Division of Applied Life Science (BK 21 plus program), Graduate School, Gyeongsang National University (GNU), Jinju-city 52828, South Korea.
Institute of Agriculture and Life Sciences (IALS), Gyeongsang National University (GNU), Jinju-city 52828, South Korea.
Sci Total Environ. 2022 Jan 15;804:150159. doi: 10.1016/j.scitotenv.2021.150159. Epub 2021 Sep 7.
Rice is the main staple food for more than half of the world's population. Yet, rice cultivation is subjected to criticism because of its important role in methane (CH) emissions. Although several agronomic practices such as controlled irrigation and conservation tillage have been widely adopted to mitigate CH emissions from rice cultivation, the benefits gained by these practices are highly dependent on site-specific soil and climate conditions, and often offset by yield reduction. The use of plant growth regulating compounds having the potential to increase the crop yield and mitigate CH emissions may be an innovative approach to sustainable agriculture. Ethylene (CH), a plant growth regulator is known to have a strong inhibitory effect on methanogenesis. However, due to gaseous form and low water solubility, CH has not been used to suppress methanogenesis in paddy fields. To develop CH as a prospective soil amendment for reducing methane (CH) emissions, ethephon (2-Chloroethylphosphonic acid), a precursor of CH was tested. We found that ethephon reduced CH formation by 43%, similar to other well known methanogenic inhibitors (2-Bromoethanesulfonate, 2-Chlomoethanesulfonate, 2-Mercaptoethanesulfonate). However, ethephon rapidly hydrolyzed to CH and methanogenic activity recuperated completely after CH removal. To slow down the release of CH, ethephon was mixed with bio-degradable polymers such as cellulose acetate and applied to paddy soils. We found that compared with the control, the CH release of ethephon slowed down to 90 days, and the CH emissions were reduced by 90%. The application of ethephon at lower concentrations did not significantly alter bacterial communities, their relative abundance, and the abundance of methanotrophs, but it significantly reduced archaeal communities and the relative abundance and expression level of methanogens in paddy soils. Results suggest that cellulose acetate-mixed ethephon has great promise to suppress CH emissions in rice paddies while ensuring sustainable yields.
水稻是世界上一半以上人口的主要主食。然而，由于其在甲烷（CH）排放方面的重要作用，水稻种植受到了批评。尽管已经广泛采用了一些农业措施，如控制灌溉和保护性耕作，以减轻水稻种植中的 CH 排放，但这些措施的益处高度依赖于特定地点的土壤和气候条件，而且往往因产量降低而抵消。使用具有增加作物产量和减轻 CH 排放潜力的植物生长调节剂可能是可持续农业的一种创新方法。乙烯（CH）作为一种植物生长调节剂，已知对产甲烷作用具有很强的抑制作用。然而，由于其气态和低水溶性，CH 尚未用于抑制稻田中的产甲烷作用。为了将 CH 开发为减少甲烷（CH）排放的有前途的土壤改良剂，我们测试了乙烯膦（2-氯乙基膦酸），这是 CH 的前体。我们发现，乙烯膦使 CH 形成减少了 43%，与其他知名的产甲烷抑制剂（2-溴乙磺酸盐、2-氯乙磺酸盐、2-巯基乙磺酸盐）相似。然而，乙烯膦迅速水解为 CH，并且在 CH 去除后，产甲烷活性完全恢复。为了减缓 CH 的释放，将乙烯膦与可生物降解的聚合物（如醋酸纤维素）混合并应用于稻田土壤。我们发现，与对照相比，乙烯膦的 CH 释放速度减慢到 90 天，CH 排放量减少了 90%。较低浓度的乙烯膦应用不会显著改变细菌群落及其相对丰度，以及甲烷营养菌的丰度，但它显著减少了稻田土壤中的古菌群落及其相对丰度和产甲烷菌的表达水平。结果表明，醋酸纤维素混合乙烯膦有望在确保可持续产量的同时抑制稻田中的 CH 排放。
