Studies of nitrogen losses from fertilized Bowdoin clay soil
by Gilbert Schumaker
A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree
of Master of Science in Soils
Montana State University
© Copyright by Gilbert Schumaker (1959)
Abstract:
Nitrogen losses from Bowdoin clay were studied in the greenhouse. Nitrogen uptake in barley was used
as an indicator of nitrogen loss in ammonium and nitrate forms by applying these sources to the clay
soil and allowing the barley to mature.
Two greenhouse experiments were conducted applying nitrogen sources to Bowdoin clay. Nitrogen
materials were applied on the soil surface at four rates with two levels of moisture in the first
experiment. More than 50% of the applied nitrogen was recovered from the nitrate source treatment.
Nitrogen recovery from the ammonium-treated pots was much less—15 to 20%. Differences were
noted in the application of nitrogen at different rates; no differences were noted between moisture
treatments.
The nitrogen materials were mixed with the soil in a second experiment to observe the effect of
placement on nitrogen uptake, again assuming nitrogen uptake to be an indicator of nitrogen loss.
Results showed a recovery of 80 to 90% of the applied nitrogen.
Nitrogen loss in the ammoniacal form was measured from Bowdoin clay in the laboratory. The clay
soil has the ammonium-fixing capacity of 8 meq. per 100 gm. of soil, much larger than in most soils.
Some volatilization of ammonia was measured; however, the amounts measured were small, with the
largest loss being 7% of the nitrogen applied.
These determinations do not necessarily account for all the ammonium source loss measured in the
greenhouse experiment with nitrogen application on the soil surface. It is possible that some of the
ammonium nitrogen became positionally unavailable.
It was shown in these studies that losses from the surface application of the ammonia source of
nitrogen can be overcome by the surface application of the nitrate source or by deeper placement of any
of the fertilizer materials studied. STUDIES OF NITROGEN LOSSES FROM
FERTILIZED BOWDOIN CLAY SOIL
by
GILBERT SCHUMAKER
'Pl
A THESIS
Subm itted to the Graduate F acu lty
in
partial
f u l f i l l m e n t of the requirem ents
f o r th e degree of
Master o f Science in S o ils
at
Montana S t a t e C o l l e g e
Approved»
Head, M ajo r D e p a r t m e n t
Bozeman, Montana
A u g u s t , 1959
2
ACKNOWLEDGEMENT
The w r i t e r w i s h e s t o e x p r e s s h i s a p p r e c i a t i o n and t h a n k s t o
D r . Mo Go K l a g e s ■f o r h i s h e l p f u l g u i d a n c e w h i l e c o n d u c t i n g t h e r e s e a r c h
on t h e t h e s i s p r o b l e m and a l s o f o r t h e many s u g g e s t i o n s he g a v e d u r i n g
the w ritin g of th is t h e s i s .
An e x p r e s s i o n o f t h a n k s i s a l s o t o be
e x t e n d e d t o D r . J . C. Hid e and D r . Hayden F e r g u s o n f o r t h e i r t i m e and
e f f o r t spent in reviewing the m anuscript.
The w r i t e r w i s h e s t o t h a n k Dr. P a u l Brown f o r t h e a s s i s t a n c e he
r e n d e r e d and Mr. David D i c k e y , who a l s o ga v e a s s i s t a n c e on s e v e r a l p h a s e s
of th e r e s e a r c h d u rin g th e absence of th e w r i t e r .
The c o o p e r a t i o n and s u p p o r t from t h e U. S . D e p a r t m e n t o f A g r i c u l t u r e ,
A g r i c u l t u r a l R e s e a r c h S e r v i c e , W e st e rn S o i l and W ate r Management R e s e a r c h
Branch, i s a ls o acknowledged.
S p e c ia l thanks are a ls o extended to
D r . F r a n k G. V i e t s , J r . , o f t h e A g r i c u l t u r a l R e s e a r c h S e r v i c e , f o r h i s
v a l u a b l e s u g g e s t i o n s i n ,the p l a n n i n g o f t h e v a r i o u s p h a s e s o f t h e r e s e a r c h .
The w r i t e r a l s o g r a t e f u l l y a c k n ow l ed g e s t h e c o o p e r a t i o n and e n c o u r a g e - ,
ment from many o t h e r s who were a s s o c i a t e d w i t h t h e t h e s i s p r o b l e m and t h e
com pletion of the t h e s i s .
/
3
TABLE OF CONTENTS
Page
ACKNOWLEDGEMENT .
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TABLE OF CONTENTS
3
LIST OF TABLES. .
5
C ontext Tables
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Appendi x T a b l e s
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LIST OF FIGURES . .
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ABSTRACT. . . . . .
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INTRODUCTION. . . .
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REVIEW OF LITERATURE o
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12
N i t r o g e n Loss by Ammonium F i x a t i o n
13
V o l a t i l i z a t i o n o f Ammonia....................
15
L o s s e s by D e n i t r i f i c a t i o n ....................
18
L o s s e s from N i t r i t e N i t r o g e n . . .
19
22
MATERIALS AND METHODS . . . . . . . . .
G r e e n h o u s e E x p e r i m e n t s ...........................................................................................
22
A g g r e g a t i o n M easure ments . . . . .
24
...............................................................
Ammonia V o l a t i l i z a t i o n . . . . . . . . . . . .
F i x a t i o n o f Ammonium ........................
. . ........................
........................
. .
. . . . . . .
25
27
................................................
27
S t a t i s t i c a l P r o c e d u r e s ...................." .............................. .... .................................
28
S o il Analyses.
. . . . . . . . . . . . .
EXPERIMENTAL RESULTS. . . . . . . . . . . . . . . . . . . . . . . .
S o il Analyses.
...........................................................................................
29
. . . .
29
..................................................................................
35
A g g r e g a t i o n A n a l y s e s . ................................ ........................ .................................
56
Greenhouse Experim ents . .
EXPERIMENTAL RESULTS c o n t i n u e d
Ammonium F i x a t i o n .
..................................
Ammonia V o l a t i l i z a t i o n Measurement
DISCUSSION. . . . . . . . . . . . . . .
SUMMARY AND CONCLUSIONS . . . . . . . .
LITERATURE CITED. . . . . . . . . . . .
APPENDIX
5
LIST OF TABLES
Page
Context Tables
Table I .
Table I I .
Table I I I .
T a b l e IV.
T a b l e V.
T a b l e VI.
N i t r o g e n r a t e s and s o u r c e s u s e d f o r g r e e n h o u s e
e x p e r i m e n t on Bowdoin c l a y . .....................................................
23
N i t r o g e n s a l t s a p p l i e d t o Bowdoin c l a y f o r t h e
m ea s u r em e nt o f ammonia v o l a t i l i z a t i o n ( m i l l i ­
grams o f n i t r o g e n a p p l i e d t o 100 gm. o f s o i l ) . . .
26
P a r t i c l e s i z e d i s t r i b u t i o n o f Bowdoin c l a y
s u r f a c e s o i l as d e t e r m i n e d by t h e p i p e t t e
m et h o d . . . . . . . . . . . .
........................ . . . . .
30
S p e c i f i c s u r f a c e o f Bowdoin c l a y as m ea s u r ed by
t h e e t h y l e n e g l y c o l r e t e n t i o n m et h o d. . . . i . . .
31
Me asu re men t o f v a r i o u s s o i l c h a r a c t e r i s t i c s o f
Bowdoin c l a y . . . . . . . . . . . . . . . . . . . .
32
P e r c e n t m o i s t u r e r e t a i n e d by Bowdoin c l a y
u n d e r v a r i o u s t e n s i o n s . .......................................................... ...
33
Table V I I . .
Average p l a n t h e i g h t o f m a t u r e b a r l e y t r e a t e d '
' Y /
w i t h s u r f a c e a p p l i c a t i o n s o f n i t r o g e n and m o i s t u r e ; ' , .
m a i n t a i n e d a t two l e v e l s . ................................................
37
Table V III.
Av er ag e w e i g h t o f p l a n t m a t e r i a l h a r v e s t e d w i t h
s u r f a c e a p p l i c a t i o n s of n i t r o g e n ............................................
39
M u l t i p l e c o m p a r i s o n t e s t s f o r mean s e p a r a t i o n
o f t o t a l b a r l e y p l a n t m a t e r i a l w e i g h t s .............................
40
Av erage m i l l i g r a m s o f n i t r o g e n u p t a k e i n b a r l e y
p l a n t m a t e r i a l w i t h s u r f a c e a p p l i c a t i o n s of
nitrogen. . . . . . . . .
....................................... . . . .
48
T a b l e IX.
T a b l e X.
T a b l e XI.
Table X II.
M u l t i p l e c o m p a r i s o n t e s t s f o r mean s e p a r a t i o n o f
n i t r o g e n c o n t e n t d a t a fro m g r e e n h o u s e e x p e r i m e n t .
.
49
Aver age m i l l i g r a m s o f n i t r o g e n r e c o v e r e d above
c h e c k t r e a t m e n t s and p e r c e n t n i t r o g e n r e c o v e r e d
o f added n i t r o g e n ( s u r f a c e a p p l i c a t i o n s o f
nitrogen) . . . . . . . . . . . . . .
.................... . .
51
6
Page
Table X I I I .
T a b l e XIV.
T a b l e XV.
T a b l e XVI.
T a b l e XVII.
Table XVIII.
Average w e i g h t o f p l a n t m a t e r i a l when n i t r o g e n
m a t e r i a l s were mixed w i t h t h e s o i l .......................................
52
Av erage m i l l i g r a m s o f n i t r o g e n u p t a k e when
n i t r o g e n m a t e r i a l s were mixed w i t h t h e s o i l
53
. . . .
Average m i l l i g r a m s o f n i t r o g e n r e c o v e r e d above
c h e c k t r e a t m e n t s and p e r c e n t r e c o v e r e d o f added
n i t r o g e n ( n i t r o g e n mixed w i t h t h e s o i l ) . . . . . .
54
Measurement o f d i s p e r s i o n r a t i o o f u n t r e a t e d
Bowdoin c l a y and s o i l t r e a t e d w i t h n i t r o g e n
m a t e r i a l s (grams o f s i l t p l u s c l a y i n a l i t e r
s u s p e n s i o n o f a 50-gm. s o i l s a m p l e ) ........................
57
M easure ment o f ammonium f i x a t i o n i n Bowdoin
c l a y u n d e r a i r - d r y c o n d i t i o n s . ...........................................
58
M i l l i e q u i v a l e n t s o f ammonia v o l a t i l i z e d from
Bowdoin c l a y . .................................................................................. ■.
59
Appendix T a b l e s
T a b l e XIX.
T a b l e XX.
T a b l e XXI.
T a b l e XXII.
Table XXIII.
T a b l e XXIV.
T a b l e XXV.
T i l l e r i n g d a t a o f b a r l e y f e r t i l i z e d on t h e s o i l
s u r f a c e ( p o t s t h i n n e d t o 10 p l a n t s ) . . .
....................
71
T i l l e r i n g d a t a o f b a r l e y when f e r t i l i z e r was
mixed w i t h t h e s o i l ( p o t s t h i n n e d t o 10 p l a n t s ) . .
72
A nalysis of v a ria n ce of to ta l, b a rle y p la n t
m a te ria l weight (n itro g e n a p p lic a tio n s a t s o i l
s u r f a c e ).
.............................................................................
73
Aver age w e i g h t o f b a r l e y g r a i n h a r v e s t e d w i t h s u r f a c e a p p l i c a t i o n s o f n i t r o g e n . . ..................................
74
.Analysis of v a r i a n c e o f b a r l e y g r a i n w e ig h t
w i t h s u r f a c e a p p l i c a t i o n s o f n i t r o g e n .............................
75
M u l t i p l e c o m p a r i s o n t e s t s f o r mean s e p a r a t i o n of
b a r l e y g r a i n t r e a t m e n t w e i g h t s ........................ ....
76
P e r c e n t n i t r o g e n i n b a r l e y g r a i n and s t r a w w i t h
n i t r o g e n t r e a t m e n t s on t h e s o i l s u r f a c e .........................
77
7
Page
T a b l e XXVI.
T a b l e XXVII.
T a b l e XXVIII.
T a b l e XXIX.
T a b l e XXX.
T a b l e XXXI.
,
T a b l e XXXII.
Grams o f g r a i n and s t r a w p r o d u c e d when n i t r o g e n
t r e a t m e n t s were a p p l i e d on t h e s o i l s u r f a c e . . . .
78
M i l l i g r a m s o f n i t r o g e n p r o d u c e d when n i t r o g e n
was a p p l i e d on t h e s o i l s u r f a c e .............................................
79
Analysis of varian ce of m illigram s of n itro g e n
p r o d u c e d by b a r l e y p l a n t m a t e r i a l w i t h s u r f a c e
a p p l i c a t i o n s o f n i t r o g e n ..................................................... ....
80
. •
Average w e i g h t o f g r a i n p r o d u c e d when n i t r o g e n
m a t e r i a l s w er e mixed w i t h t h e s o i l .......................................
81
Percent nitrogen in t o t a l barley plant m aterial
when n i t r o g e n t r e a t m e n t s were mixed w i t h t h e
s o i l ............................................................... ■.........................................
.
82
Grams o f b a r l e y g r a i n and t o t a l p l a n t m a t e r i a l
p r o d u c e d when n i t r o g e n t r e a t m e n t s were mixed
w i t h t h e s o i l . ..................................................... .... ........................
83
M illigram s of n i tr o g e n produced i n t o t a l b a r l e y
p l a n t m a t e r i a l when n i t r o g e n t r e a t m e n t s were
mixed w i t h t h e s o i l ........................................................................
84
8
LIST OF FIGURES
Page
Figure I .
F ig u re 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6 .
M o i s t u r e r e t e n t i o n c u r v e f o r Bowdoin c l a y s u r f a c e
s o i l . . ........................................... ............................................... ....
34
C o m p a ri s o n o f b a r l e y h e i g h t when n i t r o g e n s o u r c e s
wer e a p p l i e d on t h e s o i l s u r f a c e . ................................................
36
T o t a l b a r l e y p l a n t m a t e r i a l w e i g h t p r o d u c e d from
f o u r r a t e s o f n i t r o g e n ( a p p l i c a t i o n on t h e s o i l
s u rf a c e ). . . . . .
.................... . . . . . .
..............................
41
The e f f e c t o f n i t r o g e n s o u r c e t r e a t m e n t s on b a r l e y
g r a i n w e i g h t and t o t a l p l a n t m a t e r i a l w e i g h t ( a v e r a g e
o f f o u r r a t e s w i t h n i t r o g e n a p p l i c a t i o n on t h e s o i l
s u r f a c e ). . . . . . . . . . . . . . .
.......................................
42
Co m pa ris o n o f b a r l e y t o t a l p l a n t m a t e r i a l w e i g h t s
when t h r e e n i t r o g e n s o u r c e s w er e a p p l i e d a t f o u r
r a t e s on t h e s o i l s u r f a c e ....................................................................
43
B a r l e y g r a i n p r o d u c e d fro m f o u r r a t e s - o f n i t r o g e n '
( a p p l i c a t i o n on t h e s o i l s u r f a c e ) ...........................................
45
.
F ig u re 7.
Co m p a ri s o n o f b a r l e y g r a i n w e i g h t s when t h r e e
n i t r o g e n s o u r c e s we re a p p l i e d a t f o u r r a t e s on t h e
s o i l s u r f a c e . . ................................................................................................ - 46
Figure 8 .
Co m pa ris o n o f m i l l i g r a m s o f n i t r o g e n r e c o v e r e d when
t h r e e n i t r o g e n s o u r c e s wer e a p p l i e d a t t h r e e r a t e s
on t h e s o i l s u r f a c e ..................................................................................
47
Co m p a ri s o n o f t o t a l p l a n t m a t e r i a l w e i g h t s when
f o u r n i t r o g e n s o u r c e s were a p p l i e d a t t h r e e r a t e s
by m i x i n g t h e f e r t i l i z e r w i t h t h e s o i l .......................................
55
F ig u re 9.
9
ABSTRACT
N i t r o g e n l o s s e s f ro m Bowdoin c l a y were s t u d i e d i n t h e g r e e n h o u s e .
N i t r o g e n u p t a k e i n b a r l e y was u s e d as an i n d i c a t o r o f n i t r o g e n l o s s i n
ammonium and n i t r a t e form s by a p p l y i n g t h e s e s o u r c e s t o t h e c l a y s o i l
and a l l o w i n g t h e b a r l e y t o m a t u r e .
Two g r e e n h o u s e e x p e r i m e n t s were c o n d u c t e d a p p l y i n g n i t r o g e n s o u r c e s
t o Bowdoin c l a y .
N i t r o g e n m a t e r i a l s wer e a p p l i e d on t h e s o i l s u r f a c e a t
f o u r r a t e s w i t h two l e v e l s o f m o i s t u r e i n t h e f i r s t e x p e r i m e n t .
More
t h a n 50% o f t h e a p p l i e d n i t r o g e n was r e c o v e r e d from t h e n i t r a t e s o u r c e
treatm ent.
N i t r o g e n r e c o v e r y from t h e a m m o n iu m - tr e a t e d p o t s was much
l e s s — 15 t o 20%. D i f f e r e n c e s wer e n o t e d i n t h e a p p l i c a t i o n o f n i t r o g e n
a t d i f f e r e n t r a t e s ; no d i f f e r e n c e s were n o t e d b e tw e en m o i s t u r e t r e a t m e n t s .
The
iment to
as su m i n g
showed a
n i t r o g e n m a t e r i a l s wer e mixed w i t h t h e s o i l i n a se c o n d e x p e r ­
o b s e r v e t h e e f f e c t o f p l a c e m e n t on n i t r o g e n u p t a k e , a g a i n
n i t r o g e n u p t a k e t o be an i n d i c a t o r o f n i t r o g e n l o s s .
R esults
r e c o v e r y o f 80 t o 90% o f t h e a p p l i e d n i t r o g e n .
N i t r o g e n l o s s i n t h e ammoniacal form was m ea s ur ed from Bowdoin
c la y in the la b o ra to ry .
The c l a y s o i l h a s t h e am m onium- fixing c a p a c i t y
o f 8 meq. p e r 100 gm. o f s o i l , much l a r g e r t h a n i n m o st s o i l s .
Some
v o l a t i l i z a t i o n o f ammonia was m e a s u r e d ; h o w e ve r , t h e amounts measu red
w er e s m a l l , w i t h t h e l a r g e s t l o s s b e i n g 7% o f t h e n i t r o g e n a p p l i e d .
T he se d e t e r m i n a t i o n s do n o t n e c e s s a r i l y a c c o u n t f o r a l l t h e ammonium
so u rce l o s s measured in t h e greenhouse e x p e rim e n t w ith n i t r o g e n a p p l i c a ­
t i o n on t h e s o i l s u r f a c e .
I t i s p o s s i b l e t h a t some o f t h e ammonium
n i t r o g e n became p o s i t i o n a l l y u n a v a i l a b l e .
I t was shown i n t h e s e s t u d i e s t h a t l o s s e s from t h e s u r f a c e a p p l i c a ­
t i o n o f t h e ammonia s o u r c e o f n i t r o g e n c a n be overcome by t h e s u r f a c e
a p p l i c a t i o n o f t h e n i t r a t e s o u r c e o r by d e e p e r p l a c e m e n t o f any o f t h e
f e r t i l i z e r m aterials studied.
(
10
INTRODUCTION
The p u r p o s e o f t h i s d i s s e r t a t i o n i s t o d i s c u s s t h e t y p e o f n i t r o g e n
l o s s o r l o s s e s w h ic h o c c u r i n Bowdoin c l a y as i n v e s t i g a t e d i n t h e l a b o r a t o r y
and g r e e n h o u s e .
N i t r o g e n r e c o v e r y d a t a fro m n a t i v e hay e x p e r i m e n t s on Bowdoin clay'*"
hav e i n d i c a t e d t h a t o n l y a s m a l l p o r t i o n o f t h e n i t r o g e n a p p l i e d i s
r e c o v e r e d by t h e hay c r o p .
While c r o p s r e s p o n d v e r y f a v o r a b l y t o n i t r o g e n
a p p l i c a t i o n on t h e Bowdoin c l a y s o i l ,
n o t more t h a n 30% o f t h e n i t r o g e n
applied is recovered the y ear of a p p lic a tio n .
E x p e r i m e n t s hav e shown t h a t
o nly a sm all p e rc e n ta g e of th e n i t r o g e n n o t u t i l i z e d th e y e a r of a p p l i c a ­
t i o n i s t a k e n up by t h e c r o p i n f o l l o w i n g y e a r s .
Thus i t a p p e a r s t h a t t h e
n i t r o g e n n o t r e c o v e r e d i n p l a n t m a t e r i a l i s l o s t o r becomes u n a v a i l a b l e
f o r crop u s e .
L o s s e s o f v o l a t i l e forms o f n i t r o g e n and t h e f i x a t i o n of
ammonium a r e p o s s i b l e c a u s e s .
With t h e i n c r e a s e d u s e o f n i t r o g e n f e r t i l i z e r s
and w i t h a p p l i c a t i o n s
a t h i g h e r r a t e s becoming more common, a t t e n t i o n must be g i v e n t o t h e
f a c t o r s r e s p o n s i b l e f o r t h e s e l o s s e s w h ic h i m p a i r t h e e f f i c i e n c y o f
nitrogen use.
Since n i tr o g e n l o s s e s , b e lie v e d to occur h e r e , are e i t h e r in the
f o rm o f ammoniaca l o r n i t r a t e n i t r o g e n , one a p p r o a c h u s e d i n t h i s i n v e s t i g a ­
t i o n was t o m ea s u r e t h e n i t r o g e n u p t a k e by p l a n t s t r e a t e d w i t h t h e s e s o u r c e s
of n itro g e n under greenhouse c o n d itio n s.
The form o f n i t r o g e n l o s s o c c u r ­
r i n g c o u l d t h e n be d e t e r m i n e d , ' s i n c e a r e d u c t i o n o f t h e n i t r o g e n s u p p l y
IUo S . D e p a r t m e n t o f A g r i c u l t u r e , A g r i c u l t u r a l R e s e a r c h S e r v i c e , Weste rn
S o i l and W ate r Management R e s e a r c h B r a n c h , Milk R i v e r Annual R e p o r t , 1957.
11
i n t h e s o i l due t o l o s s would be r e f l e c t e d i n a r e d u c t i o n o f n i t r o g e n u p ­
t a k e by t h e p l a n t .
G r e e n h o u s e e x p e r i m e n t s w i t h b a r l e y were c o n d u c t e d i n two p h a s e s .
N i t r o g e n a p p l i c a t i o n s were on t h e s u r f a c e
iment.
in the f i r s t greenhouse exper­
F o l l o w i n g t h i s e x p e r i m e n t , a c o m p a r i s o n o f n i t r o g e n u p t a k e by
b a r l e y was made when v a r i o u s s o u r c e s o f n i t r o g e n were mixed w i t h t h e s o i l .
I n o r d e r t o v e r i f y c o n c l u s i o n s drawn from g r e e n h o u s e e x p e r i m e n t s ,
q u a n t i t a t i v e m e a s u r e m e n ts o f n i t r o g e n l o s s by ammonia v o l a t i l i z a t i o n and
ammonium f i x a t i o n were t h e n made i n t h e l a b o r a t o r y t o d e t e r m i n e t h e
i m p o r t a n c e o f t h e s e forms o f n i t r o g e n l o s s e s .
S t u d i e s o f t h e t y p e s o f n i t r o g e n l o s s e s w hi ch o c c u r from Bowdoin
c l a y w i l l be h e l p f u l i n f i n d i n g a means o f r e d u c i n g n i t r o g e n l o s s ,
r e s u l t i n g i n g r e a t e r n i t r o g e n economy and i n c r e a s e d p r o d u c t i v i t y .
12
REVIEW OF LITERATURE
From t h e r e s e r v o i r o f s o i l n i t r o g e n , tfyere i s a c o n t i n u a l removal
and r e t u r n o f n i t r o g e n d u r i n g t h e c o u r s e o f t h e n i t r o g e n c y c l e .
Black
(195 7) h a s e x p l a i n e d t h e a d d i t i o n and r e m o v a l o f n i t r o g e n from t h i s
re se rv o ir quite f ittin g ly ?
"Over e a c h a n n u a l c y c l e , some n i t r o g e n i s
m i n e r a l i z e d , and some i s i m m o b i l i z e d .
Some i s removed by p l a n t s ,
some i s r e t u r n e d i n t h e fo rm o f p l a n t r e s i d u e s .
a t m o s p h e r e , and some i s r e t u r n e d .
some added by f e r t i l i z a t i o n .
and
Some i s l o s t t o t h e
Some may be l o s t by l e a c h i n g and
Some may be l o s t by e r o s i o n o r added by
deposition."
T h i s a d d i t i o n and r em o va l o f n i t r o g e n from t h e s o i l h a s b e e n d i s ­
c u s s e d by A l l i s o n ( 1 9 5 5 ) .
He r e f e r s t o t h e n i t r o g e n b a l a n c e s h e e t s o f
a number o f l o n g - t e r m e x p e r i m e n t s and shows t h e t o t a l n i t r o g e n a d d i t i o n s
and l o s s e s d u r i n g t h e c o u r s e of t h e s e e x p e r i m e n t s .
Even when an a c c o u n t
was made o f n i t r o g e n l o s t by l e a c h i n g and e r o s i o n , a l l t h e n i t r o g e n added
c o u l d n o t be a c c o u n t e d f o r .
I t appears t h a t the only adequate explana­
t i o n o f t h e s e n e g a t i v e b a l a n c e s i s n i t r o g e n l o s s by t h e v o l a t i l i z a t i o n of
v a r i o u s forms o f n i t r o g e n and by t h e f i x a t i o n o f t h e ammonium i o n ,
rendering i t un av ailab le in the s o i l .
Early in v e s tig a tio n s
the
soil
i n d i c a t e d t h a t some o f t h e n i t r o g e n a p p l i e d t o
was l o s t i n some fo rm ; h o w e v e r , n i t r o g e n f e r t i l i z e r s were n o t
applied in larg e q u a n ti ti e s .
At t h a t t i m e , r e f i n e d met hods o f m e a s u r in g
s m a l l l o s s e s o c c u r r i n g a t s lo w r a t e s had n o t b e e n d e v e l o p e d .
Since these
l o s s e s , w hi c h wer e b e l i e v e d t o o c c u r , c o u l d n o t be m e a s u r e d , i t was
concluded t h a t th ey d id not reach s i g n i f i c a n t p r o p o r tio n s .
13
It
i s , however, re c o g n iz e d today t h a t t h e s e p r e v i o u s l y unexplored
l o s s e s c a n r e a c h s i g n i f i c a n t p r o p o r t i o n s , p a r t i c u l a r l y where n i t r o g e n
i s applied in larg e q u a n t i t i e s .
I t i s n o t l i k e l y t h a t n i t r o g e n i s l e a c h e d from Bowdoin c l a y s i n c e
t h e d e p t h o f w a t e r p e n e t r a t i o n i n t h i s s o i l i s a b o u t 30 i n c h e s .
Th is
form o f l o s s w i l l n o t be r e v i e w e d .
Forms o f n i t r o g e n l o s s wh ic h w i l l be r e v i e w e d a r e s
t h e f i x a t i o n of
ammonium, t h e v o l a t i l i z a t i o n o f ammonia, and t h e l o s s o f e l e m e n t a l n i t r o g e n
through d e n i t r i f i c a t i o n .
W hile t h e f i x a t i o n o f ammonium i s n o t a l o s s i n
a s t r i c t s e n s e , i t i s d i f f i c u l t t o r e c l a i m and i s n o t i m m e d i a t e l y a v a i l ­
a b le f o r crop growth.
N i t r o g e n Loss by Ammonium F i x a t i o n
The p r o p e r t y o f c e r t a i n s o i l s t o ch an ge added ammonium i n t o a no nexchangeable s t a t e
i s t e r m e d ammonium f i x a t i o n .
Leggett
p
d escrib es fixed .
ammonium as "ammonium w h i c h i s e n t r a p p e d b e t w e e n two a d j a c e n t m i n e r a l
p l a t e s , p r e s u m a b l y i n t h e v o i d s formed by t h e h e x a g o n a l ox yg en r i n g s i n
t h e oxy ge n l a y e r s o f some s i l i c a t e m i n e r a l s .
The e n t r a p m e n t r e s u l t s from
a d e c r e a s e in th e b a s a l s p a cin g of th e m in e ra l to th e e x t e n t t h a t the
d i s t a n c e b e tw e e n t h e a d j a c e n t m i n e r a l p l a t e s i s n o t s u f f i c i e n t t o a l l o w
exchange r e a c t i o n s t o o c c u r.
I t i s assumed t h a t f i x e d NH4 i s p r e s e n t i n
m in erals i n a p o s i t i o n s i m i l a r to t h a t of K in m icas."
McBeth ( 1 9 1 7 ) was one o f t h e e a r l i e r w o r k e r s who n o t e d t h e o c c u r r e n c e
o f ammonium f i x a t i o n .
He o b s e r v e d t h a t ammonium s a l t s added t o s o i l s c o u l d
^ L e g g e t t , G l e n E,
Ammonium f i x a t i o n i n s o i l s and m i n e r a l s .
D o c t o r of
P h ilosophy t h e s i s , S t a t e C ollege of W ashington, Pullman, p. 2 .
1958.
14
n o t a lw a ys be r e c l a i m e d f ro m t h e s o i l i n t h e same q u a n t i t y t h a t had been
added.
I n s t u d i e s r e p o r t e d i n 1917, he t r e a t e d s e v e r a l s o i l s w i t h
ammonium s a l t s b u t was a b l e t o r e c l a i m no more t h a n 95% o f t h e amount
added.
He d e s c r i b e d t h i s
A llison e t a l.
l o s s as ammonium f i x a t i o n .
( 1953a and 1 9 5 3 b ) , i n t h e i r work on ammonium f i x a ­
tio n , reported values
o f l e s s t h a n 1 .0 meq. p e r 100 gm. o f s o i l f o r n o n -
kaolinitic
s o i l s . K a o l i n i t i c s o i l s do
ammonium.
I t was a l s o shown t h a t ,
n o t ha v e t h e c a p a c i t y t o f i x
on d r y i n g t h e ammonium t r e a t e d s o i l s ,
t h e amount o f ammonium f i x e d was a l m o s t . d o u b l e d .
a m m on ium -fi xin g c a p a c i t i e s
Leggett
3
determ ined the
o f 30 s u r f a c e s o i l s and fo u n d t h a t e i g h t of
t h e s e s o i l s had a m m on ium -fi xin g c a p a c i t i e s g r e a t e r t h a n 0 . 5 meq. p e r 100
gm. o f s o i l u n d e r m o i s t c o n d i t i o n s .
Ammonium f i x a t i o n i n New York s o i l s
was s t u d i e d by Sohn and P e e c h ( 1 9 5 8 ) .
They fo u n d t h e c a p a c i t y of most
of t h e s e s o i l s t o
f i x ammonium t o be b elo w 1 . 0 meq. p e r 100 gm.
v a lu e s as h ig h as
5 . 0 meq. p e r 100 gm. o f s o i l were m e a s u r e d i n some
s o i l s c o n t a i n i n g a v e r a g e amounts o f o r g a n i c m a t t e r .
However,
I t was a l s o n o t e d
t h a t a b o u t h a l f o f t h e ammonium f i x e d was due t o s o i l o r g a n i c m a t t e r .
They i n v e s t i g a t e d t h e amm on ium -fi xin g c a p a c i t y o f s e v e r a l s o i l s h i g h i n
o r g a n i c m a t t e r and fo u nd c o n s i d e r a b l y l a r g e r amm on ium- fixin g c a p a c i t i e s
in these s o i l s .
They s u g g e s t t h a t t h e ammonium combines c h e m i c a l l y w i t h
c e r t a i n organic f ra c tio n s in the s o i l .
A llison e t a l.
( 1 9 5 3 b ) , on t h e
o t h e r h a n d , e s t i m a t e t h a t s u b s o i l s f i x a b o u t f o u r t i m e s as much ammonium
a s do s u r f a c e s o i l s .
^ I b i d = , p. 52.
T h i s would i n d i c a t e t h a t s u b s o i l s c o n t a i n a l a r g e r
15
q u a n t i t y o f amm on ium -fi xin g c l a y m i n e r a l s o r t h e am m onium- fixing
c a p a c i t y o f t h e s o i l s u r f a c e h a s be e n n e u t r a l i z e d as a r e s u l t o f ammonium
r e l e a s e by d e c o m p o s in g o r g a n i c m a t t e r .
They a l s o compared ammonium
f i x a t i o n o f s o i l s h i g h i n c e r t a i n c l a y m i n e r a l s u n d e r b o t h m o i s t and
dry treatm ents.
T h e i r d a t a shows t h a t b o t h i l l i t e
and v e r m i c u l i t e c l a y
m i n e r a l s f i x ammonium u n d e r m o i s t c o n d i t i o n s , w h i l e m o n t m o r i I I o n i t e
f i x e s ammonium upon d r y i n g .
T h i s e x p l a i n s t h e i n c r e a s e d ammonium f i x a ­
t i o n f o l l o w i n g t h e d r y i n g o f some a m m o n iu m - tr e a t e d s o i l s .
The f i n d i n g s o f t h e s e w o r k e r s ca n be su m m a riz ed .
i s f i x e d by c e r t a i n c l a y m i n e r a l s p r e s e n t i n s o i l s .
The ammonium ion
The amount of
ammonium f i x e d d e p e n d s on t h e amount of c l a y m i n e r a l s p r e s e n t i n t h e
s o i l t h a t h a v e t h e a b i l i t y t o f i x ammonium i o n s .
The amount o f f i x a t i o n
i s a l s o d e p e n d e n t on t h e m o i s t u r e c o n d i t i o n t o wh ic h t h e s o i l
is
s u b j e c t e d when m o n tm o r i l l o n i t i c c l a y m i n e r a l s a r e p r e s e n t .
Some o f t h e
ammonium added t o s o i l s
combination
a l s o becomes u n a v a i l a b l e due t o i t s
with c e r t a i n organic substances in the s o i l .
V o l a t i l i z a t i o n o f Ammonia
Loss o f ammonia t h r o u g h t h e v o l a t i l i z a t i o n o f t h i s g a s i s a n o t h e r
t y p e o f n i t r o g e n l o s s fro m t h e s o i l .
Wahhab ( 1 9 5 7 ) p r o p o s e s t h a t t h e I p s s o c c u r s as a r e s u l t o f t h e e v a p o r a
t i o n o f ammonia and w a t e r v a p o r t o g e t h e ^ .
so il,
I t i s known t h a t ,
i n an a l k a l i n e
ammonia i s p r e s e n t i n t h e f o l l o w i n g form s whi ch a r e r e a d i l y changed
t o f r e e ammonia w h ic h i s s u b j e c t t o l o s s as a g a s :
16
( NH4 ) 2 CO3 + H2 O
NH4HCOs + NH4 OH
NH4 HCO3 + H2O
— >
NH4OH + H2CQs
A
NHdOH
=SE—
^ iti NHs I + H2O
He p r o p o s e s t h a t t h e above e q u i l i b r i u m e x i s t s i n t h e s o i l s o l u t i o n betw een
t h e s e compounds as shown.
Ammonium i o n s c o n t i n u e t o e x i s t i n t h e s o i l
s o l u t i o n a s lo n g as t h e r e a r e ammonium i o n s on t h e e x c ha n g e c o m p l e x .
Then
t h e ammonium i o n s u p p l i e d t o t h e s o i l s o l u t i o n by t h e e x c ha n g e complex
becomes a p a r t o f t h e s e e q u i l i b r i u m r e a c t i o n s . , and f r e e ammonia c a n be
e v o l v e d as l o n g as t h e r e a r e ammonium i o n s on t h e e x c han ge c o m p l e x .
Wahhab ( 1 9 5 7 ) e x p l a i n s t h a t ammonia and. w a t e r v a p o r e x e r t t h e i r own p a r t i a l
p r e s s u r e s and e v a p o r a t e t o g e t h e r i n p r o p o r t i o n s w h ic h d e p e n d upon t h e i r
m olar c o n c e n t r a t io n s .
As the- c o n c e n t r a t i o n o f ammonia i s i n c r e a s e d ,
l a r g e r amounts o f ammonia w i l l be v o l a t i l i z e d .
Work by J e w i t t ( 1 9 4 2 ) g i v e s e v i d e n c e t h a t t h e c a t i o n e x c ha n g e
c a p a c i t y i s a l s o a f a c t o r i n f l u e n c i n g t h e l o s s o f ammonia i n t o t h e a i r .
L oss o f ammonia o c c u r s more r a p i d l y i n s o i l s
low i n e x c ha n g e c a p a c i t y .
He e x p l a i n s t h e r e l a t i o n o f c a t i o n e x c h an g e t o ammonia l o s s :
"The b a s e
e xc h an g e t e n d s t o m a i n t a i n t h e c o n c e n t r a t i o n o f ammonia i n s o l u t i o n a t a
constant le v e l".
S o i l s h i g h i n c a t i o n e x c h an g e c a n b u i l d up a h i g h
r e s e r v e of ammonium i o n s and m a i n t a i n a c o n s t a n t c o n c e n t r a t i o n i n t h e
s o i l s o lu tio n f o r a c o n sid e rab le len g th of tim e.
S o i l s low i n c a t i o n
e xc h an g e c a p a c i t y c a n n o t h o l d a l a r g e r e s e r v e o f ammonium i o n s and t h e
r a t e of lo ss is not m aintained a t a c o n s ta n t l e v e l .
Such s o i l s would be
c o m p a r a b l e t o a d i l u t e s o l u t i o n o f ammonium h y d r o x i d e , i n w h ic h t h e
ammonium c o n t e n t d e c l i n e s p r o g r e s s i v e l y a s e v a p o r a t i o n o c c u r s .
17
J e w i t t ( 1 9 4 2 ) and Wahhab ( 1 9 5 7 ) have r e p o r t e d v o l a t i l e l o s s e s of
ammonia from ammonium s u l f a t e a p p l i c a t i o n s .
w i t h t h e s o i l pH.
L o s s e s were fo u n d t o v a r y
Both o b s e r v e d c o n s i d e r a b l e l o s s e s f ro m a l k a l i n e s o i l s .
Wahhab ( 1 9 5 7 ) showed t h a t a r e d u c t i o n o f t h e s o i l pH from 8 . 4 t o 7 . 3
g r e a t l y r e d u c e d t h e ammonia v o l a t i l i z e d , w h i l e a f u r t h e r l o w e r i n g o f t h e
s o i l pH t o 5 . 4 r e s u l t e d i n no l o s s o f ammonia.
M a r t i n and Chapman ( 1 9 5 1 ) a l s o m e a s u r e d s u b s t a n t i a l l o s s e s o f
ammonia from a l k a l i n e s o i l s .
I n t h i s c o n n e c t i o n , t h e y fou nd t h a t n i t r o g e n
a p p l i c a t i o n s w h ic h r a i s e d t h e s o i l pH p e r m i t t e d v o l a t i l e l o s s e s o f ammonia
to occur.
They c o n c l u d e d t h a t l o s s e s fro m a l k a l i n e s o i l s c o u l d be r e d u c e d
by t h e u s e o f n e u t r a l o r a c i d ammonium f e r t i l i z e r s .
s u l f a t e h a s an a c i d pH.
A s o l u t i o n o f ammonium
The a l k a l i n e forms o f ammonia a r e a n h y d ro u s
ammonia, a qu e ou s ammonia, and ammonium c a r b o n a t e , a p r o d u c t o f t h e
hydrolysis of urea.
T h i s o c c u r s by t h e r e a c t i o n o f u r e a and w a t e r i n t h e
p r e s e n c e o f u r e a s e , an enzyme p r o d u c e d by s o i l b a c t e r i a .
This is d i s ­
c u s s e d by Con ra d ( 1 9 4 0 ) .
G i b s o n (1 9 30 ) i n v e s t i g a t e d t h e d e c o m p o s i t i o n o f u r e a in- s o i l s o f a
wide r a n g e o f c h a r a c t e r i s t i c s .
S i n c e none o f t h e s o i l s was slo w t o t r a n s ­
form u r e a i n t o ammonium, i t was c o n c l u d e d t h a t t h e h y d r o l y s i s was due t o
t h e enzyme a c t i v i t y o f u r e a s e .
J e w i t t ( 1 94 2) and Wahhab ( 1 95 7) b o t h showed t h a t n i t r o g e n l o s s , as
ammonia, i n c r e a s e s w i t h an i n c r e a s e i n t h e c o n c e n t r a t i o n o f ammonium
salts.
Wahhaby ( l 9 5 7 ) fo u nd t h a t 6 . 8% o f a 25-mgm. a p p l i c a t i o n t o a san dy
loam s o i l was l o s t as ammonia, w h i l e 13.4% o f a 100-mgm. a p p l i c a t i o n was
lost
18
M eas ur em en ts o f ammonia l o s s by v o l a t i l i z a t i o n on Putman s i l t loam
w er e c o n d u c t e d by Wagner and S m it h ( 1 9 5 8 ) .
They found t h a t t h e l o s s o f
ammonia f ro m u r e a a p p l i c a t i o n s was m o st r a p i d a t t h e t i m e when t h e
ammonium i o n was a t i t s maximum c o n c e n t r a t i o n .
The r a t e o f l o s s
i n c r e a s e d as more u r e a was t r a n s f o r m e d i n t o ammoniacal n i t r o g e n , t h e n
d e c r e a s e d as more o f t h e ammonium was n i t r i f i e d
into n i t r a t e nitrogen.
Wahhab ( 1 9 5 7 ) d e m o n s t r a t e d t h a t l a r g e r l o s s e s o f ammonia o c c u r r e d
fro m a sa nd y s o i l t h a n fro m a san dy loam .
T h i s e m p h a s i z e s t h e e f f e c t of
t e x t u r e on l o s s e s by v o l a t i l i z a t i o n o f ammonia.
Wahhab ( 1 9 5 7 ) and J a c k s o n and Chang ( 1 9 4 7 ) b o t h r e p o r t t h a t ammonia
l o s s e s c a n be r e d u c e d o r e l i m i n a t e d by t h e p l a c e m e n t o f t h e ammonium s a l t
below t h e s o i l s u r f a c e .
The r e l a t i o n s h i p o f ammonia l o s s t o m o i s t u r e l o s s was i n v e s t i g a t e d
by J e w i t t ( 1 9 4 2 ) .
He fo un d t h a t ammonia c o n t i n u e d t o be v o l a t i l i z e d as
lo n g as e v a p o r a t i o n o c c u r r e d .
L o s s e s by D e n i t r i f i c a t i o n
The l o s s o f n i t r o g e n i n t h e e l e m e n t a l fo rm from t h e s o i l t h r o u g h t h e
r e d u c t i o n of n i t r a t e n i t r o g e n i s termed d e n i t r i f i c a t i o n .
Bremner and
Shaw ( 1 9 5 8 ) d e f i n e d e n i t r i f i c a t i o n as " t h e m i c r o b i a l p r o c e s s whereby
n i t r a t e i s r e d u c e d t o g a s e o u s compounds s u c h as n i t r o u s o x i d e and n i t r o g e n " .
D e n i t r i f i c a t i o n has n o t been c o n s id e r e d a s e r i o u s l o s s o r tho u g h t to
be r e s p o n s i b l e f o r t h e l o s s o f s i g n i f i c a n t amounts o f n i t r o g e n i n w e l l drained s o i l s ,
s i n c e d e n i t r i f i c a t i o n i s u s u a l l y th o u g h t t o o c c u r only
under anaerobic c o n d itio n s .
However, B r o a d b e n t ( 19 51 ) p u b l i s h e d r e s u l t s
w hi c h showed s e r i o u s n i t r o g e n l o s s e s u n d e r a e r o b i c c o n d i t i o n s .
He found
19
t h a t a s a n d y loam s o i l c o n t a i n i n g 1 ,2 9 0 p . p . m . o f t o t a l n i t r o g e n and 64
p.p<»m'!, o f n i t r a t e n i t r o g e n l o s t 250 p.p .m * o f n i t r o g e n i n 7 d a ys u n d e r
incubation.
The work o f L o w e n s t e i n e t a l .
( 19 57 ) showed t h a t d e n i t r i f i c a t i o n
t a k e s p l a c e i n s o i l s u n d e r c o n d i t i o n s s i m i l a r t o t h o s e fo u n d i n t h e f i e l d .
T h e i r g r e e n h o u s e s t u d i e s w i t h c r o p p e d and u n c r o p p e d s o i l s r e s u l t e d i n
la r g e lo ss e s under d i f f e r e n t n itro g e n source tre a tm e n ts .
The p o s s i b i l i t y
o f d e n i t r i f i c a t i o n o c c u r r i n g u n d e r a n a e r o b i c c o n d i t i o n s was n o t r u l e d o u t ,
however.
I t was p o i n t e d o u t t h a t , d e s p i t e t h e f a c t t h a t t h e s e e x p e r i m e n t s
were c a r r i e d o u t u n d e r good a e r a t i o n ,
a s o i l may p o s s e s s o x y g e n - p o o r a r e a s
whic h c o u l d r e s u l t i n d e n i t r i f i c a t i o n .
I n a s t u d y o f t h e d e n i t r i f i c a t i o n i n e i g h t M i s s o u r i s o i l s , Wagner and
Sm it h ( 19 5 8) fou nd t h a t t h e l a r g e s t l o s s e s o c c u r r e d i n t h e Weldon s i l t loam,
w h i l e t h e S h a r k e y c l a y showed l o s s e s m o st c o n s i s t e n t l y fro m t h e d i f f e r e n t
n itro g e n sources ap p lied .
They a t t r i b u t e d t h e s e l o s s e s t o d e n i t r i f i c a t i o n .
R e g a r d i n g t h e e f f e c t o f s o i l pH on d e n i t r i f i c a t i o n ,
t h e work of
Bremner and Shaw ( 1 958 ) showed t h a t pH d o e s hav e an e f f e c t .
lo sse s of n itro g e n occurred in s o i l s
above pH 5 . 0 .
Significant
They a l s o showed t h a t
s o i l t e m p e r a t u r e was a f a c t o r a f f e c t i n g d e n i t r i f i c a t i o n .
The r e s u l t s
showed t h a t d e n i t r i f i c a t i o n i n c r e a s e d r a p i d l y w i t h a r i s e i n t e m p e r a t u r e
up t o 25° C.
I t was fo u nd t h a t n i t r o g e n l o s s o c c u r r e d m os t r a p i d l y a t 6 0 ° C.
b u t t h a t d e n i t r i f i c a t i o n was i n h i b i t e d ' a t a t e m p e r a t u r e o f 70° C.
L o s s e s from N i t r i t e N i t r o g e n
In a d d i t i o n t o t h e l o s s o f n i t r o g e n g a s by means o f d e n i t r i f i c a t i o n ,
Wahhab and Uddin ( 1 95 4) s t u d i e d t h e p o s s i b l e o c c u r r e n c e o f n i t r o g e n l o s s
20
a s a . r e s u l t o f t h e i n t e r a c t i o n o f t h e ammonium (NH4 + ) i o n w i t h t h e n i t r i t e
(N02°") i o n .
An i n t e r a c t i o n was fou nd a t h i g h e r c o n c e n t r a t i o n s o f t h e s e
two i o n s u n d e r d e s i c c a t i o n w i t h t h e r e s u l t i n g l o s s o f n i t r o g e n g a s .
out high c o n c e n tra tio n s ,
With­
lo ss occurred through the v o l a t i l i z a t i o n of the
i n d i v i d u a l compounds o f t h e s e two i o n s .
Loss t h r o u g h t h e i n t e r a c t i o n
o f t h e s e two i o n s was s i g n i f i c a n t i n h i g h l y a l k a l i n e s o i l s o f pH 10;
h o w e v e r , t h e d i r e c t l o s s o f ammonia g a s and t h e l o s s fro m s p o n t a n e o u s
d e c o m p o s i t i o n o f t h e n i t r o u s i o n wer e o f g r e a t e r s i g n i f i c a n c e i n t h e l o w e r
a l k a l i n e r a n g e t h a n was t h e i n t e r a c t i o n o f t h e two compounds,
N i t r o g e n l o s s m e a s u r e d fro m t h e d e c o m p o s i t i o n o f t h e n i t r i t e
on d e s i c c a t i o n i s o f i n t e r e s t , ho we v e r,
re p o r t t h is type of lo s s .
C aster e t a l,
ion
Madhok and Uddin ( 1 9 4 6 ) a l s o
I t may be o f s i g n i f i c a n c e i n some s o i l s .
( 1 942 ) r e p o r t t h a t ammoniaca l n i t r o g e n a p p l i e d .to c e r t a i n
a l k a l i n e d e s e r t s o i l s was o x i d i z e d o n l y t o t h e n i t r i t e s t a g e ,
(1952), in h is d is c u s s io n o f ^ n i t r i f i c a t i o n ,
ammonium t o n i t r i t e
lists
Waksman
th e o x i d a t i o n of
as t h e f i r s t l i n k i n t h e f o r m a t i o n o f n i t r a t e by
c e r ta in autotrophic b a c te ria .
c o u l d o c c u r from t h e n i t r i t e
With i n c o m p l e t e n i t r i f i c a t i o n ,
losses
formed i f c o n d i t i o n s wer e i d e a l f o r t h e
spontaneous decom position of n i t r i t e ,
Wahhab and Uddin ( 1 9 5 4 ) f e l t t h a t
l o s s t h r o u g h t h i s mechanism m i g h t be i m p o r t a n t i n some s o i l s ,
M orrill
and Dawson^ s t u d i e d t h e n i t r i f i c a t i o n p a t t e r n when s o i l s we re p e r f u s e d
w i t h ammonium s u l f a t e .
Above pH 7 , 2 , i t was fo u n d t h a t N i t r o b a c t e r , t h e
4 M o r r i l l , L, G , , and Dawson, J , E, An e x p l a n a t i o n o f t h e n i t r i f i c a t i o n .
p a t t e r n s o b s e r v e d when s o i l s a r e p e r f u s e d w i t h ammonium s u l f a t e .
Agronomy
A b s t r a c t s , 19 58, p , 15,
21
o r g a n i s m wh ic h c o m p l e t e s t h e n i t r i f i c a t i o n o f ammonia t o n i t r a t e , go es
through a lag phase, w hile Nitrosom onas. th e n i t r i t e - p r o d u c i n g b a c t e r i a ,
p ro life ra te rapidly.
The l a g was a t t r i b u t e d t o s o i l pH.
The d i s c u s s i o n o f t h e work o f o t h e r s p r e s e n t e d i n t h e f o r e g o i n g
r e v i e w g i v e s e v i d e n c e t h a t n i t r o g e n l o s s e s can o c c u r i n s o i l s
in a
s i g n i f i c a n t p r o p o r t i o n t o w a r r a n t s t e p s w h ic h w i l l r e d u c e l o s s e s .
22
MATERIALS AND METHODS
Greenhouse Experim ents
A b u l k samp le o f Bowdoin c l a y was t a k e n from t h e s u r f a c e a t a
s e l e c t e d s i t e and b r o u g h t i n t o t h e g r e e n h o u s e , where i t was c r u s h e d
f i n e l y enough t o p a s s t h r o u g h a 4-mm, s i e v e .
the sieved s o i l ,
A f t e r t h o r o u g h l y mix in g
p o t s m e a s u r i n g 6 g- i n c h e s i n d i a m e t e r and 9§- i n c h e s i n
h e i g h t w er e f i l l e d w i t h 4 kgm. o f a i r - d r y s o i l .
A t r e a t m e n t o f 570 mgm. o f t r e b l e s u p e r p h o s p h a t e was mixed w i t h
the s o i l .
T h i s was e q u i v a l e n t t o 100 pounds o f PgO^ p e r a c r e b a s e d on
th e su rface area of the p o t.
Each p o t was s e e d e d w i t h 20 k e r n e l s o f b a r l e y , t h e p o t s b e i n g
t h i n n e d t o 10 p l a n t s p e r p o t on emergence o f t h e s e e d l i n g s .
The p o t s
were s e e d e d p r e v i o u s t o t h e a p p l i c a t i o n o f t h e n i t r o g e n and w a t e r i n g o f
t h e p o t s s i n c e t h e c l a y s o i l i s v e r y d i f f i c u l t t o h a n d l e when i t i s w e t .
O n e - h a l f o f t h e w a t e r r e q u i r e d t o b r i n g t h e s o i l t o f i e l d c a p a c i t y was
th en added.
The v a r i o u s c o n c e n t r a t i o n s o f n i t r o g e n s o u r c e s w e r e added a t
t h e s o i l s u r f a c e i n s o l u t i o n form as m e a s u r e d by a 2 5 - c c . v o l u m e t r i c
p ipette.
Th e se t r e a t m e n t s a r e l i s t e d
in ta b le I .
Following the n itro g e n
tr e a tm e n t, th e rem aining w a te r r e q u ir e d to b rin g the s o i l to f i e l d
c a p a c i t y was a dd e d .
Urea was u s e d as t h e ammonium s o u r c e s i n c e ammonia
would n o t be l o s t i n t o t h e a i r d u r i n g a p p l i c a t i o n .
Two m o i s t u r e l e v e l s w er e m a i n t a i n e d - — t h e minimum m o i s t u r e c o n t e n t s
b e i n g 50 and 75% o f t h e t o t a l a v a i l a b l e m o i s t u r e .
Each p o t was we ighed
i n d i v i d u a l l y d u r i n g t h e p e r i o d o f g r o w t h , and when t h e minimum m o i s t u r e
l e v e l was r e a c h e d , s u f f i c i e n t w a t e r was added t o b r i n g t h e s o i l back t o
Table I .
N i t r o g e n r a t e s and s o u r c e s u s e d f o r g r e e n h o u s e e x p e r i m e n t on Bowdoih c l a y .
N itrogen source
- Cm. o f f e r t i l i z e r added
f o r e a ch r a t e
300 l b s . / A
100 l b s I / A -200 I b f e . / A
0
0
5.94
265
530
795
1.44
2.15
241
481
722
1.04
1.56
234
469
703
O
1.98
3.96
NHgNOg
.72
Ure a (NH4 )
.52 -
CaNOg ( h y d r a t e )
0
0
O
Check
E q u i v a l e n t mgm. of
n i t r o g e n added
100 l b s . / A 200 l b s . / A 300 I b s . / A
24
fie ld capacity.
The p o t s were a r r a n g e d i n a c o m p l e t e l y ra n d o m i z e d b l o c k d e s i g n .
A
s y s t e m o f p o t r o t a t i o n w i t h i n e a c h r e p l i c a t i o n was e s t a b l i s h e d so t h a t
none o f t h e p o t s was on t h e o u t e r e d g e s o f t h e bench d u r i n g t h e f u l l
c o u r s e of t h e e x p e r i m e n t .
P l a n t h e i g h t m e a s u r e m e n ts were made a t m a t u r i t y .
The h e a d s were
t h e n r em o ve d , and t h e r e m a i n i n g p l a n t m a t e r i a l was c l i p p e d .
The h e a d s ■
and s t r a w w er e d r i e d a t 70° C. and we ig he d t o d e t e r m i n e t h e t o t a l p l a n t
m a te ria l w eight.
The h e a d s wer e t h e n t h r e s h e d an d , a f t e r c l e a n i n g , t h e
(
w e i g h t o f t h e g r a i n was d e t e r m i n e d .
The b a r l e y g r a i n was g r o u n d i n a
l a b o r a t o r y m i l l f o r t h e d e t e r m i n a t i o n o f n i t r o g e n c o n t e n t , as was t h e
s t r a w t o w h i c h t h e c h a f f had b e e n a d d e d .
N i t r o g e n was d e t e r m i n e d by t h e
K j e l d a h l me th o d .
The s e c o n d g r e e n h o u s e e x p e r i m e n t was c o n d u c t e d i n t h e same manner
as t h e p r e v i o u s e x p e r i m e n t e x c e p t t h a t p o t a s s i u m n i t r a t e was i n c l u d e d as
a n i t r a t e source.
A p p l i c a t i o n s a t t h e r a t e o f 300 pounds o f n i t r o g e n
p e r a c r e were o m i t t e d , as was t h e 75% m o i s t u r e t r e a t m e n t .
The minimum
m o i s t u r e was m a i n t a i n e d a t 50% o f t h e t o t a l a v a i l a b l e m o i s t u r e .
This
e x p e r i m e n t was c a r e d f o r and h a r v e s t e d a s d i s c u s s e d p r e v i o u s l y .
A fter
t h r e s h i n g and w e i g h i n g t h e g r a i n , i t was combined w i t h t h e s t r a w and
c h a f f , then ground.
N i t r o g e n c o n t e n t was t h e n d e t e r m i n e d on t h e t o t a l
plant.
A g g r e g a t i o n Measurements
S in c e th e a d d i t i o n o f c a lc iu m n i t r a t e t o th e Bowdoin c l a y caused
an a p p a r e n t change i n s o i l s t r u c t u r e , a m easurem ent o f th e d i s p e r s i o n
25
r a t i o o f t h e s o i l t a k e n from t h e s u r f a c e i n c h o f t h e 300 pounds N p e r
a c r e c a l c i u m n i t r a t e p o t s , 300 pounds N p e r a c r e u r e a p o t s ,
c o r r e s p o n d i n g c h e c k p o t s was made.
and t h e
D i s p e r s i o n r a t i o was m e a s u r e d by
d e t e r m i n i n g t h e amount o f s i l t p l u s c l a y i n t h e n o n d i s p e r s e d sample
co mpared t o t h e t o t a l s i l t p l u s c l a y i n t h e samp le when d i s p e r s e d .
The
grams o f s i l t p l u s c l a y i n t h e d i s p e r s e d and n o n d i s p e r s e d s a m p l e s were
m e a s u r e d by t h e p i p e t t e method as d e s c r i b e d by M i d d l e t o n ( 1 9 3 0 ) .
Ammonia V o l a t i l i z a t i o n
Measurement o f t h e ammonia v o l a t i l i z e d fro m Bowdoin c l a y was
d e t e r m i n e d by p l a c i n g 100 gm. o f t h e s o i l i n 5 0 0 - c c . e r l e n m e y e r s u c t i o n
flask s.
A f t e r b r i n g i n g t h e s am pl e t o a m o i s t u r e c o n t e n t a p p r o x i m a t i n g
fie ld capacity,
a u r e a o r ammonium n i t r a t e
the su rface of the s o i l .
s o l u t i o n was d i s t r i b u t e d o v e r
Ammonia-free a i r , d r i e d w i t h c a l c i u m c h l o r i d e ,
was t h e n drawn by means o f a vacuum o v e r t h e s o i l s u r f a c e t h r o u g h gas
d i s p e r s i o n t u b e s , and any v o l a t i l e
su lp h u ric acid s o lu t i o n .
ammonia was c o l l e c t e d i n a . 0 2 N
At t h e end o f I week o f i n c u b a t i o n , t h e s u l p h u r i c
a c i d was t i t r a t e d w i t h s t a n d a r d sodium h y d r o x i d e .
The amount o f ammonia
v o l a t i l i z e d was d e t e r m i n e d by t h e d i f f e r e n c e i n m i l l i e q u i v a l e n t s o f a c i d
r e m a i n i n g a f t e r ammonia c o l l e c t i o n and t h a t p r e s e n t a t t h e s t a r t o f t h e
experim ent.
The s u c t i o n f l a s k s c o n t a i n i n g , t h e s o i l and t h e a c i d t r a p s were
connected in a t r a i n ;
t r e a t m e n t s were r u n i n d u p l i c a t e and i n c l u d e d a
blank s o i l tre a tm e n t.
The amount and s o u r c e s o f n i t r o g e n a p p l i e d t o Bowdoin c l a y a r e l i s t e d
in table I I.
26
Table I I 0
N i t r o g e n s a l t s a p p l i e d t o Bowdoin c l a y f o r t h e m ea s u r em e n t o f
ammonia v o l a t i l i z a t i o n ( m i l l i g r a m s a p p l i e d t o 100 gm. o f s o i l ) .
Source
Urea
Nitrogen eq u iv a len t in m illigram s
M illigram s of m a te ria l
Ammonium
nitrate*
88
176
196
526
* T h e s e r a t e s s h o u l d p r o v i d e t h e same amount o f ammonium as t h e u r e a
application.
27
F i x a t i o n o f Ammonium
The p r o c e d u r e f o l l o w e d f o r t h e d e t e r m i n a t i o n o f ammonium f i x a t i o n
was t h a t o u t l i n e d by L e g g e t t ^ w i t h a d a p t a t i o n s f o r t h e m ea s u r em e n t o f
ammonium f i x e d u n d e r a i r - d r y c o n d i t i o n s .
Both a m m o n i u m - c h l o r i d e - t r e a t e d
s o i l s a m p l e s and b l a n k s o i l s a m p l e s t r e a t e d w i t h a volume o f w a t e r
e q u i v a l e n t t o t h e ammonium c h l o r i d e s o l u t i o n wer e a e r a t e d u n t i l t h e s o i l
was a i r d r y .
Ammonia e v o l v e d d u r i n g t h e a e r a t i o n and d r y i n g was
c o ll e c t e d in acid t r a p s .
The p r o c e d u r e o f L e g g e t t ^ was t h e n f o l l o w e d
w i t h t h e a d d i t i o n o f p o t a s s i u m c a r b o n a t e and c o l l e c t i o n o f ammonia i n
t h e a c i d t r a p s ' f o r 16 h o u r s by t h e a e r a t i o n r e c o v e r y method he d e s c r i b e s .
Sam ples were r u n i n d u p l i c a t e .
S o il Analyses
The p r o c e d u r e o f J a c k s o n (1 9 5 8 ) was f o l l o w e d i n t h e d e t e r m i n a t i o n
" o f t h e c a t i o n e xc h an g e c a p a c i t y of Bowdoin c l a y , u s i n g a c e n t r i f u g e
w a s h i n g p r o c e d u r e w i t h c a l c i u m as t h e r e p l a c i n g i o n .
t h e n r e p l a c e d by t h e ammonium i o n .
The c a l c i u m was
C a l c i u m was d e t e r m i n e d by t h e
versene t i t r a t i o n .
The p a r t i c l e s i z e d i s t r i b u t i o n o f t h e c l a y s o i l was d e t e r m i n e d by
t h e p i p e t t e p r o c e d u r e o u t l i n e d i n USDA Handbook No. 60 (1954). a f t e r
d i s p e r s i n g t h e s o i l i n 2% c a l c i u m m e t a - p h o s p h a t e s o l u t i o n .
I n t e r n a l and e x t e r n a l s u r f a c e a r e a o f Bowdoin c l a y was d e t e r m i n e d
by t h e t o t a l and e x t e r n a l e t h y l e n e g l y c o l r e t e n t i o n method d e s c r i b e d i n
USDA Handbook No. 60 ( 1 9 5 4 ) .
^ L e g g e t t , o p . G i t . . p» 2 3 .
6 Ibid.
28
E x t r a c t a b l e so d iu m , p o t a s s i u m , and c a l c i u m p l u s magnesium as w e l l
as c o n d u c t i v i t y wer e d e t e r m i n e d from t h e s a t u r a t i o n e x t r a c t .
These
p r o c e d u r e s and t h e d e t e r m i n a t i o n o f s o i l pH from t h e s a t u r a t i o n p a s t e
w er e f o l l o w e d as d e s c r i b e d i n t h e s e c t i o n , "Methods f o r S o i l C h a r a c t e r i z a ­
t i o n " * o f USDA Handbook No. 60 ( 1 9 5 4 ) .
The d e t e r m i n a t i o n o f s o i l o r g a n i c m a t t e r was by t h e W a l k l e y - B l a c k
method ( J a c k s o n , "1 9 58 ).
N i t r i f i a b l e n i t r o g e n was d e t e r m i n e d a f t e r
i n c u b a t i o n o f t h e s o i l - v e r m i c u l i t e m i x t u r e f o r 2 weeks as d e s c r i b e d by
S t a n f o r d and Hanway ( 1 9 5 5 ) .
P r o c e d u r e s o f R i c h a r d s (USDA Handbook No. 6 0 , 195 4) were f o l l o w e d i n
o b ta in in g the l / l O - to 15-atmospheres m oisture e x t r a c t i o n d a t a .
p r e s s u r e p l a t e was u s e d a t t e n s i o n s o f l / l O t o I a t m o s p h e r e .
The
The
p r e s s u r e membrane was u s e d f o r t e n s i o n s o f 5 and 15 a t m o s p h e r e s .
S t a t i s t i c a l Procedures
The a n a l y s i s o f t h e d a t a c o l l e c t e d f ro m t h e g r e e n h o u s e e x p e r i m e n t s
was by t h e method o u t l i n e d by Kempthorne ( 1 9 5 2 ) f o r p a r t i a l l y f a c t o r i a l
experim ents.
The m u l t i p l e r a n g e t e s t o f Duncan was u s e d f o r mean s e p a r a ­
t i o n as d e s c r i b e d by L e C l e r g ( 1 95 7 ) wher e more t h a n t h r e e means were
involved.
The L . S . D . was u s e d wher e t h r e e means were b e i n g com pa red .
29
EXPERIMENTAL RESULTS
S o il Analyses
The r e s u l t s o f t h e m ea s u r em e n t o f p a r t i c l e s i z e d i s t r i b u t i o n show
t h a t the te x tu re is a c la y .( ta b l e
III).
A m ea s u r em e n t o f s p e c i f i c s u r f a c e d i f f e r e n t i a t e s b e tw e e n e x p a n d in g
and n o n e x p a n d in g t y p e s o f c l a y m i n e r a l s .
show a l a r g e i n t e r n a l s u r f a c e a r e a ,
The r e s u l t s r e p o r t e d i n t a b l e IV
in d ic a tin g the presence of a large
p r o p o rtio n of expanding-type c la y m in e ra ls .
'
L
V a r i o u s s a l i n e and a l k a l i c h a r a c t e r i s t i c s
s o il ch aracteristics
o f Bowdoin c l a y and o t h e r
a r e shown i n t a b l e V.
The m e a s u r e m e n t o f pH shows t h a t t h i s s u r f a c e s o i l i s s l i g h t l y
alkaline.
The p e r c e n t e x c h a n g e a b l e so d iu m i s above 15%, commonly g i v e n
as t h e l o w e r l i m i t o f t h e a l k a l i c l a s s i f i c a t i o n .
The c o n d u c t i v i t y i s
n o t h i g h enough t o p r o d u c e s a l i n e e f f e c t s d e t r i m e n t a l t o m o s t p l a n t s .
While t h e c o n d u c t i v i t y and. pH o f t h i s s o i l a r e low , i t m i g h t be c l a s s e d
a s a d e g r a d e d a l k a l i s o i l due t o i t s h i g h p e r c e n t e x c h a n g e a b l e so dium.
T he s e r e s u l t s a r e i n a g r e e m e n t w i t h Frahm ( 1 9 4 8 ) .
The c a t i o n e xc h an g e c a p a c i t y i s h i g h .
T h i s i s t o be e x p e c t e d i n
v i e w o f t h e h i g h c l a y c o n t e n t and t h e p r e s e n c e o f a l a r g e i n t e r n a l s u r f a c e
area.
This giv es evidence t h a t t h i s s o i l i s high in m o n tm o rillo n itic c la y .
The o r g a n i c m a t t e r i s q u i t e low f o r a s u r f a c e s o i l .
The n i t r i f i a b l e
n i t r o g e n i s c o r r e s p o n d i n g l y low.
M o i s t u r e r e t e n t i o n d a t a a t v a r i o u s t e n s i o n s a r e shown i n t a b l e V I,
w h i l e f i g u r e I g i v e s t h e m o i s t u r e , r e t e n t i o n c u r v e f o r t h e Bowdoin c l a y .
The a b i l i t y o f t h i s s o i l t o r e t a i n a l a r g e amount o f m o i s t u r e a t IoW
,
30
Table I I I .
Sample
P a r t i c l e s i z e d i s t r i b u t i o n o f Bowdoin c l a y s u r f a c e s o i l as
d e t e r m i n e d by t h e p i p e t t e me th o d .
% Sand
• % S ilt
% Clay
I
3.9
21.-5
74.5
2
0 .6
24.3
75.0
Average
2 .2
22.9
74.7
31
T a b l e IV.
Sample
. No.
.
S p e c i f i c s u r f a c e o f Bowdoin c l a y as m ea s u r ed by t h e e t h y l e n e
g l y c o l r e t e n t i o n met ho d.
S u r f a c e a r e a - r - s q u a r e m e t e r s o e r qm. o f s o i l
Total
external + in tern al
External
•In te rn a l
I
368
155
213
2
363
138
224
3
375
139
236
Average
369
144
224
32
T a b l e V.
Measurement o f v a r i o u s s o i l c h a r a c t e r i s t i c s o f Bowdoin c l a y .
C h aracteristic
pH
Value d e te r m i n e d ,
7.7
C a t i o n e xc h an g e c a p a c i t y
48.25
meq./lOO gm. o f s o i l
E le c tric a l conductivity
3.0
mmhos/cm.
Organic m a t t e r
1.75
percent
N itr if ia b le nitrogen
33.2
parts per m illion
Soluble c a tio n s
Sodium
2.9
meq./lOO gm. o f s o i l
Potassium
0.03
meq./lOO gm. o f s o i l
C a l c iu m + magnesium
0.43
meq./lOO gm. o f s o i l
Exchangeable c a tio n s
Sodium
P o t a s s ium
E x c h a n g e a b l e so diu m p e r c e n t a g e
12.5
meq./lOO gm. o f s o i l
2.3
meq./lOO gm. o f s o i l
2 0 .0
percent
33
T a b l e VI.
Tension—
atmospheres
P e r c e n t m o i s t u r e r e t a i n e d by Bowdoin c l a y u n d e r v a r i o u s
tensions.
Percent
_____________________________________________________________m o i s t u r e
l/io
89.2
1/3
62.2
I
53.6
5
38.2
15
32.4
A t m osp he re s t e n s i o n
34
60
Percent m oisture
Figure I .
M o i s t u r e r e t e n t i o n c u r v e f o r Bowdoin c l a y s u r f a c e s o i l .
35
tensions is i l l u s t r a t e d
in t h i s curve.
Greenhouse E xperim ents
Emergence o f t h e b a r l e y from t h e e x p e r i m e n t where t h e n i t r o g e n
m a t e r i a l s were a p p l i e d on t h e s o i l s u r f a c e was u n i f o r m , and good s t a n d s
resu lted .
A l l t r e a t m e n t s showed good c o l o r and made good g r o w t h d u r i n g
th e e a r ly sta g e s of the experim ent.
Yellowing of t h e l e a v e s , a s ig n
o f n i t r o g e n d e f i c i e n c y , became a p p a r e n t i n t h e c h e c k t r e a t m e n t s 4 t o 5
weeks f o l l o w i n g e m e r g e n c e .
also ap p aren t.
C o l o r d i f f e r e n c e s due t o n i t r o g e n r a t e were
H e i g h t d i f f e r e n c e s due t o n i t r o g e n s o u r c e wer e n o t marked
u n t i l th e p l a n t s began t o head .
rep o rted in ta b le VII.
ta lle r plants.
T h e s e p l a n t h e i g h t m e a s u r e m e n ts a r e
The h i g h e r r a t e s o f n i t r o g e n a p p l i c a t i o n p r o d u c e d
P l a n t h e i g h t w he re u r e a was a p p l i e d was d e f i n i t e l y
sh o rte r than o th er treatm ents receiving nitrogen.
m e a s u r e d were wh er e t h e n i t r a t e s o u r c e was a p p l i e d .
i n ,f i g u r e 2.
The t a l l e s t p l a n t s
This i s i l l u s t r a t e d
During th e co u rse of t h i s ex p erim en t, b e t t e r a g g re g a tio n
and an i n c r e a s e d i n f i l t r a t i o n r a t e wer e o b s e r v e d where c a l c i u m n i t r a t e
f e r t i l i z e r was a p p l i e d .
T h i s e f f e c t was i n v e s t i g a t e d f u r t h e r and i s
r e p o r t e d i n t h e s e c t i o n on s o i l a g g r e g a t i o n .
Good emergen ce was a l s o o b s e r v e d on t h e se c o n d g r e e n h o u s e e x p e r i m e n t
where t h e n i t r o g e n m a t e r i a l s were mixed w i t h t h e s o i l .
D iffe re n c e s in the
c h e c k a n d ‘ t h e o t h e r t r e a t m e n t s became a p p a r e n t i n a b o u t 5 weeks f o l l o w i n g
em er ge nc e when y e l l o w i n g o f t h e l e a v e s on t h e c h e c k t r e a t m e n t s was n o t e d .
At t h i s t i m e , a s l i g h t d i f f e r e n c e i n p l a n t h e i g h t was n o t e d b e tw e e n t h e
100 and 200 pounds o f n i t r o g e n p e r a c r e p o t s .
w er e o b s e r v e d b e tw e e n t h e f o u r s o u r c e s a p p l i e d .
No d i f f e r e n c e s
in h e ig h t
F igure 2.
Com parison o f b a r l e y h e i g h t when n i t r o g e n s o u r c e s were a p p l i e d on t h e s o i l s u r f a c e ;
( l e f t ) 100 pounds n i t r o g e n p e r a c r e , ( r i g h t ) 300 pounds n i t r o g e n p e r a c r e .
f
37
Table V II.
Av erage p l a n t h e i g h t o f m a t u r e b a r l e y t r e a t e d w i t h s u r f a c e
a p p l i c a t i o n s o f n i t r o g e n and m o i s t u r e m a i n t a i n e d a t two
levels.
Treatment
Rate
( l b s . N/A)
Nitrogen
source
Minimum""’
m oisture-50%
cm.
Minimum ”
m oisture—
75%
cm.
0
0
0
CaNO3
NH4 NO3
Urea (NH4 )
69.3
59.7
65.3
64.3
62.3
66.3
100
100
100
CaNO3
NH4N03
Urea (NH4 )
93.3
82.3
79.3
90.7
87.7
73.0
200
200
200
CaNOs
NH4 NO3
Urea (NH4 )
96.7
88.3
78.7
95.0
93.7
84.3
300
300
300
CaNO3
NH4 NO3
Urea (NH4 )
97.0
94.0
90.7
98.0
94.0
89.7
82.9
83.3
64.8
95.7
8 8 .2
82.9
64.3
94.6
91.8
82.3
M o i s t u r e t r e a t m e n t mean
N i t r o g e n s o u r c e means $
Check
CaNO3
NH4 NO3
Urea (NH4 )
38
Increases
I n t h e number o f t i l l e r s due t o c a l c i u m n i t r a t e were
n o t e d i n t h e e x p e r i m e n t wh er e n i t r o g e n was a p p l i e d on t h e s o i l s u r f a c e .
Th e se r e s u l t s
a r e shown i n a p p e n d i x t a b l e XIX.
An i n c r e a s e i n t h e number
o f t i l l e r s was n o t e d a t t h e h i g h e r r a t e s o f a p p l i c a t i o n o f b o t h c a l c i u m
n i t r a t e and ammonium n i t r a t e .
Appendix t a b l e XX shows t h e t i l l e r i n g
d a t a fro m t h e g r e e n h o u s e e x p e r i m e n t where t h e n i t r o g e n m a t e r i a l s were
mixed w i t h t h e s o i l .
T h e r e was no a p p a r e n t d i f f e r e n c e i n t i l l e r i n g
b e tw e e n t h e n i t r o g e n s o u r c e s a p p l i e d ; h o w e v e r , d i f f e r e n c e s
in n itro g en
r a t e are e v id e n t.
The w e i g h t o f p l a n t m a t e r i a l p r o d u c e d where t h e n i t r o g e n was a p p l i e d
to the s o il su rface is rep o rted in ta b le V III.
A highly s ig n if ic a n t
d i f f e r e n c e b e tw e e n n i t r o g e n s o u r c e means and a h i g h l y s i g n i f i c a n t
d i f f e r e n c e i n r a t e means w er e fo un d i n t h e a n a l y s i s o f v a r i a n c e ( a p p e n d i x
t a b l e XXI) .
T h e r e was no s i g n i f i c a n t d i f f e r e n c e b e tw e en t h e two m o i s t u r e
treatm ents.
An i n t e r a c t i o n b e tw e e n n i t r o g e n s o u r c e and n i t r o g e n r a t e
was a l s o h i g h l y s i g n i f i c a n t .
T a b l e IX, m u l t i p l e c o m p a r i s o n t e s t s , shows
t h a t e a c h n i t r o g e n s o u r c e i s s i g n i f i c a n t l y d i f f e r e n t fro m t h e o t h e r
source.
The d i f f e r e n c e s due t o n i t r o g e n r a t e a r e i l l u s t r a t e d
in
f i g u r e 3 , w h ic h shows t h e p l a n t m a t e r i a l i n c r e a s e d w i t h i n c r e a s i n g
amounts o f n i t r o g e n .
A l i n e a r r e l a t i o n s h i p was found on t h i s d a t a .
A
c o m p a r i s o n o f t h e w e i g h t o f p l a p t m a t e r i a l p r o d u c e d by t h e t h r e e n i t r o g e n
s o u r c e s where t h e n i t r o g e n was a p p l i e d on t h e s u r f a c e i s shown i n f i g u r e 4 .
F i g u r e 5 shows t h e r e l a t i v e y i e l d o f t h e t h r e e n i t r o g e n s o u r c e s a t
the four r a te s of n itro g en ap p lied .
The c a l c i u m n i t r a t e t r e a t m e n t p r o ­
du ce d t h e m o st p l a n t m a t e r i a l a t a l l r a t e s .
39
Table V I I I .
Av er ag e w e i g h t o f p l a n t m a t e r i a l h a r v e s t e d w i t h s u r f a c e
a p p lic atio n s of nitro g en .
Nitrogen
rate
( l b s . N/A)
. CaNOg
gm.
N itro q en source
NH4 NO3
- Urea (NH4 )
gm.
gm. .
Mean
nitrogen
rate
gm.
0
1 2 .2
10.9
1 2 .3
1 1 .8
100
28.7.
2 2 .6
17 .1
2 2 .6
200
36.6
30.1
2 0 .8
29.2
300
49.3
31.4
26.9
35.9
N i t r o g e n s o u r c e mean
31.7
23.6
19.3
24.9
M oisture tre a tm e n t average
Minimum m o i s t u r e , 50%
Minimum m o i s t u r e , 75%
24.3
25.4
40
T a b l e IX.
M u l t i p l e c o m p a r i s o n t e s t s f o r mean s e p a r a t i o n o f t o t a l b a r l e y
p la n t m a te ria l w eights.
N i t r o g e n s o u r c e x r a t e i n t e r a c t i o n — SSR mean s e p a r a t i o n , 5% l e v e l
Rate
Nitrogen
Mean w e i g h t
Rank
( l b s . N/A)
source
p lan t m aterial*
gm.
0
0
0
100
200
100
300
100
200
300
200
300
A
B
C
D
E
F
G
H
I
J
K
L
•
'
NH4 NO3
NO3
NH4
NH4
NH4
NH4 NOS
NH4
N%
NH4 NO3
NH4 NO3
NO3 ' .
NO3
10.9
1 2 .2
12.3
1 7 .1
2 0 .8
2 2 .6 I
26.9
28.7
30.1
31.4 I
36.6 I
49.3
^ T r e a t m e n t c o m p a r i s o n s above e a ch b r a c k e t v e r s u s t h o s e below t h e b r a c k e t
a r e s i g n i f i c a n t a t t h e 5% l e v e l .
X
N i t r o g e n s o u r c e means:
__________________N i t r o g e n s o u r c e ___________________
CaNOs________________ NH4 NO3_____________ Urea (NH4 )
31.7
Mean w e i g h t
L.S.D.
.01 = 3 . 7 4
.05 = 2.80
23.6
1 9 .3
P l a n t m a t e r i a l (g ra m s)
41
10
_______________________________________________ I------------------------------------------------------------------------- 1------------------------------------------------------------------------- L
0
Figure 3.
100
N itrogen ( l b s .
200
per acre)
300
T o t a l b a r l e y p l a n t m a t e r i a l w e i g h t p r o d u c e d from f o u r r a t e s o f
n i t r o g e n ( a p p l i c a t i o n on t h e s o i l s u r f a c e ) .
42
Grain
F ig u re 4.
Total p la n t m ate ria l
The e f f e c t o f n i t r o g e n s o u r c e t r e a t m e n t s on b a r l e y g r a i n w e i g h t
and t o t a l p l a n t m a t e r i a l w e i g h t ( a v e r a g e of f o u r r a t e s w i t h
n i t r o g e n a p p l i c a t i o n on t h e s o i l s u r f a c e ) .
Total p lan t m aterial
(g ra m s)
43
CaNO.
N itrogen ( l b s .
Figure 5.
per acre)
Comparison of b a r l e y t o t a l p l a n t m a t e r i a l w e i g h t s when t h r e e
n i t r o g e n s o u r c e s were a p p l i e d a t f o u r r a t e s on t h e s o i l s u r f a c e .
'44
The w e i g h t o f g r a i n h a r v e s t e d i n t h e g r e e n h o u s e e x p e r i m e n t i s
r e p o r t e d i n a p p e n d i x t a b l e XXII.
The a n a l y s i s o f v a r i a n c e ( a p p e n d i x
t a b l e X X I I I ) o f t h e g r a i n d a t a shows t h a t t h e n i t r o g e n s o u r c e and n i t r o g e n
r a t e e f f e c ts are highly s i g n i f i c a n t .
a c t i o n was a l s o h i g h l y s i g n i f i c a n t .
The n i t r o g e n s o u r c e by r a t e
F i g u r e 6 shows how g r a i n w e i g h t
i n c r e a s e d when n i t r o g e n r a t e was i n c r e a s e d .
Tren d r e g r e s s i o n a n a l y s i s
on t h i s d a t a shows b o t h a l i n e a r and a q u a d r a t i c r e l a t i o n s h i p
t a b l e XXII I ) .
inter­
(appendix
F ig u re 7 g iv e s a comparison of th e t h r e e n i tr o g e n sources
a t the f o u r r a t e s o f n i t r o g e n . , A comparison of the g r a i n w eight pro­
du ced from t h e t h r e e n i t r o g e n s o u r c e s i s shown i n f i g u r e 4 .
The n i t r o g e n u p t a k e was d e t e r m i n e d f ro m t h e n i t r o g e n a n a l y s i s o f t h e
g r a i n and s t r a w .
The n i t r o g e n a n a l y s i s d a t a i s r e p o r t e d i n a p p e n d i x
t a b l e XXV, w h i l e t h e n i t r o g e n u p t a k e d a t a i s r e p o r t e d i n t a b l e X.
f e r e n c e s i n n i t r o g e n u p t a k e were s i m i l a r t o d i f f e r e n c e s
p la n t m a te ria l w eights.
That i s ,
the e f f e c t s
Dif­
i n t h e g r a i n and
of n i t r o g e n r a t e and n i t r o g e n
s o u r c e were h i g h l y s i g n i f i c a n t ( a p p e n d i x t a b l e XX V I I I) .
The i n t e r a c t i o n
o f n i t r o g e n s o u r c e by r a t e was a l s o h i g h l y s i g n i f i c a n t .
The c o m p a r i s o n
o f n i t r o g e n s o u r c e s , . u s i n g t h e L . S . D . , shows t h a t t h e amount o f n i t r o g e n
u p t a k e f ro m one n i t r o g e n m a t e r i a l i s d i s t i n c t l y d i f f e r e n t from t h a t t a k e n
up by e a c h o f t h e o t h e r m a t e r i a l s .
F i g u r e 8 shows -how n i t r o g e n u p t a k e fro m t h e t h r e e n i t r o g e n s o u r c e s
c om p a r es when a p p l i e d a t t h e f o u r r a t e s .
n itrate
The n i t r o g e n u p t a k e fro m c a l c i u m
a t t h e 300 poun ds o f n i t r o g e n p e r a c r e r a t e i s d i s t i n c t l y d i f f e r e n t
fro m t h e o t h e r s o u r c e s qnd r a t e s o f a p p l i c a t i o n .
t a b l e XI.
This i s a ls o e v id e n t i n
Grain (grams)
45
OO
200
Nitrogen ( lb s . per acre)
Figure 6 .
B a r l e y g r a i n p r o d u c e d from f o u r r a t e s o f n i t r o g e n ( a p p l i c a t i o n
on t h e s o i l s u r f a c e ) .
Barley g r a i n (grams)
46
2
O
Figure 7.
100
Nitrogen ( lb s .
200
per a c re )
300
Comparison of b a r l e y g r a i n w e i g h t s when t h r e e n i t r o g e n s o u r c e s
were a p p l i e d a t f o u r r a t e s on t h e s o i l s u r f a c e .
N i t r o g e n (mgm.)
47
A
CaNO3
.©
NH4 NO3
Q
Urea (NH4 )
Nitrogen ( lb s .
Figure 8.
per acre)
Comparison o f m i l l i g r a m s o f n i t r o g e n r e c o v e r e d when t h r e e
n i t r o g e n s o u r c e s were a p p l i e d a t t h r e e r a t e s on th e s o i l
surface.
48
T a b l e X.
Ave ra ge m i l l i g r a m s o f n i t r o g e n u p t a k e i n b a r l e y p l a n t m a t e r i a l
with surface a p p lic a tio n s of n itro g e n .
Treatment
Rate '
I N itrogen
( l b s . N/A)
source
Minimum
m oisture,
50%
mgm.
Minimum
m oisture,
75%
mgm.
Means
Nitrogen
M oisture
level
rate
mgm.
mgm.
0
0
0
CaNOs
NH4 NO3
Urea (NH4 )
103
104
103
106
94
106
105
99
105
103
100
100
100
CaNO3
NH4 NO3
Urea (NH4 )
246
189
138
243
178
151
245
183
144
191
200
200
200
CaNOs
- NH4 NO3
Urea (NH4 )
394
276
186
356
291
181
375
283
184
281
300
300
300
CaNO3
NH4 NO3
Urea (NH4 )
580
326
241
703
328
235
642
327
238
402
241
248
M o i s t u r e t r e a t m e n t means
49
Table XI.
M u l t i p l e c o m p a r i s o n t e s t s f o r mean s e p a r a t i o n o f n i t r o g e n
c o n t e n t d a t a fro m g r e e n h o u s e e x p e r i m e n t .
N itrogen source x r a t e
Rank
A
B
C
D
E
F
G
H
I
J
K
L
i n t e r a c t i o n — SSR mean s e p a r a t i o n , 5% l e v e l
Rate
( l b s . N/A)
Nitrogen
source
0
0
0
100
100
200
300
100
200
300
200
300
NH4 NO3
Urea (NH4 )
CaNOg
Urea (NH4 )
NH4 NO3
Urea (NH4 )
Urea (NH4 )
CaNQ3
NH4 NO3
NIt^NO3
CaNO3
CaNO3
■
■
Mean weight.
p lan t m aterial*
mgm.
99
105
105
144
183
184
238
245
283
327
375
642
I
I
I
I
N i t r o g e n s o u r c e means:
CaNO3
341
M illigram s
L.S.D.
.01
.05
31
24
N itroqen source
NH4 NQ3
223
Urea (NH4 )
168
50
The a v e r a g e m i l l i g r a m s o f n i t r o g e n r e c o v e r e d above t h e c h e c k t r e a t ­
m ent s and t h e p e r c e n t n i t r o g e n r e c o v e r e d fro m t h e d i f f e r e n t t r e a t m e n t s
are r e p o r t e d i n t a b l e X I I .
The a p p l i c a t i o n o f t h e n i t r a t e s o u r c e on t h e
s o i l s u r f a c e as c a l c i u m n i t r a t e r e s u l t e d i n t h e h i g h e s t amount o f n i t r o g e n
, r e c o v e r e d , w h i l e u r e a ga ve t h e l o w e s t n i t r o g e n u p t a k e .
. The w e i g h t o f b a r l e y p l a n t m a t e r i a l p r o d u c e d i n t h e s e c o n d g r e e n ­
h o u s e e x p e r i m e n t i s shown i n t a b l e X I I I .
F e r t i l i z e r m a t e r i a l s were
t h o r o u g h l y mixed i n t h e s o i l i n t h i s e x p e r i m e n t .
The a n a l y s i s o f v a r i a n c e
shows a s i g n i f i c a n t d i f f e r e n c e due t o n i t r o g e n r a t e .
t h e o t h e r t r e a t m e n t s showed a s i g n i f i c a n t d i f f e r e n c e .
However, none o f
The w e i g h t o f
g r a i n p r o d u c e d i n t h i s e x p e r i m e n t i s g i v e n i n a p p e n d ix t a b l e XXIX,
sh owing a s i g n i f i c a n t i n c r e a s e i n g r a i n y i e l d due t o t h e i n c r e a s e d r a t e s
of n itro g e n .
The p e r c e n t n i t r o g e n c o n t a i n e d i n t h e t o t a l p l a n t m a t e r i a l
a p p e a r s i n a p p e n d i x t a b l e XXX.
The a v e r a g e m i l l i g r a m s o f n i t r o g e n up­
t a k e a s d e t e r m i n e d from t h e p l a n t m a t e r i a l w e i g h t and n i t r o g e n p e r c e n t a g e
d a t a a r e g i v e n i n t a b l e XIV.
The a n a l y s i s o f v a r i a n c e o f t h i s d a t a shows
s i g n i f i c a n t d i f f e r e n c e s in the m illigram s of n itro g e n uptake a t the
d i f f e r e n t r a te s of n itro g en a p p lic a tio n .
difference
F i g u r e 9 shows v e r y l i t t l e
i n p l a n t m a t e r i a l w e i g h t among t h e f o u r n i t r o g e n s o u r c e s a t
t h e two n i t r o g e n - r a t e s e x c l u d i n g t h e c h e c k .
The a v e r a g e m i l l i g r a m s o f
n i t r o g e n r e c o v e r e d above t h e c he ck t r e a t m e n t s and t h e p e r c e n t n i t r o g e n
r e c o v e r e d a r e g i v e n i n t a b l e XV.
N i t r o g e n s o u r c e d i f f e r e n c e s were n o t '
e v i d e n t i n t h i s e x p e r i m e n t , w h i l e t h e amount o f n i t r o g e n r e c o v e r e d was
good from a l l t h e s o u r c e s a t t h e two r a t e s o f a p p l i c a t i o n .
51
Table X II.
Aver age m i l l i g r a m s o f n i t r o g e n r e c o v e r e d above c h e c k t r e a t ­
ments and p e r c e n t n i t r o g e n r e c o v e r e d o f added n i t r o g e n
(su rface a p p lic a tio n s of n itro g e n ).
Treatment
Mgm. o f
■ Nitrogen
nitrogen
source
ao o lied '
I
CaNQs
NH4 NO3
Urea (NH4 )
CaNOs
NH4 NO3
Urea (NH4 )
CaNOs
NH4 NO3
Urea (NH4 )
' 265
241
234
530
481
469
795
722
703
M oisture tre a tm e n t
average
Minimum m o i s t u r e , 50%
Mgm.
% Nitrogen
recovered
recovered
143
85
35
290
172
73
476
54.0
35.3
15.0
54.7
35.6
15.6
59.9
121
138
170
Minimum m o i s t u r e , 75%
Mgm.
% N itrogen
recovered
recovered
19.6
137
84
45
249
197
75
597
234
129
51.7
34.9
19.2
47.0
41.0
16.0
75.1
32.4
18.3
34.1
194
37.3
1 6 .8
52
Table X I I I .
Av erage w e i g h t o f p l a n t m a t e r i a l when n i t r o g e n m a t e r i a l s
were mixed w i t h t h e s o i l .
Nitrogen
source
Nitroqen r a t e (lb s .
0.
100
CaNGs
KNOg
NH4 NOo
Urea (NH4 )
N i t r o g e n r a t e mean
200
Mean
nitrogen
source
gm.
n/ a )
gm.
gm.
gm.
18.7
1 8. 3
18.8
18.8
34.2
35.9
34.8
33.5
45.2
45.6
45.6
41.5
18.6
34.6
44.5
.
32.7
33.3
33.0
31.3
. 32.6
A nalysis of v a ria n c e of b a rle y p l a n t m a te ria l weight
Variance
df
SS
R eplication
Rate
Source
Source x r a t e
Error
2
2
3
6
22
25.7
4,074.6
Total
35
4,213.7
S i g n i f i c a n t a t t h e 5% l e v e l .
* * S i g n i f i c a n t a t t h e 1% l e v e l .
2 2 .1
22.3
69.0
MS
12.9
2,037.3
7.4
3.7
3.1
F
4.16*
657.2**
2.4
1 .2
53
T a b l e XIVo
Aver age m i l l i g r a m s o f n i t r o g e n u p t a k e when n i t r o g e n m a t e r i a l s
w er e mixed w i t h t h e s o i l .
N itrogen
source
N itrogen r a t e ( lb s .
O
100
CaNQg
KNO3 ,
NH4 NO3
Urea (NH4 )
N i t r o g e n r a t e mean
n/ a )
200
• Mean.
nitrogen
source
mgm.
mgm.
mgm.
182
172
188
172
377
400
375
557
557
571
552
372
374
387
179
386
559
375
392
366
A n a ly s is of v a r i a n c e o f n i t r o g e n up tak e in b a r l e y p l a n t m a t e r i a l
Variance
df
SS
R eplication
Nitrogen r a te
Source
Source x r a t e
Error
2
2
3 .
6
22
0
.87,2
.0 0 2
0
.008
Total
35
.882
^ S i g n i f i c a n t a t t h e 5% l e v e l .
MS
0
.436
.00 0 7
0
.0036
F
121.1 *
1.94
54
T a b l e XV.
Aver age m i l l i g r a m s o f n i t r o g e n r e c o v e r e d above c h e c k t r e a t ­
m en ts and p e r c e n t r e c o v e r e d o f added n i t r o g e n ( n i t r o g e n mixed
with the s o i l ) .
Nitrogen r a te
Treatment
100
Mgm. ^
Mgm. N
adde d r e c o v e r e d
( l b s . N/A)
200
. Yo N
recovered
Mgm. N
added
Mgm. N - % N
recovered recovered
CaNO3
209
195
81.6
417
375
78.5
KNO3
195
220
91.7
389
385
80.2
NH4 NO3
197
209
86.7
393
383
79.5
Urea (NH4 )
198
202
86.3
395
380
81.2
t
T otal p lant m aterial
( g ra m s )
55
100
Nitrogen ( lb s . per a c r e )
F ig u re 9.
Co m p a ri s o n o f t o t a l p l a n t m a t e r i a l w e i g h t s when f o u r n i t r o g e n
s o u r c e s wer e a p p l i e d a t t h r e e r a t e s by mix in g t h e f e r t i l i z e r
with the s o i l .
56
A ggregation Analyses
D i s p e r s i o n r a t i o was m e a s u r e d on t h e s u r f a c e i n c h o f t h e p o t s from
t h e e x p e r i m e n t where n i t r o g e n a p p l i c a t i o n was on t h e s u r f a c e .
Treatments
V
a n a l y z e d w er e u r e a and c a l c i u m n i t r a t e a t t h e r a t e o f 300 po unds o f
n i t r o g e n p e r a c r e and t h e c h e c k p o t s o f t h r e e , r e p l i c a t i o n s .
. a r e g i v e n i n t a b l e XVI.
R esults
The c h e c k and u r e a - t r e a t e d s o i l s c o n t a i n e d
s i g n i f i c a n t l y l a r g e r amounts o f s i l t p l u s c l a y i n s u s p e n s i o n i n t h e n o n d is p e r s e d sample.
T r e a t m e n t w i t h c a l c i u m n i t r a t e p r o d u c e d a more s t a b l e
aggregate.
Ammonium 'F i x a t i o n
T a b l e XVII shows t h e m i l l i e q u i v a l e n t s o f ammonium f i x e d by t h e Bowdoin
clay s o il .
The v a l u e r e p o r t e d i s a b o u t e i g h t t i m e s t h e v a l u e o f 1 . 0 meg.
p e r 100 gm. o f s o i l ,
f r e q u e n t l y r e p o r t e d t o be a maximum f o r m o st s o i l s .
Ammonia V o l a t i l i z a t i o n Measurement
M i l l i e q u i v a l e n t s o f ammonia v o l a t i l i z e d from t h e c l a y s o i l f o l l o w i n g
t r e a t m e n t and t h e e q u i v a l e n t m i l l i g r a m s o f ammonia a r e r e p o r t e d i n
t a b l e XVIII.
These r e s u l t s
show t h a t o n l y a s m a l l p e r c e n t o f t h e n i t r o g e n
a p p l i e d t o t h e s o i l was v o l a t i l i z e d i n t h e form o f ammonia.
Although th e
two m a t e r i a l s p r o d u c e d t h e same amount o f ammonia, l e s s was v o l a t i l i z e d
f ro m ammonium n i t r a t e .
T a b l e XVI.
Me asurement o f d i s p e r s i o n r a t i o o f u n t r e a t e d Bowdoin c l a y and s o i l t r e a t e d w i t h
n i t r o g e n m a t e r i a l s (grams o f s i l t p l u s c l a y i n a l i t e r s u s p e n s i o n o f a 50-gm. s o i l
sample).
Treatment
Rate
Nitrogen
( l b s . N/A)
source
0
Check
Cm. p e r l i t e r
s i l t + c la y in suspension
Undispersed
D ispersed
Rep.
300
CaNOg
U r e a (NH4 )
Dispersion
ratio
.68
.61
.61
.63
Average
dispersion
ratio
31.6
28.5
4 6 .4
4 6 .9
28.9
47.3
14.8
18.4
18.4
I
2
3
27.6
17.6
19.4
47.9
47.0
47.5
20.3
29.4
28.1
.58
.37
.41
.4 5
I
2
3
31.2
36.6
29.4
47 .0
15.8
48.4
48.4
1 1 .8
19.0
.66
.75
.61
.67
"I
2
3
300
Cm.
s i l t + clay
aggregated
.
A n a l y s i s o f v a r i a n c e o f a g g r e g a t e d s i l t p l u s c l a y (g ra m s)
if
Source
SS
C
R eplication Treatment
Error
2
2
4
35.9
187.2
47.2
Total ■
8 '■
270.3
MS
1 7 .9 5
93.6
F
1.52
7 . 93*
1 1 .8
T r e a t m e n t means— grams o f s i l t p l u s c l a y a g g r e g a t e d
Check
.17.2
CaNOg
25.9
L.S.D.
„05 = 6 . 4 7
Urea (NH4 )
15.5
58
T a b l e XVII.
Measurement o f ammonium f i x a t i o n i n Bowdoin c l a y u n d e r a i r dry c o n d itio n s .
Sample
I
M i l l i e q u i v a l e n t s o f ammonium f i x e d
p e r 100 gm. o f s o i l
7.20
.
2
Average
10.40
8.80
59
Table XVIII.
M i l l i e q u i v a l e n t s o f ammonia v o l a t i l i z e d fro m Bowdoin c l a y .
Urea (NH4 )
NH4 NO3
Treatment
%
Meq.
v olatilized
Mgm. o f
nitrogen
.v o l a t i l i z e d
V olatilized
o f added
m aterial
8 8 .2
.4 9
6.77
7.7
8 8 .1
8
Mgm. o f
nitrogen
a p p l i e d as
ammonia
2.82
3.2
60
DISCUSSION
The r e s u l t s p r e s e n t e d fro m t h e g r e e n h o u s e s t u d i e s s u g g e s t t h a t
n i t r o g e n l o s s c o u l d be t h r o u g h any o f t h r e e m e a n s .
The p r e s e n c e o f a
l a r g e i n t e r n a l s u r f a c e a r e a o f t h e c l a y m i n e r a l s i n t h e s o i l would
i n d i c a t e t h e p o s s i b i l i t y o f ammonium f i x a t i o n .
Since th e s o i l
is
s l i g h t l y a l k a l i n e , t h e v o l a t i l i z a t i o n o f ammonia c o u l d be e x p e c t e d t o
occur during the drying of the m oist c la y .
A lso, s u r f a c e a p p l i c a t i o n of
t h e f e r t i l i z e r m a t e r i a l c o u l d r e s u l t i n i n c r e a s e d v o l a t i l i z a t i o n by t h e
a d d i t i o n of a m a t e r i a l w i t h an a l k a l i n e r e a c t i o n s i n c e t h e s o i l c o u l d
become h i g h l y a l k a l i n e
i n t h e zone o f a p p l i c a t i o n .
The h i g h c l a y
c o n t e n t o f t h e s o i l and t h e h i g h m o i s t u r e - h o l d i n g c a p a c i t y g i v e an
i n d i c a t i o n t h a t e l e m e n t a l n i t r o g e n c o u l d be l o s t t h r o u g h d e n i t r i f i c a t i o n .
In the c la y s o i l ,
th e pore space i s l a r g e l y f i l l e d w ith w a te r a t the lower
t e n s i o n s , g iv in g r i s e to l o c a l anaerobic c o n d itio n s .
Some s i g n i f i c a n c e c a n be a t t a c h e d t o t h e d i f f e r e n c e i n r e s p o n s e from
t h e two g r e e n h o u s e e x p e r i m e n t s wher e t h e n i t r o g e n m a t e r i a l s were a p p l i e d
on t h e s u r f a c e i n one e x p e r i m e n t w h i l e t h e m a t e r i a l s were mixed w i t h t h e
s o i l in the o th e r experiment.
The r e s u l t s o f t h e f i r s t g r e e n h o u s e e x p e r i m e n t i n d i c a t e d a low
n i t r o g e n r e c o v e r y from t h e ammonium s o u r c e .
T a b l e X I I shows t h a t 15 t o
20% o f t h e a p p l i e d n i t r o g e n was r e c o v e r e d fro m t h e u r e a t r e a t m e n t a t t h e
different rates.
When o n l y h a l f t h e n i t r o g e n a p p l i e d was i n t h e ammonium
f o r m , 30 t o 35% o f t h e a p p l i e d n i t r o g e n was r e c o v e r e d u n d e r d i f f e r e n t
ra te s of ap p licatio n .
The p e r c e n t n i t r o g e n r e c o v e r e d was s t i l l
when t h e n i t r o g e n s o u r c e was i n t h e n i t r a t e
form.
greater
Thes e d i f f e r e n c e s
61
c o u l d be due e i t h e r t o t h e l o s s o f ammonia by v o l a t i l i z a t i o n o r t h r o u g h
t h e f i x a t i o n o f t h e ammonium i o n .
I t was b e l i e v e d t h a t d e n i t r i f i c a t i o n p l a y e d o n l y a s m a l l p a r t i n
the n itr o g e n lo s s measured.
T a b l e X I I shows t h a t 30 t o 50% o f t h e
n i t r a t e n i t r o g e n a p p l i e d was n o t r e c o v e r e d i n t h e p l a n t m a t e r i a l ; how­
e v e r , i t was s p e c u l a t e d t h a t some o f t h e n i t r o g e n was u t i l i z e d i n r o o t
g r o w t h and some s t i l l
remained in th e s o i l ,
The amount o f t h e added
n i t r o g e n r e m a i n i n g i n t h e s o i l was n o t d e t e r m i n e d s i n c e i t was f e l t
t h a t t h e e r r o r i n t h e m e a s u r e m e n t o f t o t a l n i t r o g e n would be g r e a t e r
t h a n t h e amount o f a p p l i e d n i t r o g e n a c t u a l l y r e m a i n i n g .
F u r t h e r c o n c l u s i o n s o f t h e t y p e o f n i t r o g e n l o s s e s o c c u r r i n g and
t h e c o n d i t i o n s u n d e r w h i c h t h e y o c c u r were made from t h e n i t r o g e n
u p t a k e o f t h e g r e e n h o u s e e x p e r i m e n t where 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 mixed w i t h t h e s o i l .
Wahhab (1 95 7 ) and o t h e r w o r k e r s ha v e shown
t h a t p l a c e m e n t i s a f a c t o r i n ammonia v o l a t i l i z a t i o n .
The r e s u l t s o f t h e s e c o n d e x p e r i m e n t ( t a b l e XV) showed good
n itro g e n recovery with a l l
s o u r c e s from a l l l e v e l s o f a p p l i c a t i o n .
The p o s s i b i l i t y o f any a p p r e c i a b l e l o s s o c c u r r i n g t h r o u g h d e n i t r i f i c a ­
t i o n i n Bowdoin c l a y was r u l e d o u t .
The n i t r o g e n r e c o v e r e d i n t h e p l a n t
m a t e r i a l fro m t h e c a l c i u m n i t r a t e s o u r c e i n t h i s g r e e n h o u s e e x p e r i m e n t
was a l s o h i g h , a l t h o u g h n i t r o g e n p l a c e m e n t was i n a zone o f p o o r e r
aeration.
D e e p e r p l a c e m e n t o r m ix in g t h e m a t e r i a l w i t h t h e s o i l d i d
r e d u c e t h e l o s s e s fro m t h e ammonium s o u r c e .
The s o u r c e s o f n i t r o g e n
a p p l i e d a t two r a t e s showed t h a t 80 t o 90% o f t h e n i t r o g e n a p p l i e d was
r e c o v e r e d ( t a b l e XV) .
T h i s was an impr ov eme nt o v e r t h e p e r c e n t
62
" r e c o v e r e d fro m t h e ammonium s o u r c e
( t a b l e X I I ).
The d i f f e r e n c e s i n n i t r o g e n r e c o v e r y n o t e d i n t h e two g r e e n h o u s e
e x p e r i m e n t s were due m a i n l y t o n i t r o g e n p l a c e m e n t .
While t h e ammonium
s o u r c e p l a c e d n e a r t h e s u r f a c e c o u l d hav e b e e n l o s t by means o f v o l a t i l i z a
tion,
a s e x p l a i n e d by Wahhab ( 1 9 5 7 ) , t h e r e i s a p o s s i b i l i t y o f p o s i t i o n a l
unavailability.
I n a c l a y h i g h i n c a t i o n e x c h an g e c a p a c i t y , s u c h as
Bowdoin c l a y , much o f t h e ammonium s o u r c e a p p l i e d on t h e s o i l s u r f a c e
would be a b s o r b e d by t h e c l a y .
The ammoniacal n i t r o g e n h e l d a t t h e
s u r f a c e i s n o t s u b j e c t t o l e a c h i n g , and p l a n t r o o t s c o u l d n o t r e a c h i t ,
p a r t i c u l a r l y a f t e r t h e s o i l s u r f a c e became d r y p r e v i o u s t o w a t e r i n g .
While t h i s
is not a n itro g e n lo ss ,
i t may hav e bee n r e s p o n s i b l e f o r t h e
a p p a r e n t l o s s ; h o w e v e r , u r e a would n o t be a b s o r b e d as r e a d i l y as o t h e r
ammonium m a t e r i a l s .
S i n c e t h e g r e e n h o u s e e x p e r i m e n t where n i t r o g e n was a p p l i e d on t h e
s o i l s u r f a c e showed p o o r r e c o v e r y f ro m t h e a p p l i c a t i o n o f t h e ammonium
s o u r c e , a m ea s u r em e n t o f ammonia v o l a t i l i z a t i o n and ammonium f i x a t i o n was
made on t h i s s o i l i n t h e l a b o r a t o r y .
The ammonium f i x a t i o n m ea s u r ed on Bowdoin c l a y o f 8 .8 meq. p e r
100 gm. o f s o i l was s u b s t a n t i a l ( t a b l e X V I I ) .
F i x a t i o n was m e a s u r e d on
a s am pl e w h i c h was t r e a t e d w i t h t h e ammonium i o n , t h e n a i r d r i e d .
Moody^
fo un d t h e w e t a m m on ium -fi xin g c a p a c i t y o f t h e Bowdoin c l a y t o be 0 . 4 3
meq. p e r 100 gm. o f s o i l .
Thes e d a t a i n d i c a t e t h a t m a j o r amounts o f t h e
ammonium i o n a r e f i x e d on d r y i n g .
TMoody, C. Dawson.
C o n d i t i o n s f o r f i x a t i o n on d r y i n g
P e r s o n a l communication.
63
would e x i s t on t h e s o i l s u r f a c e e i t h e r i n t h e f i e l d o r i n g r e e n h o u s e
pots.
On t h e b a s i s o f an a c r e f u r r o w s l i c e ,
t o f i x 1 , 7 0 0 pounds o f n i t r o g e n p e r a c r e .
t h i s s o i l showed t h e c a p a c i t y
W hil e t h i s maximum f i x a t i o n
o f ammonium d o e s n o t t a k e p l a c e i n one f e r t i l i z e r a p p l i c a t i o n s i n c e
a l l t h e ammonium a p p l i e d would n o t be s i t u a t e d b e tw e en t h e c r y s t a l
lattice,
a s u b s t a n t i a l l o s s due t o f i x a t i o n c o u l d o c c u r .
The s o i l m o is­
t u r e c o n t e n t u n d e r t h e s o i l s u r f a c e would n o t d r y c o m p l e t e l y , p r e v e n t i n g
maximum f i x a t i o n .
The amount o f ammonia v o l a t i l i z e d was v e r y s l i g h t .
Only 3 t o 1%
o f t h e n i t r o g e n a p p l i e d on t h e s u r f a c e was l o s t and c o l l e c t e d as a gas.
( ta b l e XV III).
While a p p r e c i a b l e l o s s e s would be e x p e c t e d t o o c c u r from
a s o i l w i t h an a l k a l i n e pH, t h e h i g h c a t i o n e x c h an g e c a p a c i t y o f t h e
s o i l a p p a r e n t l y m a i n t a i n e d t h e c o n c e n t r a t i o n o f ammonium i o n s i n t h e
s o i l s o l u t i o n a t a low l e v e l , r e s u l t i n g i n o n l y a s m a l l amount o f ammonia
being v o l a t i l i z e d .
V o l a t i l i z a t i o n was m e a s u r e d as t h e s o i l d r i e d ; t h i s
c o n d i t i o n i s t y p i c a l i n t h e f i e l d and g r e e n h o u s e .
The l o s s o f t w i c e as much ammonia from t h e u r e a - t r e a t e d s o i l as from
t h e a m m o n i u m - n i t r a t e - t r e a t e d s o i l was p e r h a p s due t o an i n c r e a s e i n
a l k a l i n i t y when t h e ammonium c a r b o n a t e was formed from u r e a .
If this
s o i l i s low i n c a r b o n a t e s , v o l a t i l i z a t i o n l o s s e s would be l e s s from
ammonium n i t r a t e t h a n f ro m u r e a b e c a u s e u r e a i s t h e o n l y m a t e r i a l t h a t
would f o rm ammonium c a r b o n a t e i n any a p p r e c i a b l e amount.
Appreciable
amounts o f ammonium c a r b o n a t e would hav e t o be form ed t o g e t . s u b s t a n t i a l
l o s s e s a t t h e pH ( 7 . 7 ) o f t h e s o i l .
While s i g n i f i c a n t amounts o f ammonia w e r e n o t r e l e a s e d fro m t h e s o i l
f
64
as a g a s d u r i n g t h e i n c u b a t i o n p e r i o d i n t h e l a b o r a t o r y , t h e o c c u r r e n c e
o f v o l a t i l i z a t i o n s h o u l d n o t be r u l e d o u t .
I t is possible th a t ideal
c o n d i t i o n s f o r e x t e n s i v e ammonia l o s s were n o t p r e s e n t d u r i n g i n c u b a t i o n
in the la b o ra to ry .
While i n c u b a t i o n was f o r a p e r i o d o f 7 d a y s , i t i s d o u b t f u l w h e t h e r
c o n t i n u e d i n c u b a t i o n would ha ve shown any g r e a t e r l o s s , s i n c e t h e s o i l
s u r f a c e was d r y a t t h e end o f t h e i n c u b a t i o n p e r i o d .
As r e p o r t e d by
Wagner and S m it h ( 1 9 5 8 ) , t h e l a r g e s t amount o f ammonia was fo u n d t o be
p r e s e n t d u r i n g t h e f i r s t week o f i n c u b a t i o n w i t h u r e a a p p l i c a t i o n s .
F o l l o w i n g t h i s p e r i o d , t h e amount o f ammonium n i t r i f i e d
increased.
It
i s d o u b t f u l w h e t h e r r e w e t t i n g o f t h e s o i l would hav e shown any g r e a t e r
v o l a t i l i z a t i o n o f ammonia.
While C a s t e r ( 1 9 4 2 ) and M o r r i l l and Dawson^ r e p o r t a . l a g i n t h e
f o r m a t i o n o f n i t r a t e i n some a l k a l i n e s o i l s w i t h an a c c u m u l a t i o n of
n itrite
and Wahhab and Uddin ( 1 9 5 4 ) g i v e e v i d e n c e o f t h e s p o n t a n e o u s
decom position of n i t r i t e ,
a l k a l i n e Bowdoin c l a y .
i t is d o u b tfu l i f t h i s lo ss occurs in the
S i n c e no a p p r e c i a b l e l o s s o c c u r r e d fro m the,
a p p l i c a t i o n o f ammoniacal n i t r o g e n when t h e m a t e r i a l s were mixed w i t h
the s o i l ,
i t is u n l ik e ly t h a t t h i s loss occurs in the c la y s o i l .
While t h e f e r t i l i z e r m a t e r i a l s were s e l e c t e d i n o r d e r t o a v o i d any
s i d e e f f e c t s , an im pr ov em en t i n s o i l s t r u c t u r e was n o t e d where, c a l c i u m
n i t r a t e was a p p l i e d on t h e s o i l s u r f a c e .
calcium n i t r a t e
I t was a l s o shown t h a t t h e
a t t h e 300 pounds N p e r a c r e a p p l i c a t i o n im pr ov ed
8 M o r r i l l and Dawson, l o c . c i t .
65
a g g r e g a t i o n ( t a b l e XVI) .
th e c a lc iu m io n .
T h i s would be a s s o c i a t e d w i t h t h e a d d i t i o n o f
The im p ro v e d s t r u c t u r e may h a v e r e s u l t e d i n im proved
s o i l a e r a t i o n and i n c r e a s e d r o o t d e v e lo p m e n t, r e s u l t i n g i n more e f f i c i e n t
use of th e n itro g e n .
Mean s e p a r a t i o n o f m i l l i g r a m s o f n i t r o g e n r e c o v e r e d
i n t h i s e x p e r i m e n t shows t h a t t h e r e c o v e r y o f c a l c i u m n i t r a t e
a t 300
po u n d s N p e r a c r e was s i g n i f i c a n t l y g r e a t e r t h a n t h e r e c o v e r y fro m any
o f t h e o t h e r s o u r c e s and r a t e s .
T h is i n c r e a s e d r e c o v e r y c o u l d h a v e b e e n
i n f l u e n c e d by t h e im p ro v e m e n t o f s o i l s t r u c t u r e .
The im p ro v e m e n t o f s o i l
s t r u c t u r e a l s o may have r e s u l t e d i n more n i t r o g e n b e i n g r e l e a s e d from t h e
s o i l o rg an ic m a tte r , in c re a s in g n itro g e n u p ta k e .
W h ile t h i s e f f e c t i s n o t d i r e c t l y c o n c e r n e d w i t h n i t r o g e n l o s s , i t
i s m e n t io n e d s i n c e i t c o u l d h a v e b e e n a f a c t o r i n t h i s s t u d y .
)
66
SUMMARY AND CONCLUSIONS
The t r e a t m e n t o f g r e e n h o u s e p o t s w i t h ammonium and n i t r a t e s o u r c e s
o f n i t r o g e n and t h e m e a s u r e m e n t o f t h e r e s u l t i n g n i t r o g e n u p t a k e by b a r l e y
p l a n t s was s e l e c t e d a s a means o f e x p l o r i n g t h e t y p e o f n i t r o g e n l o s s o r
l o s s e s w h ic h o c c u r from Bowdoin c l a y .
N i t r o g e n l o s s from t h e n i t r o g e n
s o u r c e s a p p l i e d w o u ld be r e f l e c t e d i n t h e amount o f n i t r o g e n u p t a k e o f
t h e p l a n t grown u n d e r v a r i o u s n i t r o g e n s o u r c e t r e a t m e n t s , s i n c e n i t r o g e n
l o s s w o u ld mean a r e d u c t i o n i n t h e n i t r o g e n a v a i l a b l e t o t h e p l a n t .
P o t s t r e a t e d w i t h t h e ammonium s o u r c e d i d n o t show a s l a r g e a n i t r o g e n
u p t a k e a s p o t s t r e a t e d w i t h t h e n i t r a t e s o u r c e when t h e n i t r o g e n m a t e r i a l s
w ere a p p l i e d on t h e s u r f a c e .
S i m i l a r t r e a t m e n t s showed no d i f f e r e n c e s in
n i t r o g e n u p t a k e b e tw e e n t h e s o u r c e s when t h e n i t r o g e n was m ixed w i t h t h e
so il.
F u r t h e r m o r e , 80 t o 90% o f t h e a p p l i e d n i t r o g e n was r e c o v e r e d .
From t h e r e s u l t s o f t h e s e e x p e r i m e n t s ,
i t c a n be c o n c l u d e d t h a t
n i t r o g e n l o s s c o u l d be due t o e i t h e r ammonium f i x a t i o n o r ammonia v o l a ­
tiliz a tio n .
T h e re was no e v i d e n c e i n s u p p o r t o f a p p r e c i a b l e l o s s by
d e n itrific a tio n .
D i r e c t m e a s u re m e n t o f ammonia v o l a t i l i z a t i o n and ammonium f i x a t i o n
was made on Bowdpin c l a y .
The r e s u l t s o f t h e s e d e t e r m i n a t i o n s showed
t h a t n i t r o g e n l o s s was due l a r g e l y t o ammonium f i x a t i o n upon d r y i n g o f
th e c la y s o i l .
L o s s e s du e t o v o l a t i l i z a t i o n w ere v e r y s m a l l .
N i t r o g e n p l a c e m e n t was a d e c i d i n g f a c t o r a f f e c t i n g n i t r o g e n u p t a k e .
A l s o , t h e r e w ere i n d i c a t i o n s t h a t p o s i t i o n a l u n a v a i l a b i l i t y may have
r e s u l t e d i n t h e d e c r e a s e i n n i t r o g e n u p t a k e fro m t h e ammonium s o u r c e w here
t h e m a t e r i a l s w ere a p p l i e d on t h e s o i l s u r f a c e .
67
The r e s u l t s o f t h e g r e e n h o u s e and l a b o r a t o r y e x p e r i m e n t s i n d i c a t e t h a t
n i t r o g e n l o s s fro m Bowdoin c l a y c a n be r e d u c e d .
P la c e m e n t o f n i t r o g e n
m a t e r i a l s b e lo w t h e s o i l s u r f a c e r e s u l t e d i n good n i t r o g e n u p t a k e from a l l
so u rces.
S u r f a c e a p p l i c a t i o n o f a n i t r a t e s o u r c e w ould a l s o r e s u l t i n good
n itro g e n reco v ery .
68
LITERATURE CITED
A l l i s o n , F . E.
1 9 5 5 . The enigm a o f s o i l n i t r o g e n b a l a n c e s h e e t s .
i n Agron.. 7 82 1 3 - 2 5 0 .
Adv.
A l l i s o n , F . E . , D o e t s c h , J . H ., and R o l l e r , E. M. 1 9 5 3 a . A v a i l a b i l i t y o f
f i x e d ammonium i n s o i l s c o n t a i n i n g d i f f e r e n t c l a y m i n e r a l s .
S o il S c i.
75s373-381.
A l l i s o n , F . E . , K e f a u v e r , M a r g a r e t , and R o l l e r , E. M. 1 953b. Ammonium
f ix a tio n in s o i l s .
S o i l S c i . S o c . Amer. P r o c . 1 7 : 1 0 7 - 1 1 0 .
B l a c k , C. A. 1 9 5 7 . S o i l P l a n t R e l a t i o n s h i p s .
New Y o rk .
p. 204.
Jo h n W iley ^and S o n s , I n c . ,
Bremner , J . M ., and Shaw, R.
1 958. D e n i t r i f i c a t i o n i n s o i l s
of in v e s tig a tio n .
J o u r . A gr. S c i . 5 1 : 2 2 - 3 9 .
B r o a d b e n t , F . E . 1 951.
S c i . 7 2 s l 2 9 r 13 7 .
I.
M ethods
D e n i t r i f i c a t i o n i n some C a l i f o r n i a s o i l s .
S o il
C a s t e r , A. B . , M a r t i n , W. P . , and Bueh e r , T. F .
1942. The m i c r o b i o l o g i c a l
o x i d a t i o n o f ammonia i n d e s e r t s o i l s :
I.
A r iz o n a A g r . E xp. S t a .
T ech. B u i. 96.
C onrad, J 0 P.
1 9 4 0 . H y d r o l y s i s o f u r e a i n s o i l s by t h e r m o l a b i l e c a t a l y s i s .
S o il S c i. 4 9 :253-263.
Frahm , E . E.
1 9 4 8 . C h e m ic a l and p h y s i c a l c h a r a c t e r i s t i c s o f Bowdoin c l a y
fro m t h e M ilk R i v e r V a l l e y o f M ontana. S o i l S c i . S o c . Amer. P r o c .
(1947) 13:4 5 5 -4 6 0 .
G i b s o n , T.
1 930.
1 6 :549-558.
The d e c o m p o s i t i o n o f u r e a i n s o i l s .
J a c k s o n , M. L.
1 9 5 8 . S o i l C h e m ic a l A n a l y s i s .
E nglew ood C l i f f s , New J e r s e y .
J o u r . A g r. S c i .
P re n tic e -H a ll, In c .,
J a c k s o n , M. L . , and C hang, S . C. 1 947. A nhydrous ammonia r e t e n t i o n by
s o i l s a s i n f l u e n c e d by d e p t h o f a p p l i c a t i o n , s o i l t e x t u r e , m o i s t u r e
c o n t e n t , pH v a l u e and t i l t h .
J o u r . Amer. S o c . A gron . 3 9 : 6 2 3 - 6 3 3 .
J e w i t t , T. N. 1 942. L oss o f ammonia fro m ammonium s u l f a t e when a p p l i e d
to a lk a lin e s o i l s .
S o il S c i . 5 4 :4 0 1 .
K e m p th o rn e , 0 .
1 9 5 2 . The D e s ig n and A n a l y s i s o f E x p e r i m e n t s .
and S o n s , I n c . , New Y o rk . p p . 3 6 4 - 3 6 9 .
Jo h n W iley
69
L e C l e r g , E. L. 1 9 5 7 . Mean s e p a r a t i o n by t h e f u n c t i o n a l a n a l y s i s o f
v a r i a n c e and m u l t i p l e c o m p a r i s o n s .
USDA A R S-20-3.
L o w e n s t e i n 9 H . , E n g l e b e r t 9 L. E . , A t t o e 9 0 . J . , and A l i e n , 0 . N. 1957.
N i t r o g e n l o s s i n g a s e o u s fo rm fro m s o i l s as i n f l u e n c e d by f e r t i l i z e r s
and m an a g e m e n t. S o i l S c i . S o c . Amer. P r o c . 2 1 83 9 7 - 4 0 0 .
M cBeth 9 I . G. 191 7 .
9 :1 4 1 -1 5 4 .
F i x a t i o n o f ammonia i n s o i l s .
J o u r . A g r. R e s.
Madhok 9 M. R . , and U d d in 9 F .
1 946. L o s s e s o f n i t r o u s n i t r o g e n from s o i l s
on d e s i c c a t i o n .
S o il S c i. 61:2 7 5 -2 8 0 .
M a r t i n 9 J . P . , and Chapman 9 H. D. 1 951. V o l a t i l i z a t i o n o f ammonia from
surface f e r t il iz e d s o ils .
S o il S c i. 7 1 :2 5 -3 4 .
M i d d l e t o n , H. E . 1 9 3 0 . P r o p e r t i e s o f s o i l w h ic h i n f l u e n c e s o i l e r o s i o n .
USDA T e c h . B u i. 178.
S o h n 9 Jerom e B . , and P e e c h 9 M. 1 958.
by s o i l s .
S o il S c i. 8 5 :1 -9 .
R e t e n t i o n and f i x a t i o n o f ammonia
, S t a n f o r d 9 G e o r g e 9 and Hanway 9 J o h n .
1955. P r e d i c t i n g n i t r o g e n f e r t i l i z e r
n e e d s f o r Iowa s o i l s :
II.
A s im p l if ie d te c h n iq u e f o r d e te rm in in g
r e l a t i v e n i t r a t e p ro d u ctio n in s o i l s .
S o i l S c i . S o c . Amer. P r o c .
1 9 :7 4 -7 7 .
U n ited S t a t e s S a l i n i t y L a b o r a to ry S t a f f .
1 9 5 4 . D i a g n o s i s and im provem ent
o f s a l i n e and a l k a l i s o i l s .
A g r i c u l t u r a l Handbook No. 6 0 , USDA.
W agner 9 G. H . , and S m i t h 9 G. E. 1 9 5 8 . N i t r o g e n l o s s e s fro m s o i l s
f e r t i l i z e d w ith d i f f e r e n t n itro g e n c a r r i e r s .
S o il S c i . 8 5 :1 2 5 -1 2 9 .
Wahhab 9 A. 1 9 5 7 . L o ss o f ammonia fro m ammonium s u l f a t e u n d e r d i f f e r e n t
c o n d i t i o n s when a p p l i e d t o s o i l s .
S o il S c i. 8 4 :249-255.
Wahhab 9 A . , and U d d in 9 F .
1 9 5 4 . Loss o f n i t r o g e n t h r o u g h r e a c t i o n o f
ammonium and n i t r i t e i o n s . S o i l S c i . 7 8 : 1 1 9 - 1 2 6 .
Waksman 9 S . A.
New Y o rk .
1952. S o i l M i c r o b i o l o g y .
pp. 172-183.
J o h n W iley and S o n s , I n c . 9
70
APPENDIX
T a b le XIX.
T i l l e r i n g d a t a o f b a r l e y ■f e r t i l i z e d on t h e s o i l s u r f a c e , ( p o t s t h i n n e d t o 10 p l a n t s ) .
R e p lic a tio n
. .
T reatm ents
R a te
N itro g en
( l b s . N/A)
source
No. t i l l e r s
o v e r 10
-
-
0
0
0
100
100
100
200
200
200
300
300
300
CaNGQ
NH4 NQ3
U re a (NH4 )
CaNOQ
NH4N03
U re a (NH4 )
CaNCQ
NH4 NO3
U re a (NH4 )
CaNQs_
NH4 NO3
U rea (NH4 )
6
0
0
100
100
. 100
200
200
200
300
300
300
CaNCQ
NH4 NO3
U re a (NH4 )
CaNCQ
NH4 NO3
U rea (NH4 )
CaNCQ
NH4 NO3
Ure a ( NH4 )
CaNCQ
NH4 NO3
U re a (NH4 )
2
I
.
No.
g rain
heads
3
No.
No.
g rain
tille rs
o v e r 101 h e a d s
Minimum m o i s t u r e . 50&
I
5
10
10
10
10
9*
10
11
10
8**
15
10
10
No.
g rain
heads
No. t i l l e r s
o v e r 10
'
9*
I
3
11
10
10
9*
- 9*
■ 8 **
13
10
9*
19**
8* *
10
9*
10
8**
9*
10
10
8**
10
10
19
9*
10
I (n o t headed)
9
Minimum m o i s t u r e .
I (n o t headed)
10
10
10
■ 10
10
10
8**
9*
10
11*
10
10
3
11
10
10
9*
9*
9
10
13
10
10
20 *
8**
10
I
.
3
I (n o t headed)
8
9*
10
10
10*
10
10
11**
9*
10
18
10
8 **
72
T a b l e XX,
T i l l e r i n g d a t a o f b a r l e y when f e r t i l i z e r was m ixed w i t h t h e
s o i l ( p o t s t h i n n e d t o 10 p l a n t s ) .
T reatm en t
R ate
N itro g e n
( l b s . N/A) s o u r c e
R e p l i c a t i o n Is
0
CaN03
0
KNO3
0
NH4 NO3
0
Urea (NH4 )
100
CaNOg
100
KNO3
100
NH4 NO3
1 100
Urea (NH4 )
200
CaNQ3
200
KNO3
200
NH4 NO3
200 Urea (NH4 )
R e p l i c a t i o n 2s
0
CaNO3
0
KNO3
0
Nl^NO3
0
Urea (NH4 )
100
CaNO3
100
KNO3
100
NH4 NQ3
100
Urea ( NH4 )
200
CaNO3
. 200
KNO3
200
NH4 NO3
'
200
Ure a ( NH4 )
R e p l i c a t i o n 3s
0
CaNO3
0
KNO3
0
NH4 NO3
0
Urea (NH4 )
CaNO3
100
100
KNO3
100
NH4 NO3
100
Ure a ( NH4 )
200
CaNO3
200
KNO3
200
200
NH4 NO3
Urea (NH4 )
No.
tille rs
o v e r 10
Heads
h arv ested
0
0
0
0
3
4
5
I 7
12
10
12
9
10 '
10
10
10
10
14
15
17
22
20
21
19
0
0
0
0
6
5
8
2
12
12
10
10
10
10
14
15
18
12
20
21
15
23,
12
Comments
2 p la n ts w ith 3 t i l l e r s
I p la n t w ith 2 t i l l e r s
2 p la n ts w ith 2 t i l l e r s
I p l a n t w i t h 2 t i l l e r s — n o t headec
I
I
I
I
I
p lan t
p lan t
p lan t
p lan t
p lan t
w ith
w ith
w ith
w ith
w ith
2
2
3
2
3
t i l l e r s — h e a d ed
t i l l e r s —-h e a d e d
t i l l e r s — 2 hea d ed
t i l l e r s — h e a d ed
t i l l e r s — h e a d ed
21
'
0
0
0
0
2
6
6
6
8
9
10
10
10
10
10
15
15
13
18
18
10
10
20
19
3 p la n ts w ith 2 t i l l e r s
I p l a n t w ith 2 t i l l e r s
I p l a n t w i t h I t i l l e r —-not h ead ed
2 p l a n ts w ith 2 t i l l e r s
T a b le XXI.
A n a ly sis o f v a ria n c e of t o t a l b a r le y p l a n t m a te r ia l w e ig h t ( n itr o g e n a p p lic a tio n s
at s o il su rfa c e ).
-
V a r ia n c e
SS
df
MS
F
R e p lic a tio n
2
8 .4 1
4 .2 1
N itro g e n source
2
1 ,9 0 4 .1 0
952.05
4 1 .0 9 * *
N itro g en r a t e
3
5 ,6 7 8 .8 7
1 ,8 9 2 .9 6
- 8 1 .7 0 * *
L in e ar
I
5 ,5 8 7 .7
5 ,5 8 7 .7
Q u a d ra tic
I
7 4 .2
7 4 .2
3 .1 2
C ubic
I
16.9
1 6 .9
KD==a
2 3 4 .8 **
M o istu re le v e l
I
19.95
1 9 .9 5
N source x N r a t e
6
940.62
156.77
N source x m o istu re le v e l
2
113.8.0
5 6.90
2.46
N r a t e x m o istu re le v e l
3
121.35
4 0 .4 5
1 .7 5
N source x N r a t e x m o istu re le v e l
6
1 8 0 .7 9
3 .0 1
•==—
E rro r
46
1,066.01
2 3 .1 7
T o tal
71
1 0 ,033.90
6 .7 7 * *
74
T a b l e X X II. , A ve ra g e w e i g h t o f b a r l e y g r a i n h a r v e s t e d w i t h s u r f a c e
a p p lic a tio n s of n itro g e n .
N itro g en
rate
( l b s . N/A)
CaN03
0
3 .8 6
3 .5 6
3 .9 9
3 .8 0
100
1 0 .6 7
8 .3 9
6 .5 4
8 .5 3
200
1 3 .8 5
1 1 .9 4
8 .6 1
1 1 .4 7
300
1 3 .7 7
1 2 .5 7
1 1 .1 6
1 2 .5 0
1 0 .5 4
9 .1 2
7 .5 8
9 .0 8
-
N itro g e n so u rce
mean
N itro q en so u rce
NH4 NO3
Mean
Minimum m o i s t u r e 9 50%
Minimum m o i s t u r e , 75%
9 .0 3
9 .1 3
Urea (NH4 )
Mean
n itro g e n
rate
T able X X III.
A n a ly sis of v a r ia n c e of b a rle y g r a i n w e ig h t w ith s u r f a c e a p p li c a t i o n s of n i tr o g e n .
V a ria n c e
1
df
SS
MS
F
R e p lic a tio n
2
0 .4 6
0 .2 3
N itro g e n source
2
1 0 5 .1 4
52.57
23.26**
N itro g en r a t e
3
8 2 0 .0 0
2 7 3 .3 3
1 2 0 .9 4 * *
L in ear
I
7 5 8 .4 4
7 5 8 .4 4
3 3 5 .5 9 * *
Q u a d ra tic
I
6 1 .5 5
6 1 .5 5
2 7 .2 3 * *
C ubic
I
0 .2 7
0 .2 7
—
M o istu re l e v e l
I
0 .1 9
0 .1 9
——
N source x N r a t e
6
5 1 .5 1
8 .5 9
3 .8 0 * *
N so u rce x m o istu re le v e l
2
0 .8 8
0 .4 4
—
N r a t e x m o istu re le v e l
3
0 .1 9
0 .0 6
——
N source x N r a t e x m o istu re le v e l
6
9 .1 8
1 .5 3
—™
E rro r
46
1 0 3 .8 4
2 .2 6
T o ta l
71
1 ,0 9 1 .3 9
i
76
T a b l e XXIV.
M u ltip le co m p ariso n t e s t s
g r a in tre a tm e n t w e ig h ts.
f o r mean s e p a r a t i o n o f b a r l e y
N i t r o g e n s o u r c e x r a t e i n t e r a c t i o n — SSR'mean s e p a r a t i o n , 5% l e v e l
Rank
R a te
( l b s . N/A)
0
0
0
100
100
200
100
■ 300
200
300
300
200
A
B
C
D
E
F
G
H
I
J
K
L
N itro g en
so u rce '
Mean w e i g h t
p la n t m ate ria l*
gm.
NH4 NO3
N03
Urea (NH4 )
Urea (NH4 )
NH4 NO3
• Urea (NH4 )
NO3
U rea ( NH4 )
NH4 NO3
NH4 NO3
3 .5 6
3 .8 6
3 .9 9
6 .5 4
8 .3 9
8 .6 1
1 0 .6 7
1 1 .1 6
1 1 .9 4
1 2 .5 7
1 3 .7 7
1 3 .8 5
NO3
NO3
^ T r e a t m e n t c o m p a r is o n s above e a c h b r a c k e t v e r s b s t h o s e b e lo w t h e b r a c k e t
a r e s i g n i f i c a n t a t t h e 5% l e v e l .
N i t r o g e n s o u r c e m eans:
N itro g e n so u rce
NH4NO3
CaNO3
Mean w e i g h t — grams
L .S .D .
9 .1 2
1 0 .5 4
^ o i - 1 .1 7
. 0 5 = "87
i
Urea (NH4 )
7 .5 8
77
T a b l e XXV,
P e r c e n t n i t r o g e n i n b a r l e y g r a i n and. s t r a w - w i t h n i t r o g e n
t r e a t m e n t s on t h e s o i l s u r f a c e .
T r e a t m e n t ______
N itro g e n
R a te
( l b s . NZA) s o u r c e
________________________R e p l i c a t i o n
2
I
G ra in
G ra in
S tra w
S tra w
%
%
%
%
0
0
0
100
100
100
200
200
200
300
300
300
CaNQg
NH4NOg
Urea (NH4 )
CaNQg
NH4 NOg
Urea (NH4 )
CaNO3
NH4 NQg
U rea (NH4 )
CaNOg
NH4NOg
Urea (NH4 )
Minimum m o i s t u r e , 50%
1 .4 1
1 .3 1
.61
. 1 .4 4
1 .3 1
.66
1.38
1 .3 1
.66
1 .4 4
1 .3 4
.4 3
1 .3 8
,5 3
1 .2 2
.5
0
1
.3 1
1 .2 6
1
.6 8
1 .6 5
.58
1
.
42
1 .4 1
.5 3
1
.
42
1 .3 0
.5 3
1 .1 7
2 .1 1
2 .1 4
1 .6 5
1 .7 3
.6 1
1 .4 1
.4 8
1 .4 4
0
0
0
100
100
100
200
200
200
300
300
300
CaNOg
NH4NOg
Urea (NH4 )
CaNO3
NH4NOg
U rea (NH4 )
CaNOg
NH4NOg
Urea (NH4 )
CaNO3
NH4 NOg
Urea (NH4 )
Minimum m o i s t u r e , 75%
1 .3 3
.67
1 .3 3
1
.3 0
1 .3 0
.69
1 .4 1
.6 7 .
1 .3 3
1 .3 1
1 .3 1
.5 3
1 .2 6
1 .4 1
.5 6
1 .2 6
.5 6
1 .3 8
1 .2 6
1 .5 8
.62
1 .4 1
1 .4 4
.96
1 .3 8
.53
1 .4 4
2
.0 3
1 .9 7
1 .0 9
1 .5 8
.5 4
1 .6 0
1 .4 1
1 .3 1
.5 4
3
G ra in
%
.7 2
.7 5
.5 0
.6 2
.5 8
.5 4
1 .3 4
1 .4 4
1 .4 4
1 .4 2
1 .3 8
1 .3 0
.75
1 .6 8
1 .4 4
1 .3 8
1 .9 7
1.58
1 .4 4
.5 3
.5 8
1 .0 9
.6 7
.5 6
.6 1
.6 2
.61
.67
.4 8
.53
.6 7
.53
.5 0
.88
.93
.51
1 .4 4
1 .3 8
1 .3 8
1 .4 2
1 .3 1
1 .4 4
1 .6 6
1 .3 8
1 .3 9
2 .1 3
1 .6 0
1 .2 8
S tra w
%
.5 3
.70
.5 8
.5 3
.53
.5 0
.7 5
.66
.5 6
1 .0 4
.61
.5 4
.59
.5 4
.5 4
.4 8
.5 0
.6 2
.67
.43
.5 3
.9 4
.5 9
.5 6
T a b le XXVI.
Grams o f g r a i n and s t r a w p r o d u c e d when n i t r o g e n t r e a t m e n t s w e re a p p l i e d on t h e s o i l
su rface.
T r e a t m e n t ______
N itro g en
R a te
f i b s . N /a) s o u rc e
__ ;________________________________ R e p l i c a t i o n
2
I
G ra in
G ra in
S tra w
T o tal
S tra w
0
0
0
100
100
100
200
200
200
300
300
300
CaNOg
NH4 NO3
Urea (NH4 )
CaNOs
NH4 NO3
Urea (NH4 )
CaNOS
NH4 NO3
U re a (NH4 )
CaNOs
NH4 NO3
U rea (NH4 )
7 .8 9
7 .6 7
8 .2 3
1 7 .0 3
1 1 .9 6
0
0
0
100
100
100
200
200
200
300
300
300
CaNOs
NH4 NO3
Urea (NH4 )
CaNQs
NH4 NO3
Urea (NH4 )
CaNQs
NH4N03
Urea (NH4 )
. CaNOs
NH4N03
Urea (NH4 )
1 0 .4 7
9 .1 3
7 .4 4
1 8 .4 8
1 4 .3 2
1 3 .3 3
3 0 .7 7
2 2 .1 3
1 0 .8 7
2 8 .7 7
1 9 .9 4
1 6 .7 9
8 .0 2
1 0 . io
1 2 .0 9
1 4 .5 5
2 2 .1 9
2 5 .7 9
1 7 .3 0
3 .7 3
3 .5 7
4 .2 6
1 1 .6 2
7 .6 8
5 .9 7
9 .3 3
1 0 .0 7
8 .3 5
1 2 .8 3
1 4 .6 6
12.11
M nim um m o i s t u r e , 50%
7 .7 7
3 .9 3
2 .7 7
8.03
6 .2 7
12.1
4.73
1
4
.4
2
9.98
29 .9
7 .5 7
2 0 .5
15.93
5 .7 1
15.5 ' 1 2 .9 9
2 8 .2 1
2 6 .5
14.59
1 2.61
2 4 .3
1 9 .9 9
2 2 .0
1 6 .1 4
7 .9 6
3
3
.4
6
3 3 .8
1 3 .1 4
8 .8 0
1 1 .0 5
3 9 .1
1 0 .3 7
1 8 .2 3
29.9
1 2 .7
1 1 .9
• 4 .8 1
4 .2 3
3 .8 7
1 2 .8 7
8 .5 4
7 .4 8
1 6 .4 0
12 .2 1
7 .4 5
1 1 .6 1
1 3 .3 1
1 2 .6 0
T o tal
'
Minimum m o i s t u r e , 75%
9 .6 4 .
3 .3 6
5 .6 6
3 .9 4
3 .6 7
1 1 .2 3
1 9 .2 5
8 .85
2 2 .0
1 0 .8 1
9 .1 9
7 .2 0
1 9 .3
8 .6 0
1 5 .3 8
4 0 .1
24.22
1 3 .1 7
3 2 .2
18.33
7 .8 6
1 9 .5
10.34
4 1 .6
4 9 .1 1
1 5 .0 9
8 .5 6
3 4 .6
1 8 .7 4
1 4 .3 8
1 2 .1 2
2 8 .9
1 4 .2
1 2 .7
1 1 .7
3 0 .1
1 1 .7
1 0 .8
1 1 .0
2 4 .4
2 3 .5
1 8 .7
4 2 .8
3 2 .6
2 4 .1
4 6 .6
2 0 .3
28.6
1 3 .0
9 .6
1 4 .9
2 8 .1
2 0 .0
15.8
3 9 .6
3 1 .5
1 8 .2
6 4 .2
27.3
2 6 .5
S tra w
3
G r a in
6 .7 7
7 .6 8
1 1 .1 8
2 3 .3 1
1 7 .6 8
3 .8 3
3 .0 2
3 .0 2
8 .3 7
7 .1 3
1 2 .2 4
1 1 .0 7
8 .0 4
14.71
1 4 .0 7
1 0 .5 3
2 5 .2 6
2 2 .2 3
14.46
2 8 .5 9
2 0 .6 3
1 1 .2 7
7 .6 2
6 .0 6
5 .3 0
1 5 .4 0
1 0 .8 5
1 2 .1 5
1 7 .8 2
14.08
9 .3 6
5 1 .0 8
1 8 .7 1
1 6 .5 5
9.49
8 .0 2
3 .4 8
3 .8 4
4 .4 0
11.20
9.35
5 .7 5
1 5 .1 8
12.52
9 .2 4
15.22
1 3 .7 9
9 .2 5
T o tal
10.6
1 0 .7
1 4 .2
3 2 .8
2 5 .7
1 5 .5
3 7 .5
3 3 .3
22.5
4 3 .3
3 4 .7
2 1 .8
11.1
9 .9
9 .7
2 6 .6
2 0 .2
1 7 .9
3 3 .0
26.6
1 8 .6
6 6 .3
32 .5
2 5 .8
T a b l e XXVIIo
M i l l i g r a m s o f n i t r o g e n p r o d u c e d when n i t r o g e n was a p p l i e d on t h e s o i l s u r f a c e
T reatm ent
'R a te
N itro g en
l b s . N/A)
so u rce
CO
CO
CO
—=J
Cl
0
0
0
100
100
100
200
200
200
300
300
300
Urea (NH4 )
CaNOs
NH4 NO3
Urea (NH4 )
CaNOs
NH4 NQ3
' Urea (NH4 )
CaNO3
NH4 NO3
Urea (NH4 )
O
O
' O
100
100
100
200
200
200
300
300
300
CaNOs
NH4N03
Urea (NH4 )
CaNOg
NH4 NO3
U rea (.NH4 )
CaNOs
NH4N03
Urea (NH4 )
CaNOs
NH4 NO3
U rea (NH4 )
GaNQs
NH4 NO3
G ra in
63
56
51
173
104
95
270
172
96
249
230
177
46
. 57
153
108
82
_148
1 145
5 125
253
235
159
I ________ ,__
S traw
T o tal
48
51
54
73
63
40
59
64
77
260
157
R e p lic a tio n
___________ 2 ■
G ra in
S tra w
T o tal
Minimum m o i s t u r e . 50%
56
55
111
60
107
48
65
31
105
246
144
89
167
104
92
75
135
70
329
245
236
173
180
113
278
182
149
509
212
106
81
365
59
102
83
387
260
63
50
98
80
75
191
212
58
314
108
91
Minimum m o i s t u r e , 75%
45
59
51
35
109
107
52
69
116
251
129
116
188
52 ’
46
157
91
194
339
162
185
97
357
183
39
142
307
432
567
136
174
343
171
250
73
111
108
96
233
196
145
457 286
194
643
241
251
G r a in
52
44
44 ,
135
HO
92
206
159
111
290
223
152
104
50
86
121
245
168
137
356
282
181
739
310
244
53
61
160
123
83
253
172
129
324
221
118
_____ _ _ _
3
S traw
T o ta l
36
54
65
124
94
42
189
147
81
297
126
61
88
98
109
259
204
134
395
306
192
587
349
213
45
33
95
86
90
234
177
158
372
233
179
804
331
211
29
74
54
75
119
61
50
480
HO
93
•
'j
xO
T a b l e X X V III„
A n a l y s i s o f v a r i a n c e o f m i l l i g r a m s o f n i t r o g e n p r o d u c e d by b a r l e y p l a n t m a t e r i a l
w ith s u rfa c e a p p lic a tio n s o f n itr o g e n .
V a ria n c e
df
SS
MS
F
R e p lic a tio n
2
749
375
N itro g en so u rce
2
377,908
188,954
1 1 5 .3 6 * *
N itro g en r a t e
3
884,044
294,681
1 7 9 .9 0 * *
M o istu re le v e l
I
896
896
N source x N r a t e
6
301,546
5 0 ,2 5 8
N source x m o istu re le v e l
2
1,892
946
—w
N r a t e x m o istu re le v e l
3
7,037
2 ,3 4 6
1 .4 3
N source x N r a t e x m o istu re le v e l
6
16,353
2 ,7 2 6
1 .6 6
E rro r
46
75,336
1,638
T o tal
71
1,665,761
3 0 .6 8 * *
81
T a b l e XXIX.
N itro g e n
source
A ve ra g e w e i g h t o f g r a i n p r o d u c e d when n i t r o g e n m a t e r i a l s
w ere m ixed w i t h t h e s o i l .
0
100
200
Mean
n itro g e n
source
gm.
gm.
gm.
gm.
2 1 .5 2
2 1 .7 2
20.77
1 5 .3 3
1 5 .7 9
1 5 .1 3
1 8 .7 3
14.33
2 0 .6 9
1 5 .1 5
N itro g e n r a t e
CaNOs
8 .1 9
KNQs
NH4 NO3
U rea (NH4 )
8 .3 6
8 .3 4
8 .4 2
1 6 .3 0
1 7 .3 0
1 6 .2 8
1 5 .8 3
N itro g en r a t e
mean
8 .3 3
1 6 .4 3
(lb s.
'
n/ a )
A n a ly sis o f v a ria n c e of b a r le y g r a i n w eig h t
V arian ce
df
R e p lic a tio n
R a te
Source
Source x r a t e
E rro r
2
2
I
6
22
T o tal
35
SS
•
MS
3 .6 6
' 9 4 6 .1 6
1 .8 3
4 7 3 .0 8
1 0 .1 2
1 0 .2 4
3 7 .8 0
3 .3 7
1 ,0 0 4 .3 2
1.7 1
1 .7 2
F
2 7 5 .0 5 * *
1 .9 6
— —-
82
T a b l e XXX.
P e r c e n t n i t r o g e n i n t o t a l b a r l e y p l a n t m a t e r i a l when n i t r o g e n
t r e a t m e n t s w e re m ixed w i t h t h e s o i l .
T reatm en t
R a te
N itro g en
( l b s . N/A)
source
R e p lic a tio n
I
2
3
%
%
%
.9 4
.9 4
.9 4
.93
1.01
.94
1 .0 9
.91
1 .0 7
1 .1 4
1 .1 7
1 .1 7
1 .0 9
0
0
0
0
CaNOg
KNO3
NH4 NO3
Urea (NH4 )
.9 8
100
100
100
100
CaNOg
KNOg
. NH4 N0 g
Urea (NH4 )
1 .0 7
1 .0 6
200
200
200
200
CaNOS
KNO4
NH4 NQg
U re a ( NH4 )
1 .2 6
1 .2 3
1 .2 2
1 .2 2
1 .2 3
1 .3 1
1 .2 5
1 .2 3
.93
.98
.91
1.0 9
1 .1 0
1 .1 0
1 .2 0
1 .1 5
1 .2 0
1 .2 3
1 .2 8
1 .4 7
83
T a b l e XXXI.
Grams o f b a r l e y g r a i n and t o t a l p l a n t m a t e r i a l p r o d u c e d when
n i t r o g e n t r e a t m e n t s w ere m ixed w i t h t h e s o i l .
I
T reatm en t
R a te
( l b s . N/A
T o tal
p la n t
m aterial
0
0
0
0
CaNOg
KNQg
NH4 N0 g
U rea (NH4 )
1 8 .8
1 7 .6
1 8 .4
1 9 .7
8 .0 9
100
100
100
100
CaNOg
KNO3
NH4 NOg
Urea (NH4 )
200
200
200
200
CaNOg
KNOg
NH4 NO3
Urea (NH4 )
G ra in
’ T o ta l
p lan t
m ate ria l
1 9 .1
1 9 .9
8 .3 5
8 .1 5
8 .7 2
2 0 .2
8 .9 0
1 7 .2
7.79
3 4 .8
3 6 .7
3 5 .3
3 5 .7
1 6 .5 8
1 7 .8 5
1 6 .9 6
1 6 .4 3
3 5 .1
3 4 .9
3 4 .2
3 1 .9
1 6 .3 0
3 2 .7
16.75
1 5 .2 8
3 6 .0
3 4 .8
15.49
3 2 .8
,16.03
1 7 .2 9
1 6 .5 9
1 5 .5 8
4 7 .5
4 5 .4
4 6 .5
4 3 .8
2 1 .9 2
2 0 .9 9
2 2 .1 5
4 5 .7
2 2 .5 6
4 6 .9
22.61
42 .3
4 4 .5
2 0 .0 9
2 1 .5 7
4 5 .1
4 5 .1
4 5 .1
3 5 .7
21.64
20.93
7.7 9
20.11
9.47
1 8 .5 1
1 8 .1 ■
1 7 .5
1 7 .8
1 9 .4
G r a in
8 .1 3
7.81
7.96
8 .7 5
1 5 .1 5
84
T a b l e XXXII,
M illig ra m s of n itr o g e n produced in t o t a l b a r l e y p l a n t
m a t e r i a l when n i t r o g e n t r e a t m e n t s w ere m ixed w i t h t h e
s o il.
T reatm en t
R a te
N itro g e n
( l b s . N/A)
source
'
R e p lic a tio n
2
I
mgm.
3
mgm.
A veraqe
mgm.
0
0
0
0
CaNOg
KNOg
NH4 NQg
Urea (NH4 )
183
163
180
180
180
188
191
160
182
165
194
177
182
172
188
172
100
100
100
100
CaNO3
KNO3
NH4 N0 g
Urea (NH4 )
373
388
384
394
376
396
377
392
400
352
382
392
418
378
200
200
200
200
CaNQg
KNOg
NH4 N0 g
Urea (NH4 )
.600
552
573
563
570
563
556
508
548
577
526
575
399
.
375
557
557
571
552
MONTANA STATE UNIVERSITY LIBRARIES
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762 100 5451 5
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