Effect of Steelmaking Slag and Converter Sludge on Some Properties of Acid Soil under Tea Planting.
Seyedeh Fatemeh Kiaee Jamali1, Akbar Forghani1, and Ahmad Shirinfekr2. (1) Guilan Univ, Dept of Soil Science, P.O. 41635-1314, Rasht, Iran, (2) Tea Research Center, Lahijan, Iran
Liming is effective agricultural practice for correcting soil acidity and in general liming increase soil pH, Ca and Mg. slag and converter sludge are by-products of steelmaking factories. In addition to their liming and corrective properties, these materials contain some plant nutrients such as Ca and Mg that can supply these elements for the deficient soils. To investigate the effects of slag and converter sludge of these substance effects on some soil and plant chemical properties, a field experiment was established. This work was performed in 18 plots with 40 m2 area,6 treatments (0.5% and 1% slag ,0.5% and 1% converter sludge ,0.5% slag + 0.5% converter sludge at dry soil weight and a control treatment) with 3 replicates on tea rows using a completely randomized blocks design. Treatments were mixed in 15 cm depth of soil at spring. After 2 months from mixing, soil sampling was done at 5 stages, every 45 days and from 0-15 cm and 15-30 cm depths. Leaves plucking are performed at 3 stages: spring, summer and autumn. Plant and soil samples were chemically analyzed in laboratory. The results indicated that pH increased at slag and converter sludge treatments in both depths. Slag treatments caused more pH increasing than converter sludge treatments. All treatments significantly increased available Ca and Mg of soil. One percent slag and 1% converter sludge treatments, showed the highest Ca and Mg concentrations, respectively. All treatments showed no increase in electrical conductivity (ECe) of the soil, even significant decrease in ECe was observed in 1% slag treatment. The result of plant analysis indicated that all of the slag and converter sludge treatments increased the plant Ca concentration, significantly and in 0.5% slag+0.5% converter sludge and 1% sludge converter treatments increased significantly the plant Mg concentration over the control. Keywords: pH, acid soil, slag, converter sludge.