So, application of steel slag can provide with silicon nutrition and is beneficial for sustainability of rice production. Yes C. Effect of steel slag fertilizer application on relative content of Pb in each fraction of soil in early rice. Sucrose slag organic fertilizer production line Complete plant. The application of fertilizer made of slag increased the yield by approximately 7–9% without statistically significant differences, not only in 2012 but also in 2013. Figure 16 summarizes the yield of brown rice. We found that the Cd concentration in rice grain tended to decrease with increasing application rate of steel slag. However, total concentrations of heavy metals in soil provide very limited information about their chemical behavior and potential fate [27, 28]. Application of Fertilizer Made of Steelmaking Slag in the Recovery of Paddy Fields Damaged by the Tsunami of 2011. The significant amount of slag generated result in serious environmental issues and resource losses. In the present experiment, original soil pH was 5.48, but soil pH reached 6.43–6.68 when the slag application rate was was higher or equal to 1 600 mg plant-available SiO2 per kg soil (Fig 1), which is in line with previous reports [37, 38]. Data Availability: All relevant data are within the paper and its Supporting Information files. First, steel slag fertilizer was incorporated well with 5.0 kg soil in each plastic pot. Like the old basic slag our grade of steel works slag called Super Slag Basic is principally a lime based material which has absorbed the . Summary of harvest results in 2012 and 2013. The results are summarized below. Slag, as the term will be used here, is any siliceous melt that arises in significant quantity from the various processes used in the production of iron and steel, and more particularly the solid materials that forms when such melts cool. In the present study, disease incidence and severity (e.g., blast, sheath blight and leaf spot etc.) Once slags were dumped; nowadays they are considered marketable products and only a small percentage is processed as industrial waste in landfills. Crop cultivation experiments were conducted using actual tsunami-affected paddy fields. (2) The brown rice yields increased by approximately 7–9% in 2012 and 2013 with the application of fertilizer made of slag. © 2016 by The Iron and Steel Institute of Japan, Edited and published by : The Iron and Steel Institute of Japan, 2.1. '•The slag from the Thomas-Gilchrist process for making steel has long been supposed to have valuable properties as a manure. 3, pp. 9 (2018) 4/14 3 Fertilizer Components of DM Calcium Silicate One type of slag fertilizer for growing paddy rice is slag siliceous fertilizer (registration name: Calcium Silicate) made from iron and steel slag. Although Si has not been considered as an essential nutrient for plant, there is increasing evidence proved that Si is beneficial for rice growth, development and resistance against abiotic (metal toxicity, salt and drought stress, nutrient imbalance) and biotic stress (plant diseases and insect pests) [3–6]. Steel slags have been applied as calcium silicate fertilizer in fields where plant-available silicon is deficient in soil. The sequential extraction of heavy metal in soil or slag was performed using a three-step procedure recommended by BCR , with the details presented in Table 2. https://doi.org/10.1371/journal.pone.0168163.t002. The ferrugeneous portion of LD-slag can be separated by magnetic separation technique. A consecutive early rice-late rice rotation experiment was conducted to test the impacts of steel slag on soil pH, silicon availability, rice growth and metals-immobilization in paddy soil. However, this fact sheet will mainly focus on solid co-products. fertiliser. In addition to these three components, it also contains components such as FeO, MnO, and P2O5, so it has been used for a broad range of agricultural purposes. A consecutive early rice-late rice rotation experiment was conducted to test the impacts of steel slag on soil pH, silicon availability, rice growth and metals-immobilization in paddy soil. Various efforts have been made on the utilization of blast furnace and steel slags. Application of steel slag had no significant effect on Pb concentration of rice grain. As a product of waste steel industries, steel slag used in this experiment has been shown great and sustainable potential to reduce Cd accumulation in rice grain. Thomas and Gilchrist method Table 2. broad scope, and wide readership – a perfect fit for your research every time. Both Cd and Pb concentrations in steel slag were very low, and also mainly present in the form of residual fraction, with their percentage accounting for 89.1% and 94.5%, respectively (Table 3). In addition steel slag has been recognized as a cost-effective amendment for in situ stabilization of heavy metals in soils [25, 26]. The Si content of DS with fertilizer made of slag was higher than that of the other conditions during the experiment, although the difference was not large. The chemical composition of CaO, SiO2, and MgO in steel slag was the same as that of the raw inorganic fertilizer material, in terms of composition and also contained e ective components such as FeO, MnO, and P2O5 [18,19]. J. Ma and E. Takahashi E: Soil, Fertilizer, and Plant Silicon Research in Japan, Elsevier, Amsterdam, (2002), 107. With 80% of the paddy fields in China being located in the subtropics, it is necessary to demonstrate the effects of steel slag application on rice yield and heavy metal immobilization in the subtropical Chinese paddy fields. here. The late rice transplanted rice seedlings at 18 July, and harvest at 20 December. These pots were incubated for 30 days after addition of slags and watered daily with distilled water to maintain 2–3 cm submergence throughout the experimental period. N. Maruoka, M. Okubo, H. Shibata, X. Gao, T. Ito and S. Kitamura: M. Okubo, N. Maruoka, H. Shibata, X. Gao, T. Ito and S. Kitamura: T. Ito, W. Nasukara, M. Saito and S. Kitamura: Rural Development Bureau, Ministry of Agriculture, Forestry and Fisheries, Japan: Desalting Manual of Farmland, (2011). Lead was found to be mainly distributed in the F2 (50%) and F4 (40%) fractions. Yes Slag run-off from one of the open hearth furnaces of a steel mill, Republic Steel, Youngstown, Ohio, November 1941. In this experiment, application of steel slag had no significant effect on Pb accumulation in rice grain (Fig 7B). The total iron oxide content should not be 5%. Increase in uptake of P2O5 with steel works slag over 50% more than with TSP and three times more than with gafsa.. Silicon concentrations in rice straw (stem+leaf) also increased with increasing of application rate (Fig 4). In addition, the application of the fertilizer increased Ca and Si in the stems and leaves of the rice plants. No, Is the Subject Area "Soil pH" applicable to this article? Previous studies showed that only 30% of the available Si in slag could be released during one rice season . During the rice growing period, applied to maintain a 2-cm water layer and no pesticides were applied. Our results show that application of slag at a rate above higher or equal to 1 600 mg plant-available SiO2 per kg soil increased soil pH, dry weight of rice straw and grain, plant-available Si concentration and Si concentration in rice shoots compared with the control treatment. Yes Silicon application significantly decreased Cd concentration in the xylem sap and Si-mediated detoxification of Cd in maize plants . LD steel slag as fertilizer in agriculture. Fig 7A and 7B shows the data of Cd and Pb accumulation in the grain of rice grown with different application rates of steel slag. Fertilisers from Blast Furnace and Steel Slags233 Кб. Fertilizers made of steelmaking slag are important inexpensive materials for recovering degraded paddy fields. This increased plant-available silicon concentration in soil mostly was released from slag-fertilizer. Effect of steel slag fertilizer application on Cd uptake by rice grain. Accepted for publication 16 June 2015. For more information about PLOS Subject Areas, click Steel slags contain numerous nutrient elements, such as CaO (40–50%), SiO2 (10–28%), as well as small amounts of MgO (2.5–10%), Fe-total (17–27%) and MnO (1.5–6%) . Slag, which is a by-product of ironmaking at steelworks, contains 25-30% of soluble silicic acid. Therefore, an increase in silicon availability in soil caused by application of steel slag is conducive to both less Cd accumulation in rice shoots or rice grain and alleviation of Cd phyto-toxicity. Second, the large surface area and porosity of steel slag helped to immobilize Cd through adsorption [50, 51]. The first factor influencing plant available–silicon concentration may be associated with the different weather conditions in the two seasons. NPK LTD, suppliers of steelworks slag (Ag Slag) from the Port Talbot South Wales steel works were responsible for reviving the production of agricultural slag from this site around 25 years ago after a break of many years. Silicate lime fertilisers (blast furnace lime and converter lime) are approved fertilizers in Germany since more than 60 and 30 years, respectively. No, Is the Subject Area "Heavy metals" applicable to this article? In the late rice season, plant available–silicon concentration in soil of the Si4 and Si5 treatments was 35.5% and 41.5% higher than in the control treatment, respectively. Iron oxide present in LD-slag forms a phase, tetra calcium alumino ferrite (C4AF) which has an adverse effect on the quality of cement'''. Thus, steel slags can be considered as a sustainable alternative to agricultural practice. On the other hand, application of steel slag also accelerated the transformation of amorphous silicon to soluble silicon and resulted in enhancement of Si availability . In the same treatment with slag, lower Cd concentrations were observed in the late rice than in the early rice. CaO phases dissolved quickly. Dissolution Behavior in the Paddy Environment, 3.2. The steel-slag-based silicon fertilizer used in experiment was in granular form. This development is of particular significance since the supply of low-phosphorous iron ores is diminishing at an ever increasing rate. The residual effect of the fertilizer was kept observed in 2013, although the additional fertilizer was not applied. Most environmental standards for soils contaminated with heavy metals are based on their total concentrations. Change in the Ca content of pore water in paddy field in 2012 and 2013. All data in figures and tables were shown as means ± SD of three replicates. The metals in the soil were precipitated as carbonates or hydroxides and acidification simply dissolved the precipitates . Traditionally it has been used mainly as an aggregate but for some types there are other applications, such as a raw material for cement or as a fertiliser. In addition, the incremental trend of silicate contents in the pore water in the slag application plots was similar to the results of the column test a more apparent than. Fertilizers made of slag are categorized as slag silicate fertilizer, lime fertilizer, slag phosphate fertilizer, and iron matter of special fertilizer ( Ito, 2015 ). Many studies demonstrate that steel slag–based silicate fertilizer was effective in improving both the quality of the degraded paddy soils and the yield and quality of crops [22, 33, 38]. In addition, the area and intensity of paddy soil acidification in the South China have been gradually increasing because of long-term overuse of N fertilizer and acid deposition . M. Numata, N. Maruoka, S-j. Soil samples were collected both before rice transplanting and after rice harvesting in each rice season. Basic slag It is a by-product from the steel industry. This trend was difficult to simulate by the column test. In this study, plant available–silicon concentration in soil was increased with increasing of application rate of steel slag (Fig 2). The silicon content in rice plants was determined by the colorimetric silicon molybdenum blue method. In conclusion, application of steel slag reduced soil acidity, increased plant–availability of silicon, promoted rice growth and inhibited Cd transport to rice grain in the soil-plant system. Thus Table 1 also shows the estimated contents of metals in soil with 10.0% slag application, which are calculated by summing up 90% of metal contents in soil and 10% of metal contents in Mo slag. Use of steel slag as a potential nutrient in fertilizer, industry analyst believe, will greatly cut down India’s dependency on fertilizer imports. '•The slag from the Thomas-Gilchrist process for making steel has long been supposed to have valuable properties as a manure. Si deficiency in paddy soil has been recognized as a limiting factor for rice production [2, 8]. No significant accumulation of total cadmium (Cd) and lead (Pb) was noted in soil; rather, the exchangeable fraction of Cd significantly decreased. The slag is then dehydrated or pulverized into pellet-like shapes to become the final product. CEO Choi said not only the fertilizer will improve the taste of rice and help boost income for farmers, but it will also enhance soil quality while helping reduce greenhouse gas emissions. The feasibility of steel slag used as an iron fertilizer was studied in a pot experiment with corn. After the vessel had been cooled, the solution was filtered and diluted to 25 mL with 0.5 M HCl. K. Saito, A. Yamamoto, T. Sa and M. Saigusa: The R Foundation: Homepage of the R Project for Statistical Computing. The heavy metal contaminated croplands have reached 20 Mha, and most of them are still cultivated . This decrease, however, could not be only attributed to the pH-rise-caused immobilization of Cd in soil. The fertilizer made of slag increased Ca and Si but the change in Na was not evident. Data are means of three replicates. https://doi.org/10.1371/journal.pone.0168163.s005, A. Silicon is taken up by roots in the form of silicic acid (H4SiO4), and mainly distributed in rice straw (leaf + stem) . In the past steelmaking processes were exclusively designed for the production of specific quality of iron and steel. and the phosphorous extracted to produce fertilizer. Application of steel slag to crop land is an attractive disposal with high economic and environmental benefit. Rice is also a typical Si hyper-accumulating plant species, containing Si up to 10% in shoots on a dry weight basis . A representative sample of up to 0.5 g was digested in 9 mL of concentrated nitric acid (HNO3) and 3 mL of concentrated hydrofluoric acid for 15 minutes in a suitable laboratory microwave system. The authors gratefully acknowledge the financial support provided by ISIJ innovative program for advanced technology, Iron & Steel Institute of Japan (ISIJ). For more information about PLOS Subject Areas, click Click through the PLOS taxonomy to find articles in your field. Each pot was loaded with 5 kg of air-dried and sieved (2 mm) latosol. Figure 15 shows the changes in Na content of pore water in 2012. Application of steel slag decreased the percentage of F1 and increased the percentage of F3, whereas there was little change in F2 or F4 fractions (Fig 6C and 6D). The Cd concentration of early rice grain and late rice grain was 48% and 63.5% lower in the Si5 treatment than in the control treatment, respectively. Siliceous slag fertilizer is made with slag, which is stony by-product separated from molten iron during the smelting or refining of ore. https://doi.org/10.1371/journal.pone.0168163.s001, https://doi.org/10.1371/journal.pone.0168163.s002, https://doi.org/10.1371/journal.pone.0168163.s003, https://doi.org/10.1371/journal.pone.0168163.s004. The dissolution behaviors of nutrient elements from fertilizer made of slag were investigated by the column test. 1. Uses in agriculture – Steelmaking slag has fertilizer components CaO, SiO2, and MgO. — Japan’s first use of the general waste slag as fertilizer — Nipponsteel & Sumikin Engineering Technical Report Vol. lignite sludge pond sludgeSucrose slagstarch pulp Bentonite clay Diatomite c materials mix with mineral materials Organic Ball Pellets Fertilizer Production Line Organic fertilizer production line is a complete set of equipment from raw materials collection to the organic fertilizer granules packing However, solid-phase diffusion into the lattice of oxides or into the micropores of these oxide materials were considered more stable than pH-moderated sorption of heavy metals in soils . Changes in soil pH in paddy field in 2012. Pb concentrations of rice grain in all the treatments were below the maximum allowable limit value (0.2 mg kg-1). Steel slag is derived in iron and steel production. 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