Akademik Veri Yönetim Sistemi
African Journal Of Agricultural Research, cilt.7, ss.1073-1086, 2012 (SCI-Expanded)
The effect of varying humic acid supplies (0, 0.05 and 0.1% w/w) on some agro-physiological properties
and ionic balance of bean plants in different salt source and doses were investigated. Plants were
treated with eight salt sources [sodium chloride (NaCl), sodium sulphate (Na2SO4), calcium chloride
(CaCl2), calcium sulphate (CaSO4), potassium chloride (KCl), potassium sulphate (K2SO4), magnesium
chloride (MgCl2) and magnesium sulphate (MgSO4)] in four different concentrations (0, 30, 60, and 120
mM doses) for 60 days in a growth media. The highest salt doses; 120 mM of NaCl, CaCl2, MgCl2 and
KCl2 at no humic acid applications caused plant death, but no plant death was obtained in humic acid
application (0.05 and 0.1%) doses in all of the salt types and doses except for CaCl2. Total chlorophyll
and nitrate contents of plants decreased with increasing salt doses, but were negatively related to
humic acid application doses. Proline contents of plant were increased with increasing salt doses and
the highest value was obtained for NaCl application. The effects of salt concentrations in nitrogen and
phosphorus content of plants were significant. Humic acid added to saline soil significantly improved
the variables affected by high salinity and also increased plant nitrate, nitrogen and phosphorus,
reduced soil electricity conductivity, proline and electrolyte leakage of plant, enhanced plant root and
shoot dry weight by allowing nutrients and water to be released to the plant as needed. The result
suggested that humic acid have great potential in alleviating salinity stress on plant growth and growth
parameter in saline soils of arid and semi-arid areas. This humic acid appeared to be highly effective for
soil conditioners in vegetable growth, to improve crop tolerance and growth saline conditions.