Ecology and Biodiversity Group, Institute of Environmental Biology, Utrecht University, Utrecht, the Netherlands.
Microbiology Group, Institute of Environmental Biology, Utrecht University, Utrecht, the Netherlands.
Environ Microbiol. 2024 May;26(5):e16627. doi: 10.1111/1462-2920.16627.
Soil structure and aggregation are crucial for soil functionality, particularly under drought conditions. Saprobic soil fungi, known for their resilience in low moisture conditions, are recognized for their influence on soil aggregate dynamics. In this study, we explored the potential of fungal amendments to enhance soil aggregation and hydrological properties across different moisture regimes. We used a selection of 29 fungal isolates, recovered from soils treated under drought conditions and varying in colony density and growth rate, for single-strain inoculation into sterilized soil microcosms under either low or high moisture (≤-0.96 and -0.03 MPa, respectively). After 8 weeks, we assessed soil aggregate formation and stability, along with soil properties such as soil water content, water hydrophobicity, sorptivity, total fungal biomass and water potential. Our findings indicate that fungal inoculation altered soil hydrological properties and improved soil aggregation, with effects varying based on the fungal strains and soil moisture levels. We found a positive correlation between fungal biomass and enhanced soil aggregate formation and stabilization, achieved by connecting soil particles via hyphae and modifying soil aggregate sorptivity. The improvement in soil water potential was observed only when the initial moisture level was not critical for fungal activity. Overall, our results highlight the potential of using fungal inoculation to improve the structure of agricultural soil under drought conditions, thereby introducing new possibilities for soil management in the context of climate change.
土壤结构和团聚体对于土壤功能至关重要，特别是在干旱条件下。在低湿度条件下具有很强适应性的腐生土壤真菌，因其对土壤团聚体动态的影响而受到关注。在这项研究中，我们探索了真菌改良剂在不同水分条件下增强土壤团聚体和水文特性的潜力。我们使用了从干旱条件下处理的土壤中回收的 29 种真菌分离物，这些分离物的菌落密度和生长速率不同，用于在低水分（≤-0.96 MPa）或高水分（≤-0.03 MPa）条件下对灭菌土壤微宇宙进行单菌株接种。8 周后，我们评估了土壤团聚体的形成和稳定性，以及土壤性质，如土壤含水量、土壤水疏水性、吸水性、总真菌生物量和水势。我们的研究结果表明，真菌接种改变了土壤的水文特性并改善了土壤团聚体，其效果因真菌菌株和土壤水分水平而异。我们发现真菌生物量与增强的土壤团聚体形成和稳定呈正相关，这是通过菌丝连接土壤颗粒和改变土壤团聚体吸水性来实现的。只有在初始水分水平对真菌活动不是关键的情况下，才观察到土壤水势的改善。总的来说，我们的研究结果突出了在干旱条件下使用真菌接种来改善农业土壤结构的潜力，从而为气候变化背景下的土壤管理引入了新的可能性。
