中国南部カルスト農地におけるリン利用制限の微生物的要因を解明(Microbial Limits to Phosphorus Availability Uncovered in Karst Farmlands of Southern China)

2026-02-04 中国科学院(CAS)

中国科学院の亜熱帯農業研究所を中心とする研究チームは、中国南部のカルスト農地を対象に、土壌微生物がリン(P)の利用可能性を制限する仕組みを解明した。地域規模の調査により、耕起頻度が高く、肥料や農薬投入量の多い高強度農業ほど、微生物のリン欠乏関連遺伝子が増加し、リンを可溶化・輸送する機能遺伝子が減少することが判明した。中性に近い石灰質土壌ではリン循環微生物の多様性と量が高い一方、酸性の赤色土では種多様性と機能多様性が強く連動していた。高強度農業が微生物のリン循環機能を弱めることが、農地でのリン制限の主要因であると示され、持続可能な養分管理戦略の科学的基盤を提供する成果である。

<関連情報>

土壌管理の強度と土壌の種類が土壌リン循環微生物の群集形成と機能的ポテンシャルに及ぼす影響 Effects of soil management intensity and soil type on the community assembly and functional potential of soil phosphorus cycling microbes

Xianwen Long, Xionghui Liao, Jiangnan Li, Wenjun Zhang, Jiachen Wang, Wei Zhang, Kelin Wang, Jie Zhao
Agriculture, Ecosystems & Environment  Available online: 13 January 2026
DOI:https://doi.org/10.1016/j.agee.2026.110236

Highlights

  • Stochastic processes of P-cycling microbial communities increase with agricultural management intensity.
  • High-intensity agricultural management reduced the soil P-cycling microbial functional potential.
  • Enhanced stochasticity decouples the link between taxon and functional diversity in P-cycling microbes.

Abstract

Revealing the community assembly process of soil phosphorus (P) cycling microbes is conducive to a better understanding of soil P-cycling processes in agricultural ecosystems. Previous studies have documented that soil microbial diversity or community composition drives soil P cycling. However, little is known about how agricultural management intensity and soil type affect community assembly processes of P-cycling microbes and the related microbial functional potential. Here, four typical agricultural land use types with a gradient of management intensity in both calcareous and red soils were selected in southwest China, including pasture, sugarcane farmland, rice paddy fields, and maize cropland (from low to high management intensity). The results showed that the abundance of the total P-cycling, P-solubilization, P-mineralization, and P-transporter gene in calcareous soil was significantly higher than that in red soil. Agricultural management practice and soil type significantly affected the P-cycling microbial community structure, with tillage frequency, herbicide application frequency, and soil pH being the main influencing factors. Stochastic processes dominated the P-cycling microbial community assembly in both calcareous and red soils, and the stochastic processes were more predominant in calcareous soil than in red soil. The relative importance of stochastic assembly processes increased with agricultural management intensity. In particular, fertilization frequency, pesticide, and herbicide application frequency were the key predictors of stochastic processes of P-cycling microbes. Intensive agricultural management reduced the abundance of total P-cycling, P-solubilization, and P-transporter functional genes across different land use types and soil types but promoted the abundance of P-starvation regulation genes. In particular, we found that the relationship between taxonomic and functional diversity of P-cycling microbes was controlled by deterministic factors (e.g., soil pH and TP), and high stochastic processes will decouple the relationship between the taxonomic and functional diversity of P-cycling microbes. Overall, these findings strengthen our understanding of the community structure and functional potential of P-cycling microbes under different soil types and agricultural management practices.

1202農芸化学
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