Lim Ji Yeon, Kang Yeong Gyeong, Sohn Keon Mok, Kim Pil Joo, Galgo Snowie Jane C
Institute of Agriculture and Life Sciences, Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Republic of Korea.
Korea Foundation of Korean Foundation for Quality, 13th Fl, Woolim Lion's Valley B, 168, Gasan digital 1-ro, Geumcheon-gu, Gasan dong, Seoul, Republic of Korea.
Sci Total Environ. 2022 Feb 1;806(Pt 4):150961. doi: 10.1016/j.scitotenv.2021.150961. Epub 2021 Oct 14.
Blast furnace slag (BFS), a by-product of iron making, has been utilized as silicate fertilizer in Korean and Japanese rice paddy. Silicate fertilizer, which has high contents of active iron and manganese as electron acceptor, was newly known to suppress methane (CH) emission in flooded rice paddies, but the effect of its long-term application on rice cropping environment is still debatable. To evaluate the effect of silicate fertilization on suppressing CH emissions, the changes of CH index, indicating the ratio (%) of seasonal CH flux at the silicate fertilization treatment to that at the control, were generalized using the global investigation data (42 observations from 8 fields in Bangladesh, China, and Korea). Seasonal CH fluxes significantly decreased with increasing silicate fertilization levels. In CH index changes, 1.5 Mg ha of silicate fertilizer application (the recommended level of rice cultivation in Korea) decreased by 15% of seasonal CH fluxes. Rice grain yield highly increased with increasing silicate fertilization rates and maximized at approximately 4 Mg ha with 18% higher than no-silicate fertilization due to overall improvement of soil properties. To evaluate the long-term silicate fertilization effect on rice cropping environments, silicate (1.5 Mg ha year) and non-silicate fertilization treatments were installed in a typical temperate-monsoon climate paddy field in South Korea in 1990. Periodic silicate fertilization significantly increased rice grain productivity by an average of 14% over the control for the last 28 years. This fertilization evidently improved rice quality without changes in chemical quality. Consecutive silicate fertilization effectively improved soil physical and chemical properties but did not increase any acid extractable heavy metal concentration in soil. In conclusion, BFS as silicate fertilizer could be a beneficial amendment to mitigate CH emission in the rice paddy and improve soil properties and rice productivity and quality without hazardous material accumulation.
高炉矿渣（BFS）是炼铁的副产品，在韩国和日本的稻田中已被用作硅酸盐肥料。硅酸盐肥料含有高含量的活性铁和锰作为电子受体，最近发现它能抑制淹水稻田中的甲烷（CH）排放，但其长期施用对水稻种植环境的影响仍存在争议。为了评估硅酸盐施肥对抑制CH排放的效果，利用全球调查数据（来自孟加拉国、中国和韩国8个田地的42次观测），对CH指数的变化进行了归纳，CH指数表示硅酸盐施肥处理下季节性CH通量与对照处理下季节性CH通量的比率（%）。随着硅酸盐施肥水平的提高，季节性CH通量显著降低。在CH指数变化方面，施用1.5 Mg/ha的硅酸盐肥料（韩国水稻种植的推荐水平）使季节性CH通量降低了15%。随着硅酸盐施肥量的增加，水稻籽粒产量大幅提高，在约4 Mg/ha时达到最大值，比不施硅酸盐肥料时高出18%，这是由于土壤性质的整体改善。为了评估长期施用硅酸盐肥料对水稻种植环境的影响，1990年在韩国一个典型温带季风气候的稻田中设置了硅酸盐（1.5 Mg/ha·年）和非硅酸盐施肥处理。在过去的28年里，定期施用硅酸盐肥料使水稻籽粒生产力比对照平均显著提高了14%。这种施肥明显改善了水稻品质，而化学品质没有变化。连续施用硅酸盐肥料有效地改善了土壤物理和化学性质，但没有增加土壤中任何酸可提取重金属的浓度。总之，作为硅酸盐肥料的BFS可能是一种有益的改良剂，可减轻稻田中的CH排放，并改善土壤性质以及水稻生产力和品质，而不会积累有害物质。
