土壤盐渍化是一个严重的环境问题,限制了植物的生产力和生态系统的功能。秸秆改良可以通过提高微生物活性和碳固存来提高盐渍土的肥力,然而,在不同的土壤盐度下添加秸秆后,潜在的真菌分解剂的适应性和生态偏好仍然难以捉摸。这里,通过将小麦和玉米秸秆掺入一系列盐度的土壤中进行了土壤微观世界研究,分别。我们表明,秸秆的修正增加了MBC,SOC,DOC和NH4+-N含量降低75.0%,17.2%,88.3%和230.9%,分别,但NO3--N含量减少了79.0%,无论土壤盐分如何,秸秆添加后,这些参数之间的联系增强。尽管土壤盐分对真菌α-和β-多样性有更深远的影响,秸秆改良也显著降低了真菌香农的多样性,改变了群落组成,特别是对于严重的盐渍土。秸秆添加后,真菌共生网络的复杂性得到了具体加强,小麦和玉米秸秆处理的平均程度从对照的11.9增加到22.0和22.7,分别。有趣的是,每个盐渍土壤中富含秸秆的ASV(扩增子序列变体)之间几乎没有重叠,表明潜在真菌分解剂的土壤特异性参与。特别是,在严重的盐渍土壤中,属于头孢菌和未分类的Sordariales的真菌物种对秸秆的添加反应最大,而轻质盐渍土支持秸秆添加后的鸡腿草和裂殖草物种的富集。一起,我们的研究提供了一个新的见解,对土壤化学和生物学特性的共同和具体的响应在不同盐分水平下秸秆管理,这将有助于指导精确的基于微生物的策略,以在未来的农业实践和盐碱地的环境管理中促进秸秆分解。
Soil salinization is a severe environmental problem that restricts plant productivity and ecosystem functioning. Straw amendment could increase the fertility of saline soils by improving microbial activity and carbon sequestration, however, the adaptation and ecological preference of potential fungal
decomposers after straw addition under varied soil salinities remains elusive. Here, a soil microcosm study was conducted by incorporating wheat and maize straws into soils with a range of salinities, respectively. We showed that the amendment of straws increased MBC, SOC, DOC and NH4+-N contents by 75.0 %, 17.2 %, 88.3 % and 230.9 %, respectively, but decreased NO3--N content by 79.0 %, irrespective of soil salinity, with intensified connections among these parameters after straw addition. Although soil salinity had a more profound effect on both fungal α- and β-diversity, straw amendment also significantly reduced fungal Shannon diversity and changed community composition, especially for severe saline soil. Complexity of the fungal co-occurrence network was specifically strengthened after straw addition, with average degree increasing from 11.9 in the control to 22.0 and 22.7 in wheat and maize straw treatments, respectively. Intriguingly, there was very little overlap among the straw-enriched ASVs (Amplicon Sequence Variants) in each saline soil, indicating the soil-specific involvement of potential fungal
decomposers. Particularly, fungal species belonging to Cephalotrichum and unclassified Sordariales were the most responsive to straw addition in severe saline soil, whereas light saline soil supported the enrichment of Coprinus and Schizothecium species after straw addition. Together, our study provides a new insight on the common and specific responses of soil chemical and biological characteristics at different salinity levels under straw management, which will help guide precise microbial-based strategies to boost straw decomposition in future agricultural practice and environmental management of saline-alkali lands.