The influence of different soil types, treatments, and soil properties on the efficiency of water storage
by Raymond T Choriki
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 Raymond T Choriki (1959)
Abstract:
Moisture storage efficiency of four soils and five treatments on one soil type was determined during
1958 in a lysimeter study, and comparisons were made between 1957 and 1958 data. The effect of soil
differences and soil treatments on percolation and evaporation was studied. In addition, an attempt was
made to determine the differences in soil properties that accounted for differences in moisture lost
during a drying cycle in Huffine and Bridger silt loams.
Water that falls on the soil can be stored, evaporated, or percolated. Alteration of any one of these
variables will have a direct influence on the others.
Seasonal influences were noted on moisture efficiency in 1958 as in 1957.
In 1957 and 1958, Huffine soil evaporated less and percolated more water than the other soils studied,
with a storage efficiency of 20.4% in 1957 and 6.2% in 1958. This was followed by Bridger, instead of
Manhattan, in 1958. Again Huntley was very inefficient.
Rock mulch repeated as the outstanding treatment with a season-long efficiency of 29.8% in 1958
compared to 60.4% in 1957. The remaining treatments were relatively ineffective in 1958, although the
VAMA treatments were slightly better than the other treatments, as in 1957.
The importance of rainfall distribution in obtaining high moisture efficiency is illustrated by comparing
the efficiencies in 1957 and 1958. The higher efficiency in 1957 was associated with the distribution of
rainfall which was concentrated in the months of May and June and before the soil had lost much of the
moisture stored from the winter snow. The amount of rainfall was similar in the 2 years.
The soil properties that were found to be appreciably different were pore size distribution, percent
organic matter, and bulk density. Texture, percent aggregation, aggregate stability, and unsaturated and
saturated flow were almost alike in the two soils. It is believed that differences in pore size distribution
account for the differences in moisture loss between Huffine and Bozeman silt loams, but this
hypothesis needs additional testing. "THE INFLUENCE OF DIFFERENT SOIL TYPES, TREATMENTS, AND
SOIL PROPERTIES ON THE EFFICIENCY OF WATER STORAGE
'
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>v
■
RAYMOND To CHORIKI
A THESIS'
Subm itted to th e Graduate F a c u lty
p a r t i a l f u l f i l l m e n t of th e req u irem en ts
f o r th e degree o f
M aster of Science i n S o il s
at
-i
Montana S t a t e C ollege
Approved$
Head, Major Department
in in g Committee
Dean, Gradu
Bozeman, Montana
August, 1959
2
ACKNOWLEDGEMENT
The a u th o r wishes to e x p re ss s in c e r e a p p r e c ia tio n to h is major pro­
f e s s o r , Dr. J 0 Co Hide, f o r h i s g u id an ce, s u g g e s tio n s , and a s s i s t a n c e in
th e p r e p a r a t i o n of t h i s r e s e a r c h and p r e s e n t a t i o n of th e t h e s i s .
The a u th o r w ishes to e x p re ss thanks to Dr. A. H. Ferguson f o r h is
v a lu a b l e a s s i s t a n c e i n th e p r e p a r a t i o n of th e la b o r a to r y equipment and
advice on th e ch o ice of th e p h y s ic a l p r o p e r t i e s s tu d ie d .
The a u th o r a ls o w ishes to e x p ress a p p r e c i a t i o n t o Dr. A. H. P o s t,
Dr. M. G. K la g e s , Dr. R. A. O lsen, and to a l l th e p e rso n n el of the
Agronomy and S o il s Department who have c o n tr ib u te d t h e i r time f o r sug­
g e s ti o n s and use of t h e i r equipment n e c e s sa ry f o r t h i s s tu d y .
F u r t h e r acknowledgement is due th e Western Regional R esearch P r o je c t
W-30 f o r t h e i r s u p p o rt of t h i s stu d y .
TABLE OF CONTENTS
ACKNOWLEDGEMENT . . . . . .
e e e e o e o o o o e e e e a o e e o e
TABLE OF CONTENTS . . . . .
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LIST OF TABLES. . . . . . .
Context T a b le s .. . . .
Appendix T ables. . . . o o o o o o o o e o o o e o o o o o o o
LIST OF FIGURES . . . . . .
ABSTRACT. . . . . . . . . .
INTRODUCTION. . . . . . . .
REVIEW OF LITERATURE. . . . . . . . . . . . . . . . . . . . . . . .
RESULTS AND DISCUSSION. . .
•
MATERIALS AND METHODS . . .
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E f f e c t of S o il Types and S o il Treatm ents on E v ap o ratio n
and P e r c o l a t i o n f o r D i f f e r e n t C lim a tic P e rio d s
Warm-Dry P erio d —■ June 16 to June 26, 1958 . . . . . . .
Warm-Wet P erio d --» June 26 to August 4 , 1958. . . . . . .
C ool-M oist Perio d —■ A p ril 12 to May 28, 1958 . . . . . .
Cool-Wet P erio d —- May 28 to June 16, 1958. . . . . . . .
Hot-M oist P e rio d »»- August 4 t o August 28, 1958 , . . . .
Cool-Dry P erio d —- August 28 to O ctober 30, 1958. . . . .
Seaso n al M oisture E f f ic ie n c y
P e rc o la tio n
. . . . . . o .
. . . . . .
E v a p o ra tio n . . .
Drying C h a r a c t e r i s t i c s of H uffine and B rid g e r S o il and
Rock Mulch Treatm ent . o o a o a e o a o a o e e e o a o
o
o
e
4
Page
P h y s ic a l P r o p e r t i e s o f B rid g e r and H u ffin e S i l t Loams..................
47
Mechanical A n a ly s is , Organic M a tte r, and Bulk
D e n s i t y ...................................
47
Degree of A g g r e g a t i o n ..............................
52
S a tu r a te d Flow.......................... ■
.................................................................
52
U n sa tu rate d Flow............................................................
54
E f f e c t of S o il Depth on Drying P r o p e r t i e s ............................................
SUMMARY AND CONCLUSIONS . . . . . . .
LITERATURE CITED. . . . . . . . . .
................................................
62
. . .
65
.................. . .................. . . . . .
67
APPENDIX. . . .................. . . . . . . . . . .
.......................... ....
70
5
LIST GF TABLES
Page
C ontext Tables
Table I .
P e r c o l a t i o n from snowmelt f o r w in te r and s p rin g
months ( i n m i l l i l i t e r s ) , 1957-58* ........................................
24
P e rio d s i n t o which d a ta was su b d iv id ed and
c lim a tic in fo rm a tio n by p e rio d s ............................................
25
D aily p r e c i p i t a t i o n ( in c h e s ) in 1958 as re c o rd ed
by th e r a i n gauge lo c a te d a d ja c e n t to the
l y s i m e t e r s ..................................................................................
26
D aily maximum te m p e ratu re ( i n d eg rees F a h re n h e it)
f o r 1958 as re c o rd ed by th e U. S . Weather Bureau
c o o p e r a tiv e s t a t i o n a t Montana S t a t e C o lle g e ..................
27
B asis f o r c l a s s i f y i n g p e rio d s from average
maximum te m p e ra tu re and r a i n f a l l c a l c u l a t e d to
30 d a y s ................................................................................................
28
D aily e v a p o r a tio n from a f r e e - w a t e r s u rfa c e as
compiled from the U. S. Weather Bureau c o o p e r a tiv e
s t a t i o n a t Montana S ta te C o lle g e ............................................
30
P r e c i p i t a t i o n and e v a p o r a tio n ( i n grams) f o r
l y s im e te r a r e a s , A p ril 12 to O ctober 30, 1958 . . . .
31
P r e c i p i t a t i o n and p e r c o l a t i o n ( i n grams) f o r
ly s im e te r a re a s and p e r c o l a t i o n e f f i c i e n c y
e x p ressed as p e r c e n t of t o t a l r a i n f a l l by
s e l e c t e d p e r i o d s , A p ril 12 to October 30, 1958. . . .
32
Table IX.
Mechanical a n a ly s is by th e p i p e t t e method ........................
48
Table X.
P e rc e n t c l a y , p e rc e n t o rg an ic m a tte r , and
ag g re g ate s t a b i l i t y of B rid g e r and H uffine
s i l t loams................................... ............................................... .... .
49
P e rc e n t s i l t and c la y ag g reg ated i n B rid g er and
H u ffin e s i l t loams. . . . . .
................................................
50
Table TI.
Table I I I .
Table IV.
Table V.
Table VI.
Table V II.
Table V I I I .
Table XI.
Table X II.
Table X I I I .
Bulk d e n s i t y f o r H uffine and B rid g e r s i l t loams . . .
"K" v a lu e s and i n f i l t r a t i o n r a t e ( c c . ) of B rid g e r
and H u ffin e s i l t l o a m s . ................................... ..........................
51
53
6
Page
Table XIV.
Table XV.
Param eters A9 B9 E9 and F o f i n f i l t r a t i o n
a g a i n s t tim e .......................................................................................
55
P e rc e n t pore space d ra in e d a t v a rio u s te n s io n s
(pore s iz e d i s t r i b u t i o n ) .............................................................
61
Appendix Tables
Table XVI.
Perio d d a te s and c l a s s i f i c a t i o n as determ ined .
by c l i m a t i c f a c t o r s , 1957 ...................... ..................................
Table XVII.
P r e c i p i t a t i o n and e v a p o r a tio n ( i n grams) f o r
l y s im e te r a re a s f o r p e rio d May 3 t o October 30,
Table XVIII.
P r e c i p i t a t i o n and p e r c o l a t i o n ( i n grams) f o r
l y s im e te r a re a s and i n f i l t r a t i o n e f f i c i e n c y
ex p re ssed as p e r c e n t o f t o t a l r a i n f a l l by
p e r io d s , May 3 to October 30, 1957........................................
70
72
7
LIST OF FIGURES '
Page
F ig u re I .
F ig u re 2.
Apparatus f o r measuringAQ/^Vt as a f u n c tio n of
tim e .............................................................................................................
17
Apparatus f o r conducting w a te r through a porous
membrane to s tu d y th e m o is tu re c h a r a c t e r i s t i c s of
s o i l a t low t e n s i o n s ..........................................................................
21
F ig u re 3.
Drying c h a r a c t e r i s t i c
of H uffine s i l t loam............................
43
F ig u re 4.
Drying c h a r a c t e r i s t i c
of B rid g e r s i l t loam. . ....................
44
F ig u re 5.
Drying c h a r a c t e r i s t i c
of rock mulch tre a tm e n t . . . . .
45
F ig u re 6 .
F ig u re 7.
Rate of i n t a k e , A Q / Y t , as a f u n c tio n of tim e , t ,
w ith h y d r o s t a t i c head as the p a ra m ete r f o r H uffine
and B rid g e r s i l t loams......................................................................
55
V e r t i c a l d i s t a n c e of advance of th e w etted f r o n t , S,
as a f u n c tio n of tim e , t , w ith h y d r o s t a t i c head as
th e p a ra m ete r f o r B rid g e r and H uffine s i l t loams. . . .
56
M oisture t e n s i o n curve f o r B rid g e r and H uffine s i l t
loams between 0 and I atmospheres t e n s i o n ...........................
59
M oisture t e n s i o n curve f o r H uffine and B rid g e r s i l t
loams between I and 15 atmospheres t e n s i o n ...........................
60
F ig u re 10. E f f e c t of s o i l d e p th on d ry in g p r o p e r t i e s . ■........................
63
F ig u re 8.
F ig u re 9.
8
ABSTRACT
M oisture s to ra g e e f f i c i e n c y of f o u r s o i l s and f iv e tr e a tm e n ts on
one s o i l ty p e was d eterm in ed d u rin g 1958 i n a ly s im e te r s tu d y , and
comparisons were made between 1957 and 1958 d a t a . The e f f e c t of s o i l
d i f f e r e n c e s and s o i l tr e a tm e n ts on p e r c o l a t i o n and e v a p o r a tio n was
s t u d i e d . In a d d i t i o n , an a tte m p t was made to determ ine th e d i f f e r e n c e s
•in s o i l p r o p e r t i e s t h a t accounted f o r d i f f e r e n c e s in m o istu re l o s t du rin g
a d ry in g c y c le i n H uffine and B rid g e r s i l t loams.
Water t h a t f a l l s on th e s o i l can be s t o r e d , e v a p o ra te d , o r perco­
l a t e d . A l t e r a t i o n o f any one o f th e s e v a r i a b l e s w i l l have a d i r e c t
in f lu e n c e on th e o t h e r s .
S easo n al in f lu e n c e s were noted on m o istu re e f f i c i e n c y i n 1958 as
i n 1957.
In 1957 and 1958, H uffine s o i l ev ap o rate d le s s and p e r c o la te d more
w a te r th a n th e o t h e r s o i l s s t u d i e d , w ith a s to ra g e e f f i c i e n c y of 20.4% in
1957 and 6.2% in 1958. This was followed by B rid g e r, i n s t e a d of Manhattan,
in 1958. Again Huntley was v ery i n e f f i c i e n t .
Rock mulch re p e a te d as th e o u ts ta n d in g tre a tm e n t w ith a se a so n long e f f i c i e n c y of 29.8% in 1958 compared to 60.4% in 1957. The remaining
tr e a tm e n ts were r e l a t i v e l y i n e f f e c t i v e in 1958, although th e VAMA t r e a t ­
ments were s l i g h t l y b e t t e r th a n the o t h e r tr e a t m e n t s , as in 1957.
The im portance o f r a i n f a l l d i s t r i b u t i o n i n o b ta in in g h ig h m oisture
e f f i c i e n c y i s i l l u s t r a t e d by comparing th e e f f i c i e n c i e s i n 1957 and 1958.
The h ig h e r e f f i c i e n c y i n 1957 was a s s o c ia te d w ith the d i s t r i b u t i o n of
r a i n f a l l which was c o n c e n tra te d in th e months of May and June and before
th e s o i l had l o s t much o f th e m o istu re s to r e d from the w in te r snow. The
amount of r a i n f a l l was s i m i l a r i n the 2 years..
The s o i l p r o p e r t i e s t h a t were found to be a p p re c ia b ly d i f f e r e n t were
pore s i z e d i s t r i b u t i o n , p e r c e n t org an ic m a t t e r , and bulk d e n s i t y . T e x tu re ,
p e r c e n t a g g r e g a tio n , a g g re g a te s t a b i l i t y , and u n s a tu r a te d and s a tu r a te d
flow were alm ost a l i k e in th e two s o i l s . I t i s b e lie v e d t h a t d i f f e r e n c e s
i n pore s i z e d i s t r i b u t i o n account f o r th e d i f f e r e n c e s i n m o istu re lo s s
between H uffine and Bozeman s i l t loams, b u t t h i s h y p o th e sis needs
ad d itio n a l te s tin g .
9
INTRODUCTION
Because o f th e im portance of m o is tu re in p l a n t growth and crop pro­
d u c tio n , s t u d i e s are being conducted in an a tte m p t to in c r e a s e m o istu re
c o n s e r v a tio n by red u cin g e v a p o r a tio n .
Hide (21) has emphasized the
im portance o f t h i s m o istu re which i s being l o s t by e v a p o r a tio n .
He
e s ti m a te s t h a t 60 to 75% o f th e t o t a l p r e c i p i t a t i o n i s l o s t by evapora­
t i o n in d ry la n d a r e a s .
P e te r s (29) found t h a t a p l a s t i c c o v er over the
s o i l reduced th e w a te r r e q u ir e d to grow a c o rn crop by 50% in th e humid
areas.
Campbell (10) p la c e d enough im portance on e v a p o r a tio n to s t a t e ,
"The d a n g er to th e farm er from e v a p o r a tio n can n o t be e s ti m a te d , . i . . I f
t h e r e was no w a te r l o s t or w a ste d , th e d e s e r t s would bloom".
C onsidering
t h i s , i t i s s u r p r i s i n g t o f in d very few i n v e s t i g a t i o n s on th e many f a c e t s
of th e complex e v a p o r a tio n p ro c e s s .
In r e l a t i o n to th e s e comments, Hide and Brown (2 2 ), in 1956,
completed a stu d y on th e n a t u r a l d ry in g p a t t e r n of th r e e d i f f e r e n t s o i l
ty p e s , of which only two w i l l be d is c u s s e d , to observe the d i f f e r e n c e in
e v a p o r a tio n c y c l e .
s e a so n .
C o n sid e ra b le d i f f e r e n c e was observed th ro u g h o u t the
They found t h a t H uffine s o i l l o s t w a te r r a p i d l y from the
d i f f e r e n t s o i l l a y e r s i n th e e a r ly s ta g e s o f th e dry in g c y c l e , and then
lo s s alm ost c ea sed .
B rid g e r s o i l l o s t w a te r f o r a lo n g e r p e rio d and l o s t
a t o t a l of 0 .7 5 inch o f w a te r w hile H uffine s o i l l o s t only 0 .5 0 inch of
w a te r i n a d ry in g c y c le .
In 1957, a s e t o f ly s im e te r s was c o n s tr u c te d , and th e in flu e n c e of
s o i l ty p e s and s o i l tr e a tm e n ts upon m o is tu re s to ra g e was s t u d i e d .
su b m itte d a t h e s i s f o r h i s m a s t e r 's deg ree in co n n ec tio n w ith t h i s
Brown (6)
10
ex p erim en t.
The
experim ent was co n tin u ed in 1958, and th e p r e s e n t study
in c lu d e s s i m i l a r d a ta to t h a t o b tain ed in 1957 and a comparison between
th e 2 y e a r s .
In a d d i t i o n t o t h e l y s i m e t e r s tu d y , work was u n d ertak en in 1958 to
determ in e th e f a c t o r s which cause the d i f f e r e n c e in the d ry in g p a t t e r n
o f H uffine s i l t loam and B rid g e r s i l t loam.
B rid g e r s i l t loam was taken
from an a re a c l a s s i f i e d as B rid g e r c la y loam, b u t m echanical a n a ly s is
showed i t to be a s i l t loam.
A knowledge co n cern in g th e p ro c e ss o f e v a p o ra tio n i s d e s i r a b l e
because i t may aid in d e v is in g a method t o in c r e a s e m o istu re conserva­
t i o n by s o i l tr e a tm e n t and s im u lta n e o u s ly in c r e a s e crop p ro d u c tio n .
11
REVIEW OF LITERATURE
When c u l t i v a t e d a g r i c u l t u r e was f i r s t imposed on th e p l a i n s of the
U nited S t a t e s , th e r e was only very l im it e d in fo rm a tio n a v a i l a b l e on
growing cro p s under r e s t r i c t e d m o istu re s u p p l i e s .
At th e b eginning of
th e tw e n t i e t h c e n tu r y , th e r e seemed to be a s p r in k lin g of i n t e r e s t in the
s tu d y o f e v a p o r a tio n i n an e f f o r t t o i n c r e a s e th e m o istu re supply a v a i l ­
able f o r p l a n t growth.
Buckingham (8) was among th e f i r s t t o stu d y the
phenomena of c a p i l l a r y flo w .
He assumed c a p i l l a r y a t t r a c t i o n t o c o n s t i t u t e
a c o n s e r v a tiv e fo r c e f i e l d and d e fin e d c a p i l l a r y p o t e n t i a l , th e g r a d ie n t
o f which was equal to th e c a p i l l a r y f o r c e .
This concept of c a p i l l a r y flow
le d to th e id e a t h a t r a p id i n i t i a l l o s s of m o istu re reduced l a t e r lo s s by
forming a d ry mulch.
King (26) p re s e n te d d a ta showing t h a t a t h i n l a y e r of d r y , loose
m a t e r i a l d e c re a se d w a te r l o s s .
Campbell (10) p u b lic iz e d th e importance
o f t h i s d ry l a y e r and developed i n t e r e s t among the w o rk ers.
King’ s work,
however, was done under a s o i l c o n d itio n where a w ater t a b l e was p r e s e n t.
C a ll and Sewell (9) showed t h a t , i n th e absence of a w a te r t a b l e , most
o f th e w a te r t h a t could be l o s t by e v a p o r a tio n had been l o s t b efo re the
s u rfa c e was d ry enough f o r c u l t i v a t i o n .
When i t was found t h a t s u rfa c e mulches had only l im it e d in flu e n c e on
e v a p o r a tio n l o s s , s t u d i e s on e v a p o r a tio n were c u r t a i l e d .
t i o n appeared i n the n ex t 20 to 25 y e a rs on t h i s s u b j e c t .
L im ited informa­
Beginning about
1930 and c o n tin u in g t o th e p r e s e n t tim e , th e r e has been an ex pansion of
r e s e a r c h on th e p h y sics of m o istu re movement.
Buckingham’ s co ncept o f c a p i l l a r y flow was u sed .
Gardner and h is
12
a s s o c i a t e s (15) p o in te d ou t t h a t Buckingham's p o t e n t i a l was c l o s e l y
r e l a t e d t o th e p r e s s u r e i n th e w a ter f i l m s .
R ichards (31) some y ears
l a t e r developed an e x p r e s s io n which e s tim a te d m o istu re d i s t r i b u t i o n in
so ils.
No r e a l p r o g r e s s , however, was made in developing a method to
c o n t r o l e v a p o r a tio n d u rin g t h i s p e rio d .
An i n t e r e s t has been developing c o n cern in g e v a p o ra tio n c o n t r o l ,
e s p e c i a l l y i n th e l a s t 10 y e a r s .
Various chem icals have been u sed .
H edricks and Mowry (20) have used HPAN to in c r e a s e w a ter a g g reg ate
s t a b i l i t y and c r e a t e a d ry l a y e r by r a p id i n i t i a l lo s s of m o is tu re .
VAMA-stabilized a g g re g a te s and HPAN have been used by A llis o n and
Moore ( 2 ) , and th e y found an in c r e a s e in pore space and i n f i l t r a t i o n
r a t e w ith no adverse e f f e c t on m o istu re r e t e n t i o n .
Hanks (16) used Arquad 2HT, a w a ter r e p e l l e n t m a t e r i a l , to reduce
c a p i l l a r y flow t o th e s u r f a c e and form, a d ry mulch.
s i m i l a r l y seems to reduce e v a p o r a tio n .
Use of Naptha soap
Soap i s used to reduce th e s u rfa c e
t e n s i o n of th e wet f i l m around th e s o i l p a r t i c l e to reduce movement of
w a te r toward th e s u r f a c e .
done by Kolasew (2 7 ) .
This was quoted by Lemon (28) from th e work
P a i n t s were used by Army (3) to reduce e v a p o ra tio n
and t o in c r e a s e th e le n g th of time w a te r i s h e ld n ear th e s u r f a c e o f the
s o i l and in c r e a s e seed g e rm in a tio n .
Tsiang (34) re p o rte d t h a t rock
mulches have been s u c c e s s f u l l y used i n th e d ry s e c tio n s of China to
reduce e v a p o r a tio n .
Brown and D ic k e y 's (7) e v a p o ra tio n c o n t r o l stu d y on c o rn shows t h a t
p l a s t i c used on n o n i r r i g a t e d p l o t s reduced th e t o t a l w a te r used by the
p la n t.
This means t h a t l e s s w a te r was needed because th e lo s s of w a ter
13
was reduced by th e c o v e r.
Lemon (28) b r i e f l y m entions the review Kolasew made on th e e f f e c t
of s t r a t i f i c a t i o n which red u ces the e v a p o r a tio n lo s s of m o is tu re .
Some o f the work done has been on s o i l f a c t o r s t h a t in flu e n c e
e v a p o r a tio n .
In 1913, H a r r is and Robinson (19) quoted Widstoe as saying
t h a t e v a p o r a tio n of w a te r from bare s o i l in c re a s e d w ith s a t u r a t i o n of
th e s o i l .
The r e s u l t s are confirmed by F i s h e r (13) and Keen e t a l . (2 3 ).
E v a p o ra tio n i s p r a c t i c a l l y c o n s ta n t a t h ig h m o istu re c o n te n t .
F o r t i e r (14)
concluded t h a t th e r a t e of e v a p o r a tio n from s o i l v a r i e s d i r e c t l y w ith
th e amount of m o istu re in the to p l a y e r .
S t a n h i l l (32) compared s o i l
m o istu re e v a p o r a tio n w ith f r e e - w a te r e v a p o r a tio n .
There were no d i f f e r ­
ences in e v a p o r a tio n as long as th e s u rfa c e l a y e r of s o i l remained wet.
King (25) showed t h a t th e d a r k e r - c o lo r e d s o i l s absorb more h e a t
and cause a r i s e in te m p e ra tu re which i n c r e a s e s e v a p o r a tio n .
Bowie (5) claim s t h a t lo s s due to wind i s caused by th e more in tim a te
c o n ta c t of th e a i r w ith m o is t s u r f a c e s .
An average wind v e l o c i t y between
2 .4 and 4 .0 m iles p e r h our and an average w a te r tem p eratu re o f 70° F.
in c re a s e d e v a p o ra tio n due t o wind movement about .5% f o r each m ile of
in c r e a s e in wind v e l o c i t y .
Water vap o r t r a n s f e r becomes the p r i n c i p a l f a c t o r in v o lv ed in w ater
lo s s -once a d ry l a y e r i s formed.
made in v o lv in g t h i s p r o c e s s .
I t i s n e c e s sa ry t h a t some s tu d y be
Hanks (17) found t h a t p o r o s i t y and depth
o f d ry s o i l in flu e n c e d w a te r movement.
d e c re a s e m o is tu re l o s s c o n s id e r a b ly .
A d ry l a y e r of .25 in ch w i l l
Hanks and Woodruff (18) found t h a t
wind v e l o c i t y of O to 25 m ile s p e r hour was shown to in c r e a s e w a te r vapor
14
movement.
Three tr e a tm e n ts were u sed , and s o i l mulch seemed to be the
most s a t i s f a c t o r y .
This i s i n agreement w ith Penman (3 0 ) , who concluded
t h a t a d ry l a y e r 2 mm. th ic k w i l l reduce e v a p o r a tio n by about 90%.
P r i n c i p p i , as quoted by H a rris and Robinson (1 9 ) , found t h a t evapora­
t i o n from m a t e r i a l s w ith th e l a r g e s t pore space was r a p i d .
Wollny (37)
found t h a t c a p i l l a r i t y c e a s e s when th e d ia m e te r o f the p a r t i c l e exceeds
2 mm. in s i z e .
H a rris and Robinson (19) worked w ith d i f f e r e n t - s i z e d
p a r t i c l e s and found d e c r e a s in g m o istu re lo s s w ith d e c re a s in g p a r t i c l e
size .
15
MATERIALS AND METHODS
The l y s i m e t e r p o r t i o n of t h i s study i s a c o n tin u a tio n of th e work
r e p o r te d in a t h e s i s su b m itte d by Bernard L. Brown ( 6 ) , which p re s e n ts
th e method of c o n s t r u c t i o n of th e ly s i m e t e r , as w ell as s o i l ty p es and
tr e a tm e n ts s t u d i e d .
The 1958 d a ta and p re v io u s work i n d i c a t e d t h a t th e r e was a d i f f e r ­
ence i n th e e v a p o r a tio n c y c le of H uffine and B rid g e r s i l t loams.
It
appeared t h a t th e p h y s ic a l p r o p e r t i e s , in a d d i t i o n to th e m e te o ro lo g ic a l
f a c t o r s , were in v o lv e d .
In an e f f o r t t o d eterm in e the s o i l p r o p e r t i e s
t h a t account f o r th e d i f f e r e n c e s , a d d i t i o n a l d e te r m in a tio n s were made in
1958.
For the d e t e r m i n a t i o n s , lo o se samples were tak en from
th e a re a su rro u n d in g the ly s im e te r p l o t s .
These samples were
a i r d r i e d and screen ed th ro u g h a 4-mm. s ie v e f o r a g g reg ate
a n a ly s e s and a 2-mm. s ie v e f o r the rem aining a n aly se s d i s ­
cussed in th e t h e s i s .
Uhland sam plers were used to g e t the
core samples n e c e s sa ry f o r th e p e r m e a b ility and pore s i z e
d i s t r i b u t i o n s tu d y .
I.
Mechanical a n a ly s e s were run on B rid g e r and H uffine s i l t
loams, u sin g th e p i p e t t e method as d is c u s s e d in A g r i c u l t u r a l
Handbook No. 6 0 . ( 3 6 ) .
P r i o r to t h i s d e te r m in a tio n , organic
m a t e r i a l was o x id iz e d w ith hydrogen p eroxide t o reduce th e
cementing m a t e r i a l and to o b ta in b e t t e r d i s p e r s i o n .
A c o n s ta n t- t e m p e r a tu r e b ath was used to e lim in a te th e
change in te m p e ratu re which -would a f f e c t th e s e t t l i n g v e l o c i t y
16
o f th e d is p e r s e d p a r t i c l e s .
Data o b ta in e d were r e p o rte d
as p e r c e n t s i l t p lu s c l a y , p e rc e n t c l a y , p e rc e n t s i l t , and
p e r c e n t sand.
2.
U n satu rated f lo w .— In an a tte m p t to determ ine the cause
o f d i f f e r e n c e in e v a p o r a tio n of B rid g e r and H uffine s i l t
loams, w a te r in ta k e r a t e was s t u d i e d .
The a p p aratu s used
f o r measuring Q, th e i n t a k e , and d Q /d t, th e r a t e of i n t a k e ,
i s shown in f i g u r e I .
The w a te r supply (D) p a ssin g through
th e h o r i z o n t a l c a l i b r a t e d b u r e t t e (E) i s drawn from th e
b e ak e r (B) in which a c o n s ta n t w a te r l e v e l i s m a in ta in e d ,
u sin g M a r io tte ’ s p r i n c i p l e .
The w a te r supply (A) i s th e
so u rce of w a te r which m a in ta in s the c o n s ta n t w a ter l e v e l .
The amount of w a ter p a ss in g in t o th e s o i l ( I ) i s measured
by in tr o d u c in g an a i r bubble (C) w ith a hypodermic needle
i n t o th e c a l i b r a t e d tu b e , and by r e c o rd in g th e tim e , t ,
r e q u ir e d f o r i t to pass through t h i s known volume ( .1 m l . ) ,
d a ta i s o b ta in e d t o c a l c u l a t e the r a t e of w a te r e n te r in g
i n t o th e s o i l .
im ent.
Two s to p watches were used d u rin g th e ex p er­
One s to p watch was used to re c o rd th e t o t a l tim e , t ,
e la p s e d , and th e o t h e r was used to re c o rd th e t i m e , A t ,
r e q u ir e d f o r the a i r bubble to pass th ro u g h the known
volume, dQ.
The a i r bubble was c o l l e c t e d in a t r a p ( p ) .
Water r e s e r v o i r (G) was used to f l u s h th e a i r c o l l e c t e d in
th e system .
The w a te r a p p l i c a t o r (H) has a f in e b ra s s
s c re e n s e a le d to th e bottom to p ro v id e a source of w a te r
Water supply (A)
Elapsed time
Watch (A t)
Water r e s e r v o i r
A ir t r a p (F) p
Water a p p l i c a t o r (H)
Air bubble supply (C)
C a lib r a te d c a p i l l a r y tube
T e st s o i l
(I)
Manometer
F ig u re I .
Apparatus f o r measuring AQ/At as a f u n c tio n of tim e.
18
a t a c o n s ta n t head.
A manometer ( j ) , connected to the
w a te r supply (B ), i s lo c a te d a d ja c e n t to th e t e s t s o i l to
f a c i l i t a t e a d e te r m in a tio n of th e h y d r o s t a t i c head.
The s o i l c o n t a i n e r used c o n s is te d of a g la s s tube 18
in c h e s long (4 5 .7 cm.) w ith an in s id e d ia m e te r of 25 mm.
This tube was c lo se d a t th e bottom w ith c h e e s e c lo th to
l e t th e a i r escape f r e e l y .
Only l i n e a r flow was c o n sid e re d
in t h i s ex p erim en t.
Emphasis was p la c e d on th e uniform packing of th e s e
tu b e s .
T h e re fo re , in f i l l i n g , a tube s m a lle r in s i z e was
p la ce d i n s id e th e l a r g e r tu b e .
Excess s o i l was p laced
in s i d e th e s m a lle r tube and p u lle d ou t a t c o n s ta n t r a t e to
allow th e s o i l to run o u t.
A v i b r a t o r was used sim u lta n e o u s ly
to in c r e a s e u n if o r m ity of packing.
once from a h e ig h t of I cm.
These tubes were dropped
All th e tu b e s were f i l l e d and
packed in a s i m i l a r manner.
In measuring th e i n f i l t r a t i o n r a t e , th e s o i l tube was
p o s itio n e d v e r t i c a l l y .
Zero p r e s s u r e was ap p lie d th ro u g h ­
o u t th e experim ent (w a te r le v e l being equal to th e s u rfa c e ,
o f th e s o i l ).
The d i s t a n c e of th e w etted f r o n t from the source of
w a te r was re c o rd ed as a f u n c tio n of tim e .
Data o b ta in e d was computed and p re s e n te d as dQ /dt and
t o t a l tim e .
This was p u t on lo g -lo g c o o rd in a te graph
p a p e r, and th e slo p e of th e l i n e was o b ta in e d .
19
3.
For deg ree o f a g g re g a tio n , th e method d e s c rib e d in
A g r i c u l t u r a l Handbook No. 60 (36) was u sed .
The method
in v o lv ed measuring th e c o n c e n tr a tio n of th e su sp en sio n of
th e two samples of each s o i l .
The p i p e t t e method was used
to g iv e t o t a l s i l t p lu s c la y ; and th e hydrometer method
was used in measuring unaggregated s i l t p lu s c la y .
The
w a t e r - s t a b l e a g g re g a te s l a r g e r th an 50 microns in s i z e
were determ ined by th e d i f f e r e n c e in c o n c e n tr a tio n between
th e two s u sp e n sio n s.
The d a ta o b ta in e d was r e p o r te d as
p e r c e n t s i l t and c l a y ag g reg ated i n to s t a b l e a g g re g ate s
l a r g e r th a n 50 microns in s i z e .
4.
S a tu r a te d flow and pore s iz e d i s t r i b u t i o n were
determ ined u sin g th e Uhland and O 'N eil (35) te c h n iq u e .
To p ro v id e a r e s e r v o i r , a 1 -in c h e x te n s io n was placed on
to p o f the 3 -in c h c y l i n d e r s c o n ta in in g the u n d is tu rb e d s o i l
sam ples.
C h ee sec lo th was used, on th e bottom to keep th e
s o i l in p la ce and to l e t th e w a te r o u t f r e e l y .
A ta n k ,
4 f e e t x I f o o t x 6 in c h e s , provided a source of w a te r .
A
c o n s ta n t h y d r o s t a t i c head was m a in ta in ed by flowing ex cess
w a te r in to the tank which was pro v id ed w ith an o v erflo w .
P e r c o l a t i n g w a te r was re c o rd ed a f t e r each hour and c o n tin u ed
f o r 3 h o u rs .
The d a ta are p re s e n te d as "K" v a lu e s , a
p e r m e a b il ity c o n s ta n t c a l c u l a t e d from th e e q u a tio n , Q = . .fefot.
where "Q" = q u a n t i t y of HgO p e r c o l a t e d , "K" = a v a lu e
depending upon s o i l p r o p e r t i e s , "a" = th e area of th e
20
c o n t a i n e r , Mh" = th e "head" a p p lie d , " t " = th e time in
m in u te s , and " I " = th e le n g th o f th e s o i l column.
The s a t u r a t e d s o i l samples were p la c e d on a ceramic
t e n s i o n cup and p la c e d a t 0, 10, 30, 6 0 , 100, and 150 cm.
o f w a te r t e n s i o n f o r a p e rio d of I , 2, 4 , 4 , 12, and 12
h o u rs , r e s p e c t i v e l y .
reach e q u ilib r iu m .
This is r e q u ir e d f o r th e system to
The lo s s of m o istu re was reco rd ed by
weighing a f t e r each r e s p e c t i v e tim e.
From th e d a t a , th e minimum :pore s i z e d ra in e d was
c a l c u l a t e d f o r each t e n s i o n u sed .
The ra d iu s of th e pore
s i z e i s c a l c u l a t e d u sin g the e q u a tio n , TT = -g-hdgr, where
y = th e s u r f a c e t e n s i o n of w ater a t 25° Q ., "h" = th e h e ig h t
a t which th e t e n s i o n cup was p laced from th e re f e r e n c e p o i n t ,
"d” = th e d e n s it y of w a te r , "g" = a c c e l e r a t i o n of g r a v i t y ,
and " r " = th e r a d iu s of th e pore sp ac e .
P e rc e n t of th e
t o t a l p o res d ra in e d between each p a i r of te n s io n s was computed
from th e e q u a tio n , (A_z_S) x 100. (A - B) i s th e w eig h t lo s s
C
between two te n s io n s and C i s th e t o t a l grams o f w a te r a t
s a t u r a t i o n (w eight o f s a t u r a t i o n minus dry w eight of s o i l ) .
From th e s e d a t a , a d e s o r p tio n curve was p rep ared and
p r e s e n te d .
In fo rm a tio n was o b ta in e d concerning the w a te r
r e l a t i o n in the s o i l and th e amount of w a te r h eld a t v a r io u s
energy ra n g e s.
The a p p aratu s used f o r t h i s experim ent i s shown in
f i g u r e 2.
21
P l a s t i c co v er
1 -in ch e x te n s io n
3 -in c h c y l i n d e r c o n ta in in g
s o i l sample
Ceramic t e n s i o n cup
cm. te n s io n
F ig u re 2.
Apparatus f o r co n d u ctin g w a te r th rough a porous membrane to
study th e m o istu re c h a r a c t e r i s t i c s of s o i l a t low te n s i o n s .
22
E f f e c t of S o il Depth on Drying P r o p e r t i e s
To a s s i s t in e v a lu a tin g th e im portance of th e d i s ­
c o n t i n u i t y a t a d epth o f 4 inches in th e l y s i m e t e r , two
s e c t i o n s of tu b e , 4 and 18 inches lo n g , were f i l l e d and
packed w ith each of H u ffin e and B rid g e r s o i l .
These tu b e s
were f i l l e d and packed s i m i l a r l y by th e method d is c u s s e d in
th e e a r l i e r s e c t i o n s .
In t h i s e x p erim en t, th e 4 -in c h tu b e s f i l l e d w ith s o i l
were s a t u r a t e d w ith w a te r w ith th e a p p a ra tu s shown in f i g u r e I .
To p re v e n t s o i l lo s s d u rin g w e ttin g , a f i l t e r p ap er was
p la c e d i n th e bottom of the tube and h e ld in p lace w ith a
p la s t ic screen.
The q u a n t i t y of w a te r e n te r in g in t o th e s o i l
was measured by w eighing th e s o i l b e fo re w ater was a p p lie d and
a fte r sa tu ra tio n .
This same q u a n tity of w a ter was p la c e d in
th e 1 8 -in c h -lo n g tu b e , and th e tu b e was s e t asid e f o r d ry in g .
In th e 4 - in c h tu b e , p a r a f f i n was used t o s e a l the bottom to
avoid w a te r lo s s from th e bottom.
M oisture l o s t was determ ined
by d a i l y weighing of each sample.
The tem p e ratu re i n th e room
in which th e d e te r m in a tio n s were made f l u c t u a t e d from 24° C.
to about 30° C.
23
RESULTS AND DISCUSSION
This stu d y is a c o n t i n u a t i o n of th e work i n i t i a t e d by Brown ( 6 ) ,
who p re s e n te d th e 1957 d a ta in t h e s i s form.
While the m ajor u n d ertak in g
in the stu d y is a p r e s e n t a t i o n and i n t e r p r e t a t i o n of the 1958 d a t a ,
Brown's (6) d a ta i s f r e q u e n t l y used f o r com parative p u rp o se s.
The 1958
d a ta c o n s i s t e d of r a i n f a l l re c o rd s and semiweekly ly s im e te r w eights and
p e r c o l a t i o n re c o rd s f o r each ly s im e te r .
Only r a i n f a l l d a ta was c o l l e c t e d f o r th e w in te r months, s in c e snowcovered ground and fro z e n s o i l s made th e c o l l e c t i o n of p e r c o l a t i o n d a ta
im p rac tic al.
Leachate from th e s p rin g snowmelt ( t a b l e I ) was c o l l e c t e d ,
b u t no i n t e r p r e t a t i o n of th e w in te r s to ra g e e f f i c i e n c y could be made
because of th e wide v a r i a b i l i t y w ith in th e tre a tm e n ts'.
I t i s b e lie v e d
t h a t th e fr o z e n s o i l caused th e w a te r to accumulate on th e s u rfa c e of the
ly s im e te r s which e i t h e r overflow ed th e fre e b o a rd or e v a p o r a te d , w hile the
lower s o i l in the ly s im e te r s was s t i l l fr o z e n and p rev en ted p e r c o l a t i o n .
For convenience in i n t e r p r e t a t i o n , th e d a ta p re s e n te d in t a b l e TI
has been summarized by c l i m a t i c p e rio d s on th e b a s is of r a i n f a l l ( t a b l e I I I )
and te m p e ratu re ( t a b l e IV).
The s u b d iv is io n s were: (a ) c o o l-w e t; (b) warm-
d r y ; (c ) warm-wet; (d) h o t- m o is t; and ( e ) c o o l- d r y , as o u tlin e d in
t a b l e V.
The te m p e ratu re and r a i n f a l l ran g es used f o r s e l e c t i n g p erio d s
i n 1958 d i f f e r e d somewhat from th o se used i n 1957.
When Brown's (6) d a ta
i s r e f e r r e d t o , th e p e rio d s have been r e c l a s s i f i e d acco rd in g to p re s e n t
te rm in o lo g y .
These p e rio d s were su b d iv id ed t o a id in d i f f e r e n t i a t i n g between the
d ry in g p a t t e r n in th e d i f f e r e n t p e r io d s .
Not a l l s ix p e rio d s o b tain ed
24
Table 1«
P e r c o l a t i o n from snowmelt f o r w in te r and s p rin g months (in
m i l l i l i t e r s ) , 1957-58.
S o i l s and
tre a tm e n ts
Box
No.
Nov. I , 5 7 Mar. 26» 58
Mar. 26, 58Apr. 9» 58
Apr. 9, 5 8 Apr. 12. 58
T o tal f o r
p eriod
Manhattan
I '
19
21
4 ,730
68
0
4,730
4 ,7 3 0
1,950
42
10 .
170
9,502
4,808
2,120
H uffine
9
15
23
0
2,675
235
4 ,7 3 0
0
525
187
97
140
4,917
2,772
900
Huntley
3
18
27
0
1,000
1,200
4,730
1,450
4,730
196
52
84
4,926
2,514
6,014
B rid g e r
6
11
29
100
1,050
• 4,730
4,730
4,730
4 ,7 3 0
160
118
145
4,990
5,898
9,605
Rock mulch
10
13
25
3,000
225
125
100
4,730
4,730
8
275
145
3,108
5,220
5,000
Straw mulch
I
12
22
1,925
275
4 ,7 3 0
0
0
0
22
5
157
1,947
280
4,887
VAMA c o a rse
2
16
28
4,730
230
0
675
0
3,275
137
133
111 ‘
5,542
363
3,386
S u rfa c ta n t■
5
14
24
4,730
4,730
30
0
4,730
0
230
102
89
4,960
9,562
119
VAMA fin e
4
20
30
0
460
4,730
4,730
4 ,7 3 0
4 ,7 3 0
62
43
93
4,792
5,233
9,553
Check
8
17
26
4,730
• 55
4,730
0
4 ,730
4,730
322
48
376
5,052
4,833
9,836
*
.
Table I I .
P e rio d s i n t o which d a ta was subdivided and c lim a tic in fo rm a tio n by p e rio d s .
Perio d
Days
in
p e rio d
A p ril I 2-May 28
46
May 28-June 16.
Average
E vaporation
maximum
. (in c h e s ) •
P e rio d
P r e c i p i t a t i o n tem pera- from f r e e ­
PE
c la ssific a tio n
( in c h e s )
tu re
w a ter s u rfa c e index
C ool-m oist
1 .54
65 .5
9.7 4
16
. 19
Cool-wet
2.08
6 7 .8
3.44
60
June 16-June 26
10
Warm-dry
0.73
76.9
3.36
22
June 26-August 4
39
Warm-wet
4.43
76.5
10.20
43
August 4-August 28
24
H ot-m oist
1.86
83.3
6.4 7
29
August 28-O ctober 30
63
C ool-dry
2.05
67.3
9.20
22
26
Table I I I .
A p ril
I
2
3
4
5
6
7
8
9
10
T o ta l
J u ly
August
0 .0 0
0 .00
0 .02
.46
0.00
.08
.39
.08
.43
.09
0.11
.09
.27
.03
• T
.05
.16
.02
.14
.03
.08
.48
.06
.67
.31
.24
.10
.02
.02
.13
.24
.21
.02
.12
.02
.56
.09
.60
.04
.10
.14
.07
2.23
0.0 0
.06
October
0.20
.04
.17
.06
.02
.12
.20
.06
September
.04
.01
.02
.01
O
O'
21
22
23
24
25
26
27
28
29
30
31
June
.05
.05
.47
.02
CM
O
11
12
13
14
15
16
17
18
19
20
May
CO
CO
Day
D aily p r e c i p i t a t i o n (in c h e s ) in 1958 as reco rd ed by th e r a i n
gauge lo c a te d a d ja c e n t t o th e l y s i m e t e r s .
.87
.09
.01
.03
.22
.03
.04
.20
.03
.63
.34
.43
.02
.02
.06
.32
.11
0.8 0
.11
.18
.21
.41
. 16
.27
2.55
3.6 7
2.55
T o ta l p r e c i p i t a t i o n f o r p e rio d A pril to O ctober, 1958
1.37
=
0.47
13.64 inches
27
Table TV.
Day
D aily maximum te m p e ratu re ( i n d e g re es F a h re n h e it) f o r 1958 as
re c o rd ed by th e U. S . Weather Bureau c o o p e r a tiv e s t a t i o n a t
Montana .S ta te C o lle g e .**
A p ril
May
June
J u ly
August
9
10
53
51
53 .
49
40
40
46
41
44
46
64
69
69
66
73
72
61
68
70
78
68
65
57
72
68
73
72
68
64
65
68
69
65
65
70
69
65
74
78
78
86
89
82
77
77
82
90
90
73
83
11
12
13
14
15
16
17
18
19
20
50
57
68
67
68
63
67
62
55
52
78
73
59
63
71
74
73
74
83
84
64
59
57
68
72
76
75
75
62
69
81
85
86
69
71
80
79
80
79
82
89
88
88
88
88
90
87
82
80
77
87
80
64
59
61
75
68
67
74
59
21
22
23
24
25
26
27
28
29
30
31
52
42
33
37
47
45
39
39
50
58'
80
82.
80
75
83
82
81
84 ■
51
70
67
/
80
84
75
69
80
91
88
75
61
82
85
86
77
82
76
72
85
78
72
81
80
81
76
81
85
85
85
82
75
69
79
76
75
71
45
58
60
69
60
63
. 54
1
2
co
in xo r- co
— I n d i c a t e s no re c o rd a v a i l a b l e .
* W ithin o n e - h a lf m ile o f ex p erim en tal s i t e .
September
.
87
74
75
72
73
77
87
89
82
77
.
October
49
63
72
75
79
71
64
57
.
B toaa
60
73
78
75
«™
75
67
70
80
72
44 48
50
60
—
• 46
52
53
52
58
56
—
28
Table V.
B asis f o r c l a s s i f y i n g p e rio d s from average maximum tem perat u r e and r a i n f a l l c a l c u l a t e d to 30 d ays.
R ain fall c la s s if ic a tio n
0-1 inch
Dry
1-3 inches
Moist
> 3 inches
Wet
Temperature c l a s s i f i c a t i o n
< 6 9 ° F.
Cool
70-79° F.
Warm
> 800 f .
Hot
29
in 1958 were s i m i l a r to th o s e encountered i n 1957.
For i n s t a n c e , i n 1958,
no h o t- d r y p e rio d was e n c o u n te re d , a lth o u g h one occurred i n 1957.
e v e r , a warm-wet and a warm-dry p e rio d p r e v a ile d in 1958.
How­
S ince compar­
a t i v e d a ta f o r th e s e p e rio d s are no t a v a i l a b l e , th ey are d is c u s s e d ahead
o f and s e p a r a te from th e o t h e r p e rio d s d u rin g th e p r e s e n t a t i o n of " E ff e c t
of S o il Types and S o il Treatm ents on E v a p o ra tio n and P e r c o l a t i o n f o r
D i f f e r e n t C lim a tic P e r io d s " .
T h o rn th w aite (33) has p re s e n te d a map on "C lim ates o f th e United
S t a t e s " , based on th e PE in d ex .
The PE in d e x , ta b le I I , was c a lc u la te d
t o d e cid e what c l i m a t i c type of p e rio d s o ccu rred in 1958.
According to
h i s c l a s s i f i c a t i o n , th e c o o l- m o is t, warm-dry, h o t- m o is t, and c o o l-d ry
p e rio d s are a l l c l a s s i f i e d as " s e m ia rid " type of c lim a te .
The cool-w et
p e rio d i s " m o is t, subhumid" c lim a te ; w hile th e warm-wet p e rio d is
c l a s s i f i e d as "d ry , subhumid".
and no d i s c u s s i o n w i l l be made.
This was p re s e n te d e n t i r e l y f o r i n t e r e s t ,
E v a p o ra tio n d a ta i s shown in t a b l e VI.
E f f e c t of S o il Types and S o il Treatmen ts on
E v a p o ra tio n and P e r c o l a t i o n f o r D i f f e r e n t C lim atic P e rio d s
The fo llo w in g p r e s e n t a t i o n w i l l be a d i s c u s s i o n of th e r e s u l t s
o b ta in e d f o r th e 2 y e a r s .
Table VII shows th e r e s u l t s f o r e v a p o ra tio n
d u rin g each p e r io d , and t a b l e V III shows th e amount of p e r c o la te d w ater
c o l l e c t e d f o r th e same p e rio d i n 1958.
For comparison between y e a r s ,
Brown's (6) 1957 d a ta has been in clu d ed as appendix t a b l e s XVI, XVII, and
XVIII.
I t was b e lie v e d t h a t , i n s e v e r a l p e r i o d s , small amounts o f w ater
d i s t i l l e d from th e lower b o u n d aries of th e s o i l .
Since no s e p a r a tio n
30
Table VI.
Day
D aily e v a p o r a tio n from a f r e e - w a t e r s u rfa c e as compiled from
th e U. S . Weather Bureau c o o p e r a tiv e s t a t i o n a t Montana S ta te
C o lle g e .
A p ril
May
E v ap o ratio n in inches
June
J u ly
August
September
October
*
*
.94
.05
0.24
.27
.23
.23
.27
.35
.12
.15
.22
.25
0 .1 7
.17
.06
.22
.25
.15
.27
.20
.17
.10
0.17
.29
.17
.15
.27
.34
.20
.15
.50
.09
*
*
1.00
0.26
.30
.39
.26
.39
.10
.24
0 .39
.21
.19
.21
.20
.23
.28
.27
.20
.05
0 .0 2
.06
.12
.13
.17
.19
.11
.15
.12
.08
11
12
13
14
15
16
17
18
19
20
' .1 2
.16
.18
.22
.22
.14 '
.18
.14
.18
.14
.33
.22
.16
.33
.21
.30
.31
.35
.41
.29
.26
.09
.20
.01
.30
.21
.27
.21
.32
.11
.44
.32
.35
.23
.25
.34
.37
.24
.25
.27
.28
.23
.30
.33
.38
.35.
.28
.29
.18
.21
.34
.15
.19
.12
.16
.17
.20
.15
.19
.20
.08
.17
.13
.08
.25
.28
.11
.27
.23
.01
21
22
23
24
25
26
27
28
29
30
31
.08
.00
.10
.05
.1 2
*
*
*
.25
.08
.27
.27 '
.29
.26
.30
.34
.40
.29
.31
.15
.15
.22
.23
.31
.29
.22
.30
.46
.42
.20
.10
.46
.34
.39
.19
.37
.17
.19
.33
.26
.13
.42
.26
.20
.29
.23
.28
.32
.38
.19
. 16
.23
.06
.24
.15
*
*
.07
.10
.13
.03
.19
.13
.06
.05
.07
.05
.0 8 .
.09 '
.05
.03
.05
.06
.07
6 .4 9
8 .6 4
8.27
5 .1 4
I
2
3
4
5
6
I
8
9
10
T o ta l
0.28
.03
.04
——
4 .1 1 * *
8.2 7
.
3 .4 2
T o ta l e v a p o r a tio n f o r p e rio d A pril 26 to October 30, 1958 = 40.56 inches
—No re c o rd a v a i l a b l e .
* Amount in c lu d e d i n th e fo llo w in g measurement.
**A djusted to f u l l month.
Table V II.
P r e c i p i t a t i o n and e v a p o ra tio n ( i n grams) f o r ly s im e te r a r e a s , A p ril 12 to October 30,
1958.
A p ril 12JMav \28
Coolm o ist
Treatment
P re c ip ita tio n ,
q m s . / l j 0 6 l cm.2
Manhattan
H uffine
Huntley
B rid g er
Rock mulch
Straw mulch
VAMA c o arse
VAMA fin e
S u r f a c ta n t
B ridgdr check
Average
E v a p o ra tio n
E v a p o ra tio n
E v ap o ratio n
- E v ap o ratio n
E v ap o ratio n
E v a p o ra tio n
E v ap o ratio n
E vap o ratio n
E vaporation
E v ap o ratio n
May 28June 16
C o o lwet
S e le c te d p e rio d
June 16- June 26Auq. 4
June 26
Warm■ Warmdry
wet
Aug. 4 Auq. 28
Hotm o ist
Aug. 28Oct. 30
Cooldry
Seasonal
to ta l
4,150
5,606
- 1,967
11,939
5,013
5,525
34,200
8,299
7,999
9,986
8,703
6,497
8,829
8,757
8 ,602
8,427
8,644
4,393
3 ,936
4,049
4,012
2,393
3,817
4,337
4,234
4,021
3,999
2,003
2,083
1,867
1,967
1,827
2,061
1,935
1,996
1,915
1,982
11,375
10,435
10,989
10,875
- 7,022
10,249
11,192
11,396
11,218
10,853
5 ,4 5 2
5,501
5,589
5,512
4,047
5,427
5 ,529
5*499
5,532
5,524
5,509
4,956
5,887
5,203
4,295
5,442
5,248
5,426
5,632
5,150
37,031
34,910
38,367
36,272
26,081
35,825
36,998
37,158
36,, 745
36,154
8,474
3,919
1,964
10,560
5,361
5,275
35,554
Table V I I I .
P r e c i p i t a t i o n and p e r c o l a t i o n ( i n grams) f o r l y s im e te r a re a s and p e r c o la ti o n
e f f i c i e n c y ex p re ssed as p e rc e n t o f t o t a l r a i n f a l l by s e l e c t e d periods, A p ril 12
to O ctober 3 0 , 1958.
S e le c te d p eriod
A p ril 12- May 28- June 16- June 26- ■ Aug. 4 - Aug. 28May 28
June 16 June 26
Auq. 4 Auq. 28 Oct. 30
1958
Seasonal
WarmHotCoolWarm.C oolC oolm o ist
wet
viet
d ry
dry
m oist
average
T reatm ent
P rec ip ita tio n ,
q m s . / l , 0 6 l cm.^
Manhattan
_
H uffine
____________ _
Huntley
_
B rid g er
_
Rock mulch
_
Straw mulch
_
VAMA c o a rse
_
VAMA f in e
_
S u rfactan t
_
B rid g e r check
4,150
5,606
P e r c o la tio n
172
32
^ .E ffic ie n c y . _
3 .5 . _ 0 . 6
. P e r c o la tio n
147
27
. / ^ . E f f i c i e n c y _ _ 2 .9 _. _ 0.5
P e r c o la tio n
42
18
. ^ . E f f i c i e n c y . - 0 . 8 _. - 0 . 3
150
P e r c o la tio n
18
3 .0
.^ .E ffic ie n c y _
0.3
P e r c o la tio n
1,511
1,014
- ^ - E f f i c i e n c y _ - 3 0 .0 . _ -1 8 .1
P e r c o la tio n
145
13
. ^ . E f f i c i e n c y . - 2 .9 _- - 0 . 2
P e r c o la tio n
115
29
. ^ . E f f i c i e n c y _ _ 2.3 .
0 .5
P erco latio n
152. ■
50
^ - E f f i c i e n c y . . _ 3 . 0 _ _ 0. 9
P e r c o la tio n
124
22
- ^ - E f f i c i e n c y . . . _ 2 .5 .- _ 0 . 4
P e r c o la tio n
137
15
% E f f ic ie n c y
2 .7
0 .3
1*967
49
- - _2JL
51
_.__2^_
13
■ 0. 6
36
1.8
196
_ - IOzO35
_____ I J L
42
_____ 2J L
50
_ _ -2 JL
37
_____ L 9 _
33
1.7
/ V
11,939
5,013
333
--2.8
1,054
8 .8
162
_ _ 1- 1
701
-----—*—
4,624
- -3 8 .1
855
-- I.2
387
--3 .2
220
_ _ 1 '8
346
--2.9
653
5 .4
197
--3.9
159
--3 .2
81
- - 1.6
169
__3.4
1,419
- -2 8 .3
193
___ 3. 8
140
--2 .8
145
--2.9
150
_ _ f .o
148
3 .0
5*525
1957
Seasonal
average
34,200
193
1,026
3 .5 - - 2. 9
736
2,174
_ _ 1 3 J - - - 6 .2
. 68
389
_____ lz.2—
470
1,668
8. 5 - _ 1-8
1,683
10,447
- - 3 0 J )_ - -2 9 .8
473
1,715
8. 5 - - 1 . 9
. 417
1,133
3.2
______T J L
243
861
_
_
2. 5
_____ 4J L
83
762.
2 .2
_____ Ij-O521
1,513
9 .4
~4.3
30,696
_
_
_
_
_
_
_
_
5,646
17.6
6,554
20.5
2,191
6 .8
4,570
_ - 1 4 .3
19,328
6 0,4
5,014
15.7
5,888
_ - 1 8 .4
5,185
- - 1 6 .2
4,663
14.6
4,896
15.3 .
33
between p e r c o l a t i o n and d i s t i l l a t i o n could be made, any p e rio d in which
100 c c . o r l e s s w a te r was c o l l e c t e d was assumed to be d i s t i l l a t i o n .
Warm-Dry P e rio d — June 16 to June 26, 1958
E f f e c t o f S o il D iff e re n c e s
Throughout t h i s p e r i o d , th e fo u r s o i l s behaved s i m i l a r l y w ith reg ard
to e v a p o r a tio n .
Huntley s o i l had th e l e a s t e v a p o ra tio n ( l ,867 grams) and
th e l e a s t d i s t i l l a t i o n (13 gram s).
H uffine s o i l , however, l o s t the
g r e a t e s t amount of w a ter by e v a p o r a tio n (2,083 grams) and d i s t i l l e d the
most w a te r (51 gram s).
In t h r e e o f th e s o i l s , e v a p o ra tio n exceeded th e t o t a l amount of r a i n ­
f a l l (.7 3 in c h ) which o c cu rred d u rin g t h i s p e r io d .
This was l o s t a t th e
expense o f th e s to r e d m o istu re from th e p re v io u s p e rio d .
D istilla tio n
in c re a s e d o v er the p re v io u s p e rio d ( c o o l—w e t) , and i t appears t h a t the
h ig h e r s o i l tem p e ratu re in th e second p e rio d encouraged d i s t i l l a t i o n .
E f f e c t of S o il T reatm en ts
Rock mulch was most e f f e c t i v e in red u c in g m o istu re lo s s by evapora­
t i o n ( l , 8 2 7 gram s).
of m o is tu re .
This tr e a tm e n t a ls o p e r c o la te d o r d i s t i l l e d 196 grams
S ince 185 grams o f t h i s amount was c o l l e c t e d i n th e d ata
ta k e n on June 26, i t i s assumed t h a t th e 185 grams was m ostly p e r c o l a t i o n .
The d i f f e r e n c e s among tr e a tm e n ts d u rin g t h i s p e rio d were n o t la r g e enpugh
to m a t e r i a l l y in flu e n c e se a s o n a l e f f i c i e n c y .
Warm-Wet P e rio d — June 26 t o August 4, 1958
E f f e c t of S o il D iff e re n c e s
I t was d u rin g t h i s p e rio d i n 1958 t h a t th e h ig h e s t r a i n f a l l was
re c o rd ed (4 .4 3 in c h e s ) .
This p e rio d fo llo w e d .a dry p e r io d , b u t th e r e was
34
s u f f i c i e n t r a i n f a l l f o r th e s o i l to absorb th e w ater and s t i l l p e r c o la te
some w ater.. . H u f f in e 9 d u rin g t h i s p e r io d , had th e h ig h e s t p e r c o l a t i o n of
1,054 grams and 440 grams l e s s e v a p o ra tio n th an B rid g er which was the
second h i g h e s t in p e r c o l a t i o n .
Huntley and Manhattan follow ed c l o s e l y
behind w ith l e s s e f f i c i e n c y th a n B rid g e r.
H uffine seems to have the b e s t
p r o p e r t i e s f o r red u cin g e v a p o r a tio n in t h i s c l i m a t i c p a t t e r n .
D espite
having 4.4 3 inches of r a i n f a l l , alm ost a l l o f th e 11,939 grams of r a i n f a l l
was e v a p o ra te d .
This high e v a p o ra tio n i s p ro b ab ly due to th e s c a t t e r i n g
showers which enabled th e m o istu re to r e t u r n to th e atmosphere w ith o u t
p a ss in g th ro u g h th e s o i l .
Only once was t h e r e s u f f i c i e n t r a i n f a l l in
excess of e v a p o r a tio n t o s a t u r a t e th e s o i l and i n i t i a t e p e r c o l a t i o n .
E f f e c t of S o il Treatm ents
In 1958, rock mulch was th e o u ts ta n d in g tr e a tm e n t, lo s in g only 7,022
grams of w a te r by e v a p o r a tio n arid p e r c o la ti n g 4,624 grams.
H alf of the
t o t a l p e r c o l a t i o n f o r th e e n t i r e season o ccu rred du rin g t h i s p e rio d .
Straw mulch was th e n e x t most e f f i c i e n t tr e a tm e n t w ith 855 grams of w ater
p e r c o l a t i n g f o r s to r a g e and lo s in g 10,249 grams by e v a p o r a tio n -.'
Again th e
d i f f e r e n c e s in th e rem aining tre a tm e n ts f o r e v a p o r a tio n were s m a ll,
grouped t o g e t h e r , and d id n o t d i f f e r much from th e check.
In m o istu re
s t o r a g e , th e rem aining tr e a tm e n ts showed low c a p a b i l i t y of p e r c o la ti n g
w a te r.
ness.
I t may be t h a t some of th e tr e a tm e n ts are lo s in g t h e i r e f f e c t i v e ­
Some s o i l ten d s t o d i s p e r s e a f t e r t r e a tm e n t, making w a te r more
a v a i l a b l e f o r e v a p o r a tio n by rem aining on th e s u r f a c e , and thus d e c re a sin g
p e rc o latio n .
35
C ool-M oist P e rio d - - A p ril 12 to May 28, 1958
E f f e c t of S o il D iff e re n c e s
The p e rio d A p ril 12 to May 28 showed H uffine to have th e l e a s t
e v a p o r a tio n lo s s e s (7 ,9 9 9 g ram s), follow ed by Manhattan (8 ,2 9 9 gram s),
B rid g e r (8,703 g ram s), and Huntley (9,986 gram s).
In c o n t r a s t ,
Manhattan p e r c o la te d 172 gramsj B rid g e r, 150 grams; H u ffin e , 147 grams;
and H u n tley , 42 grams. '--When th e p e rio d s t a r t e d , th e i n d iv id u a l w eights
o f th e ly s im e te r s i n d ic a te d them to be f u l l y s a t u r a t e d .
Most of the
e v a p o r a tio n , t h e r e f o r e , o ccu rred a t th e expense of th e m o istu re s to re d
d u rin g th e w in te r months.
This was i l l u s t r a t e d , b y th e f a c t t h a t many of
th e ly s im e te r s ev ap o rated tw ic e th e amount of r a i n f a l l t h a t occurred
d u rin g th e p e r io d .
In 1957, the. c o o l-m o is t p e rio d o ccu rred between May 3 and June 6.
E v a p o ra tio n d id n o t exceed r a i n f a l l , bu t i t i s b e lie v e d t h a t some of the
m o is tu re was l o s t p r i o r to t h i s p e r io d .
However, th e p a t t e r n of evapora­
t i o n was s i m i l a r t o 1958, w ith H uffine lo s in g th e l e a s t amount of w a te r.
A lso, H u ffin e was th e most e f f i c i e n t in p e r c o l a t i o n w ith 2,551 grams;
follow ed by M anhattan, 1,699 grams; B rid g e r, 1,095 grams; and H untley,
12 grams.
In 1957, n e a r ly 95% of th e t o t a l p e r c o l a t i o n o ccu rred in th e
months of May and Ju n e, w h ile in 1958, i t was d i s t r i b u t e d th ro u g h o u t th e
seaso n .
E f f e c t of S o il Treatm ents
Rock mulch has th e u n u su al p ro p e rty of red u cin g e v a p o r a tio n through­
o u t th e s e a so n .
The i n i t i a l p e rio d in 1958 showed rock mulch to have th e
l e a s t amount of w a te r l o s t by e v a p o ra tio n (6,497 gram s).
Of th e remaining
36
t r e a t m e n t s , s u r f a c t a n t was th e only tr e a tm e n t t h a t was more e f f e c t i v e
th a n th e check.
In p e r c o l a t i o n , rock mulch was th e most e f f i c i e n t w ith
1,511 grams, and th e rem aining tre a tm e n ts d id n o t d i f f e r g r e a t l y from
th e check.
In 1957, rock mulch, f o r th e comparable p e r io d , was a ls o th e most
e f f e c t i v e s o i l , lo s in g only 2,227 grams as compared to B rid g e r check which
l o s t 6,543 grams.
check in 1957.
The two VAMA tre a tm e n ts were more e f f e c t i v e th a n th e
In 1957, rock mulch c o l l e c t e d 6,155 grams of p e rc o la te d
w a te r , which was alm ost f o u r tim es as much as in 1958.
In 1957, straw
mulch p e r c o la te d only about 65% as much w a te r as th e check.
Cool-Wet P e rio d — May 28 t o June 16, 1958
E f f e c t of S o il D iff e re n c e s
During t h i s p e r io d , th e maximum d i f f e r e n c e in e v a p o r a tio n occurred
between H u ffin e and Manhattan.
The lo s s e s in excess of t h a t from Huffine
were M anhattan, 457 grams; B rid g e r, 76 grams; and H untley, 113 grams.
There was v e ry l i t t l e d i s t i l l a t i o n d u rin g t h i s p e rio d , Manhattan having
th e h i g h e s t d i s t i l l a t i o n of 32 grams and H uffine 27 grams.
Between
w eig h in g s, th e p e r c o l a t i o n c o l l e c t e d n ev er exceeded 25 grams in any
i n d iv id u a l l y s i m e t e r , and i t i s b e lie v e d t h a t t h i s w a ter c o l l e c t e d as a
r e s u l t of d i s t i l l a t i o n r a t h e r th a n p e r c o l a t i o n .
The 2.08 in c h es of w a ter
t h a t f e l l d u rin g th e p e rio d was e i t h e r ev ap o rate d o r s to r e d in the s o i l .
This a g re es w ith th e d a ta !secured f o r the second comparable p e rio d
I
(August 26 t o September 3) in 1957, but ap p ro x im ately h a l f of th e t o t a l
1957 p e r c o l a t i o n was c o l l e c t e d d u rin g th e f i r s t c o o l-w et p e rio d ( June 6
to June 2 8 ).
The c o o l-w e t p e rio d (August 26 to September 3) in 1957
37
follow ed a h o t- d r y p e r io d , and i t i s b e lie v e d t h a t the s o i l s were d ry
enough t o ab so rb th e r a i n f a l l w ith in th e 4 -in c h l a y e r .
The p e rio d from
June 6 to June 28 follow ed a m o ist p e r io d , in a d d itio n t o r e c e iv in g a
t o t a l of 4 .5 5 in ch es of r a i n f a l l d u rin g th e p e r io d .
E f f e c t of S o il Treatm ents
Rock mulch was th e o n ly tre a tm e n t t h a t allowed an a p p re c ia b le
amount of w a te r ( l,0 1 4 grams) t o p e r c o l a t e , w hile th e sm all amounts c o l­
l e c t e d u n d e r o th e r' tr e a tm e n ts were c o n sid e re d to be from d i s t i l l a t i o n .
Rock mulch l o s t th e l e a s t amount o f w a ter by e v a p o ra tio n (2,393 gram s).
The rem aining t r e a t m e n t s , ex cep t straw mulch, exceeded th e check in
e v a p o r a tio n and amount o f d i s t i l l a t i o n c o l l e c t e d .
The w a te r l o s t by e v a p o r a tio n in 1957 agreed w ith th e p e rio d occur­
r in g i n 1958.
H alf o f th e e n t i r e s e a s o n ’ s p e r c o l a t i o n o c c u r r e d ■during
th e p e rio d June 6 to June 28, w hile no p e r c o l a t i o n was. .c o lle c te d f o r the
second c o o l-w e t p e rio d o c c u rrin g from August 26 to September 3 , 1957.
Hot-M oist P erio d ■— August 4 t o August 28, 1958
E f f e c t of S o il D iff e re n c e s
B rid g e r was th e most e f f e c t i v e s o i l i n th e h o t-m o is t p e rio d of 1957.
I t had th e lo w est lo s s of w a te r by e v a p o r a tio n and the h i g h e s t p e rc o la ­
t i o n among th e f o u r s o i l s .
M anhattan, H u ffin e , and: Huntley follow ed in
th a t order.
In 1958, t h i s p e rio d occurred in August as compared t o J u ly in 1957.
Under t h i s c o n d i t i o n , Manhattan in s te a d of B rid g e r (as i t was in 1957)
was th e most e f f e c t i v e in red u cin g e v a p o r a tio n and in c r e a s in g p e r c o l a t i o n .
H uffine and B rid g e r had ap p ro x im ately th e same e f f i c i e n c y d u rin g t h i s
38
p e r i o d , w h ile Huntley a g a in showed th e l e a s t e f f i c i e n c y .
All th e s o i l s
l o s t more w a te r by e v a p o r a tio n th a n th e t o t a l amount of r a i n f a l l , but
some of th e w a te r came a t th e expense o f th e s to r e d m o istu re from previous
p e rio d s.
E f f e c t of S o i l Treatm ents
In th e h o t- m o is t p e rio d of 1957, rock mulch allowed the h ig h e s t
p e r c o l a t i o n b u t was somewhat c l o s e r t o th e rem aining tre a tm e n ts in evapora­
t i o n th an d u rin g th e o th e r p e r i o d s .
VAMA c o a rs e i s th e only tre a tm e n t
o th e r th a n rock mulch which was more e f f i c i e n t th a n the check.
In 1958, rock mulch was again th e most e f f e c t i v e t r e a t m e n t , and i t
was th e only one to lo s e l e s s m o istu re th a n was re c e iv e d in r a i n f a l l .
The
rem aining tre a tm e n ts behaved s i m i l a r l y t o th e check w ith v e ry l i t t l e
d i f f e r e n c e in p e r c o l a t i o n and e v a p o r a tio n .
As i t was e x p la in e d e a r l i e r ,
some of th e w a te r l o s t d u rin g t h i s p e rio d came from the p re v io u s p e r io d s ,
e n a b lin g th e s o i l d u rin g t h i s p e rio d to lo s e more w a ter th a n o ccu rred as
ra in fa ll.
Cool-Dry P e rio d — August 28 to October 30, 1958
E f f e c t o f S o il D iff e re n c e s
The c o o l- d r y p e rio d o ccu rred a t alm ost th e same time i n 1958 as i t
d id i n 1957.
The p a t t e r n o f e v a p o ra tio n d i f f e r e d in both p e r io d s .
H uffine l o s t l e a s t w a te r by e v a p o ra tio n in 1958, followed by B rid g e r,
M anhattan, and H untley.
In c o n t r a s t , th e 1957 d a ta showed Huntley as the
most e f f e c t i v e in red u c in g lo s s of m o istu re by e v a p o r a tio n , follow ed by
B r i d g e r , M a n h a t t a n , and H u f f in e .
1958 p e r io d .
This i s a complete r e v e r s a l o f the
I t i s b e lie v e d t h a t d i f f e r e n c e s in c lim a tic p a t t e r n may
39
have been r e s p o n s ib le f o r th e d i f f e r e n c e s i n b e h av io r in th e 2 y e a r s .
H uffine was th e most e f f i c i e n t i n p e r c o l a t i o n in 1958 w ith 736 grams as
compared to 162 grams in 1957.
The g e n e ra l p a t t e r n behaved s i m i l a r l y
f o r th e rem aining s o i l s f o r both y e a r s .
.
D if f e r e n c e s in s to r e d m o istu re
••
a t th e end of th e p re v io u s p e rio d i s b e lie v e d to be r e s p o n s ib le f o r
d i f f e r e n c e s i n p e r c o l a t i o n o c c u rrin g in th e c o o l- d r y season of 1958.
E f f e c t of S o i l Treatm ents '
Rock mulch was a g ain th e o u ts ta n d in g tr e a tm e n t i n co n se rv in g mois­
t u r e by red u cin g e v a p o r a tio n (4*295 grams) and p e r c o la ti n g most w ater
( l ,683 g ram s).
This p a t t e r n agreed w ith th e d a ta o b ta in e d i n 1957.
The rem aining tr e a tm e n ts in 1957, ex cep t s u r f a c t a n t , showed s l i g h t l y
l e s s e v a p o r a tio n th a n th e check.
D i s t i l l e d w a te r c o l l e c t e d i n 1957 did
n o t v a ry g r e a t l y from th e check.
In 1958, no tre a tm e n t e x c e p t rock mulch.,
was more e f f e c t i v e th a n th e check in red u c in g e v a p o r a tio n .
B rid g e r check-
c o l l e c t e d 521 grams of p e r c o la te d w a te r , b u t none of th e rem aining t r e a t ­
m ents, e x ce p t rock mulch, exceeded th e check.
I t i s b e lie v e d t h a t c lim a tic
f a c t o r s were r e s p o n s ib le f o r t h i s b e h a v io r , i n a d d itio n to some d e t e r i o r a ­
t i o n of th e s t a b i l i t y and e f f e c t i v e n e s s of some tr e a tm e n ts .
Seaso n al M oisture E f f ic ie n c y
P erco latio n
Table V III was developed to determ ine which s o i l and tr e a tm e n t r e t a i n e d
most of th e r a i n f a l l .
The p e rc e n t e f f i c i e n c y was determ ined by e x p re ssin g
p e r c o l a t i o n as a p e rc e n ta g e of th e r a i n f a l l .
E f f e c t of S o i l D iff e re n c e s
In 1958, H uffine was th e h ig h e s t i n e f f i c i e n c y f o r th e seaso n w ith
40
6.2%, follow ed by B rid g e r w ith 4.8%, Manhattan w ith 2.9%, and Huntley '
w ith 1.1%.
In 1957, H u ffin e was th e most e f f i c i e n t w ith 20.5%, followed
by Manhattan w ith 17.6%, B rid g e r w ith 14.3%, and Huntley w ith 6.8%.
It
i s obvious t h a t th e e f f i c i e n c y d e crea se d t o about one-rsixth of t h a t
o b ta in e d f o r some s o i l s d u rin g th e 1957 growing seaso n .
I t i s b e lie v e d
t h a t th e r a i n f a l l d i s t r i b u t i o n p a t t e r n was the major cause of t h i s d i f f e r
en ce.
In 1957, th e major p o r t i o n of th e r a i n f a l l o ccu rred in May and
J u n e , w h ile in 1958, i t was d i s t r i b u t e d in th e months of A p r i l , June,
J u l y , August, and September.
In 1957, 6 .4 8 in ch es of the t o t a l 10.49
in ch es o c c u rrin g i n the e n t i r e season f e l l d u rin g May and Ju n e.
For
h ig h m o istu re e f f i c i e n c y , i t i s e s s e n t i a l t h a t th e r a i n s come f r e q u e n tly
enough so t h a t the s o i l does n o t dry ou t between r a i n s .
Under th e se
c irc u m s ta n c e s , th e r a i n f a l l p a t t e r n i n 1957 was more fa v o ra b le th an th e
p a t t e r n in 1958.
E f f e c t of S o il Treatm ents
Rock mulch was th e o u ts ta n d in g tr e a tm e n t in 1958, w ith a m oisture
e f f i c i e n c y of 29.8% as compared to 60.4% in 1957.
In 1957, VAMA co arse
showed a 20% in c r e a s e in s to r a g e over th e ch eck , w hile th e rem aining
tr e a tm e n ts d id n o t v ary g r e a t l y from th e check.
In 1958, stra w mulch
was th e only tr e a tm e n t i n a d d itio n to rock mulch t h a t had a h ig h e r
e f f i c i e n c y th a n th e check.
A low er e f f i c i e n c y was observed f o r a l l the tre a tm e n ts in 1958 than
in 1957.
Again th e r a i n f a l l d i s t r i b u t i o n as i t was d is c u s s e d e a r l i e r i s
b e lie v e d t o be th e p r i n c i p a l c a u s e .
In a d d i t i o n , some of th e chem icals
used may have d e t e r i o r a t e d and l o s t t h e i r e f f e c t i v e n e s s .
41
D e sp ite th e low e f f i c i e n c y o b ta in e d i n 1957, i t i s i n th e range t h a t
was p r e s e n te d by Aasheim ( l ) , who s tu d ie d th e m o istu re e f f i c i e n c y on
fallow ed s o i l .
E v ap o ratio n
E f f e c t of S o il D iff e re n c e s
H u ffin e s i l t loam l o s t th e l e a s t amount o f w ater by e v a p o r a tio n in
1958, follow ed by B rid g e r, Manhattan, and H untley.
This i s a s l i g h t l y
d i f f e r e n t arrangem ent th a n was found in 1957 because Manhattan in s te a d
o f B rid g e r follow ed H uffine s o i l .
This d i f f e r e n c e i s b e lie v e d to be
caused by c l i m a t i c f a c t o r s .
In 1958, H uffine was th e only s o i l in which e v a p o r a tio n d id not
exceed th e t o t a l r a i n f a l l .
M oisture s to r e d d u rin g the w in te r months
pro b ab ly s u p p lie d th e e x t r a m o istu re f o r e v a p o r a tio n .
In 1957, Huntley was th e only s o i l in which e v a p o r a tio n exceeded
ra in fa ll.
The p e rio d in 1957 was s t a r t e d on May 3 , and i t i s b e lie v e d
t h a t some of th e w i n t e r - s t o r e d m o is tu re was l o s t p r i o r to t h i s d a t e .
E f f e c t of S o il Treatm ents
The rock mulch tr e a tm e n t in 1957 and 1958 was th e o u ts ta n d in g t r e a t ­
ment w ith th e l e a s t amount of w ater l o s t by e v a p o r a tio n .
I t l o s t 10,073
grams l e s s th a n th e B rid g e r check s o i l in 1958 and 12,435 grams l e s s than
th e check in 1957.
Among th e o th e r t r e a t m e n t s , both of th e VAMA t r e a t ­
ments and th e straw mulch tr e a tm e n t showed some encouragement by having
s l i g h t l y low er e v a p o r a tio n i n 1957 th a n th e check.
However, i n 1958,
straw mulch was th e only tr e a tm e n t t h a t d id n o t exceed th e check in
e v a p o r a tio n .
42
B esides rock mulch, stra w mulch was th e only tre a tm e n t t h a t d id no t
lo s e more w a te r by e v a p o r a tio n than was added by r a i n f a l l .
In 1957,
s u r f a c t a n t was th e only tr e a tm e n t which caused th e s o i l to lo s e more
w a te r th a n th e t o t a l r a i n f a l l r e c e iv e d .
This is b e lie v e d t o have been
l o s t from p r e v io u s ly s to r e d m o is tu re .
Drying C h a r a c t e r i s t i c s of H uffine and B ridqer S o il
and Rock Mulch Treatm ent
In an e f f o r t to p r e d i c t from c l i m a t i c d a ta when w a te r s to ra g e can
be a n t i c i p a t e d , th e d i s p o s i t i o n of w ater from some of th e ly s im e te r s was
e v a lu a te d d u rin g th e p e rio d June 26 t o August 4 , 1958.
F ig u re s 3 , 4,
and 5 were developed f o r H uffine and B rid g e r s i l t loam and rock mulch
tre a ted s o il.
The d a ta in th e s e graphs in c lu d e r a i n f a l l , p e r c o l a t i o n ,
e v a p o r a tio n , and s to ra g e w eight between w eig h in g s.
The d a ta below the
r e f e r e n c e l i n e r e p r e s e n t a l l th e w a te r t h a t was l o s t , w h ile th e d a ta
above in c lu d e a l l th e s to r e d m o is tu re .
Follow ing a p e rio d of continuous r a i n f a l l , f i e l d c a p a c ity was
assumed t o be e s t a b l i s h e d f o r th e se l y s i m e t e r s , and th e average fieldc a p a c ity w eig h ts f o r th e ly s im e te r s were B rid g e r, 18,881 grams; H u ffin e ,
18,283 grams; and rock mulch, 22,595 grams.
The average d ry w eight of
each l y s i m e t e r was B rid g e r, 13,842 gram s; H u ffin e , 14,079 grams; and
rock mulch, 17,691 grams.
From t h i s d a t a , approxim ately 5 ,0 3 9 grams of
m o is tu re was. r e q u ir e d t o induce p e r c o l a t i o n i n th e B rid g er s o i l , 4,204
grams f o r H u ffin e , and 4,904 grams f o r th e rock mulch t r e a t e d s o i l .
The l y s i m e t e r se rv e s as a r e s e r v o i r in which th e above amounts of w a ter
can be s t o r e d .
S ince d ry in g from th e t h r e e s e t s of l y s im e te r s proceeds
Date in 1958
19,000
6/26
6/30
7/3
7 /7
7/10
7 /l4
7 /l7
7/21
7 /2 4
7/28
7/31
8 /4
F ie ld c a p a c ity
18
E = E v ap o ratio n
R = R ainfall
S = Storage
P = P e r c o la tio n
Shaded = L ysim eter Weights
L ysim eter w eight
17
6
1,965
Fig u re 3 .
Drying c h a r a c t e r i s t i c of H uffine s i l t loam. (When e v a p o ra tio n exceeded r a i n f a l l between
w e ig h in g s, the r a i n f a l l was added to e v a p o ra tio n and shown below the base l i n e . O ther­
w ise, r a i n f a l l was shown above th e base l i n e as s to re d o r p e rc o la te d w a te r ).
Date in 1958
19.000
6 /3 0
7/3
6/26_________________
7 /7
7/10
7/14
7/17
F ie ld c a p a c ity
7/24
7/28
7/31
8 /4
E = E vap o ratio n
R = R ainfall
S = Storage
P = P e r c o la tio n
Shaded = L ysim eter Weights
18
L ysim eter w eight
7/21
17
I
I
I'
£
b-
R
E
*2#
2.379
F ig u re 4.
Drying c h a r a c t e r i s t i c of B rid g er s i l t loam. (When e v a p o ra tio n exceeded r a i n f a l l between
w eig h in g s, th e r a i n f a l l was added to e v a p o ra tio n and shown below the base l i n e . O ther­
w ise, r a i n f a l l was shown above th e base l i n e as s to re d or p e rc o la te d w a te r ).
|*^643-gm. e r r o r
I I
Date in 1958
I / l , , 7 /l0
7 /l4
7 /l7
7/21
I
6/26
6/30
7/3
7/24
7/28
7/31
8/4
23.000
F ie ld c a p a c ity
L ysim eter weig
E = E vap o ratio n
R = R ain fall
S = S torage
P = P e r c o la tio n
Shaded = Lysim eter Weights
Ul
F ig u re 5.
Drying c h a r a c t e r i s t i c of rock mulch tr e a tm e n t. (When e v ap o ra tio n exceeded r a i n f a l l between
w eig h in g s, the r a i n f a l l was added to e v a p o ra tio n and shown below the base l i n e . Other­
w is e , r a i n f a l l was shown above th e base l i n e as s to re d or p e rc o la te d w a te r ) .
46
a t d i f f e r e n t r a t e s , i t i s e v id e n t t h a t th e amount of r a i n f a l l n e c e ssa ry
t o induce p e r c o l a t i o n on any tre a tm e n t w i l l be dependent upon the
amount of w a te r ev ap o rate d from the r e s e r v o i r s in c e i t was l a s t f u l l .
Since the rock mulch was q u i t e e f f e c t i v e in reducing e v a p o r a tio n , i t
fo llo w s t h a t l e s s r a i n f a l l would u s u a l l y induce p e r c o l a t i o n on t h i s
tr e a tm e n t th an f o r o th e r tr e a tm e n ts .
H u ffin e and B rid g er ev ap o rate d a
h ig h p e rc e n ta g e of th e m o is tu re s to r e d in th e ly sim et e r , and they
r e q u ir e d more r a i n f a l l th a n was n e c e s sa ry f o r rock mulch to induce
p e rc o latio n .
H uffine in comparison t o B rid g e r r e q u ire d s l i g h t l y le s s
r a i n f a l l because i t ev ap o rate d l e s s m o is tu re th a n B rid g e r.
Only once d u rin g t h i s p e rio d was th e r e s u f f i c i e n t r a i n f a l l to
i n i t i a t e p e r c o l a t i o n i n H uffine and B rid g e r.
Rock mulch allowed p e rc o la ­
t i o n of w a te r th r e e tim es d u rin g t h i s p e r io d , which i n d i c a t e s again t h a t
rock,m ulch reduced e v a p o r a tio n .
Rock mulch p e r c o la te d 872 grams between J u ly 28 and J u l y .31 and
302 grams between J u ly 31 and August 4.
Continuous re c o rd s would probably
have shown t h a t th e ly s im e te r s reached f i e l d c a p a c ity before, p e r c o la ti o n
was in d u ced , b u t e v a p o r a tio n again lowered th e ly s im e te r w e ig h ts below
t h i s v a lu e p r i o r to the n e x t w eighing.
H uffine and B rid g e r d id not
accumulate s u f f i c i e n t m o is tu re to i n i t i a t e p e r c o l a t i o n .
The d i f f e r e n c e between th e w eight of a l y s im e te r a t any time and
i t s w eig h t a t f i e l d c a p a c ity i n d i c a t e s th e amount of r a i n n e c e s sa ry to
induce p e r c o l a t i o n .
47
P h y s ic a l P r o p e r t i e s of B rid q e r and H uffine S i l t Loams
S in ce Hide and Brown (22) found t h a t th e m o istu re lo s s a s s o c ia te d
w ith d i f f e r e n t d epth l a y e r s d i f f e r e d c o n s id e ra b ly w ith time in B rid g er
and H uffine s i l t loams, an a tte m p t was made t o determ ine th e p h y s ic a l
p r o p e r t i e s which account f o r t h i s d i f f e r e n c e .
Mechanical A n a ly s is , Organic M a tte r, and Bulk D en sity
Mechanical a n a ly s is d e te r m in a tio n s were made u sin g th e p i p e t t e
method, and th e r e s u l t s are shown i n t a b l e IX.
The mechanical a n a ly s e s show v e ry l i t t l e d i f f e r e n c e i n t e x t u r e
between the two s o i l s .
Kemper (24) a ls o found th e s e two s o i l s t o be
s i m i l a r in c la y c o n t e n t , alth o u g h he found somewhat h ig h e r c la y c o n te n ts
th a n th o s e p re s e n te d above.
I t d o e s n 't seem p ro b ab le t h a t t h i s small
d i f f e r e n c e i n t e x t u r e would m a t e r i a l l y a f f e c t th e e v a p o r a tio n p a t t e r n .
Mechanical a n a ly s e s show both s o i l s to be s i l t loams, alth o u g h on the
s o i l survey of th e are a by DeYoung and Smith ( l l ) , th e B rid g e r s o i l i s
c l a s s i f i e d as a c la y loam.
D e sp ite th e same c la y c o n t e n t , th e w a ter­
h o ld in g c a p a c ity o f B rid g e r s i l t loam i s g r e a t e r than H uffine s i l t loam,
and i t i s b e lie v e d t h a t th e d i f f e r e n c e in org an ic m a tte r i n th e s e two
s o i l s i s r e s p o n s ib le f o r t h i s p r o p e r ty .
The o rg a n ic m a tte r c o n te n t of B rid g e r and H uffine s i l t loams is
p r e s e n te d in t a b l e X.
B rid g e r (5.1%) has a h ig h e r organic m a tte r
c o n te n t th a n H uffine (2.8% ).
The bulk d e n s i t y ( t a b l e X II) f o r th e two s o i l s d i f f e r e d by about
10%, w ith B rid g e r and H uffine having 1.04 and 1 :1 4 , r e s p e c t i v e l y .
The
48
Table IX.
Mechanical a n a l y s i s by th e p i p e t t e method.
% Clay
% S ilt
% Sand
H uffine s i l t loam
21.1
58.9
19.9
B rid g e r s i l t loam
18.8
6 3 .2
18.0
S o il type
49
Table X.
S o i l type
P e rc e n t c l a y , p e r c e n t organic m a t t e r , and a g g re g ate s t a b i l i t y
of B rid g e r and H uffine s i l t loams (2 4 ).
% Organic m a tte r _____ % Clay_____
Aggregate s t a b i l i t y
Vacuum wet
Immersion
H uffine
2 .8
25.1
81.1
2 4 ,2
B rid g e r
5.1
2 5 .4
72.4
22.2
50
Table XI.
S o il type
P e rc e n t s i l t and c la y ag g reg ated i n B rid g er and H uffine s i l t
loams.
% S i l t and c la y
aggregated
H uffine
67.7
B rid g e r
66.8
51
Table X II.
Bulk d e n s i t y f o r H uffine and B rid g e r s i l t loams.
Bulk d e n s it y
H uffine
1.14
B rid g e r
1.04
52
d i f f e r e n c e c o n firm s, however, t h a t B rid g e r could have a l a r g e r s t o r in g
c a p a c ity th a n Huff i n e .
The h ig h e r o rg an ic m a tte r c o n te n t of B rid g er
pro b ab ly accounts f o r i t s g r e a t e r amount of pore space and lower bulk
d e n s i t y th an H u ffin e .
Degree of A ggregation
Table XI shows th e p e r c e n t s i l t and c la y ag gregated (degree of
a g g re g a tio n ) f o r H uffine and B rid g e r s i l t loams.
Table X shows Kemper's (24) r e s u l t s of p e rc e n t c l a y , p e r c e n t
o rg an ic m a t t e r , and a g g re g ate s t a b i l i t y o f B rid g e r and H uffine s i l t
loams.
Only sm all d i f f e r e n c e s in agg reg ate s t a b i l i t y were found i n the
two s o i l s , w ith H uffine having a s l i g h t l y h ig h e r a g g re g a tio n th an B rid g e r.
Yet th e low bulk d e n s i t y of B rid g e r i n d i c a t e s t h a t i t c o n ta in s a g r e a t e r
amount of pore sp ace.
Thus a p p a r e n tly n e i t h e r degree of a g g re g a tio n nor
a g g re g ate s t a b i l i t y p ro v id e s a good measure of pore d i s t r i b u t i o n .
F ie ld
■
o b s e r v a tio n i n d i c a t e s t h a t th e B rid g e r s o i l i s more porous and has le s s
tendency to c r u s t th a n th e H u ffin e .
S a tu r a te d Flow
In s a t u r a t e d s o i l s , movement of w a te r ta k e s p la ce th ro u g h o u t the
s o i l pore spaces t h a t c o n ta i n l i t t l e o r no a i r .
For t h i s ex p erim en t,
assum ptions are made t h a t no a i r i s en tra p p ed w ith in th e p o re s .
The r e s u l t s of th e w a te r c o l l e c t e d and th e 11K11 v a lu e s c a lc u la te d
f o r 1 - , 2 - , and 3 -h o u r i n t e r v a l s are shown in t a b l e X I I I .
The p e r m e a b ility c o n s ta n t "K" v a lu e s o b ta in e d , as d e fin e d by Baver ( 4 ) ,
a re dependent upon th e s o i l p ro p e rtie s ? —p a r t i c u l a r l y s i z e of p a r t i c l e s ,
53
Table X I I I .
"K" v a lu e s and i n f i l t r a t i o n r a t e ( c c . ) of B rid g e r and
H uffine s i l t loams.
F i r s t hour
H u ffine*
Second hour
In filtra tio n
T hird hour
196
154
147
242
220
202 '
Average
219
187
174
K
.061 cm./min.
.026 cm./min.
.018 cm./min.
In filtra tio n
261
208
185
256
191
172
157
134
120
332
257
231
Average
252
198 _
177
K
.069 cm./min.
.027 cm./min.
.019 cm./min.
B rid g e r
^Two samples were d is c a r d e d .
54
a g g r e g a te s , and n a tu re o f th e s o i l pore sp a c e .
only d u rin g th e f i r s t hour of i n f i l t r a t i o n .
a p p ro x im ately th e same in th e two s o i l s .
A small d i f f e r e n c e o ccu rred
T h e r e a f t e r , i n f i l t r a t i o n was
The B rid g er soM has a s l i g h t l y
h ig h e r i n f i l t r a t i o n r a t e f o r the f i r s t hour of i n f i l t r a t i o n , b u t in
su cceed in g h o u rs , the. i n f i l t r a t i o n f o r the two s o i l s becomes s i m i l a r .
U n satu rated Flow
The problem of i n f i l t r a t i o n has re c e iv e d much a t t e n t i o n by th o se
concerned w ith i r r i g a t i o n , e r o s io n c o n t r o l , and m o istu re c o n s e rv a tio n .
Few a tte m p ts have been made t o fin d th e in tim a te r e l a t i o n s h i p between
w a t e r e n t r y un d er u n s a tu r a te d c o n d itio n s and w a te r moving ou t of the
s o i l to meet th e e v a p o r a tio n demands of th e atmosphere.
The w a te r move­
ment is dependent upon, among o th e r f a c t o r s , th e p e rc e n t pore sp ace,
n a tu re of pore sp ac e , p a r t i c l e s i z e , and a g g re g a tio n .
For convenience,
th e r e s u l t s of th e u n s a tu r a te d flow are shown in f ig u r e s 6 and 7 and
t a b l e XIV as p a ra m ete rs A, B, E, and F where B and F are th e slo p e
o b ta in e d from f i g u r e s 6 and 7 , r e s p e c t i v e l y , A i s o b ta in e d from the
e q u a tio n
= At®,,and E i s o b ta in e d from th e e q u a tio n S = E t ^ .
When
t = I,
=A B , Q = A , and S = E .
Thus, th e l a r g e r th e param eters A and
dt
E, th e l a r g e r th e i n i t i a l i n f i l t r a t i o n .
P aram eters A and B show a small d i f f e r e n c e in t h e i r u n s a tu r a te d
flow c h a r a c t e r i s t i c s .
The s l i g h t l y l a r g e r v a lu e of B rid g e r i n d i c a t e s
a h ig h e r r a t e of in ta k e of w a te r i n i t i a l l y and a lower in ta k e of w ater
w ith r e s p e c t to tim e.
P aram eters E and F are s l i g h t l y d i f f e r e n t .
The
l a r g e r v a lu e of E and s m a lle r v a lu e of F i n d i c a t e th e change i n s o i l
p r o p e r t i e s o f B rid g e r w ith r e s p e c t to time i s g r e a t e r th a n in H u ffin e .
I n f i l t r a t i o n r a t e , dQ /dt (cm .^/m in .)
2 .0
u>
Ul
—
.1
—
— •
B rid g er
___________ _ o
H uffine
i
5
Figure 6 .
I
6
I
7
8 9 10
20
T o tal time ( in m inutes)
40
50
J— L60 70 80 90 100
Rate o f in t a k e , A Q A t, as a fu n c tio n of tim e, t , w ith h y d r o s t a t i c head as the
p aram eter f o r H uffine and B ridger s i l t loams.
D istan c e to w etted f r o n t . S (cm.)
B ridger
Huffine
6
F ig u re 7 .
7 8 9 10
20
T o tal time ( i n m inutes)
40
50
60 70 80 90 100
V e r tic a l d i s t a n c e of advance of the w etted f r o n t , S, as a fu n c tio n of tim e, t , w ith
h y d r o s t a t i c head as th e p aram eter f o r B rid g er and H uffine s i l t loams.
57
Table XIV.
P aram eters A, B, E, and F of i n f i l t r a t i o n a g a i n s t tim e.
S o il
A
B
H uffine
2 .9
.49
1.55
.47
B rid g e r
3 .3
.50
1.73
.45
E
F
58
For f u r t h e r e v a l u a t i o n , d e s o r p tio n d a ta was c o l l e c t e d .
U ndisturbed
samples were used f o r th e t e n s i o n range from 0 to 0.150 atm ospheres, and
d i s t u r b e d samples were used from 0.150 to 15 atmospheres t e n s i o n .
According
t o E l r i c k and Tanner (1 2 ) , as much as 30% d i f f e r e n c e can be expected between
d is tu r b e d and u n d is tu rb e d samples a t te n s i o n s below I atm osphere.
The
r e s u l t s o b ta in e d f o r t h i s m o istu re curve ( f i g u r e 8) were w ell w ith in t h i s
p e r c e n t e r r o r from the l i n e drawn.
This curve i n d i c a t e s t h a t , between
0 and 100 cm. w a te r t e n s i o n , which i s ap p ro x im ately th e range above f i e l d
c a p a c i t y , B rid g e r r e l e a s e d 14.5% m o istu re w h ile H uffine r e le a s e d 9.8%
m o is tu re .
From 100 to 150 cm. w a ter t e n s i o n , B rid g e r a g ain re le a s e d
more m o istu re th an H u f f in e .
The p o in ts o b ta in e d from th e d i s t u r b e d samples could n o t s a t i s f a c ­
t o r i l y meet th e p o in ts o b ta in e d from th e u n d is tu rb e d sam ples.
In o rd e r
to complete th e curve t o a h ig h e r t e n s i o n , th e d o tte d l i n e was drawn
from 150 to 1,000 cm. w a te r t e n s i o n , d is r e g a r d in g th e p o in t a t l / 3 atmos­
phere!.
I t was in t h i s t e n s i o n range t h a t th e m o istu re r e l e a s e d by th e
two s o i l s was n e a r ly e q u a l.
I t i s e v id e n t from the s i m i l a r i t y o f the
curves ( f i g u r e 9) between 3 and 15 atmospheres t h a t the two s o i l s were
alm ost i d e n t i c a l in th e amount of m o istu re re le a s e d in t h i s ra n g e .
F u r t h e r work was done to d ecid e what p r o p e r ty of B rid g e r s o i l caused
i t to r e l e a s e more m o istu re th an H u ffin e .
The p e r c e n t pore space d ra in e d f o r each te n s io n i s shown in
t a b l e XV.
There was l i t t l e d i f f e r e n c e i n th e p e rc e n t p o re space d ra in e d
f o r th e pore s i z e of .0146 to .0015 cm. r a d i u s , but th e B rid g e r s o i l had
a much h ig h e r p e rc en ta g e o f pores i n th e s i z e range of .0015 to .001 cm.
59
1,000
I B rid g e r
.
Tension (cm. w ater)
800
I H uffine
----- D is tu rb e d samples
___ U ndisturbed samples
% M oisture
F ig u re 8 .
M oisture t e n s i o n curve f o r B rid g e r and H uffine s i l t loams
between 0 and I atmospheres tens-ion.
60
B rid g er
Atmospheres te n s io n
H uffine
% M oisture
F ig u re 9.
M oisture t e n s i o n curve f o r H uffine and B rid g er s i l t loams between
I and 15 atmospheres t e n s i o n . Data by Brown ( 6 ) .
61
Table XV..
P e rc e n t pore space d ra in e d a t v a rio u s te n s io n s (pore s iz e
d istrib u tio n ).
Water
te n s i o n
(cm .)
Radius of
pore space
i n cm.
10
.0146
2 .9
2 .4
30
.0049
8 .2
7 .6
60
.0024
7 .5
6.1
100
.0015
7 .2
7 .3
150
.0010
2 .9
5 .8
28.8
29 .2
T o ta l p o re s c o a r s e r
th an .001 cm.
I
% Pore space d ra in e d
H uffine
•B rid q e r
62
ra d iu s.
Thus th e two s o i l s .have, s i m i l a r amounts of la rg e p o r e s , but
th e B rid g e r s o i l has a c o n s id e ra b ly h ig h e r p e rc en ta g e of medium-sized
p o re s .
These medium-sized pores which pro b ab ly do no t d r a i n un d er the
in f lu e n c e of g r a v i t y may se rv e as a source of w a ter t h a t can be moved
to th e s u r f a c e f o r e v a p o r a tio n .
E f f e c t of S o il Depth on Drying P r o p e r tie s
A m ajor c r i t i c i s m of th e shallow l y s i m e t e r approach i n d eterm in in g
th e s e a s o n a l w a ter regime i s t h a t the d i s c o n t i n u i t y a t th e bottom of
th e l y s i m e t e r may s e r i o u s l y in flu e n c e th e n a tu re of the regim e.
In an
e f f o r t t o e v a lu a te t h i s l i m i t a t i o n , s t u d i e s o f e v a p o ra tio n l o s s e s from
4 - and 1 8 -in ch columns o f s o i l were u n d e rta k en in the la b o r a t o r y .
r e s u l t s are shown i n f i g u r e 10.
The
For both s o i l s , th e 4 -in c h column tu b e ,
r e p r e s e n t i n g the l y s i m e t e r , ev ap o rated more th a n the 1 8 -in ch tu b e , which
r e p r e s e n te d th e normal s o i l c o n d itio n .
However, the p a t t e r n through
which w a te r was l o s t remained s i m i l a r i n th e two tu b e s .
G r e a t e r lo s s e s
from th e 4 -in c h column are due to th e f a c t t h a t w a ter does n o t d r a i n from
th e bottom of th e l y s i m e t e r u n t i l th e m o istu re c o n te n t i s r a i s e d so t h a t
t e n s i o n becomes e s s e n t i a l l y z e r o .
In a c o n tin u o u s s o i l column, the
m o is tu re would be moved downward under c o n s id e r a b le t e n s i o n .
Thus the
4 - in c h column c o n ta in s more m o istu re when i t y i e l d s no f u r t h e r p e r c o la te
th a n i t would have c o n ta in e d had th e r e been a d d itio n a l s o i l in t o which
t h i s e x cess m o is tu re could have moved.
The f a c t t h a t more w a te r was
l o s t from th e 4 -in c h columns th an was l o s t from the deep columns i n d i c a t e s
t h a t fa llo w would s t o r e more w a te r th a n p e r c o la te d th rough th e l y s i m e t e r s .
Thus th e d a ta f o r e f f i c i e n c y as p re s e n te d would tend to be low er th an
H uffine s i l t loam
B rid g e r s i l t loam
4 -in c h column
1 8-inch column
Time ( i n days)
F ig u re 10.
E f f e c t of s o i l d e p th on d ry in g p r o p e r t i e s .
64
would be e n co u n tered in th e f i e l d .
This c o n d itio n e n a b le s th e s u rfa c e to remain wet lo n g e r , which
accounts f o r th e g r e a t e r l o s s .
As long as th e s u r f a c e was w e t, evapora­
t i o n was c o n s ta n t in both th e 4 - and 1 8 -in ch tubes of both s o i l s , but
H u ffin e , d u rin g th e f i r s t 2 d a y s, l o s t more w a te r than B rid g e r.
A fte r
4 d a y s, both s o i l s were lo s in g about th e same amount of m o is tu re ; but
a f t e r 8 d a y s , H uffine had alm ost ceased lo s in g w a te r w hile B rid g e r was
s t i l l r e l e a s i n g w a te r f o r e v a p o r a tio n .
This continued l o s s of m oisture
in B rid g e r s o i l , even a f t e r 8 d a y s, i s th e m ajor f a c t o r r e s p o n s ib le f o r
i t s e v a p o ra tin g more w a te r th a n H u ffin e.
v-
65
SUMMARY AND CONCLUSIONS
M oisture e f f i c i e n c y was s tu d ie d f o r f o u r s o i l s and f iv e t r e a t ­
ments on one s o i l in 1958, and comparisons were made w ith th e d a ta
o b ta in e d i n 1957.
In a d d i t i o n , s tu d ie s of p h y s ic a l p r o p e r t i e s of
H u ffin e and B rid g e r s i l t loams were u n d e rta k en i n an e f f o r t t o account
f o r th e d i f f e r e n c e in t h e i r e v a p o r a tio n p a t t e r n .
S ince th e l y s im e te r p o r t i o n of t h i s stu d y i s a comparison between
y e a r s u s in g th e same s o i l s and t r e a t m e n t s , th e summary and c o n clu sio n s
w i l l be made in a s i m i l a r manner t o t h a t which Brown (6) p re s e n te d in
1957.
Among th e s o i l d i f f e r e n c e s , cum ulative d a ta f o r th e e n t i r e p erio d
showed t h a t H uffine had th e low est e v a p o r a tio n l o s s , follow ed by B rid g e r,
M anhattan, and H untley.
In 1957, Huff i n e , Manhattan, B rid g e r, and
Huntley follow ed i n t h i s o r d e r .
The d i f f e r e n c e i s b e lie v e d to be
in flu e n c e d by c li m a t i c d i f f e r e n c e s .
The s o i l s t h a t were low i n e v a p o r a tio n were i n v a r ia b ly high in
p e r c o l a t i o n , alth o u g h p e r c o l a t i o n was much lower i n 1958 th a n in 1957.
S eason-long e f f i c i e n c y f o r 1958 f o r H u f f in e , B rid g e r, Manhattan,
and Huntley was 6 . 2 , 4 . 8 , 2 . 9 , and 1.1%, r e s p e c t i v e l y , i n c o n t r a s t to
2 0 .5 , 1 4 .3 , 1 7 .6 , and 6.8% i n 1957.
The r a i n f a l l d i s t r i b u t i o n accounts
f o r th e reduced e f f i c i e n c y i n 1958.
Both e v a p o r a tio n and p e r c o l a t i o n f o r each s o i l v a r ie d from period
'
to p e r io d , depending on th e c lim a tic p a t t e r n . H uffine was not the most
e f f e c t i v e s o i l in a l l th e p e r io d s ; however, i t was the most e f f i c i e n t
s o i l th ro u g h o u t th e e x p erim en tal p e rio d f o r the 2 y e a r s .
66
Among th e s o i l tr e a tm e n ts s t u d i e d , rock mulch re p e a te d as th e o u t­
s ta n d in g tr e a tm e n t and had a sea so n -lo n g p e r c o l a t i o n e f f i c i e n c y of 29.8%
as compared to 60.4% in 1957.
This i s s t i l l s ix times h ig h e r th a n straw
mulch and t h e u n tr e a te d s o i l which were th e n ex t h i g h e s t .
In 1958,
p e r c o l a t i o n e f f i c i e n c y v a r ie d from p e rio d t o p e rio d , w ith a high of 38.7%,
whereas in 1957, i t was 79.8%.
The rem ainder o f the tre a tm e n ts were l e s s e f f e c t i v e th a n th e check,
b u t d u rin g c e r t a i n p e r i o d s , straw mulch as in 1957 showed some e f f i c i e n t
c h a r a c t e r i s t i c s , w h ile a t o th e r tim e s , i t was v e ry i n e f f e c t i v e .
Most of
th e tr e a tm e n ts used had only minor in f lu e n c e on the e f f i c i e n c y of p e rc o la ­
t i o n , b u t th e e f f e c t i v e n e s s of rock mulch and the d i f f e r e n c e s found between
s o i l s encourage c o n tin u e d e f f o r t s t o d e v is e more e f f i c i e n t tr e a tm e n ts .
Among th e v a rio u s p h y s ic a l p r o p e r t i e s s t u d i e d , pore s i z e d i s t r i b u ­
t i o n , p e r c e n t organic m a t t e r , and bulk d e n s i t y d i f f e r e d
and B rid g e r s o i l s .
between Huffine
The t e x t u r e , a g g reg ate s t a b i l i t y , p e r c e n t aggrega­
t i o n , and m o istu re movement under s a t u r a t e d and u n s a tu r a te d c o n d itio n s
d id no t d i f f e r g r e a t l y .
The d i f f e r e n c e s t h a t were ob serv ed , however,
do no t d i r e c t l y account f o r th e d i f f e r e n c e s t h a t o ccu rred between Huffine
and B rid g e r s i l t loams i n e v a p o r a tio n .
I t appears t h a t s i z e and volume
o f pore space are th e most p robable s o i l f a c t o r s to account f o r d i f f e r e n c e s
i n e v a p o r a tio n lo s s i n a d ry in g c y c le .
A stu d y in v o lv in g a g r e a t e r number of s o i l s should be u n d ertak en to
e sta b lis h a d e fin ite re la tio n sh ip .
67
LITERATURE CITED
1.
Aasheim, T0 S 0 I n t e r r e l a t i o n s h i p s o f p r e c i p i t a t i o n , s o i l m oisture
and s p rin g wheat p ro d u c tio n in n o rth e rn Montana. T h esis sub=
m itte d f o r M aster of Science degree in agronomy a t Montana
S t a t e C o lle g e . 1954.
2.
A l l i s o n , L ..E o , and Moore, D. L. E f f e c t of VAMA and HPAN s o i l
c o n d i t i o n e r s on a g g re g a tio n , s u rfa c e c r u s t i n g and m o istu re
r e t e n t i o n in a l k a l i s o i l s . S o il S c i . Soc. Amer . P r o c . 20s
143-146. 1956.
3.
Army, T. J . E v a p o ra tio n c o n tr o l r e s e a r c h papers p re s e n te d a t th e
j o i n t ARS-SCS workshop on r e s e a r c h p e r ta in in g t o G reat P la in s
c o n s e rv a tio n program, F ebruary 3 - 7 , 1958.
4.
Baver , L. D.
1956.
5.
Bowie, H. J . , J r .
6.
Brown, B. L. The in f lu e n c e of d i f f e r e n t s o i l ty p e s and tre a tm e n ts
,on the l o s s of m o istu re from fallo w ed l y s i n i e t e r s . T h esis sub­
m itte d f o r M aster of Science deg ree i n s o i l s a t Montana S ta te
C o lle g e . 1958.
7.
Brown, P. L ., and D ickey, D. D. Annual Research R ep o rt, Western
S o il and W a te r' Management Research Branch, Bozeman, Montana.
1958.
8.
Buckingham,' E. S tu d ie s on movement of s o i l m o is tu re .
of Agr. Bur. o f S o il s Bui. 38. 1907.
9.
C a l l , L. E . , and S e w e ll, M. C.
Agron. 9849-61. 1917.
S o il P h y s ic s .
John Wiley and Sons, I n c . , New York.
P rac tic al Irrig a tio n .
New York.
The s o i l mulch.
1908.
U. S. Dept.
J o u r . Amer . Soc.
10.
Campbell, H. W. S o i l C u ltu r a l Manual. S c i e n t i f i c S o il C u ltu re
Company, B i l l i n g s , Montana. 1917.
11.
DeYoung, W., and Sm ith, L. H. S o il su rv ey o f th e G a l l a t i n V alley
a r e a , Montana. USDA S e rie s 1931, No. 16.
12.
E l r i c k , D. E . , and Tanner, C . B .
on s o i l m o is tu re r e t e n t i o n .
282. 1955.
13.
F i s h e r , E. A. Some f a c t o r s a f f e c t i n g th e e v a p o r a tio n of w a ter from
s o i l . J o u r . Agr. S c i . 13s121-143. 1923.
In flu e n c e of sample p r e tre a tm e n t
S o il S c i . Soc. Amer. P ro c. .198 279—
68
14.
F o r t i e r s Samuel= S o il mulches f o r checking e v a p o r a tio n .
of Agr. Yearbook, 1908?465-472. 1909.
U. S. Dept
15.
Gardner,. W., I s r a e l s e n , 0. W., Edlefse.n, N. E ., and Conrad, H. The
c a p i l l a r y p o t e n t i a l f u n c tio n and i t s r e l a t i o n to i r r i g a t i o n
p r a c t i c e . Phys. Rev. Ser= 2, 20&196. 1922.
16.
Hanks, R. J . E v a p o ra tio n c o n tr o l r e s e a r c h papers p re s e n te d a t the
j o i n t ARS-SCS workshop on r e s e a r c h p e r ta in in g to G reat P la in s
c o n s e rv a tio n program, February 3 - 7 , 1958.
17.
Hanks, R= J . The v a p o r t r a n s f e r in d ry s o i l s .
Proc= 22:372-374= 1958.
18.
Hanks, R= J=, and Woodruff, N= P= In flu e n c e of wind on w a te r vapor
t r a n s f e r through s o i l , g r a v e l , and straw m ulches. S o il S c i.
86:160. 1958.
19.
H a r r i s , F. S . , and R obinson, J . S. F a c to rs a f f e c t i n g th e evapora­
t i o n of th e m o istu re from the s o i l . J o u r . Agr. Res. 7 :4 3 9 461. 1916.
20.
H e d ric k s, R. M., and. Mowry, D. I . E f f e c t of s y n t h e t i c p o l y e l e c t r o ­
l y t e s on a g g reg atio n ', a e r a t i o n , and w a ter r e l a t i o n s h i p s of
s o i l . S o il S c i . 73:427. 1952.
21.
Hide, J . C. O b se rv a tio n on f a c t o r s i n f l u e n c i n g . t h e e v a p o ra tio n of
s o i l m o is tu r e . S o il S c i. Soc.■ Amer. P ro c . 18:234-239. 1954.
22.
Hide, J . C . , and Brown, B. L. The n a t u r a l dry in g c y c le of s e le c te d
s o i l s . To be p u b lis h e d in S o il S c i . Soc. Amer. P r o c .
23.
Keen, B. A., C row ther, E. M., and C o u t t s , J= C= H. The e v ap o ra tio n
of w a ter from s o i l . III= A c r i t i c a l study of th e te c h n iq u e .
Jour= Agr. S c i. 16:105-122. 1926.
24.
Kemper, W= D= Colorado p ro g re s s r e p o r t to T ech n ical Committee of
Western R egional R esearch P r o j e c t W-30, 1958.
25.
King, F. H=
A Textbook of th e P h y sics of A g r ic u ltu r e , Ed. 2.
26.
King, F= H=
1907.
Textbook of the P h y sics of A g r ic u ltu r e , p= 161-203.
27.
Kolasew, F= E. Ways of su p p re ssin g e v a p o r a tio n o f s o i l m o is tu re .
Shorn. Rab. Agron. F i z . 3 :6 7 . 1941.
28.
Lemon, E= R.= P o t e n t i a l i t i e s f o r d e c r e a s in g s o i l m o istu re evapora­
t i o n l o s s . S o il S c i . Soc. . Amer. P ro c . 20:120-125. 1956.
S o il S c i. Soc. Amer.
1901.
69 .
29.
P e t e r s , Do B0 E v a p o ra tio n i s im p o rta n t f a c t o r i n w a te r l o s s .
P ro g re ss i n Soil, and Water C o n se rv a tio n R esearch, Q u a rte rly
R eport No. 15, p . 22. 1958«
30.
Penman, H, L, L ab o rato ry experim ents on e v a p o ra tio n from fa llo w
s o i l . J o u r . Agr, S c i . 31$454. 1941.
31.
R ic h a rd s , L, A, C a p i l l a r y co n d u ctio n of l i q u i d th rough porous
membrane. J o u r , of Agr. Res. 20s719, 1928.
32.
S t a n h i l l , G. E v a p o ra tio n of w a te r from s o i l under f i e l d c o n d itio n s
Nature 176:82. 1955.
33.
Thornthwai t e , C. W, A tla s o f c l i m a t i c ty p e s in th e U. S . 19001939. U. S. D ept, of Agr. M isc. P u b l. 421. 1941.
34.
Tsiang., T. C„ S o il c o n s e r v a tio n , an i n t e r n a t i o n a l s tu d y ,
84. FAO U nited N a tio n s , W ashington, D. C. 1948.
35.
Uhland, R. E . , and O 'N e il, A. M. S o il p e r m e a b ility d e te r m in a tio n s
f o r use in s o i l and w a ter c o n s e r v a tio n . USDA SCS-TP-101„
1951.
36.
U nited S t a t e s S a l i n i t y L aboratory S t a f f . D iagnosis and Improvement
of S a lin e and A lk a li S o i l s . USDA Handbook No. 6 0 . 1954. •
37.
Wollny, Ewald. The p h y s ic a l p r o p e r t i e s of th e s o i l . - P a r t 2 in
Exp. S t a . R e c ., Vol. 6 , p. 853-863. 1895.
pp. 83-
/. I
n
70
APPENDIX
Table XVI.
P e rio d d a te s and c l a s s i f i c a t i o n as determ ined by c lim a tic
f a c t o r s , 1957.
. Days
in
p e rio d
P erio d
c la ssific a tio n
May 3-Ju n e 6
34
C ool-m oist*
June 6 - June 28
22
June 2 8 -Ju Iy 31
J u ly 3 I -A ugust 26
P e rio d d a te s
P re c ip ita ­
Maximum
t i o n in
average
tem p eratu re
in ch es
2.93
66.0
. Cool-wet*
4 .55
67 .5
33
H ot-m oist
1.52
81.8
26
H ot-dry
0 .00
85.0
August 26-September 3
8
Cool-wet*
1.00
67.3
September 3 -O cto b er 30
57
C ool-dry
1.29
62.3
*Data from Brown ( 6 ) , b u t c l a s s i f i c a t i o n changed to co rresp o n d w ith t h a t
used i n 1958.
■
Table XVII.
Treatm ent
P r e c i p i t a t i o n and e v a p o r a tio n (in g ra m s)fo r ly s im e te r a re a s f o r p e rio d May 3 to
O ctober 30, 1957.*
.
.
Msy 3™ June 6 June 6 . June 28
S e le c te d p e rio d
June 28- J u ly 3 1 J u ly 31
Auq. 26
Aug. 26S e p t. 3
S e p t. 3 Oct. 30
T o tal
P re c ip ita tio n
7,896
12,262
4,096
0
2,965
3,477
30,696
E a n h a tta n
E v ap o ratio n
6,240
8,754
4,274
3,704
2,277
3,722
28,971
H uffine
E v ap o ratio n
5,397
8 ,4 5 9
4,441
3 ,7 5 2
2,197
4,277
28,523
Huntley
E v ap o ratio n
7,876
10,387
4,945
4,916
2,328
3,653
34,105
Bridgep
E v ap o ratio n
6,881
9,075
4,133
3,964
2,260
3,914
30,227
Rock mulch
E v ap o ratio n
2,227
2,476
4,000
4,796
1,752
2,279
17,530
Straw mulch
E v ap o ratio n
7,059
8,136
4,711
4,139
2,153
3,367
29,563
VAMA c o a rse
Evaporation.
5 ,9 5 2
8,963
4,223
4,046
2,322
3,889
29,395
VAMA f in e
E v ap o ratio n
5,988
9,671
4,385
4,118
2,308
3,308
29,778
S u rfa cta n t
E v ap o ratio n
6,558
9,513
4,439
4,061
2,318 .
3,834
30,723
Check
E v ap o ratio n
6,543
8,852
.4,483
3,914
2,197
3,976
29,965
*Data_ c o l l e c t e d by Brown ( 6 ) .,
P r e c i p i t a t i o n and p e r c o l a t i o n ( i n grams) f o r ly s im e te r a re a s and i n f i l t r a t i o n
e f f i c i e n c y e x p re ssed as p e r c e n t o f t o t a l r a i n f a l l by p e r io d s , May 3 to October 30,
1957.*
Treatment
2,965
0________ 0
0________ 0
0________ 0
0I
0
O
O
O
O
*Data c o l l e c t e d by Brown ( 6 ) .
3,635
275
_ _ _ 2?JS_ _ _ _6^7_ _
253
3,588
_ _ _ 29J3_ — ____6 ,2 ___
• 250
1,883
_ _ 15z4_ ___ —6 ,1 — _
2,960
434
_ - - 2 W _ - - 10^6- _
1,220
9,79029
_
_ _ Z9A.
138
3,928.
- _ _ 32X)_ _____ 3^4_ _
3,457
369
_ _ 28^2_ _____ ______
223
2,868.
23.4 — ____5^4_ _
.2 ,8 0 7
202
- - 22^9_ - _ _4^9_ _
3,215
234
26 .2
5 .7
0
O
1,699
_ _ - 2 1 .5
2,551
_ _ - 3 2 .3
12
0.15
_
1,095
_ - 13,87
. 6,155
78.0
_
896
_ _ - i i - 'l
2,028
25.7
_
1,567
_
19.8
2,100
_
26.6
1,404
17.8
4,096
O
P e rc o la tio n
_ ^ .E ffic ie n c y .
P erco latio n
H uffine
_ J L E f fIc ie n c z
Huntley
P erco latio n
_ ^ -E ffic ie n c y .
P e rc o la tio n
B rid g er
_ - ^ - E f f ic i e n c y .
Rock mulch
P e r c o la tio n
_ - ^ - E f f ic i e n c y .
Straw mulch
P erco latio n
_ - ^ .E f f i c i e n c y .
VAMA c o a rse
P erco latio n
_ - ^ - E f f ic i e n c y .
S u rfactan t
P e r c o la tio n
_ - ^ - E f f ic i e n c y .
VAMA f in e
P e r c o la tio n
- - ^ - E f f ic i e n c y .
Check
P e r c o la tio n
'•^"E fficie n c y
Manhattan
12,262
01
7,896
S e le c te d p erio d
June 28- J u ly 31- Aug. 26J u ly 31 Auq. 26 S e p t. 3
Cool—
Hotr' Hotrm oist
dry
wet
Ol
P re c ip ita tio n
June 6 June 28
Cool—
wet
O
May 3 June~6
Ooolm oist
JO
Table XVIII.
O
O
S e p t, 3—
Oct. 30
Cool—
dry
T o ta l
3,477
37
5,646
- - I . # , . ______ 17,6
162
6,554
- - 4.70—______ 20^5.
46
2,191
_ - l- 3 0 _ - - - 6 . 8 4
81
4,570
- - 2 . 3 0 - _____ 1 4J3
2,163
19,328
- - 62*2- i_____ 60^4
52
5,014
_ _ 1 .5 0 - _____ 15/7
34
5,888
- - 0 . 9 7 - _____ 18.4
5
4,663
- - 0 . 1 4 - ______ 14.6
76
5,185
16 .2
_ _ 2.20
43
4,896
' 1.20
15.3
-j
ND
MOMTAMA STATF nim /CMT-rw ___________
»
3 1762 10013330 3