Changes in Growth Parameters of Moringa oleifera and Soil Physical Properties in Different Salinity Treatments

Abstract

The salt tolerance and growth parameters of Moringa oleifera Lam. and the improvement of soil permeability by its roots were examined under different salinity treatments (ECe = 0, 4, 8 and 16 dS/m). The mineral concentrations in the organs of moringa were also investigated. Moringa showed no negative effect of salinity on its growth parameters up to 4 dS/m and those parameters were greatest when moringa was cultivated at 4 dS/m. Negative effects of salinity on the parameters became apparent at 8 dS/m and significant growth inhibition was observed at 16 dS/m. The sodium concentration in each organ increased as the soil salinity increased. The calcium and potassium concentrations in the leaves and the iron concentration in the stems decreased, and the phosphorus concentration in the roots increased with increasing salinity. There were no significant differences in the concentrations of phosphorus, copper, magnesium and zinc regardless of soil salinity or organs. The saturated hydraulic conductivity increased to 10-5 m/s at 0 and 4 dS/m and to 10-6 m/s at 8 and 16 dS/m compared to 10-8 m/s for the soil without moringa cultivation. These findings suggest that growing moringa at 4 dS/m resulted in the greatest growth parameters. The results also indicate that moringa can improve soil permeability through root growth, and therefore, moringa can be grown as a conversion crop in low permeability paddy (Oryza sativa) fields to improve soil physical properties under saline conditions.