Division of Applied Life Science (BK21+ Program), Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea.
Institute of Agriculture and Life Sciences, Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea.
Sci Total Environ. 2022 Nov 1;845:157296. doi: 10.1016/j.scitotenv.2022.157296. Epub 2022 Jul 12.
Blast furnace slag (BFS), a byproduct of iron-producing process, has been applied as silicate fertilizer in rice paddy. Silicate fertilizer contains lime and silicate as main components and iron and manganese as electron acceptors. This amendment improves soil productivity and mitigates methane (CH) emissions. However, its suppression effect was limited to <20 % at a field level, and its functionality needs improvement to encourage recycling. We hypothesized that the effect of silicate fertilizer on suppressing CH emission might improve by increasing electron acceptor concentration. To investigate the feasibility of electron acceptor added silicate fertilizer on increasing CH flux suppression, four byproducts of the iron-production process (basic oxygen slag-BOF, ferromanganese slag-FerroMn, iron rust, and Kambara reactor slag-KR) were selected and compared through soil incubation test. Iron rust effectively suppressed CH production by 67 %, which is comparable with a 15-30 % reduction of others. To find the optimum mixing ratio of iron rust, it was mixed to BFS with the rate of 0-5 % (wt wt), and their effect on CH flux was compared. The 3 % mixing ratio highly increased the BFS functionality on suppressing CH production. To confirm the field adaptability of the improved BFS, three types of silicate fertilizer (mixing iron rust with the ratios of 0, 2.5, and 5 %) were applied with the recommendation level (1.5 Mg ha) before rice transplanting. Seasonal CH flux was significantly decreased by the original silicate fertilizer (BFS) application to 20 % over control. This effectiveness was enhanced by adding 2.5 % iron rust but thereafter, not more increased. Silicate fertilization (BFS) significantly increased rice grain productivity by 9 % over control, and the improved silicate fertilizer (BFS) more highly increased by 13 %. In conclusion, the BFS's functionality to increase rice productivity and suppress CH emission could be improved by adding an effective electron acceptor such as FeO.
高炉渣（BFS）是炼铁过程的副产品，已被用作稻田中的硅酸盐肥料。硅酸盐肥料的主要成分是石灰和硅酸盐，电子受体是铁和锰。这种改良剂提高了土壤生产力并减轻了甲烷（CH）排放。然而，其抑制效果在田间水平上仅限制在<20％，需要改进其功能以鼓励回收利用。我们假设通过增加电子受体浓度，可以改善硅酸盐肥料对抑制 CH 排放的效果。为了研究添加电子受体的硅酸盐肥料增加 CH 通量抑制的可行性，通过土壤培养试验选择并比较了炼铁过程的四种副产品（碱性氧气炉渣-BOF、锰铁渣-FerroMn、铁锈和 Kambara 反应堆渣-KR）。铁锈有效地抑制了 CH 的产生，抑制率为 67％，与其他物质的 15-30％的减少量相当。为了找到铁锈的最佳混合比例，将其与 BFS 以 0-5％（wt wt）的比例混合，并比较它们对 CH 通量的影响。3％的混合比例极大地提高了 BFS 抑制 CH 产生的功能。为了确认改良 BFS 的田间适应性，在插秧前按照推荐用量（1.5 Mg ha）将三种类型的硅酸盐肥料（与 0、2.5 和 5％的铁锈混合）施用于田间。与对照相比，原始硅酸盐肥料（BFS）的应用使季节性 CH 通量显著降低了 20％。通过添加 2.5％的铁锈，这种效果得到了增强，但此后并没有进一步增加。硅酸盐施肥（BFS）使水稻籽粒产量比对照增加了 9％，改良后的硅酸盐肥料（BFS）的增加幅度更高，达到了 13％。综上所述，通过添加有效的电子受体（如 FeO）可以提高 BFS 增加水稻生产力和抑制 CH 排放的功能。
