This file was created by scanning the printed publication.
Errors identified by the software have been corrected;
however, some errors may remain.
Summer Establishment of Four Sonoran
Desert Shrubs Using Line Source Sprinkler
Irrigation
Hossein Heydari
Bruce A. Roundy
Carolyn Watson
Steven E. Smith
Bruce Munda
Mark Pater
expense of controlling weeds such as Russian thistle (Salsola
kali), and loss of ecological and aesthetic value (Meitl and
others 1983).
Much of the abandoned farmland in Arizona is in the
south-central part of the state in the Santa Cruz Valley and
along the Gila River between Phoenix and Yuma. These
lands are characterized by fine-textured soils and annual
rainfall often less than 250 mm (Jackson and others 1991;
Gelt 1993). Reinvasion of these lands from native shrubs
such as creosotebush (Larrea tridentata) and desert saltbush (Atriplex polycarpa) is limited by lack of dispersal
vectors (Jackson 1992), as well as aridity and poor soil
physical conditions. Some abandoned farmlands with comparatively coarser-textured soils and higher annual rainfall
may be colonized by desert broom (Baccharis spp.) and
burroweed (lsocoma tenuisecta), while others remain bare or
dominated by Russian thistle over 25 years after abandonment (Karpiscak 1980).
Revegetation of abandoned farmland without irrigation
requires some form of water harvesting and concentration.
The Natural Resource Conservation Service and Jackson
and others (1991) have successfully established native shrubs
between runoff areas and catchment berms near Redrock
and Eloy, Arizona, respectively.
Use offunctioning irrigation systems to establish adapted
plants the first year of abandonment is a promising approach to revegetating abandoned farmlands in arid areas
with erratic precipitation (Cox and Thacker 1992). However,
establishment and persistence of irrigation-established
plants is highly dependent on site conditions and drought
tolerance of the seeded species. For example, Cox and
Madrigal (1988) failed to permanently establish forage
grasses on a silty clay loam soil at the San Xavier Indian
Reservation but Cox and Thacker (1992) succeeded in establishing grasses on sandy loam and clay loam soils in the Avra
Valley in southeastern Arizona. In the latter study, plant
establishment required sufficient irrigation to keep the soil
surface moist until seedling roots were 5- to 15-cm long (4 to
6 weeks ofirrigation). To successfully establish, many warmseason grasses may require rather extended periods of
available soil moisture at the soil surface to develop adventitious roots (Roundy and others 1993).
Ifirrigation systems can be used to revegetate farmlands
the first year after abandonment, we need to identify adapted
plant materials and their associated water requirements for
Abstract-A line source irrigation system was used to create a
water application gradient and determine establishment requirements for native Sonoran desert shrubs and trees. Mesquite (Prosopis
juliflora var. veluntina, catclaw acacia (Acacia greggii), blue palo
verde (Cercidium floridum) and jojoba (Simmondsia chinensis) all
established when 2 weeks of irrigation were followed by summer
rainfall. J ojoba seedlings emerged about 2 weeks later than those of
the other species. Because the soil profile was initially at field
capacity, the line source system mainly created a difference in water
availability between irrigated and unirrigated soils. This study
suggests a possible strategy for using in-place irrigation systems to
revegetate farmlands during the first year of abandonment. Soils
could be heavily irrigated after sowing to fill the soil profile.
Subsequent irrigation for about 2 weeks to keep the soil surface wet
until seedlings emerge should result in high establishment. For the
coarse-loamy soil in this study that would require about 5 to 10 em
of total irrigation. Establishment on drier areas sites with finertextured soils would require more water.
Since the early 1950's, over 400,000 ha of once-irrigated
farmland have been abandoned in Arizona (Charney and
Woodward 1990). Abandonment is the result ofvariability in
costs of production and also in demand and returns for
agricultural products over the years. When Arizona's 1980
Groundwater Management Act restricted pumping in certain Active Management Areas, cities began purchasing
farmlands for water sources (Gelt 1993). Future purchase of
such so-called water farms has now been prohibited by the
1990 Groundwater Transportation Act but large tracts of
grandfathered water farms still lie abandoned. Problems
with abandoned farmlands include wind erosion and hazardous dust storms that have resulted in highway fatalities,
I?: Barrow, Jerry R.; McArthur, E. Durant; Sosebee, Ronald E.; Tausch,
Robm J., comps. 1996. Proceedings: shrubland ecosystem dynamics in a
changing environment; 1995 May 23-25; Las Cruces, NM. Gen. Tech. Rep.
INT-GTR-338. Ogden, UT: U.S. Department of Agriculture, Forest Service
Intermountain Research Station.
'
Hossein Heydari and Carolyn Watson were Graduate Research Assistants
at the School of Renewable Natural Resources, University ofArizona, Tucson,
~ 85721. Bruce A. Roundy is Professor, Department of Botany and Range
Sclence, Brigham Young University, Provo, UT 84602. Steven E. Smith is
Professor, Department of Plant Science, University ofArizona, Tucson. Bruce
Munda and Mark Pater are Director and Assistant Director, USDA, Natural
Resources Conservation Service Plant Materials Center, 3241 North Romero
Road, Tucson, AZ 85705.
129
establishment. The line source sprinkler system (LSS) produces a gradient in applied water that has been used mainly
to determine crop production response to irrigation (Sorenson
and others 1980; Miller and Hang 1980). LSS has the
advantage of providing a continuous gradient in irrigation
from excess to no irrigation within a small area as distance
increases from the line source (Hanks and others 1976;
Fernandez 1991). The objective of our research was to use
LSS to determine water requirements for establishment of
adapted shrubs and trees in the Sonoran desert.
Methods
Results
----------------------------------
Natural precipitation after sowing for July and August
totalled 76.2 and 68.1 mm in 1992 and 1993, respectively
(fig. 1). Total irrigation plus precipitation for July and
August after sowing ranged from 356.7 to 106.9 mm in 1992
and from 285.2 to 106.6 mm in 1993 from 1.5 to 13.5 m from
the line source. For both years, irrigation was most frequent
right after sowing in July, while natural precipitation was
most frequent in August (fig. 2). This pattern of water
inputs, as well as the initially wet soil profile, mainly
resulted in differences in soil water availability between
irrigated and unirrigated soils, rather than differences within
irrigation levels (figs. 3, 4). Surface soil water up to 10.5 m
from the line source was highly available through mid
August while unirrigated soils were dry at seed depth until
natural precipitation fell in early August. Soil water was
available below 18 em through July and August for irrigated
and unirrigated soils.
PMR differed significantly (p > 0.05) with distance from
the line source for all· dates measured in 1992 and 1993.
Significance of species and the species x distance interaction
varied for different dates ofPMR measurement. Differences
---------------------------------
The study site was at the Tucson Plant Materials Center
of the Natural Resources Conservation Service. Elevation is
773 m and mean annual precipitation is 294 mm with 54%
(159 mm) falling between July and October (Sellers and
others 1985). Soil is of the Anthony series, coarse-loamy,
mixed, calcareous, thermic family of Typic Torrifluvents.
We seeded velvet mesquite (Prosopisjuliflora var. velutina),
catclaw acacia (Acacia greggii), jojoba (Simmondsia
chinensis), and blue paloverde (Cercidiumfloridum) in 1992
and 1993 in July prior to the summer rainy season. Shrubs
(catclaw and jojoba) and trees (mesquite and paloverde)
were seeded at the rate of33 and 16 pure live seeds per m of
row, respectively, in rows 0.41-m apart using a no-till planter.
Rows were seeded perpendicular and to a distance of 16.5 m
on both sides of the line source sprinkler. The soil was
preirrigated on both years prior to sowing to fill the soil
profile and create similar antecedent soil moisture conditions throughout the field. An extra sacrifice row of each
species was seeded next to each row in two of the six total
replications for root measurements.
The LSS had nine sprinklers 6-m apart on 1.6-m high
risers with each sprinkler producing an overall wetted
radius of 13.5 m. Irrigation water was applied daily for 10
days after sowing to maintain available moisture in the
upper 3 cm of soil nearest the line source.
Applied water was measured in catch cans after every
irrigation and plants per m ofrow (PMR) were counted every
1 to 2 weeks until November at distances of1.5, 4.5, 7;5,10.5,
13.5, and 16.5 m from the line source. Soil matric potential
was measured every minute and hourly averages recorded
using gypsum blocks connected to electronic microloggers.
Two blocks were placed at depths of 1-3,8-10, and 18-20 cm,
while one block was placed at depths of 38-40 and 58-60 cm
in each of three replications at distances of 1.5,6, 10.5, and
16.5 m from the line source.
Plant height was measured every 1 to 2 weeks on the same
five plants of each species at distances of 1.5, 7.5, and 13.5 m
from the line source. Tap root length of excavated plants was
measured at the same distances as plant height.
Since irrigation treatments using LSS are not randomized, significance of distance from the line source and interactions of species x distance were based on Wilk's Lamda
from multivariate repeated measures analysis of variance
(Fernandez 1991; Torabi-Zadeh 1991). Means of species
were compared by LSD at each distance from the line source
for each sample date.
400
1 6 JULY - 31 AUGUST 1 992
BBBB8 IRRIGATION
c:::=l PRECIPITATION
300
'i'
~
a::
LLI
200
!;(
~
100
0
1.5"
4.S
7.5
10.5
13.5
16.5
400
22 JULY - 31 AUGUST 1993
300
285.2
'i'
~
[t:
~
200
3:
100
o~~~~~~~--~~~----~--~~~--
1.5
4.5
7.5
10.5
13.5
DISTANCE FROM UNE SOURCE (M)
Figure 1-lrrigation and precipitation at six distances from a line source sprinkler in 1992, 1993.
130
16.5
in PMR were mainly associated with differences in the
pattern of surface soil water availability between irrigated
and unirrigated soils (figs 5, 6). In 1992, acacia, mesquite,
and paloverde had high initial emergence on all but the
lowest and nonirrigated soils. J ojoba emerged about 2 weeks
after the other species and eventually had high PMR at all
but the lowest and nonirrigated soils. All other species
eventually produced at least 4 PMR on the lowest and
nonirrigated soils in response to August precipitation. A
similar pattern of emergence occurred in 1993, except that
acacia PMR was less than in 1992 (figs. 5, 6). Jojoba again
emerged slower than the other species. Palo verde andjojoba
eventually had higher PMR on unirrigated than lowest
irrigated soils. Plant establishment was acceptable for all
species for all irrigated and unirrigated treatments for both
years, except for jojoba on unirrigated soils in 1992.
Although plants established at all irrigation levels, plant
growth was less on lowest and unirrigated soils than on soils
receiving higher irrigation (fig. 7). Tap root length was
greatest for mesquite and least for jojoba (fig. 8). Tap root
length of acacia, mesquite, and palo verde was over 60 em by
October or November.
20
10
18
21
24
27
30
33
36
39
42
45
48
51
54
57
60
DAYS SINCE 1 JULY 1992
DISTANCE FROM
UNE SOURCE (M)
_ _ 1.5
~4.5
~ 7.5
20
I?ZZZ.a 1 0.5
13.5
c::::J 16.5
I:::: :1
Discussion --------------------------------
10
The initially wet soil profile and frequent irrigation resulted in long periods of soil water availability and excellent
establishment of all four of these woody species at all but the
lowest irrigation and on unirrigated soils. The LSS did not
create a strong gradient in soil water availability in this
study. Use of the LSS on initially dry soils would probably
o~~~~~~~~tim~um~ww~~~~~~
15
18
21
24
27
30
J3
36
39
42
45
48
51
54
57
60
DAYS SINCE 1 JULY 1 993
Figure 2-D ate and amount of summer rainfall
and irrigation from a line source sprinkler.
........
c
DISTANCE FROM
a..
~
LINE SOURCE (M)
...I
:!!;
I-
0
1.5
7.5
10.5
16.5
C
!
w
,-,-,-0-,-,---~-----~----
b
a..
a:::
w
~
~
...I
a
(Jl
-0.1 ~"'!" ...~~._...._~.- ....... _ ..... _._. __ ... _ .. __~ ........
8-10C"
~z:! ; ~:::
~ ~:::
a:::
~
z
-1.1
I
\
: : : : : : : : : :\ : : : :
:r. :::: :: :: ::::::::::
\ '
::::::::::::..\:rI ::::::::::::::::::
,
················It··· ............... .
-0.1
-0.3
-0.5 . . • . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
-0.7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
-0.9
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _'"
-1.1
...........••........................
~
...I
-1.3
-1.3
(Jl
-1.5
-1.5
a
20
'0
a..
~
-0.1
-0.3
30
rr····
.........
~-~CM
40
50
60
!"":'!-................. -.;: ••• :~ •.
~ .... I
..........................•..........
-I
•.•••••.•......-~."". . . . . . . . . . . . -........ .
18-20CM
20
~
50
60
=::: ~:~:~ ~~:~~ ~:~:~ ~ ~:~ ~ ;:~:~ ~:~:~
58-60CM
:!!;
-0.5
-0.5
...••..............•.................
W
I-
-0.7
-0.7
.................................... .
a..
-0.9
-0.9
. . . . . . . . • . . . . . . . _ . . . . . . . . . . . . . . -. -'"
~
~
-1.1
-1.1
.................................... .
-1.3
a
-1.3
......•............•...•.............
-1.5
-1.5
...............•.....................
~
o
a:::
-I
(Jl
20
30
40
50
DAYS SINCE 1 JULY 1992
60
20
30
40
50
DAYS SINCE 1 JULY 1992
131
60
Figure 3-Soil matric potential at four distances
from a line source sprinkler for five soil depths in
summer 1992.
........
c
DISTANCE FROM
0..
LINE SOURCE (M)
-0.3
~
-O.!!
...J
t-
7.5
c
-0.1
e
-0.3
0..
~
~a..
-0.9
~
~
a::
...J
6
(IJ
-0.7
10.5
---~---
16.5
----<i<----
..
-0.11
~
-1.1
a::
~
-1.3
6(IJ
-1.5
...J
20
..
jl'
····~··························.V····
.::::::::::::::::::::::::.~/.:::~
-0.3
-0.5
-0.7
::: :. ::: ::: : :: : ::: :: : :::: :: :::: :: :: :: lj
_--- .. - ........ .
-1.1
....•........•.•.....•...•...........
-1.3
-1.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8-10CM
-1.5 . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . .
-1.5
-0.3
30
50
60
.......................................
38-4OCM
20
30
-0.1
50
60
. . . . . . . . . . • . • . . . . . . • . • . . . . . . . . . . .;
-0.5
-0.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . .
58-60CM
-0.5 . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
-0.7
-0.7 •...•...•.....••......•...•..........
-0.9
-0.9 . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
...J
Lo.J
60
-1.1
-0.1
~
-0.1
50
18-20CM
......
_-_ ...... -- ......
0'
o
a..
a::
40
30
-0.9
e
~
-0.7
0..
:~: ~~~~~:~~::::::: :~~ .~:
20
a..
~
......:._.-0-._.-
··t·······~FJ~ ....·.... -..:.~
...J
-0.5
z
O
1.5
-0.1
e
i
-1.1
-1.1
-1.3
-1.3 . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6(IJ
-1.5
...J
........•....•.......................
-1.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20
30
40
50
60
20
30
DAYS SINCE 1 JULY 1993
40
50
60
DAYS SINCE 1 JULY 1993
Figure 4-Soil matric potential at four distances from a line source
sprinkler for five soil depths in summer 1993.
20~~~-.~~~-r~-r~~~~~~~
23JULY1992
18
- .... -
16
~
....
o
10
A
8
A
A
B
i
JOJOBA
14
12
6
0..
A
A
10
A
8
B
6
4
2
o
o
o
2
4
6
8
10
12
1416
o
18
14AUGUST 1992
18
16
14
14
::
12
12
~
10
10
4
o
A
A
A
4
6
8
10
12
14
16
18
18
~
!:
2
20~--~~T---~--~---r~-r~~--~~~
16
2
A
A
A
A
4
2
20r---~~T-~~--~~-r~~~~~~~~
o
6 AUGUST 1 992
16
'- MESQUITE
...-- PALO
VERDE
14
12
20~--~T-~~'-~~~-r~-r~~~~~~
18
-+- ACACIA
8
6
A
4
A
2
A
AS
AS
B
o~--~--~--~--~--~~~--~--~~~
4
6
10
12
14
2
8
16
18
o
2
...
6
B
10
12
14
16
18
o~--~--~--~--~--~~--------~~~
DISTANCE FROM UNE SOURCE (M)
DISTANCE FROM UNE SOURCE (M)
Figure 5-Plants per meter of row for four woody species at seven distances from a
line source sprinkler on four dates in summer and fall 1992. Similar letters in vertical
order indicate no differences for species at that distance and date by LSD (p < 0.05).
132
20r-~r-~r-~~~~~~~------------'
30 JULY 1993
18
A
A
16
o
12
10
A
A
~..:.: ~~~~ITE
A_+-_ PALOVERDE
8
'="......\' -' - - - - - - - - ' 1
_ ..... ...- .....-.....
" A
\.
\
i:
a..
A
........" - ...
t---+--..
- ........ A
~ 14
L...
..-._.- ...
A
\ A
8
B
c
';..,
8
4-
2
o
4
2
....
,.
~
L...
o
:I
!
14
12
10
8
6
....... ~
AS
A
12
10
'- < .......x!,
.. -;.»
• ........
....
..
10
12
16
14
........
AS
A
-~
AS'
-._.-.,-
B
4-
.....
\.
A
" \. AS
,'.BC
A
A8
\ ~-.-.-.~
,
\ ..
--_.
20~--r---r-~~~~~~~~~~--'-~
A
A
AS
..... --1'-~ .. ---- __..8', AS /
AS...'
Be
AS
"8/
~.-.-.......
....
...... _\ /
........
A
~---;::~
0~--2~--4~~·6--~8---1·0~-1·2~-1~4~-1~6~~18·
18
18
,!.. __
AS...'
L
A
A
B
29 OCTOBER 1993
16
AS'
8
14-
A
2
A
~...........
A
4
30 AUGUST 1993
16
A
6
20~--~--r---r-~r-~r-~~~~~~--~
18
6 AUGUST 1 993
16
o
8
6
18
8
AS
o
C
C
o
20r---r-~~~~~~~~~~~~~.---~
___ ACACIA
"
I
A ..................
12
..
10
/
8
'='. . . .....
"
A
~
14
6
AS
B
v" 7.t<
i\
B./'"
............AS,
... ~
..... , \
'i_ ........ BC
~'-'-.......
........
4
~~
A
A
AB __ -~
\
A
A
A
AB
~
../....
. BC
BC"~ A ... 7
•...-.-.- ...-.-.~.. ~/
BC
C
~'''''
..... C
B
.,
2
2
_
50
......
4
8
10
12
14
6
DISTANCE FROM UNE SOURCE (M)
ACN:.IA
30
§a..
20
~
10
/
A
B
°0~--2~--4~--6~~8~~1·0---1·2~-1~4~-1~6--~18
" •
A·
/
B
"
C,,/
D /
B
A
18
DISTANCE FROM UNE SOURCE (M)
1.5 t.I FROM LINE SOURCE
:.:::: ~~~11E
- . - PALO VERDE
~ ~I-'------.....IA
!i:
B
CI
16
Figure 6-Plants per meter
of row for four woody species at seven distances from
a line source sprinkler on
four dates in summer and
fall 1993. Similar letters in
vertical order indicate no differences for species at that
distance and date by LSD
(p< 0.05).
~--~
~ __ -
A
B
C
D
//
/
-"-'-'-'-"-'-'-'-'-'50
60
70
80
90
100
50
......
~
!i:
40
~
30
~
20
::z::
A
B
B
C
A
B
A
10
~~0---3~0~~~----~50~~60~~7~0---8~0---9·0~-1~0-J0
13.5 MFROM UNE SOURCE
A
B
50
~ ~
C
D
......
./'
!i:
~
30
~
20
::z::
A
10
S
A
A
B
~~0--~3~0~a~~~~50~~60~~70~~8~0---9·0~-1~0~0
DAYS SINCE 1 JULY 1992
Figure 7-Plant height for four woody species at three distances from a line source
sprinkler during summer 1992. Similar letters in vertical order indicate no differences for
species at that date and distance by LSD (p < 0.05).
133
11 SEPTEMBER 1992
--...- - ... -
100
ACACIA
JOJOBA
MESQUITE
PALOVERDE
A
A
A
A
A
B
B
C
AB
B
C
B
40
20
7 OCTOBER 1992
A
~
.----------------.----------------.
A
~
A
A
B
80
80
60
100
B
_ .....
.. ----.-:::.":":>-~~-.-.-.-.-.-.-.
60
.-.-
40
c
20
.---------------~.----------------.
c
0~----3~~~5~--7~--~9--~1·1--~13~~15·
30 OCTOBER 1993
100
80
60
A
A
AS
21 NOVEMBER 1993
A
A
B
B
.. - _
.... '
A
--- ----
-.-.=:.-:::::..."':':.~'''''
40
..... · ....
...............
B
B
100
80
•
60
0~~--3~~~5~--7~~~9--~1·1--~1~3--~15
---:----------------~
A
C
20
~
o~
A
A
B
____~~~~~~B~~~~__~__~
3
DISTANCE FROM UNE SOURCE (M)
5
7
9
11
DISTANCE FROM UNE SOURCE (M)
13
15
Figure&-Tap root length
for four woody species at
three distances from a line
source sprinkler in late
summer and fall 1992 and
1993. Similar letters in
vertical order indicate no
differences for species at
that distance by LSD
(p < 0.05).
Cox, J. R.; Madrigal, R. M. 1988. Establishing perennial grasses on
abandoned farmland in southeastern Arizona. App. Ag. Res.
3: 36-43,
Fernandez, G. C. J. 1991. Repeated measures analysis ofline-source
sprinkler experiments. Hort. Sci. 26: 339-342.
Gelt, J. 1993. Abandoned farmland often is troubled land in need
of restoration. Arroyo. 7: 1-8.
Hanks, R. J. ; Keller, J.; Rasmussen, V. P. ; Wilson, G. D. 1976. Line
source sprinkler for continuous variable irrigation-crop production studies. Soil Sci. Soc. Am. J. 40: 426-429.
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create a stronger gradient in soil water availability and
better define water requirements for establishment of these
species. The pattern of irrigation or precipitation influenced
establishment of some of these species. Greater establishment of palo verde and jojoba on unirrigated than lowest
irrigated soils in 1993 suggests that seeds on the latter soils
germinated but died before August precipitation.
Rapid germination and fast root growth of most of these
species suggests that they could be established by sowing,
then irrigating sufficiently to fill the soil profile. Continued
supplemental irrigation to keep the soil surface wet until
seedlings emerge in about 2 weeks should result in high
seedling establishment on similar soils. For the sandy soil of
this study about 3 to 5 cm of water were needed to fill the
upper 60 em to field capacity and an additional 2 cm of water
applied over a 1.5- to 3-week period resulted in high plant
establishment. More frequent and longer duration irrigation would probably be necessary to establish these species
on finer-textured soils. Use of an existing irrigation system
to establish adapted woody species as well as grasses (Thacker
and Cox 1992) should be considered to revegetate lands
abandoned after farming. From a practical standpoint, this
strategy will be most successful if done right after abandonment before the irrigation system falls into disrepair. Establishment of these woody species on similar soils without
irrigation is possible, but highly dependent on rainfall pattern and amount. Abnormally high precipitation would be
necessary for successful revegetation.
References
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Charney, A; Woodward, G. 1990. Socioeconomic impacts of water
farming on rural areas of origin in Arizona. Amer. J. Agric. Econ.
72: 1193-1199.
134