Table 2 Different fractionations of P as affected by N fertilizer and green manures (mg kg−1).
NaHCO3-Pi | NaHCO3-Po | NaOH-Pi | Total labile P | NaOH-Po | HCl-P | Residual-P | Total-P | Olsen-P | |
|---|---|---|---|---|---|---|---|---|---|
2012 | |||||||||
Control | 40.63 ± 0.44c | 42.32 ± 2.82b | 72.06 ± 0.65c | 155.01 ± 3.56c | 36.42 ± 1.92a,b | 193.60 ± 1.18b,c | 47.37 ± 3.41b | 471.98 ± 3.82c | 18.71 ± 0.21c |
Alfalfa | 46.33 ± 4.25b | 68.13 ± 4.85a | 89.43 ± 6.89a,b | 203.89 ± 7.46a,b | 36.79 ± 1.22a,b | 194.94 ± 3.53b,c | 60.84 ± 3.36a | 536.44 ± 14.26b | 21.51 ± 0.30b |
Broad bean | 45.54 ± 0.50b | 63.43 ± 4.49a | 85.32 ± 5.41b | 194.29 ± 2.91a,b | 38.15 ± 1.79a | 192.18 ± 1.23c | 50.76 ± 2.21a,b | 522.40 ± 7.10b | 20.89 ± 1.38b,c |
N fertilizer | 42.80 ± 2.58c | 30.82 ± 2.74b | 84.06 ± 3.60b | 157.68 ± 3.93c | 35.57 ± 0.54a,b | 196.99 ± 0.13b,c | 44.43 ± 3.12b,c | 494.73 ± 8.07b,c | 19.63 ± 1.08b,c |
Alfalfa + N | 58.32 ± 1.84a | 63.79 ± 5.02a | 103.16 ± 8.81a | 225.27 ± 15.56a | 34.16 ± 2.65a,b | 199.54 ± 2.67a,b | 47.67 ± 5.21b | 601.08 ± 11.10a | 24.67 ± 0.83a |
Broad bean + N | 48.64 ± 0.51b | 62.81 ± 4.51a | 95.55 ± 1.64a,b | 207.00 ± 6.66a,b | 30.41 ± 3.43b | 204.72 ± 0.96a | 35.27 ± 2.66c | 537.33 ± 29.71b | 22.05 ± 0.29b |
2014 | |||||||||
Control | 42.76 ± 1.11c | 43.35 ± 0.54b | 79.28 ± 2.70c | 165.39 ± 3.81c | 37.26 ± 0.85a | 182.58 ± 4.00b | 46.65 ± 0.72b,c | 442.15 ± 8.11d | 16.16 ± 0.38b,c |
Alfalfa | 48.21 ± 1.61b | 72.02 ± 0.57a | 100.56 ± 4.37a | 220.79 ± 5.69a | 36.70 ± 2.68a | 270.55 ± 17.18a | 59.21 ± 3.04a | 652.54 ± 22.85a | 19.20 ± 0.53a |
Broad bean | 47.80 ± 0.89b | 63.14 ± 6.19a | 104.11 ± 1.08a | 215.05 ± 4.82a | 32.23 ± 2.29a,b | 265.70 ± 16.71a | 54.59 ± 3.45a,b | 627.56 ± 24.61a,b | 18.53 ± 1.456a |
N fertilizer | 33.97 ± 2.63d | 44.00 ± 3.76b | 85.24 ± 1.58b,c | 163.21 ± 1.59c | 26.59 ± 1.74b | 210.92 ± 21.84a | 47.20 ± 2.48c | 476.27 ± 18.32d | 14.22 ± 0.49c |
Alfalfa + N | 47.38 ± 0.88b | 70.97 ± 5.56a | 107.62 ± 3.40a | 225.97 ± 4.79a | 34.06 ± 2.08a | 191.86 ± 9.43b | 54.70 ± 0.51a,b | 595.77 ± 13.54b,c | 17.98 ± 0.65a,b |
Broad bean + N | 54.23 ± 1.46a | 45.80 ± 4.53b | 89.40 ± 4.29b | 189.43 ± 9.32b | 31.57 ± 0.92a,b | 217.23 ± 7.62a | 40.76 ± 0.17c | 554.19 ± 17.69c | 17.70 ± 0.46a,b |