Effect of soil salinity and compaction on some physiological characteristics of corn (Zea mays L.)

This research was performed to investigate the combined effect of soil salinity and compaction on some physiological characteristics of corn. For this purpose a factorial pot experiment on the basis of completely randomized design with three replications was performed. The experimental factors were three levels of soil salinity (saturated paste extract electrical conductivity 1.5, 2.5 and 4.5 dS/m) and three levels of soil compaction (bulk density 1.3, 1.55 and 1.75 g/cm3. For creating salinity, different amounts of NaCl was dissolved in the required volume of distilled water to raise the mass water content to 16% and then added to soil. For creating soil compaction a cylinder mass with 4.5 kg weight that it was allowed to fall freely to the soil surface in the pots from 45 cm elevation. Soil salinity led to significant increase in stomatal resistance, proline concentration and Na concentration. Soil compaction significantly decreased leaf water potential and increased stomatal resistance At the applied range of soil salinity and compaction, soil salinity caused more adverse effect than soil compaction on physiological characteristics of corn. Despite that combined effect of soil salinity and compaction became statistically significant only on stomatal resistance, combination of soil salinity and compaction led to increase in proline and Na concentration and to decline in leaf water potential, RWC, K concentration and K/Na. Combined effect of salinity and compaction led to more drastic effects than their individual. Therefore, one of the approaches of soil salinity alleviation may be to avoid or reduce soil compaction.