Land use type affects the contribution of heterotrophic nitrification in New Zealand soils

作者：Hongyu Wu, Timothy J. Clough, Andriy Podolyan, Chris Chisholm, Ju‐Pei Shen, Peng Li, Chengjun Zhang, Hong Pan, L. Zhang, Qiang Zhang, Hong J. Di · 发表于：Geoderma · 年份：2026 · DOI：10.1016/j.geoderma.2026.117954 · 研究领域：Soil Carbon and Nitrogen Dynamics、Soil and Water Nutrient Dynamics、Pasture and Agricultural Systems

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 c...