https://www.selleckchem.com/pr....oducts/ssr128129e.ht
We observed no age effect. We suggest that sampling leaves after 4 days of 15N labeling is sufficient to detect mature tree N uptake preference in situ. Whole tree 15N-ammonium recovery equaled that of 15N-nitrate 30 days after 15N addition, implying the importance of both ammonium and nitrate to mature larch N use in the long run. We conclude that our method is promising for studying mature tree N uptake preference in situ and can be applied to other conifer and broadleaf species. We suggest using highly enriched 15N tracer to overc