Abstract

Intensively managed agriculture land is a significant contributor to nitrous oxide (N₂O) emissions, which adds to global warming and the depletion of the ozone layer. Recent studies have suggested that fungal dominant N₂O production may be promoted by pathogenic fungi under high nitrogen fertilization and continuous cropping. Here, we measured the contribution of fungal communities to N₂O production under intensively managed strawberry fields of three continuous cropping years (1, 5, and 10 years) and compared this adjacent bare soil. Higher N₂O emission was observed from the 10-year field, of which fungi and prokaryotes accounted for 79.7% and 21.3%, respectively. Fungal population density in the 10-year field soil (4.25 × 10⁵ colony forming units per g (CFU/g) of air-dried soil) was greater than the other cropping years. Illumina MiSeq sequencing of the nirK gene showed that long-term continuous cropping decreased the diversity of the fungal denitrifier community, but increased the abundance of Fusarium oxysporum. Additionally, F. oxysporum produced large amounts of N₂O in culture and in sterile 10-year field soil. A systemic infection displayed by bioassay strawberry plants after inoculation demonstrated that F. oxysporum was a pathogenic fungus. Together, results suggest that long-term intensively managed monocropping significantly influenced the denitrifying fungal community and increased their biomass, which increased fungal contribution to N₂O emissions and specifically by pathogenic fungi.

Key points

• Distinguishing the role of fungi in long-term continuous cropping field.

• Identifying the abundant fungal species with denitrifying ability.

中文翻译：

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在集约经营的草莓种植土壤中，病原真菌对N 2 O排放的贡献随时间增加

摘要

集约化管理的农业用地是造成一氧化二氮（N ₂ O）排放的重要因素，这加剧了全球变暖和臭氧层的消耗。最近的研究表明，在高氮施肥和连作的情况下，致病真菌可促进真菌优势N ₂ O的产生。在这里，我们在连续种植三年（1、5和10年）的集约经营草莓田中，测量了真菌群落对N ₂ O生产的贡献，并比较了邻近的裸土。在10年的田间观察到较高的N ₂ O排放，其中真菌和原核生物分别占79.7％和21.3％。十年田土中的真菌种群密度（4.25×10每克风干土壤每克^5个菌落形成单位（CFU / g），高于其他种植年限。Ilir MiSeq基因对nirK基因的测序表明，长期连续种植降低了真菌反硝化菌群落的多样性，但增加了尖孢镰刀菌的丰度。此外，尖孢镰孢产生的大量的N个₂中培养并在无菌的10年田间土壤O操作。接种后通过生物测定草莓植物显示出的全身感染表​​明，F。oxysporum是一种致病真菌。总之，结果表明，长期严格管理的单作显着影响了反硝化真菌群落并增加了其生物量，从而增加了真菌对N ₂ O排放的贡献，特别是病原性真菌的贡献。

关键点

•区分真菌在长期连续种植领域中的作用。

•确定具有反硝化能力的丰富真菌种类。