Addition of High-Quality Plant Residue Alters Microbial Keystone Taxa and Network Complexity and Increases Soil Phosphorus Availability

• Published in: Agronomy (Basel) 2024-12, Vol.14 (12), p.3036
• Main Authors: Miao, Yi, Zhou, Fei, Ding, Shuai, Zhu, Zhenke, Huo, Zhichao, Chen, Qing, Liu, Zhongzhen
• Format: Article
• Language: English
• Subjects: Abundance; Acid phosphatase; acidic soil; Acidic soils; Agronomy; Availability; Bacteria; Carbon; Cellulose; co-occurrence network; Community composition; Community structure; Decomposition; Ecological function; Ecosystems; Experiments; Fungi; Immobilization; Keystone species; Lignin; Mangoes; Microbial activity; microbial keystone taxa; Microbiomes; Microorganisms; Mineralization; Nitrogen; Nutrient cycles; Phosphatases; Phosphorus; phosphorus availability; Phosphorus content; plant residue quality; Pumpkins; Residues; Rice; Rice straw; Soil bacteria; Soil fertility; Soil improvement; Soil investigations; Soil microorganisms; Soil structure; Soils; Stover; Straw; Structure-function relationships; Sugarcane; Taxa
• ISSN: 2073-4395; 2073-4395
• DOI: 10.3390/agronomy14123036

Incorporation of plant residues in soil affects microbial community structure and ecological function, which can improve soil fertility. It is reported that substrate qualities could regulate microbial keystone taxa and their interactions, wielding an important effect on nutrient cycling in ecosystems, such as soil labile phosphorus (P) transformation. However, there is little understanding of the specific microbial mechanisms governing P’s availability in acidic soils following the incorporation of plant residues of various qualities. In this 210-day incubation experiment, two high-quality residues of pumpkin stover and mango branch and one low-quality residue of rice straw, different in terms of their labile carbon (C) content and carbon/phosphorus ratio (C/P), were separately mixed with an acidic soil. The aim was to investigate how the residues affected the community composition, keystone species, and interaction patterns of soil bacteria and fungi, and how these microbial characteristics altered soil P mineralization and immobilization processes, along with P availability. The results showed that adding high-quality pumpkin stover significantly increased the soil’s available P content (AP), microbial biomass P content (MBP), and acid phosphatase activity (ACP), by 63.7%, 86.7%, and 171.7% compared to the control with no plant residue addition, respectively. This was explained by both the high abundance of dominant bacteria (Kribbella) and the positive interactions among fungal keystone species. Adding mango branch and rice straw induced cooperation within fungal communities while resulting in lower bacterial abundances, thereby increasing AP, MBP, and ACP less than the addition of pumpkin stover. Moreover, the labile C of plant residues played a dominant role in soil P transformation and determined the P availability of the acidic soil. Therefore, it may be suitable to incorporate high-quality plant residues with high labile C and low C/P into acidic soils in order to improve microbial communities and enhance P availability.