t s de mi n i s h e d , even t h o ugh t h e s e

l a s t

wer e s u p p l i e d a t

an ampl e

l e v e l

i n a l l t r e at me nt s . The

r a t i o

o f t h e a b s o r b e d

n u t r i e n t s , ,

t h e r e f o r e

r e mai ns a p pr o x i ma t e l y

t h e same

t h r o ugh

out t h e

s e r i e s

a t 2: 1: 21.

T h i s

r a t i o

h e l d

i n

s p i t e

o f t h e

f a c t t h a t t h e n i t r o g e n i n t h e f e r t i l i z e r a p p l i c a t i o n s was

v a r i e d

downwar d t o 1/ 20 o f t he h i g h e s t a p p l i c a t i o n .

Tab l e 4. Pe r c e nt a ge Co mpo s i t i o n o f Ra s pb e r r y

P l a n t s .

( eac h

f i g u r e i s an

aver age

o f f o u r r e p l i c a t e s )

N i t r o g e n

Tr e a t me nt

( gm)

N i t r o g e n

( N)

(%)

Pho sp ha t e

( P

2

O

5

) ( %

Po t a s h

( K

2

0)

( %

Check 0. 60 0. 30 0. 70

0. 12 0. 83

0. 41

1. 05

0. 33

0. 80

0. 39

0. 87

0. 54 0. 80

0. 38

0. 86

0. 67 0. 81 0. 39 0. 93

1. 34

0. 79

0. 39

0. 88

2. 01

0. 92

0. 41

0. 82

The most n o t i c e a b l e r e s u l t shown by t h e a n a l y s i s d at a

was t he

l a c k

o f a ny

t r e n d

I n t h e pe r c e nt age c o mpo s i t i o n o f

t h e p l a n t s r e f l e c t i n g t h e f e r t i l i s e r t r e at me nt wh i c h t h e


29/64

p l a n t s r e c e i v e d . That i s , r e g a r d l e s s o f t h e s i z e o f p l a n t

o r t h e s t a t e o f n u t r i e n t

u nb al a nc e ( e x c e pt

i n t h e

c h e c k

p o t )

t h e pe r c e nt age c o mpo s i t i o n

r e ma i n ed

appr o x i ma t e l y c on s t an t .

The pe r c e nt a ge c o mp o s i t i o n o f t h e

c h e c k

p l a n t , wher e

ph o s ph a t e andpo t a s h as w e l l a s n i t r o g e n wer e p r e s e nt i n

l i m i t i n g

amoun t s , was, h oweve r , d e f i n i t e l y

l o we r t h an

t h a t

o f

t h e

t r e a t e d p l a n t s ( Tab l e

5 ) .

Tab l e 5. Compa r i s on o f Pe r c e nt a ge Co mp os i t i o n o f Tr e at e d

. and

Un t r e at e d

P l a n t s

Co mpo s i t i o n

o f 24

Co mpo s i t i o n

o f

Tr e at e d

P l a n t s , %

Un t r e at e d

P l a n t , %

N 0. 8 + 0. 03 0. 6

P

2

0

5

0. 4 0. 02 0. 3

K

2

0 0. 9 0. 08 0. 7

Al t h o ugh i t i s u n f o r t u na t e t h a t t h e

c h e c k

p l a n t was

no t

r u n i n

q u a d r u p l i c a t e ,

t h e

d i f f e r e n c e

b e t ween

i t s

com

p o s i t i o n

and

t h a t

o f t h e

t r e a t e d p l a n t s a pp ea r s s i g n i f i c a n t .

Co nc l u s i o ns

on t h e

Raspbe r r y Exper i men t

Th i s ex pe r i me nt s u p p l i e s a d d i t i o n a l i n f o r m a t i o n

t o t h e

wor k o f Woods and H a r r i s ( 14) b y s h owi ng t h e q u a n t i t a t i v e


30/64

e f f e c t

o f I n c r e a s i n g t h e n i t r o g e n f e r t i l i z a t i o n . T h e n i t r o

g e n s u p p l y wa s i n c r e a s e d

u n t i l

i t wa s t we nt y t i me s t h e

amount o f n i t r o g e n o r i g i n a l l y p r e s e n t i n t h e s o i l . B y f a r

t h e most s a t i s f a c t o r y gr o wt h wa s o b t a i n e d i n t h e h i g h n i t r o

g e n t r e a t me n t ,

wher eas

t h e g r o wt h o b t a i n e d i n t h e l o w

n i t r o g e n p o t wa s q u i t e c o mpa r a b l e t o poo r f i e l d p l a n t a t i o n s ,

a

5 0

y i e l d b e i n g c l a s s e d h e r e a s

d e f i n i t e l y

p oo r g r o wt h .

T h e

e x pe r i me n t

a l s o i n d i c a t e s t h a t t h e r e i s a

d e f i n i t e

amount o f n i t r o g e n wh i c h w i l l g i v e a c e r t a i n amount o f cane

gr owt h . when t h e o t h e r

gr o wt h

f a c t o r s , i n c l u d i n g wa t e r , a r e

p r e s e n t i n

s u f f i c i e n t

amount s . F o r i n s t a n c e , b 0

gr o wt h

i s

o b t a i n e d f r o m a

s a nd - pe a t

mi x t u r e

when

n i t r o g e n i s p r e s e n t

a t 0 . 4 gm p e r p o t . I n

t h i s e x pe r i me nt ,

t h e r e f o r e , o n e

f o o d

u n i t

i s 0 . 4 gm n i t r o g e n p e r p o t . I n t e r p r e t i n g

t h i s

i n

t e r ms o f n i t r o g e n p e r a c r e ( 6 d ee p) , i t

amount s

t o 2 3 0

p o u n d s ( c a l c u l a t e d o n a

s o i l

we i gh t b a s i s ) , wh i c h i s i n

mar k ed

agr eement

w i t h t h e r e c o g n i z e d

Ba ul e

u n i t o f n i t r o g e n ,

2 2 5 pounds p e r a c r e ( 1 5 ) .

F r o m

t h e s t a n d p o i n t o f

ma k i n g

f e r t i l i z e r

r e c o mme nd at i o ns ,

t h e

most

i mp o r t a n t i n f o r ma t i o n

shown

I s t h e

f a c t

t h a t t h e

b e s t gr o wt h wa s o b t a i n e d when t h e

n i t r oge n. was

t wo t i me s

h i g h e r t h a n t h e

p h os p h at e

o r p o t a s h . I n p r e l i m i n a r y r a s p

b e r r y t r i a l s ( u n p u b l i s h e d ) c anes wer e gr own s u c c e s s f u l l y i n

t h e

gr e e nh o u s e ,

w i t h

good

gr o wt h a n d f r u i t i n g , when t h e

n i t r o g e n wa s f i v e t i me s h i g h e r t h a n t h e ph o s p h at e a n d 2


31/64

t i me s h i g h e r t h a n t h e p o t a s h .

A l t h o u g h t h e t o t a l amount o f a b s o r b e d n u t r i e n t s i s p r o

p o r t i o n a l t o t h e i n c r e a s e i n t h e y i e l d a n d t h e r e f o r e t o t h e

i n c r e a s e i n t h e s o i l n u t r i e n t s , t h e r a t i o o f t h e a b s o r b e d

n u t r i e n t s b e a r s n o r e l a t i o n t o t h e r a t i o o f t h e

same n u t r i

e n t s i n t h e

s o i l .

T h i s seems t o i n d i c a t e t h a t t h e t o t a l

amount s o f t h e n u t r i e n t s i n t h e r a s p b e r r y p l a n t a r e a b s o r b e d

i n

a

d e f i n i t e

r a t i o

r e g a r d l e s s o f t h e s t a t e o f t h e n u t r i e n t

u nb al a nc e a n d s i z e o f p l a n t .

T h e

a p pa r en t c o ns t a nc y

o f t h e pe r c e nt a ge c o mp o s i t i o n

shown i n

t h i s

wor k i s n o t i n a c c o r d w i t h t h e r e s u l t s o f t h e

f o l l o w i n g

e x pe r i me n t w i t h o a t s , n o r w i t h t h e p u b l i s h e d d a t a

o f M i t s c h e r l i c h ,

P f e i f f e r , Mac y,

e t a l , ( 6 ) .

On t h e wh o l e t h e r e s u l t s o b t a i n e d a r e

s u f f i c i e n t l y

i n d i c a t i v e t o wa r r a nt t h e f u r t h e r u s e o f t h e M i t s c h e r l i c h

met hod i n r a s p b e r r y n u t r i t i o n wo r k , e s p e c i a l l y w i t h a n i m

pr o ve d

t e c h n i q u e . On e m a t e r i a l dr awbac k i s t h e f a c t t h a t

s e c o nd y e a r gr o wt h c anno t b e meas u r ed

s a t i s f a c t o r i l y ,

t h a t

i s ,

i t

c anno t

b e

measu r ed

i n dependen t

o f t h e

f i r s t

y e a r ' s

gr o wt h . S t r i c t l y s p e a k i n g , t h e r e f o r e , t h i s met hod i s

con

f i n e d t o , t h e

f i r s t

y e a r ' s gr o wt h ,

e x c e p t

f o r q u a l i t a t i v e

o b s e r v a t i o n s , s u c h a s t h e d e f i c i e n c y s ympt oms , i n c i d e n c e o f

v i r u s d i s e a s e , d y i n g o f

b u d s ,

a n d q u a l i t y o f p r o d u c t . S i n c e

t h e r a s p b e r r i e s i n t h i s

e x pe r i me n t

wer e o n l y s t u d i e d f o r t h e

f i r s t

y e a r o f

g r o wt h ,

o b s e r v a t i o n s o f

t h i s

t y p e c o u l d n o t

b e

made.


32/64

- 3 0 -

P a r t

I I

AN EXPERI MENT

WTH OATS


I n v i ew of t h e v e r y

mode r a t e s u c c e s s

w i t h t he r a s p b e r r y

e xpe r i me nt , p a r t i c u l a r l y i n

r e g a r d

t ot h e


g r o wt h

l a w ,

a

mor e e x t e n s i v e

e x p er i me nt

w i t h o at s

was

de s i gne d.

I n t h i s

e x pe r i me nt , a pea r

o r c h a r d

s o i l f r o m

t h e E x p e r i

ment S t a t i o n

atSaan i c h t o n B. C. was

u s e d

as t heg r o wt h

med i um.

The

s i z e

of

p o t u s e d

was 1/6 t he

s i z e

of

t h a t u s ed

b y M i t s c h e r l i c h

and

muc h s ma l l e r

and of a

d i f f e r e n t t ype t h a n

t h a t u s e d i nt her a s p b e r r y e x pe r i me nt . Oat s wer e c h o s e nas

t h e p l a n t I n d i c a t o r b e c a u s e t heg e n e t i c v a r i a t i o ni n t hes eed

i s

p r a c t i c a l l y

n e g l i g a b l e ,

t h u s

e l i m i n a t i n g

t he

g r e a t e s t

s o u r c e

of e r r o r t h a t was p r e s e nt i n t he r a s p b e r r y e xpe r i me nt .

T h i s e x pe r i me n t was r un i n t h r e e s e r i e s ( n i t r o g e n , p ho s ph at e ,

a n d

po t a s h )

i no r d e r

t oc h e c k

t h e y i e l d l a w w i t h a l l t h r e e

n u t r i e n t .

S i n c e r a p i d c h e mi c a l s o i l t e s t i n g i s a v e r y po pu l a r

met hod of e v a l u a t i n g s o i l

f e r t i l i t y ,

s p e c i a l a t t e n t i o nwas

p a i d

i nt h i s e x pe r i me n t t o a c o mpa r i s o n of t he

r a p i d

c h emi c a l

t e s t s w i t h t h e M i t s c h e r l i c h p l a n t

met hod of s o i l

t e s t i n g .

T h e a n a l y s i s

of

t h e p l a n t m a t e r i a l ,

as i n t he

r a s p b e r r y

e x pe r i me nt , was c a r r i e dout as a c h e c k on t h e

y i e l d

phenomena

a n d

as a

s t udy

on t he

r e l a t i o n

b e t ween

s o i l

f e r t i l i t y

and

n u t r i e n t

a b s o r p t i o n .


33/64

- 31-

Ex pe r i me nt a l

Appa r a t u s .

I n s t e a d o f t he l a r ge ename l ed me t a l po t u s e d by

M i t s c h e r l i c h ,

Capo,

Magi s t ad>

e t

a l ,

l aque r e d t i n

cans

o f

4 d i amet er and 4 s o i l d ept h wer e us e d. Th e i r c a p a c i t y was

one k i l o g r a m o f s c r e en ed

s o i l

and t he y had an ar ea of 12. 56

s quar e i n c h e s o r 0. 000002 a c r e .

These

p o t s , 44 of t hem

c o mpr i s i ng e l e ve n t r ea t ment s i n q ua dr u pl i c a t e ,

wer e

p l a c e d

i n a r a c k a r r anged s o t h a t s ma l l l a que r e d t i ncans c o u l d be

p l a c e d under

t h e m

t o a c t as d r a i n age p an s . The pot s

wer e

pr o v i de d wi t h a c e n t r a l dr a i nage h o l e . W r e s u ppor t s wer e

pr o v i d e d f o r t h e p l a n t s .

S o i l

Sampl es

S o i l

s amp l es

wer e t ak e n f r om h a l f an ac r e of a g r a v e l y

l oam pear o r c h a r d

s o i l

a t t h e Domi n i o n Expe r i men t S t a t i o n a t

Sa an i c h t o n , B. C. Si x t e e n s a mpl e s , amo unt i ng t o appr o x i ma t e l y

150 pounds o f s o i l ,

wer e

t a k en t o a de pt h o f 8 i n c h e s wi t h a

spade .

Th i s was s c r e e ne d i n a

- J -

i n c h r i d d l e and, f r om t he

we i gh t o f s c r e en i n gs , t h e s o i l was f o und t o b e app r o x i ma t e l y

20

s t o ne s . A s amp l e o f

s o i l

was k ep t f o r a n a l y s i s . F r om

t h e appar en t

s p e c i f i c

g r a v i t y , t h e a c r e we i gh t o f

t h i s

s o i l

was de t e r mi ned as 2

m i l l i o n po u nd s .

M i x i n g P r o c e du r e

The s c r eened s o i l was t h o r o u gh l y mi x e d i n a ga l v an i z e d


34/64

- 32-

i r o n t u b . Ei g h t k i l o gr ams

o f

t h i s

wer e we i gh e d o ut i n a n

enamel

b a s i n . The appr o x i ma t e amount s o f s t o c k s o l u t i o n s f o r

one o f t h e t r e at me nt s wer e t h en p i p e t t e d i n t o t h e

s o i l ,

c a r e

b e i n g t ak en; no t

t o

s pr a y i t

on t h e

s i d e s

o f t h e

b a s i n .

The

s o i l

was

t h en t h or o ugh l y mi x e d

b y h a n d, ma k i n g

s u r e a l l

mo i s t l umps wer e b r o k e n u p. I t was t h e n d i v i d e d i n t o f o u r

e qua l p a r t s b y we i g h t and t r a n s f e r r e d t o t h e po t s wh i c h wer e

t h e n

l a b e l e d

as t h e

f o ur

r e p l i c a t e s

o f a

s i n g l e

t r ea t ment .

Each o f t h e

e l e ve n t r e at me nt s

was

mi x e d

I n

t h i s

manner . The

b o t t o m 3 t o 4 c e nt i me t e r s wer e t amped down and t h e t o p

s o i l

l e f t

r e l a t i v e l y l o o s e . The r e p l i c a t e s wer e s t a gge r e d on t h e

r a c k s o t h at none wer e ad j a c e n t .

P l a n t M a t e r i a l

and

St and

V i c t o r y oa t s ( s / 2, 1940) wer e t r e a t e d wi t h CU2CO3 dus t .

Seeds

wer e

s e l e c t e d

t o a

u n i f o r m s i z e

and wer e

p l a n t e d

t o a

de pt h o f 1. 5 c en t i me t e r s , 12 I n e a c h po t . The

s o i l

was

mo i s t ened wi t h

d i s t i l l e d

wat e r and c ove r e d wi t h a s h ee t o f

heavy wax paper u n t i l

ge r mi na t i o n

was

c o mpl e t e d.

At t h e

second

l e a f

s t age ( Augus t 9, 1941) , t h e y wer e t h i nne d o ut

t o

6 p l a n t s p e r po t , c ar e b e i n g t ak en t o r emove seeds i n t h e

o p e r a t i o n ( f o r c eps

wer e

us e d) .

Wa t e r i n g

When

i t a pp ear ed n e c es s a r y, t h e po t s wer e b r o ugh t as

n e a r l y

t o s a t u r a t i o n as p o s s i b l e wi t h o u t o v e r f l o wi n g t o t h e


35/64

- 33-

dr a i nage

pan. I f t h e

po t s

wer e

a c c i d e n t a l l y f l o od e d,

t h e

wat er was r e t u r n e d f r o m t h e d r a i nage pans t o t h e i r r e s p e c t i v e

p o t s b e f o r e

t h e

ne x t wa t e r i n g. Car e

was

t ak en

t o

a v o i d ov er

wa t e r i ng i n

o r d er

t o

gu ar d a g a i n s t poor

a i r a t i o n .

D i s t i l l e d

wat er

was

u s e d. Wa t e r i n g

was

d i s c o n t i n u e d

a

week b e f o r e

t h e

h a r v e s t .

C o n t r o l o f

Co nd i t i o n s

The e xpe r i men t was c a r r i e d on i n a r e l a t i v e l y

c o o l

gr een

h ous e a t t h e

Expe r i men t S t a t i o n .

F o r t h e f i n a l t wo

weeks

i t

was r emoved t o a war mer h ous e i n

o r de r

t o

h as t e n ma t u r i t y .

The

p l a n t s

wer e

d us t e d

s e v e r a l

t i mes wi t h s u l ph ur

and wer e

s p r a ye d

once

wi t h

n i c o t i n e

s u l ph at e

f o r t h e

c o n t r o l

o f

aph i d s .

They wer e

a l s o du s t e d

once

wi t h

a

l e a d

a r s e n a t e - n i c o t i n e

d u s t t o c o n t r o l c h e wi n g i n s e c t s .

F e ed i ng P l a n

and

St o c k So l u t i o n s

The

e x pe r i me n t

h ad

t h r e e s e r i e s ( n i t r o g e n , p h os ph at e ,

and p o t a s h ) .

I n

each s e r i e s a l l g r owt h

f a c t o r s wer e

s u pp l i e d

a t

a n ampl e

l e v e l e x c e p t

t h e

v a r i a b l e , wh i c h

was

v a r i e d down

war d i ne q ua l I nc r e me nt s t o a z e r o a p p l i c a t i o n . The ampl e

l e v e l s i n

t h i s

e x pe r i me n t wer e c h o s e n as one Ba ul e u n i t o f

eac h , t h a t

i s , 225 pounds

n i t r o g e n ,

45 pounds^2

Q

b*

a n d 8 2

pounds K

2

0 pe r

a c r e .

The amoun t s pe r po t we r e c a l c u l a t e d

f r o m

t h i s on an

a r e a

b a s i s . The

ge ne r a l p l a n

was as

f o l l o w s :


36/64

- 34-

Tab l e 6 F e ed i ng P l a n o f Oa t Ex pe r i me nt

S e r i e s P o t Number

N i t r o g e n

( gm)

P

2

0

5

( gm)

K

2

0 ( gm)

A l l h i g h

1

0. 204

0. 039

0. 075

2

0. 136

0. 039

0. 075

N

3

0. 068

0. 039

0. 075

4

0. 000

0. 039

0. 075

5

0. 204

0. 026

0. 075

P2O5

6

0. 204

0. 013

0. 075

7 0. 204

0. 000

0. 075

8 0. 204 0. 039 0. 050

K

2

0

9

0. 204

0. 039

0. 025

10 0. 204

0. 039

0. 000

Check

11

0. 000

0. 000

0. 000

I n

Tab l e 6 t h e

l l h i g h

p o t

r e c e i v e s

t h e

g r e a t e s t

amount

o f

e a c h

o f t h e

gr o wt h f a c t o r s

and was ,

t h e r e f o r e ,

t h e

t o p p o t f o r

e a c h

o f t h e s e r i e s .

The n i t r o g e n was s u p p l i e d as

( NH ) gS04

a n d

NaW0

3

i n

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

each

s a l t .

The

amount s

o f t h e

s a l t s

u s e d

a r e

r e p r e s e n t e d

b y t h e

f o l l o w i n g

v a l u e s

f o r t h e ' ' a l l

h i g h

p o t .


37/64

- 35-

Tab l e

7.

S a l t We i gh t s o f t h e Hi gh e s t A p p l i c a t i o n s .

Un i t

( NH

4

)

2

S0

4

Sup e

r

pho s

pha t e

18$

K

2

S 0

4

gm pe r po t 0. 48

0. 62

0. 21

0. 14

l b s

p e r

a c r e

530

682

250

150

The

n i t r o ge n s t o c k s o l u t i o n

was

made

up by

d i s s o l v i n g

17. 28 gm ( BH

4

- ) gS0

4

an d 22. 32 gm

NaN0

3

I n

wa t e r

and mak i ng

i t up t o 270 ml . Then 30 ml c o n t a i ne d 4 u n i t s ; t h e

amount

r e q u i r e d f o r t h emaxi muma p p l i c a t i o n f o r 4 po t s ( r e p l i c a t e s ) .

Thus 20 ml c o n t a i ne d enough f o r t h e 2/ 3

u n i t l e v e l

f o r 4

r e p l i c a t i o n s , and 10 ml

c o n t a i ne d

enough f o r t h e 1/ 3

u n i t

l e v e l

f o r 4

r e p l i c a t i o n s .

Us i n g M i t s c h e r l i c h ' s p r o c e d u r e ^o r d i s s o l v i n g s up e r

ph o s p ha t e ( 13) , 8. 28 gm o f i t wer e d i s s o l v e d and admi n i s t e r e d

as a b ov e. I n t h e s ame manne r , 5. 04 gm K 2S0

4

wer e d i s t r i b

u t e d .

Ha r ve s t

Met hods

The

h e i gh t

o f t h e

t ops

we r e meas u r ed . The heads we r e

s t r i p p e d o f f , t h e s t r a w c u t o f f a t t h e g r o u nd , and t h e r o o t s

wer e was hed

c l e a n .

Gr een we i gh t s o f t h e s t r aw and

g r a i n

wer e

o b t a i ne d.

The

number

o f

s t a l k s

wer e

a l s o

c o unt e d.

The

m a t e r i a l

was

d r i e d

i n an o ve n a t

90*0

f o r 24

h o u r s .

Dr y


38/64

- 36-

we i gh t s of r o o t s s t r aw and g r a i n

wer e

r e c o r d e d s e p a r a t e l y .

The gr o wi n g

p e r i o d was 127

days f r om August

3, 1941 t o

December 7, 1941.

The

ma t e r i a l was

g r o u nd

t o a

powder

and s t o r e d

i n

en

v el o pe s

f o r

a n a l y s i s .

Met hods of A n a l y s i s

The

s o i l

s amp l es wer e

a na l ys e dby

means

of t he r a p i d

c h e mi c a l t e s t s of

Spur way ( 12)

and

Mor gan ( 10) .

The t o t a l

ph o s ph a t e

c o n t e nt of t hes o i l was

de t e r mi ne d

by

t h e

A. O A. C.

met hod ( 1) mo d i f i e d f o r use w i t h Ts c h opp' s c o l o r i m e t r i e

met hod

and t he B. D H s t andar d c o l o r d i s c s

( 3 ) .

The

p l a n t m a t e r i a l was a na l ys e d

f o r

t o t a l n i t r o g e n ,

p h os p h a t e ,

and

po t a s h .

The

n i t r o g e n a n a l y s i s

was

c a r r i e d

o u t w i t h t he K j e l d a h l me t h od ( 1) u s i n g onegr am s a mpl e s .

F o r

p h os p h at e s ,

t he 0. 3

g ram s amp l es wer e

d i g e s t e d I npe r

c h l o r i c

a c i d , n e u t r a l i z e d , and t hede t e r mi na t i o n c a r r i e d

o u t by

Ts c h opp' s met hod

asmo d i f i e d

f o r

use w i t ht he

B. D H N e s s l e r i z e r c o l o r d i s c s , ( 3 ) . The po t a s hwas det e r m

i n e d by t heS h e r r i l l met hod ( 11) on t he ash s o l u t i o n s

o b t a i ne d f r o m

one

gr am s a mpl e s .

R e s u l t s of t he Oat

Ex pe r i me nt

Dr y Wei gh t Dat a

The

f o l l o w i n g t a b l e s

and

gr aph s

ar e

c ompos ed

of t he

meas ur ement s made on t hegr o wt h of t hep l a n t s and i n d i c a t e


39/64

- 3 7 -

t h e t r e n d

o f t h e

r e s u l t s wh i c h w i l l

h e

d i s c u s s e d

i n

g r e a t e r

d e t a i l l a t e r .

The d r y

we i gh t s

g i v e n

i n

Tab l e

8

i n c l u d e

t h e

we i gh t s

o f t h e

r o o t s , s t r a w,

and

g r a i n .

Tab l e

8.

T o t a l

Dr y

We i ght

o f

Oat s R e s u l t i n g

f r o m

D l f f e r e n

t i a l F e r t i l i z i n g

w i t h N i t r o g e n ,

Ph o s p h a t e ,

and

Po t as h .

Tr ea t men t

( gm)

R e p l i c a t i o n s

Aver age

N

0. 204

. 1. ; .

P

25

0. 039

1 1 . 5 1 0 . 6 9. 6

1 0 . 2

1 0 . 5

0. 8

K

2

0

- - 0. 075

0. 136

1 1 . 6 1 0 . 5 1 1 . 1 1 0 . 1 1 0 . 8

0. 7

N

0. 068 1 0 . 6

9. 4

1 0 . 0 1 0 . 0

1 0 . 0 0. 5

0. 000 4. 9

4. 6

4. 9

4. 6

4. 75

0. 2

0. 026

1 1 . 6 1 1 . 9

1 1 . 6 1 0 . 5

1 1 . 4

0. 3

P25

0 . 0 1 3

1 2 . 4

9. 7

1 0 . 7

1 1 . 5 1 1 , 1 1. 1

0. 000

1 1 . 5 1 0 . 9 1 1 . 1 .

1 1 . 2 1 1 . 2

0. 2

0. 050 1 1 . 1

1 0 . 9

9. 8

1 0 . 5

1 0 . 6

0. 6

K

2

0

0. 025

1 0 . 9

1 0 . 7

1 0 . 6

1 0 . 6

1 0 . 7

0. 1

0. 000

1 0 . 7

1 0 . 7

1 0 . 4

1 0 . 2

1 0 . 5

0. 2

Check ( 0 - 0 - 0 )

4. 6

4. 5

4. 4 4. 5

4. 5

0. 1

St a nd ar d d e v i a t i o n

= /i=Li l

/ 71 /


40/64

38-

The d a t a g i v e n i n Tab l e 8 a r e

g r a p h i c a l l y

r e pr e s en t e d I n

F i g u r e s 4, 5, and 6.

A l l

o f t he

meas ur ement s

made on t h e o a t s

r e f l e c t

t h e

s ame t r e nd s as do t h e

t o t a l

d r y we i gh t s . F or t h e s a k e o f

s i m p l i c i t y ,

t h e r e f o r e , o n l y

t o t a l

d r y we i gh t s o f t h e o at

p l a n t s a r e r e po r t e d.

I t i s no t ewor t hy t h a t t he r e p l i c a t e s i n

a l l

t r e at me nt s

agr e e v e r y c l o s e l y , h a vi n g an a ve r age s t andar d d e v i a t i o n o f

0. 4

gr ams

f o r t he e l e ve n t r e at me nt s . No

s i n g l e

t r e at me nt

shows

a s t andar d de v i a t i o n g r e a t e r t han 1. 1 gr ams ( Tab l e 8) .

The n i t r o ge n s e r i e s shows a ge ne r a l I nc r e as e I n

y i e l d ,

i n d i c a t i n g a good r es pons e t o n i t r o ge n

f e r t i l i z a t i o n

( Ta b l e 8

and F i gu r e 4) . Bo t h t h e

phosphat e : - and

t h e po t as h s e r i e s

show

no g en er a l i n c r e as e I n

y i e l d ,

I n d i c a t i n g

t h a t t h e r e i s

no p o s i t i v e r e s po ns e t o

f e r t i l i z a t i o n

wi t h t h es e e l ement s

( F i g u r e s 5 and 6) .

The'

a l l

h i g h t r e a t me n t , wh i c h r e c e i v e d t he g r e at e s t

amount o f e a c h of t he gr o wt h

f a c t o r s

and wh i c h was t h e h i g h

e s t

t r ea t ment f o r

e a c h

o f t he t h r e e s e r i e s , un f o r t u n a t e l y gave

a l owe r y i e l d t han was expec t ed , e s p e c i a l l y i n r e s pe c t t o t he

n i t r o g e n and p h os p h at e

s e r i e s .

Th i s

a p pea r ed

t o be due t o

ex c es s n i t r o g e n , j u dg i n g by t he dar k gr een

c o l o r

o f t h e

l e a v e s , much b r a nc h e d h a b i t , s h o r t e r s t r aw, and l ow g r a i n

f o r m a t i o n . I t i s

u n l i k e l y , h oweve r ,

t h a t i t was due t o

ex c es s n i t r o ge n a l o ne ,

b e c a u s e

a l l

o f t he po t s i n b o t h

phos

ph at e and po t a s h s e r i e s r e c e i v ed t he same h i g h amount o f


41/64


42/64

- 40=

n i t r o ge n( 0. 204 gmn i t r o g e nperp o t ) . I n

s p i t e

of t h i s , t he

pho spha t e s e r i e s

s howed t he

h i gh e s t

y i e l d s

i n t he e x pe r i me nt

and n e i t h e r t he pho sphat e or t hepo t a s h s e r i e s showedany

ex c es s n i t r o ge n

s ympt oms .

A l l

po t s of b o t h t hen i t r o g e nandpo t as h

s e r i e s ,

as

w e l l

as t he h i g h ph os ph at e t r e at me nt of t he pho spha t e

s e r i e s ,

r e

c e i v e d

P

2

5

t 0. 039 gr ams

perp o t .

Howev er ,

t he r e ma i n de r

o f

t he

pho spha t e

s e r i e s ,

wh i c h

a l l

r e c e i v e d

l e s s

t h a n

0. 039

gr ams P

2

0g per pot i n c l u d i n g t he

t r ea t ment wh i c h r e c e i v e d

no

ph o s ph a t e ,

c o n s i s t a n t l y gave y i e l d s t h a t wer e

one

gr am

h i gh e r

t h a n anyo t h e r t r ea t men t i n t he ex pe r i me nt .

An

i mpo r t an t p o i n t r e ve al e dby t heda t a ofTab l e 8 i s t he

l a c k of a s i g n i f i c a n t d i f f e r e n c e b e t weent he no n i t r o g e n

t r e at me nt wh i c h r e c e i v e d ph os ph at e

and

po t as h

f e r t i l i z e r , and

t h e c hec k t r e at me nt wh i c h r e c e i v e dno

f e r t i l i z e r

at

a l l .

Si nc e t hepho spha t e andpo t a s h s e r i e s showednomeas ur e -

ab l e

r e s pons e , i t

was notp o s s i b l e t o make c a l c u l a t i o n s on

t h e s e

s e r i e s .

C a l c u l a t i o n s

f o r

t hen i t r o ge n

s e r i e s we r e ,

howeve r ,

c a r r i e d

o u t .

The

Maxi mumP o s s i b l e

Y i e l d

Si nc e t he n i t r o ge n c ur ve e x h i b i t s a d e c l i n e at

t h e

h i g h

end of t he s e r i e s , t hec a l c u l a t e d v a l u e f o r t he maxi mum y i e l d

( 10. 9 gm i ss l i g h t l y l o we r t h an t heh i g h e s t aver age y i e l d

( 11. 4

gm. I t

s eemed

wi s e ,

t h e r e f o r e ,

t o use 11. 4

gr ams

as

t he

maxi mumy i e l d ,

a l t h o u gh i t

mak es

l i t t l e

d i f f e r e n c e t o t he

c a l c u l a t i o n s .


43/64

- 41-

P r o p o r t i o n a l i t y

Co ns t a nt

When no n i t r o g e n was added t o a po t , a

y i e l d

o f 4. 75 gm

was o b t a i ne d . Th i s was t he r e s u l t o f an amount o f n i t r o g e n ,

b ,

wh i c h

was i n t h eno r ma l

s o i l .

The

who l e y i e l d

c u r v e was

t h e r e f o r e , d i s p l a c e dupwar ds b y an amount o f 4. 75 gm. The

f e r t i l i t y o f t h e s o i l i s t h en r e pr e s en t e d b y , x +b , wh i c h

i n c l u d e s

b ot h t h e

o r i g i n a l

f e r t i l i t y , b , a nd t h e k no wn f e r t i l

i z e r , :

x . Th i s t e r m, i t

w i l l

b e r e me mb er e d, i s

i n c l u d e d

i n

e qua t i o n ( V) wh i c hi s

l o g ( A- y ) = l o gA- c ( x - t - b )

Si nc e b ot h b a nd c we r e , a s ye t , unknown q u a n t i t i e s i n

t h i s

e qua t i o n , t wo s uc h e q ua t i o ns wer e s o l v ed s i mu l t ane ous l y

u s i n g t h e condensed

f o r m

( VI ) wh i c hi s

l o g ( A- y x ) - l o g ( A - y

2

)

C = '.

v.

. .

/

\

x

2 ~ * 1

Si nc e

A was 11. 4, y

1

was 4. 75, y

2

was 10. 0,

x i

was 0. 000,

and x

2

was 0. 068, t h e n

l og( 11. 4 - 4. 75) - l o g( 11. 4- 10. 0)

c = ' .

0. 068 ~ 0. 000

c 10

Th i s means t h at t h ev a l u e o f t h e p r o p o r t i o n a l i t y c o ns t ant


44/64

- 4 2 -

wh i c h

i s

c h a r a c t e r i s t i c

o f t h e s l o p e o f t h e c u r v e o b t a i n e d i n

t h e n i t r o g e n s e r i e s o f

t h i s e x pe r i me nt

wa s 1 0 . U s e i s

made

o f

t h i s

number i n t h e f o l l o w i n g c a l c u l a t i o n s f o r t h e s o i l

n i t r o g e n

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

application of mithserlich methods-1942

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