不同磷源对土壤镉有效性的影响

本研究采用湖北省具有代表性的黄棕壤和潮土进行室内培养试验,研究了5种磷源和5个施磷量（0、0.1、0.2、0.4、0.8g.kg-1,以每kg土中有效态P2O5含量计）对土壤镉（Cd）有效性的影响.结果表明,培养8周后,随着磷酸氢二铵（DAP）、磷酸二氢铵（MAP）和过磷酸钙（SSP）施入量的增加,两种土壤的pH均显著...

Effect of different phosphate sources on availability of cadmium in soil

To investigate the effects of five phosphates with five application rates (0, 0.1, 0.2, 0.4, 0.8g (P₂O₅)·kg^-1 (soil)) on the availability of soil cadmium (Cd), soil incubation experiment was carried out with yellow brown and fluvo-aquic soil, two types of typical soil, collected from Wuhan, Hubei, China. The results showed that, after eight weeks incubation, the pH of two types of soils significantly reduced and the available phosphorus (P) and available Cd concentrations significantly increased, with increasing rate of diammonium phosphate (DAP), monoammonium phosphate (MAP) and superphosphate (SSP). Dicalcium phosphate (DCP) and tricalcium phosphate (TCP) had no significant effect on pH of two types of soils, but available P significantly increased and available Cd significantly decreased with increasing rate of DCP and TCP. The capability of five phosphates in acidifying soil varied in following order: DAP>MAP>SSP> DCP, TCP. At the same rate of phosphate addition, soil available P in yellow brown soil followed the sequence of SSP>MAP, DAP> DCP>TCP, and the difference increased with elevated rate of phosphates. Available P in fluvo-aquic soil was in order of DAP>SSP>MAP> DCP>TCP, and its difference reduced with increasing rate of phosphates. In all phosphate treatments except for DCP treatment, a negative correlation was observed between soil pH and available Cd. This suggested that DAP, MAP, SSP and TCP could influence available Cd by reducing soil pH, while DCP may also introduce other reactions that may affect available Cd.