Table 2 Soil P status
From: Organic phosphorus leaching risk from agricultural soils across China
Soils | TP (mg kg−1) | APT (mg kg−1) | API (mg kg−1) | APO (mg kg−1) | APO/APT (%) | CaCl2-PT (mg kg−1) | CaCl2-PI (mg kg−1) | CaCl2-PO (mg kg−1) | CaCl2-PO/CaCl2-PT (%) |
|---|---|---|---|---|---|---|---|---|---|
Total soils (n = 63) | |||||||||
 Min | 378 | 1.55 | 0.27 | 0.03 | 0.23 | 0.97 | 0.16 | 0.20 | 8.13 |
 Max | 3387 | 767 | 281 | 727 | 94.8 | 9.33 | 8.57 | 3.80 | 88.5 |
 Mean | 1118 | 147 | 58.2 | 89.2 | 56.8 | 2.43 | 1.60 | 0.83 | 34.7 |
 SD | 576 | 174 | 69.3 | 128 | 24.8 | 1.99 | 1.52 | 0.80 | 14.5 |
Paddy soils (n = 21) | |||||||||
 Min | 535 | 12.3 | 2.38 | 4.8 | 19.9 | 1.03 | 0.16 | 0.20 | 17.5 |
 Max | 2690 | 264 | 107 | 204 | 92.6 | 1.76 | 1.25 | 1.20 | 88.5 |
 Mean | 1252a | 72.8b | 24.6b | 48.2b | 67.5a | 1.38b | 0.87b | 0.52a | 36.8a |
 SD | 517.37 | 65.3 | 28.9 | 49.3 | 21.9 | 0.22 | 0.23 | 0.26 | 16.1 |
Red soils (n = 11) | |||||||||
 Min | 556 | 1.55 | 0.27 | 1.28 | 15.3 | 1.03 | 0.75 | 0.20 | 15.2 |
 Max | 1797 | 659 | 271 | 470 | 84.3 | 7.23 | 5.65 | 3.80 | 77.1 |
 Mean | 1114a | 253ab | 110a | 143a | 53.9ab | 2.93a | 1.86ab | 1.07a | 32.5a |
 SD | 373 | 266 | 104 | 172 | 21.2 | 2.41 | 1.86 | 1.25 | 20.4 |
Chernozem (n = 13) | |||||||||
 Min | 378 | 13.1 | 10.6 | 0.03 | 0.23 | 1.26 | 0.75 | 0.37 | 26.2 |
 Max | 2501 | 506 | 139 | 367 | 86.2 | 6.40 | 4.72 | 2.41 | 56.8 |
 Mean | 1089a | 134ab | 54.5b | 80.0ab | 41.9b | 2.89a | 1.87ab | 1.02a | 36.9a |
 SD | 584 | 148 | 52.5 | 108 | 27.2 | 2.06 | 1.47 | 0.67 | 8.05 |
Other soils (n = 18) | |||||||||
 Min | 382 | 33.4 | 9.66 | 11.5 | 6.30 | 0.97 | 0.58 | 0.29 | 8.13 |
 Max | 3387 | 767 | 281 | 727 | 94.8 | 9.33 | 8.57 | 3.77 | 50.8 |
 Mean | 985a | 179a | 68.5ab | 111ab | 56.7ab | 3.03a | 2.11a | 0.93a | 32.0a |
 SD | 727 | 182 | 70.7 | 165 | 24.2 | 2.44 | 1.94 | 0.91 | 12.1 |