Work

Glucose and Lignin Differentially Drive Phosphorus Fractions to Vary in Mollisols (WRB) and Fluvo-Aquic Soil (Chinese Soil Taxonomy) via Microbial Community Shifts

Year: 2026

Type: article

Abstract: Carbon (C) is crucial for nutrient cycling and the assembly of microbial populations in the soil. However, it is still unclear how the C-source utilization characteristics of microbes in distinct types of soils respond to changes in soil phosphorus (P) activity. This study investigated how the addition of different C sources with different decomposition rates (glucose, hemicellulose, and lignin) affects P transformation in two distinct agricultural soils (i.e., Mollisols and Fluvo-aquic soil). Results revealed that the short-term glucose addition to soil induced rapid acidification and microbial biomass accumulation, thereby significantly increasing labile P (NaHCO3-Pi, NaOH-Po) content in Fluvo-aquic soil. Lignin amendment promoted gradual HCl-P release in Mollisols, reflecting differential microbial utilization strategies. Glucose stimulated phosphatase activity (2.5–3.0× control) and phoD gene abundance (4.8×) in Fluvo-aquic soil in the early stage, favoring the growth of Pseudomonas and Burkholderia, whereas lignin sustained the mineralization of fungal-associated P in Mollisols (1.8–2.3× phosphatase activity) by enhancing the abundance of Streptomyces and Bradyrhizobium. Soil type dictated P mobilization efficiency. The Fluvo-aquic soil exhibited rapid but transient P release via bacterial dominance, while Mollisols retained slower yet persistent P availability through specialized microbial consortia. Notably, glucose enhanced organic P mineralization by stimulating C decomposition by microbes, particularly in C-rich Mollisols. Lignin increased P availability in Mollisols via Fe/Al-P desorption. However, in Fluvo-aquic soil, lignin reduced the availability of P through microbial immobilization. These findings highlight that C source degradability and soil properties interactively govern microbial-mediated P cycling in soil. Therefore, organic amendments in contrasting agroecosystems need to be optimized.

Source: Agriculture

DOI: 10.3390/agriculture16020213