296
H. WALTER AND E. STADELMANN
TABLE X X I V
GROWTH OF Salicornia herbacea IN SALINE SOILS"
Parameter
Number of nodes on main stem
Fresh weight of plant (in gm)
Dry weight of plant (in gm)
6
Control
18.7
1.33
0.33
Sulfate
salinity
17.0
3.19
0.60
Chloride
salinity
21.8
6.36
0.82
a From Strogonov (1964, p . 57, Table 23).
b Most probably including the salts accumulated in the plant.
each other on the same soil, since certain species take up chlorides almost
exclusively, while others also absorb relatively great amounts of sulfates
in addition to the chlorides. The former species are succulent, the latter
xeromorphic (Walter, 1936, p. 186ff).
The increase in dry weight for 100 cm
2
leaf surface found in Table XXIII
for plants grown in the salt-containing soil may be largely caused by salt
accumulation in the leaves. Transpiration (which also decreases with
higher NaCl concentrations; see Önal, 1971, p. 2) is highly reduced in the
chloride soil compared to the sulfate containing soil, while the degree of
succulence increases in the chloride soil. The increased succulence results in
a water content per unit surface area which is greater than twice the control value, whereas in sulfate-containing soil the water content per surface
unit of the (less succulent) leaf is only 24% higher than the control.
When salt mixtures (natural soils always contain mixtures of salts) with
a preponderance of the sulfate ion over the chloride ion are added to
the soil, the osmotic potential of the expressed leaf sap does not differ
from the control (ψ 8 = — 9.6 atm), while ψ 3 considerably decreases
(to —13.3 atm) for plants grown in soils with preponderate^ chloride
ions. Protoplasmic viscosity (determined as plasmolysis time) for the epidermal cells of leaves of Gossypium herbaceum grown in the chloride-rich
soil is about nine times as high as that of the control, but in sulfate-rich
soils only about four times the value of the control (Strogonov, 1964, p.
110). This viscosity change clearly indicates the impact of the Cl" ion on
the protoplasmic qualities: A lower degree of protoplasmic hydration results than with sulfate-rich soil. Chloride salinity of soils causes halo-succulence, sulfate salinity causes haloxeromorphism.
While growth of crop plants is greatly inhibited by soil salinity (and
with chloride salinity much more than with sulfate salinity), chloride
salinitv of soil causes enhanced growth in Salicornia herbacea (Table
XXIV).
H. WALTER AND E. STADELMANN
TABLE X X I V
GROWTH OF Salicornia herbacea IN SALINE SOILS"
Parameter
Number of nodes on main stem
Fresh weight of plant (in gm)
Dry weight of plant (in gm)
6
Control
18.7
1.33
0.33
Sulfate
salinity
17.0
3.19
0.60
Chloride
salinity
21.8
6.36
0.82
a From Strogonov (1964, p . 57, Table 23).
b Most probably including the salts accumulated in the plant.
each other on the same soil, since certain species take up chlorides almost
exclusively, while others also absorb relatively great amounts of sulfates
in addition to the chlorides. The former species are succulent, the latter
xeromorphic (Walter, 1936, p. 186ff).
The increase in dry weight for 100 cm
2
leaf surface found in Table XXIII
for plants grown in the salt-containing soil may be largely caused by salt
accumulation in the leaves. Transpiration (which also decreases with
higher NaCl concentrations; see Önal, 1971, p. 2) is highly reduced in the
chloride soil compared to the sulfate containing soil, while the degree of
succulence increases in the chloride soil. The increased succulence results in
a water content per unit surface area which is greater than twice the control value, whereas in sulfate-containing soil the water content per surface
unit of the (less succulent) leaf is only 24% higher than the control.
When salt mixtures (natural soils always contain mixtures of salts) with
a preponderance of the sulfate ion over the chloride ion are added to
the soil, the osmotic potential of the expressed leaf sap does not differ
from the control (ψ 8 = — 9.6 atm), while ψ 3 considerably decreases
(to —13.3 atm) for plants grown in soils with preponderate^ chloride
ions. Protoplasmic viscosity (determined as plasmolysis time) for the epidermal cells of leaves of Gossypium herbaceum grown in the chloride-rich
soil is about nine times as high as that of the control, but in sulfate-rich
soils only about four times the value of the control (Strogonov, 1964, p.
110). This viscosity change clearly indicates the impact of the Cl" ion on
the protoplasmic qualities: A lower degree of protoplasmic hydration results than with sulfate-rich soil. Chloride salinity of soils causes halo-succulence, sulfate salinity causes haloxeromorphism.
While growth of crop plants is greatly inhibited by soil salinity (and
with chloride salinity much more than with sulfate salinity), chloride
salinitv of soil causes enhanced growth in Salicornia herbacea (Table
XXIV).