Abstract

Phytoremediation of soils of different salinity levels have been investigated in this study using salt tolerant forage crop. Soil was salinized with 5 levels of  NaCl (0, 50, 100,150, 200 mmol L⁻¹) in 100 cm height and 50 cm diameter lysimeters . Millet (Pennisetum glaucumL.) was planted as a reclament crop for saline soil.

  Results showed that ECe, Na⁺ and Cl^- reduced in all soil layers soil occurred post cultivation of millet crop. It is found that shoot and grain yield significantly (p≤ 0.05) reduced as NaCl levels increased. Ionic concentrations of Na⁺ and Cl^- in shoot and grain significantly increased with NaCl increasing levels. Before cultivation millet, soil salinity of 200 mmol L^-1 treatments was above threshold leading to yield loss as a response to elevated salinity. Relative yield (the ratio between saline treatment and non-saline treatment) obtained from 200 mmol L^-1  treatment was 74, 77 and 75% for shoot, grain and total biomass weight, respectively which considered acceptable from economic aspect. It was noticed that cultivation facilitated salt leaching through the root zone and the vegetative cover provided by the millet crop prevents capillary rise of which could lead to salinization, instead desalinization was the main process which occurred in the soil at all salinity levels. General trend showed that using with SALINITY model capture the essential features of leaching saline soil. However, it was concluded that SALINTY model did not take phytoremediation into consideration which led to higher predicted ECe values comparing with the measured values. Modeling salt and water during phytoremediation is needed to submit new criteria of saline soil reclamation.