Ministry of Education Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Sci Total Environ. 2024 Sep 10;942:173681. doi: 10.1016/j.scitotenv.2024.173681. Epub 2024 Jun 4.
Soil microbial food web is crucial for maintaining crop production, while its community structure varies among fertilization regimes. Currently, the mechanistic understanding of the relationships between microbial food web and crop production under various nutrient fertilizations is poor. This knowledge gap limits our capacity to achieve precision agriculture for ensuring yield stability. In this study, we investigated the abiotic (i.e., soil chemical properties) and biotic factors (i.e., microbial food web, including bacteria, fungi, archaea and nematodes) that were closely associated with rice (Oryza sativa L.) production, using soils from seven fertilization regimes in distinct sampling locations (i.e., bulk vs rhizosphere soil) at a long-term experimental site. Organic manure alone fertilization (M) and integrated fertilization (NPKM) combining manure with inorganic fertilizers increased soil pH by 0.21-0.41 units and organic carbon content by 49.1 %-65.2 % relative to the non-fertilization (CK), which was distinct with inorganic fertilization. The principal coordinate analysis (PCoA) revealed that soil microbial and nematode communities were primarily shaped by fertilization rather than sampling locations. Organic fertilization (M, NPKM) increased the relative abundance of both r-strategist bacteria, specific taxa within the fungal (i.e., Pezizales) and nematode communities (i.e., omnivores-predators), whereas inorganic fertilization increased K-strategist bacteria abundances relative to the CK. Correspondingly, network analysis showed that the keystone taxa in the amplicon sequence variants (ASVs) enriched by organic manure and inorganic fertilization were mainly affiliated with r- and K-strategist bacteria, respectively. Structural equation modeling (SEM) analysis found that r- and K-strategist bacteria were positively correlated with rice production under organic and inorganic fertilization, respectively. Our results demonstrate that the response patterns of r/K-strategists to nutrient fertilization largely regulate rice yield, suggesting that the enhanced soil fertility and r-strategists contribute to the highest crop production in NPKM fertilization.
土壤微生物食物网对于维持作物生产至关重要，但其在不同施肥制度下的群落结构存在差异。目前，对于各种养分施肥下微生物食物网与作物生产之间的关系的机制理解还很欠缺。这种知识差距限制了我们实现确保产量稳定的精准农业的能力。在这项研究中，我们使用来自长期实验站点不同采样地点（即根际土壤和非根际土壤）的七个施肥制度的土壤，调查了与水稻（Oryza sativa L.）生产密切相关的非生物因素（即土壤化学性质）和生物因素（即微生物食物网，包括细菌、真菌、古菌和线虫）。与不施肥（CK）相比，单独施用有机肥（M）和结合有机肥与无机肥的综合施肥（NPKM）分别使土壤 pH 值增加了 0.21-0.41 个单位，有机碳含量增加了 49.1%-65.2%。主坐标分析（PCoA）表明，土壤微生物和线虫群落主要受施肥而不是采样地点的影响。有机施肥（M、NPKM）增加了 r-策略菌、真菌（即 Pezizales）和线虫群落（即杂食动物-捕食者）特定类群的相对丰度，而无机施肥增加了与 CK 相比，K-策略菌的丰度。相应地，网络分析表明，有机肥和无机肥富集的扩增子序列变体（ASVs）中的关键类群主要与 r-和 K-策略菌分别相关。结构方程模型（SEM）分析发现，r-和 K-策略菌与有机和无机施肥下的水稻产量呈正相关。我们的结果表明，r/K-策略菌对养分施肥的响应模式在很大程度上调节了水稻的产量，这表明增强的土壤肥力和 r-策略菌有助于 NPKM 施肥下的最高作物产量。
