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Test results of different sampling periods in rural areas of Yantai from 2015 to 2018
| Water type | Nitrate nitrogen content (mg/L) | Number of samples | Qualified rate(%) |
|---|---|---|---|
| Dry season | 21.6 ± 18.1 | 1174 | 48.98 |
| Wet season | 22.2 ± 18.2 | 1174 | 46.76 |
| total | 21.9 ± 18.3 | 2348 | 48.59 |
