Provisional values of the content of foliar nitrogen (g per kg dry matter) for the estimation of N-deficiency in the leaves in the period from early August to mid-September (4,8,9).
| Tree species | N-Supply | |||
|---|---|---|---|---|
| Too low | Low | Normal | Optimal | |
| Acer campestre | < 15 | 15-17 | 18-22 | > 22 |
| Acer negundo | < 13 | 13-16 | 17-22 | > 22 |
| Acer platanoides | < 17 | 17-22 | 23-27 | > 27 |
| Acer pseudoplatanus | < 17 | 17-22 | 23-27 | > 27 |
| Acer saccharinum | < 13 | 13-18 | 19-27 | > 27 |
| Aesculus hippocastanum | < 14 | 14-18 | 19-22 | > 22 |
| Alnus glutinosa | < 22 | 22-25 | 26-30 | > 30 |
| Alnus incana | < 20 | 20-24 | 25-30 | > 30 |
| Betula pendula | < 18 | 18-22 | 23-30 | > 30 |
| Carpinus betulus | < 15 | 15-19 | 20-27 | > 27 |
| Corylus avellana | < 18 | 18-22 | 23-25 | > 25 |
| Corylus colurna | < 18 | 18-22 | 23-30 | > 30 |
| Crataegus laevigata | < 15 | 15-18 | 19-22 | > 22 |
| Crataegus monogyna | < 15 | 15-18 | 19-22 | > 22 |
| Fagus sylvatica | < 18 | 18-20 | 21 -28 | > 28 |
| Fraxinus excelsior | < 18 | 18-22 | 23-28 | > 28 |
| Gleditsia triacanthos | < 16 | 16-19 | 20-25 | > 25 |
| Juglans nigra | < 15 | 15-20 | 21 -26 | > 26 |
| Juglans regia | < 20 | 20-25 | 26-35 | > 35 |
| Liquidambar styraciflua | < 14 | 14-17 | 18-28 | > 28 |
| Liriodendron tulipifera | < 20 | 20-25 | 26-30 | > 30 |
| Malus domestica (*) | < 17 | 17-22 | 23-25 | > 25 |
| Platanus x acerifolia | < 15 | 15-19 | 20-26 | > 26 |
| Populus alba (*) | < 14 | 14-18 | 19-25 | > 25 |
| Populus x canescens (*) | < 14 | 14-17 | 18-25 | > 25 |
| P. x euramericana (*) | < 22 | 22-25 | 26-28 | > 28 |
| Populus nigra (*) | < 20 | 20-24 | 25-28 | > 28 |
| Populus tremula | < 15 | 15-18 | 19-25 | > 25 |
| Prunus avium (**) | < 15 | 15-18 | 19-26 | > 26 |
| Prunus cerasus | < 15 | 15-18 | 19-26 | > 26 |
| Prunus domestica | < 18 | 18-21 | 22-25 | > 25 |
| Pyrus communis (*) | < 18 | 18-23 | 24-28 | > 28 |
| Quercus palustris | < 18 | 18-20 | 21 -28 | > 28 |
| Quercus robur | < 18 | 18-20 | 21 -28 | > 28 |
| Robinia pseudoacacia | < 20 | 20-25 | 26-30 | > 30 |
| Salix alba (*) | < 18 | 18-21 | 22-28 | > 28 |
| Salix triandra | < 18 | 18-22 | 23-30 | > 30 |
| Salix viminalis | < 20 | 20-22 | 23-30 | > 30 |
| Sorbus aria | < 15 | 15-18 | 19-22 | > 22 |
| Sorbus aucuparia | < 15 | 15-18 | 19-22 | > 22 |
| Tilia americana | < 21 | 21-26 | 27-31 | > 31 |
| Tilia cordata | < 17 | 17-20 | 21 -24 | > 24 |
| Tilia x euchlora | < 17 | 17-21 | 22-26 | > 26 |
| Tilia platyphyllos | < 17 | 17-21 | 22-28 | > 28 |
| Tilia x vulgaris | < 17 | 17-24 | 25-28 | > 28 |
| Ulmus carpinifolia | < 18 | 18-22 | 23-27 | > 27 |
| Ulmus glabra | < 18 | 18-22 | 23-27 | > 27 |
| Ulmus x hollandica (*) | < 18 | 18-22 | 23-27 | > 27 |