Daoud, A. M.a; R. I. Fayeda; Amal H. Mahmouda and E. M. El-Zahabyb ( 2013). Impact of steel slag application on nutrients availability and corn yield grown on saline soilJ. Soil Sci. and Agric. Eng., Mansoura Univ., Vol. 4 (8): 777 - 791, 2013
Abstract: A greenhouse pot experiment was conducted to evaluate the effectiveness of arc furnace steel slag as a silicon source on the nutrients availability and corn yield in alluvial soil. The experimental treatments were 0, 500 and 1000 kg steel slag/fed, and 1.68, 3.0 and 6.0 dSm-1 soil salinity treatments. Response variables easured included yield of grains and stover, content of nutrients and metals in leaves and grains, and the available nutrients and metals remained in the soil after corn harvest. Grains and stover yields decreased progressively with increasing salinity levels in the absence of steel slag. Application of steel slag mitigated the deterioration effect of salinity stress. Grain yield markedly increased with slag applications and optimized (16.7%) with 500 kg slag rate at 3.0 dSm-1 salinity level. At 6.0 dSm-1 salinity, the increase in grains yield was mild (10.6%) at both rates of slag (500 and 1000 kg fed-1). Stover yield, though increased with slag application under salinity stress, but the increase was inconsistent. Steel slag applications significantly reduced Na and increased Ca, Mg, K and P contents in leaves and grain under saline conditions, with a greater response for P. Zinc content increased, and Fe decreased in leaves and grain with salinity in absence of steel slag, while applications of steel slag did not affect Zn content in grain and straw at any level of salinity but promoted Fe content.
The changes in Cu content were very limited. The contents of Cd, Ni, Pb and Cr were slightly changed with slag application and lie within the ranges being sufficient for corn. The available K increased with salinity in absence of slag. When slag added, available K content was rather increased with no consistent trend. Available P tended to decrease with salinity increasing, but markedly increased in the presence of slag at the same level of salinity. At 1000 kg slag rate, the available P was nearly twice than that of control either at 3.0 or 6.0 dS m-1 salinity level. Available Na and Si were higher in saline soils-untreated with slag. When slag applied, available Na decreased at any level of salinity, while available Si was slightly affected. This pattern was abundant with 500 kg slag rather than 1000 kg slag rate, suggesting that most of available Si combined with Na which inhibited Na translocation to plant tissues and hence its phytotoxicity. Available Fe increased with salinity, but rather increased with steel slag application. Copper, Zn and Ni availability were not affected with either salinity or slag application. In all cases the availability of the tested metals was not higher than the guide values assessing soil contamination by heavy metals. The application of the steel slag at 500 kg fd-1 was found to be more safety from the environmental point of view and agronomic benefits. However, field trails are still needed to confirm the greenhouse results.
Keywords: (Salinity, steel slag, corn, available nutrients heavy metals.)
