Aplikasi steel slag, dolomit, silica gel dan pupuk mikro pada tanaman padi di tanah gambut

Abstract

Steel slag as a by-product formed in the process of steel manufacturing consists of iron-making slag or blast furnace slag (BFS) and steel-making slag or electric furnace slag (EFS) had been used as Si fertilizer and liming materials. Steel slag containing silicate, micro elements, and bases can be used to improve chemical properties of peat soil that are poor in nutrients. Steel slag contains a lot of silicate needed by especially Si accumulator plants such as paddy rice plant. This research aimed to compare paddy rice plant’s response of IR64 and Air Tenggulang to EF slag, BF slag, dolomite, silica gel and micro fertilizer application for improving chemical properties of peat soil, to know the reason of paddy rice plant’s response on peat soil to steel slag application and to evaluate steel slag effect in content of hazardous heavy metal in brown rice. This research consisted of an incubation and a greenhouse experiments. Both of them were single factor experiment arranged in a completely randomized design. The treatments were both EFS and BFS (0%, 2%, 4%, 6%, 8% w/w of the soil), both dolomite and silica gel equivalent EFS dosage and also micro nutrients with three replications. The results showed that application of EFS on peat soil significantly improved the availability of Fe and Mn, BFS on peat soil significantly improved the availability of Si and Mg and dolomite on peat soil significantly improved soil pH and availability of Ca. Paddy rice grown on peat soil highly responded to steel slag application. Plant height, number of tillers, weight of spikilets, SiO2 of straw were significantly raised with EFS application and content of hazardous heavy metal in brown rice still within limit of food maximum pollution, but Pb and Hg were not detected. In general, the highest rice yield was achieved at dosage of EFS 8%. In conclusion, paddy rice grown responded to steel slag application was associated in increasing soil pH, the availability of Ca, Mg, Fe, Mn and Si on peat soil. Generally, Paddy rice grown on peat soil highly responded to EFS application better than the others. It meaned that not only silicate as the main factor in improving peat soil chemistry and rice yield, but also increasing soil pH, availability of Ca, Mg and micro nutrients.