Research Article
Citric Acid Promotes the Mobilization of Phosphorus under the Lower Concentration of Low Molecular Weight Organic Acids in Acidic Forest Soil
Table 1
The variations of P fractions induced by organic acids compared with other reports.
| Soil type | Concentrations (mM) | Area | Organic acids | Soluble-Pi | Soluble -Po | NaHCO3-Pi | NaHCO3-Po | NaOH-Pi | NaOH-Po | HCl-P | Reference |
| Acid soil | 100 | Southwest China | Citric acid | ↑ | ↑ | ↑ | ↑ | ↓ | ↓ | ↓ | This study | Oxalic acid | ↑ | ↑ | ↑ | ↑ | ↑ | ↑ | ↓ | Malic acid | ↑ | ↑ | ↑ | ↑ | ↓ | ↑ | ↓ | Acid soil | 10 | Northeast China | Citric acid | ns | ns | — | ↓ | ↓ | — | — | [24] | Oxalic acid | ns | ns | — | — | — | — | — | Malic acid | ns | ns | — | — | — | — | — | Neutral soil | Citric acid | ns | ns | — | ↓ | — | — | — | Oxalic acid | ns | ns | — | — | — | — | — | Malic acid | ns | ns | — | — | — | — | — | Alkaline soil | Citric acid | ns | ns | — | — | — | — | — | Oxalic acid | ns | ns | — | — | — | — | — | Malic acid | ns | ns | — | — | — | — | — | Acid soil | 10 | Australia | Citric acid | — | ↑ | ns | ns | ns | ns | ns | [10] | Oxalic acid | — | ↑ | ns | ns | ns | ns | ns | Malic acid | — | — | ns | ns | ns | ns | ns | Alkaline soil | 100 | East China | Citric acid | ↑ | ns | ↓ | ↓ | ↓ | — | ↓ | [41] | Oxalic acid | ↑ | ns | — | ↑ | ↓ | — | ↓ | Malic acid | ↑ | ns | ↓ | ↑ | — | — | ↓ | Acid soil | 1 | South China | Citric acid | ↑ | ↑ | ns | ns | ns | ns | ns | [5] | Oxalic acid | ↑ | ↑ | ns | ns | ns | ns | ns | Malic acid | — | — | ns | ns | ns | ns | ns |
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Note: ns means no data; ↑ or ↓ means increase or decrease relative to control; - means no significant variation.
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