| dc.description.abstract | Indonesia is located in the tropical climate area with high temperature and rainfall, and generally has acidic soils with low fertility. Latosol is one of the highly weathered soils that has low organic matter content, low CEC, low BS, and high to very high clay fraction in all soil horizons. The fertility of Latosol can be improved by addition of ameliorans such as steel slag and organic matter. Steel slag is byproduct of purification process of iron ore in steelmaking. Previous studies showed that steel slag is potential to be used as soil amelioran since it has 20-50% or more CaO, and contains Mg, Si, Fe and some other elements. Previous studies also showed that steel slag as liming material was better than dolomite. Utilization of steel slag as soil amelioran in Indonesia, however, is limited by the Indonesian regulation that categorized all steel slags as hazardous and toxic wastes (limbah B3 = limbah bahan berbahaya dan beracun). Since there are various steelmaking processes, not all steel slags included in hazardous and toxic wastes as indicated by previous studies. The objective of this research is to analyze soil chemical properties that include pH, macro nutrients content (N, P, K, Ca and Mg), and heavy metals content (As, Pb, Sn, Cd and Hg) after cultivation of caisim in Latosol that treated with steel slag, organic matter, and their combination. The research was conducted in Factorial Randomized Block Design with three factors. The first factor was the type of steel slags that comprised of S1 (converter steel slag from Japan) and S2 (electric furnace steel slag from Indonesia). The second factor was the dosages of steel slag (4 dosages namely T0, T1, T2, T3), while the third factor was organic matter (B0 and B1). The each treatment was consisted of 4 replication such that there were 64 experimental units. The results showed that the soil pH increased with the increasing of steel slag dosages, and the type of the steel slags gave the same effect toward soil pH. Available P was increased by S2 treatment but not by S1 treatment. Exch-Ca and exch-Mg were increased by both slags. S1 treatments increased the exch-Ca by 113-265%, and the exch-Mg by 27%. The S2 treatments increased the exch-Ca by 91-144%, and the exch-Mg by 75-326%. Organic matter treatments increased pH, available P, and exch-Ca of the soil. Combination of slags and organic matters treatments increased exh-Mg, but decreased exch-K. Slag, organic matter, and their combination treatments decreased the soluble Pb and Hg of the soil. In some combination treatments, however, soluble Cd, soluble As, and soluble Sn were increased consecutively to 0.01 ppm, 0.01-0.02 ppm, 0.08-0.15 ppm from undetected concentration of the untreated soil. | en |
