2026/07/24 by Hongyu Wu, Timothy J. Clough, Andriy Podolyan +10
Agricultural and Biological Sciences · Environmental Science · #Heterotroph #Hydrology (agriculture) #Land use #Nitrification #Pasture and Agricultural Systems #Soil Carbon and Nitrogen Dynamics #Soil and Water Nutrient Dynamics #Soil water
paper · doi:10.1016/j.geoderma.2026.117954
published in Geoderma 472, 117954 (Elsevier BV)
openalex publication_date 2026/07/24 · openalex created_date 2026/07/25 · openalex updated_date 2026/08/01
Heterotrophic nitrification is considered a potentially important N cycling process, contributing to nitrate production in terrestrial ecosystems. The specific impacts of land-use change on this process, and its underlying microbial communities, are not well characterised. Here we report on a study examining the contribution of heterotrophic nitrification to total nitrification in four land use soils (dairy pasture, sheep pasture, long-term cropland and pine forestry), using ¹⁵N isotope labelling ((¹⁵NH₄)₂SO₄ and ¹⁵N-glycine) incubation, a nitrification inhibitor, and molecular techniques. The results showed that the pine forest soil had the highest contribution (>78%) of heterotrophic nitrification to total nitrification, despite having the lowest overall nitrification. The addition of glycine enhanced the contribution of heterotrophic nitrification in cropland compared to dairy and sheep pastures, with this value in cropland being approximately 1.9-fold higher. The contribution of heterotrophic nitrification to total nitrification was positively correlated with soil fungal abundance and the fungi to bacteria ratio, indicating that fungi might be the main contributor of heterotrophic nitrification in the studied soils. Known heterotrophic nitrifiers, Penicillium was a potential candidate to play a significant role in pine forest soil with a relative gene abundance of 9.7%, whereas Mortierella was potentially prevalent in the dairy pasture (12.7%), sheep pasture (19.4%) and cropland (14.0%) soils, suggesting that the composition of potential heterotrophic nitrifiers varied between pine forest and agricultural (pasture and cropland) soils. The filamentous Ascomycota fungus Sagenomella, not previously known to perform heterotrophic nitrification may be a potential heterotrophic nitrifier in the studied forest soil, which warrants further investigation. This research improves our comprehensive understanding of heterotrophic nitrification in different land use soils, important for under standing the nitrogen cycle in different terrestrial ecosystems.