Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; School of Geographic Information and Tourism, Chuzhou University, Chuzhou 239000, China.
Callaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Jiangsu Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Sci Total Environ. 2022 Dec 20;853:158643. doi: 10.1016/j.scitotenv.2022.158643. Epub 2022 Sep 9.
There is recognition that biochar addition is an appropriate measure to mitigate methane (CH) emissions by promoting potential methane oxidation (PMO) in the field. However, the mechanism for different field-aged biochars and effective duration after field application are not well documented. Based on a long-term field experiment, biochar was field aged and separated from two contrasting acidic (Ba) and saline (Bs) paddy fields. Then, the effects of different aged biochars on PMO in acidic and saline paddy soils were explored by incubation experiment. There were five treatments for each soil group: soil without biochar (CK), biochar-enriched paddy soil (2 or 6 years) (NB), fresh biochar amendment (Bf), aged biochar separated from acidic paddy soil amendment (Ba), and aged biochar separated from saline paddy soil amendment (Bs). Results showed that saline paddy soils had a significantly higher PMO than acidic paddy soils under treatment without biochar, and that PMO in acidic paddy soil was enhanced by various biochar amendments, whereas those biochar amendments had no significant effects on PMO in saline paddy soil. PMO was positively correlated with pmoA abundance, N consumption rate and pH of soil-biochar mixture. Aged biochar separated from different fields had conflicting influences on soil pH, N consumption rate and PMO. Ba lost its initial effect on changing PMO as compared to Bf treatment when added back into acidic paddy soil. To the contrary, the acidic paddy soil NB treatment containing biochar added six years before possessed the highest value of PMO among all ten treatments. This study suggested that acidic paddy soil with biochar amendment could mitigate CH emissions by promoting PMO for a prolonged period, though aged biochar separated from the same field had a limited impact on reducing CH emissions.
人们认识到，添加生物炭是一种通过促进田间潜在甲烷氧化（PMO）来减少甲烷（CH）排放的适当措施。然而，不同田间老化生物炭的机制以及田间应用后的有效持续时间尚未得到很好的记录。本研究基于一项长期田间实验，对生物炭进行了田间老化，并从两个具有对比性的酸性（Ba）和盐渍（Bs）稻田中分离出来。然后，通过培养实验探索了不同老化生物炭对酸性和盐渍稻田土壤 PMO 的影响。每个土壤组有五个处理：无生物炭的土壤（CK）、生物炭富集的稻田土壤（2 年或 6 年）（NB）、新鲜生物炭添加（Bf）、从酸性稻田土壤添加物中分离出的老化生物炭（Ba）和从盐渍稻田土壤添加物中分离出的老化生物炭（Bs）。结果表明，在没有生物炭处理的情况下，盐渍稻田土壤的 PMO 明显高于酸性稻田土壤，而各种生物炭添加物均能增强酸性稻田土壤的 PMO，而这些生物炭添加物对盐渍稻田土壤的 PMO 没有显著影响。PMO 与土壤-生物炭混合物中的 pmoA 丰度、N 消耗率和 pH 值呈正相关。从不同田地分离出的老化生物炭对土壤 pH 值、N 消耗率和 PMO 的影响存在冲突。当添加回酸性稻田土壤时，与 Bf 处理相比，Ba 失去了改变 PMO 的初始效果。相反，在添加生物炭六年之前的酸性稻田土壤 NB 处理具有所有十种处理中 PMO 值最高。本研究表明，添加生物炭的酸性稻田土壤可以通过促进 PMO 来延长时间，从而减少 CH 排放，尽管从同一田地分离出的老化生物炭对减少 CH 排放的影响有限。
