TABLE 1.
Nutrient content of rhizosphere soils from fields with alfalfa continuous cropping for 1, 7, and 14 years.
| CC yeara | Alkali-hydrolyzed Nb (mg/kg) | Available Pb (mg/kg) | Available Kb (mg/kg) | Available Bb (mg/kg) | Available Feb (mg/kg) | Available Mnb (mg/kg) | Available Cub (mg/kg) | Available Znb (mg/kg) | Available Mgb (mg/kg) |
| 14 | 75.5 a | 2.2 a | 102 a | 0.46 a | 11.2 b | 3.86 b | 1 b | 1.5 b | 139 b |
| 7 | 101 b | 3.1 a | 97.1 a | 0.56 a | 8.2 a | 2.9 a | 0.71 a | 0.88 a | 122 a |
| 1 | 147.6 c | 3.1 a | 159 b | 0.9 b | 34.2 c | 7.56 c | 0.58 a | 0.85 a | 191 c |
aIndicates alfalfa continuous cropping (CC) for 1, 7, and 14 years. Values followed by different letters were significantly different according to Duncan’s multiple range tests (P < 0.05).
brepresents the content of each nutrient.