Abstract Microbial diversity and their activity in the rhizosphere and bulk soil areas were measured in a long-term field trial (started in 1956), where maize has been grown for the last 20 years with and without N fertilisation. Various microbial groups and their substrate feeding strategies (i.e. demonstrating activities) were identified through phospholipid fatty acids (PLFAs) analysis and their δ13C values. Microbial abundance (esp. fungi) remained unaffected by long-term N fertilisation. However, fungi dominated over bacteria with 2–3 times higher biomass in the rhizosphere than bulk soil. The δ13C of PLFAs showed that fungi had the highest values, particularly in fertilised rhizosphere areas, indicating that this was the most active group (than any other microbial group) for assimilation of maize rhizodeposits.

中文翻译：

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真菌在 20 年玉米生长的 63 年长期田间试验中的重要性

摘要 在长期田间试验（始于 1956 年）中测量了根际和大块土壤区域的微生物多样性及其活性，在过去 20 年中，无论是否施氮肥都种植了玉米。通过磷脂脂肪酸 (PLFA) 分析及其 δ13C 值确定了各种微生物群及其底物饲养策略（即展示活动）。微生物丰度（尤其是真菌）不受长期施氮的影响。然而，真菌在根际生物量比大块土壤高 2-3 倍的细菌中占主导地位。PLFAs 的 δ13C 表明真菌具有最高值，特别是在受精的根际区域，表明这是同化玉米根际沉积物最活跃的群体（比任何其他微生物群体）。