Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, People's Republic of China.
Key Laboratory of Urban Environmental Processes and Pollution Control, Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, Ningbo, 315800, People's Republic of China.
Environ Sci Pollut Res Int. 2018 Jan;25(3):2932-2941. doi: 10.1007/s11356-017-0690-y. Epub 2017 Nov 16.
Paddy soil experiences repeated anaerobic and aerobic changes during rice growth, the dramatic dynamics of soil water status accompanied by changes in redox condition and O availability. However, the effect of rapid water status change on soil microbial biomass and community composition is not well explored. Here, we present a comprehensive study focusing on the short-term water status change in 13 Chinese paddy soils. In order to gain a reliable way to determine soil microbial biomass carbon (MBC) in flooded or water-saturated soils, we also evaluated two different procedures (nitrogen bubbled and 100 °C water bath) to remove chloroform in extracts during the fumigation process. Compared to non-flooded paddy soils, the flooded paddy soils tended to have a lower microbial biomass, and this was much clearer using adenosine 5'-triphosphate (ATP) and phospholipid fatty acid (PLFA) analysis compared to biomass measured by the fumigation method. Fungal biomass, which was indicated by both ergosterol and the PLFA 18:2ω6,9c, also decreased after short-term flooding. Changes in soil microbial community composition (determined by PLFA biomarkers) were observed after short-term flooding, but the extent varied between soils. This study indicates that the dynamics of short-term water status altered the soil microbial biomass (ATP, MBC, and total PLFA) and community composition. Finally, our results suggested that liquid fumigation combined with the nitrogen-bubbled method is the best choice for analyzing MBC concentrations in water-saturated soils.
水稻生长过程中，稻田土壤经历反复的厌氧和好氧变化，土壤水分状况的剧烈变化伴随着氧化还原条件和 O 供应的变化。然而，快速水分状况变化对土壤微生物生物量和群落组成的影响尚未得到充分探索。在这里，我们进行了一项综合研究，重点关注 13 种中国稻田土壤中的短期水分状况变化。为了获得一种可靠的方法来确定淹水或水饱和土壤中的土壤微生物生物量碳（MBC），我们还评估了两种不同的程序（氮气吹脱和 100°C 水浴），以在熏蒸过程中去除提取物中的氯仿。与非淹水稻田相比，淹水稻田的微生物生物量往往较低，与熏蒸法相比，使用腺苷 5'-三磷酸（ATP）和磷脂脂肪酸（PLFA）分析时更为明显。真菌生物量（由麦角固醇和 PLFA 18:2ω6,9c 指示）在短期淹水后也减少。短期淹水后观察到土壤微生物群落组成的变化（通过 PLFA 生物标志物确定），但在不同土壤之间变化程度不同。本研究表明，短期水分状况的动态变化改变了土壤微生物生物量（ATP、MBC 和总 PLFA）和群落组成。最后，我们的结果表明，液体熏蒸结合氮气吹脱法是分析水饱和土壤中 MBC 浓度的最佳选择。
