Salinity and salt composition effects on seed germination and root length
of four sugarbeet cultivars
A. A. JAFARZADEH and N. ALIASGHARZAD
Department of Soil Science, Faculty of Agriculture, University of Tabriz, 51664 Tabriz, I.R. of Iran
Salinization is one of the most important factors affecting agricultural land in the world. Salinization occurs
naturally in arid and semiarid regions where evaporation is higher than rainfall. Sugar beet yield declines
with an increase in salinity, but the sensitivity to salts varies with salt composition in water and sugar beet
growth stage. The aim of this study was to determine the effect of water salinity levels and salt composition
on germination and seedling root length of four sugar beet cultivars (PP22, IC2, PP36, and 7233).
The experiments were undertaken with irrigation water with two salt compositions (NaCl alone and mixture
of MgSO4 + NaCl + Na2SO4 + CaCl2) in three replicates. Thirteen salinity levels with electrical conductivity
(EC) of the irrigation water ranging from 0 to 30 dS/m were applied to each cultivar in both experiments.
Seed germination percentage and seedling root length growth were determined in 13 days. Statistical analysis
revealed that germination and root length were significantly affected by salt composition, cultivars and salinity
levels. Regardless of salt composition, seed germination and seedling root length were significantly affected
by the irrigation water with EC up to 8 dS/m and 4 dS/m, respectively. Except for cultivar PP22, the adverse
effect of salinity of the irrigation water on seed germination and seedling root length was higher for NaCl alone
than for the salt mixture, which refers to lower salt stress in field conditions with natural salt composition.
A. A. Jafarzadeh and N. Aliasgharzad
Střelcová, K., Škvarenina, J. & Blaženec, M. (eds.): “BIOCLIMATOLOGY AND NATURAL HAZARDS”
International Scientific Conference, Poľana nad Detvou, Slovakia, September 17 - 20, 2007, ISBN 978-80-228-17-60-8
salinity, salt composition, sugar beet, germination, root length
Land affected by salinization in arid and semiarid regions
of South Asia is about 42 million hectares (FAO, 1994).
Approximately 33 M ha are in I.R. of Iran, where about
55% of all agriculture lands are shown as being affected.
Therefore salinity can be hazardous to plant growth
in nearly every irrigated area of Iran, which is affected
by salt accumulation. Salt accumulation in the root zone is
a serious problem in crop fields in semi-arid regions, which
are affected by dynamics of water and ion transport in the
soil-plant-atmosphere continuum (Volkmar et al., 1998).
Although water and ion transport in crop fields is driven
through physical and physiological processes, the transport
phenomena in the root zone have been studied mainly
through physical processes because of the difficulties
in quantitative analysis of root physiological functions
The results of the monitoring of saline soil development
prove that the main source of salts in soil is the salinity
of shallow groundwater (El Lateef et al., 2006). In areas
with an evaporation water regime of the soil, such
as the many part of Iran dissolved salts are transported from
a groundwater level to the soil profile by means of vertical
flow. Moreover, using such groundwater for irrigation also
leads to the accumulation of salts in the soil profile. In both
processes groundwater is drawn by evapotranspiration,
and soluble salts coagulate on the surface of soil particles
and sodium ions are adsorbed into the soil colloidal system.
Irrigation with secondary treated wastewater can also
be the source of salts in soil (El Lateef et al., 2006).
The suitability of water depends on how it can be used
under specific conditions. These conditions include
the tolerance of crops to salts (Burger, Čelková, 2001) various
physical and chemical properties of soil, management
of irrigation methods, and climatic conditions in the given
The term salinity relates to the total concentration
of the main dissolved inorganic ions, i.e. Na+, Ca2+, Mg2+,
K+, HCO3–, SO4
and drainage waters (Epstein, Rains, 1987). In some saline
soils the predominant anion often is SO4, not Cl, and Mg
concentration may exceed those of Ca by large factors.
Magnesium and Ca combined may exceed the concentration
of Na (Epstein, Rains, 1987). The particular concentrations
of these cations and anions can be expressed by means
of chemical equivalents (mmolc/l) or on a mass basis
(mg/l). The total concentration of salts (i.e. the salinity)
is then expressed as the sum of the individual cations
and anions in mmolc/l, or in mg/l. For the reasons
of analytical simplification, the real salinity indicator
is the electrical conductivity of water (EC) expressed
in dS/m, or in mS/m or µS/cm. Electrical conductivity
is always expressed at a standard temperature of 25°C
2– and Cl– in groundwater, channel waters