Table 1.
NH4+- and NO3−-specific absorption rates of tea plants grown with different N forms and root-zone pH (means±s.d., n =4)
| Treatment |
Specific absorption rate (μmol g−1 root d. wt d−1) |
|||
|---|---|---|---|---|
| N form | pH | NH4+ | NO3− | Total N |
| NH4+ | 4·0 | 165·9±21·8 | 165·9±21·8 | |
| 5·0 | 194·2±23·8 | 194·2±23·8 | ||
| 6·0 | 151·2±27·0 | 151·2±27·0 | ||
| NO3− | 4·0 | 60·9±9·4 | 60·9±9·4 | |
| 5·0 | 96·3±13·5 | 96·3±13·5 | ||
| 6·0 | 43·6±2·3 | 43·6±2·3 | ||
| NH4++NO3− | 4·0 | 124·8±39·2 | 20·1±7·6 | 144·9±46·0 |
| 5·0 | 121·2±40·7 | 18·7±11·8 | 139·9±51·1 | |
| 6·0 | 103·6±13·7 | 6·4±3·2 | 110·0±16·6 | |
| ANOVA (F-value) | ||||
| N form | 20·31** | 200·71** | 41·90** | |
| pH | 2·16 | 26·21** | 6·72** | |
| N form×pH | 0·66 | 12·38** | 0·61 | |
**, P<0·01.