Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Niigata Agricultural Research Institute, Niigata, Japan.
ISME J. 2021 Aug;15(8):2427-2439. doi: 10.1038/s41396-021-00948-4. Epub 2021 Mar 4.
Nitrous oxide (NO) is an important greenhouse gas and an ozone-depleting substance. Due to the long persistence of NO in the atmosphere, the mitigation of anthropogenic NO emissions, which are mainly derived from microbial NO-producing processes, including nitrification and denitrification by bacteria, archaea, and fungi, in agricultural soils, is urgently necessary. Members of mesofauna affect microbial processes by consuming microbial biomass in soil. However, how microbial consumption affects NO emissions is largely unknown. Here, we report the significant role of fungivorous mites, the major mesofaunal group in agricultural soils, in regulating NO production by fungi, and the results can be applied to the mitigation of NO emissions. We found that the application of coconut husks, which is the low-value part of coconut and is commonly employed as a soil conditioner in agriculture, to soil can supply a favorable habitat for fungivorous mites due to its porous structure and thereby increase the mite abundance in agricultural fields. Because mites rapidly consume fungal NO producers in soil, the increase in mite abundance substantially decreases the NO emissions from soil. Our findings might provide new insight into the mechanisms of soil NO emissions and broaden the options for the mitigation of NO emissions.
一氧化二氮（NO）是一种重要的温室气体和消耗臭氧层物质。由于大气中 NO 的持久性长，因此迫切需要减少人为 NO 排放，这些排放主要来自农业土壤中微生物的 NO 产生过程，包括细菌、古菌和真菌的硝化和反硝化作用。土壤中型动物通过消耗土壤中的微生物生物量来影响微生物过程。然而，微生物消耗如何影响 NO 排放在很大程度上是未知的。在这里，我们报告了食真菌螨——农业土壤中型动物的主要群体——在调节真菌产生的 NO 方面的重要作用，其结果可应用于减少 NO 排放。我们发现，椰子壳（椰子的低值部分，通常用作农业土壤改良剂）施用于土壤中，由于其多孔结构，可以为食真菌螨提供有利的栖息地，从而增加农业领域中的螨类丰度。由于螨虫在土壤中迅速消耗真菌性的 NO 产生者，因此螨类丰度的增加会大大减少土壤中的 NO 排放。我们的发现可能为土壤 NO 排放的机制提供新的见解，并拓宽减少 NO 排放的选择。
