A laboratory incubation study was conducted on a temperate grassland soil to quantify the main mineral nitrogen (N) transformation rates and pathways via a¹⁵N tracing approach. Soil samples were taken from a long-term phosphorus (P) trial to investigate the effects on gross N transformations under high and low phosphorus amendment. The soils were incubated over a 2-week period and treated with ammonium-nitrate (NH₄NO₃) which was applied to the soil both with and without a glucose amendment and labelled with ¹⁵N either on the ammonium (NH₄⁺) or nitrate (NO₃⁻) moiety at 50% atom enrichment. The results showed immobilisation to greatly outweigh mineralisation and that NO₃⁻ was predominantly produced via heterotrophic nitrification. Individual pathways for NO₃⁻ production were quantified including oxidation of NH₄⁺, recalcitrant and labile organic N. Oxidation of labile organic N to NO₃⁻, a newly considered pathway, accounted for between 63 and 83% of total NO₃⁻ production across the various treatments and P levels. This process was significantly higher in the low-P rather than the high-P soils (p < 0.05), highlighting the effect of soil P on the microbial community.

在温带草原土壤上进行了实验室孵化研究，以通过¹⁵ N示踪方法量化主要矿物质氮（N）的转化率和途径。土壤样品来自一项长期的磷（P）试验，以研究在高磷和低磷条件下对总氮转化的影响。将土壤孵育2周，然后用硝酸铵（NH ₄ NO ₃）处理，硝酸铵可在有或没有葡萄糖改良剂的情况下施用到土壤上，并在铵盐（NH ₄ ⁺）或¹⁵ N上标记硝酸盐（NO ₃ ^-）原子富集度为50％的部分。结果表明固定化到大大超过矿化和NO ₃ ^-中主要通过异养硝化制备。对NO的各专用路径₃ ^-生产进行定量，包括NH氧化₄ ⁺，顽固的和不稳定的有机氮不稳定有机N.氧化为NO ₃ ^- ，新考虑途径，占总NO：63和83％之间的₃ ^-生产跨越各种治疗和P水平。在低磷土壤而不是高磷土壤中，这一过程明显更高（p <0.05），突显了土壤磷对微生物群落的影响。