培养温度和时间对磷肥在黑土中转化的影响

采用室内培养试验研究了培养温度和时间对磷酸二氢钙(MCP)、磷酸二氢铵(MAP)和磷酸氢二铵(DAP)在黑土中转化的影响。结果表明:温度升高增加了黑土对肥料磷的固定,且有利于Al-P的形成;培养50 d后,温度由5℃升至25℃时,We-P在添加MAP和MCP处理的土壤中占外源磷的比例分别降低51%和42%,同时Al-P分别上升110%和45%;在培养初期,温度对Ca8-P和Fe-P形成的影响不显著,但随培养时间的延长,差异显著。25℃时,培养时间对Ca2-P和Ca8-P形成的影响较小;Al-P在培养初期形成速率很快,随培养时间的延长,形成速率下降,而Fe-P的形成速率与之相反;Al-P的增加量与We-P的下降量呈显著线性正相关。与MAP和MCP相比,DAP更适合在黑土中施用。

IInfluences of temperature and duration of incubation on transformation of phosphate fertilizers in black soil

Influences of temperature and duration of incubation were investigated through laboratory incubation experiment on transformation of monocalcium phosphate monohydrate (MCP), monoammonium phosphate (MAP) and diammonium phosphate (DAP) in black soil. Results show that high temperature increased fixation of the selected fertilizers in black soil and favored formation of Al-P; an increase of temperature from 5°C to 25°C and 50 days of incubation resulted in reduction of We-P in Treatments MAP and MCP by 51% and 42%, respectively, and simultaneously in increase in Al-P by 110% and 45%, respectively; at the initial stage of the incubation, not much influence of temperature on formation of Ca₈-P and Fe-P was observed, but it was getting obvious with the incubation going on. At 25°C, the formations of Ca₂-P and Ca₈-P were not much affected by duration of the incubation; at the beginning of the incubation, Al-P was formed rapidly, but the formation rate declined with the incubation going on; the formation of Fe-P displayed a reverse trend; the formation of Al-P was in significant negative linear correlation with that of We-P. Compared with MAP and MCP, DAP was more suitable for application in black soil.