plant growth by its effects on ion transfer at the root level by
activating the oxidation-reduction state of the plant growth
medium and so increased absorption of nutrients by preventing
precipitation in the nutrient solution. Furthermore, it enhances
cell permeability, which in turn made for a more rapid entry of
nutrients into root cells and so resulted in higher uptake of plant
nutrients (Sayed et al., 2007). Jianguo et al. (1998) found that
humic acid application improved the nutritional regulation of
plants as indicated by changes in various physiological and
biochemical indexes. These effects were associated with the
function of hydroxyls and carboxyls in these compounds
(Osman and Ewees, 2008). Taken together, these amendments
enable plants to overcome the adverse effects of soil salinity.