摘要： 对河北省低磷石灰性土壤磷肥后效以及试验周期中水溶性磷肥的固定转化规律及其有效性进行了研究,并对磷肥不同分配方式的经济效果做了评价.结果表明,磷肥后效明显,且随施磷量增加后效期延长.一次亩施16公斤P₂O₅,至少可维持四年的后效作用.磷肥施入土壤后,以速效态存在者约20%,约80%转化为难溶性磷酸盐.以后难溶性磷酸盐仍会被释放出来为作物吸收.四年中Al-P进一步向Ca-P转化,说明Al-P可视为活性较强的一种过渡形态.而且Al-P与速效磷含量之间呈高度显著正相关,Al-P每增加10ppm,速效磷约增加3ppm.每年亩施4公斤P₂O₅效果最好,隔年施8公斤和四年一次施16公斤其效果约为每年分施的70～90%.

关键词: 石灰性土壤, 磷肥后效, 磷素形态转化, 施肥

Abstract: The residual effect and the fixation and transformation principles , the efficiency of water-soluble phosphorus fertilizer during experiment period on a calcarious soil are studied from 1982 to 1989.The economic efficiency of different distributions is also evaluated. The results show a significant residual effect for phosphorus fertilizer exists and, a longer dosage, the residual effect duration is longer. At the application rate of 16kg/P2O5/mu, its residual effect lasts at least 4 years. There is less than 20% of phosphorus which remained soluble and about 80% of phosphonus which converted into insoluble phosphates after been applying the soil. The formed afterwards insoluble phosphate in soil can be released and used by the crop again. The forms of phosphorus converted to insoluble phosphate are mainly Ca-P and Al-P which is converted to Ca-P during the 4 year period. Al-P also has a high correlation with available phosphorus. The correlative equation shows every 10ppm increase in Al-P may result in 3ppm increase in available phosphorus. Therefore, it is regarded that Ai-P has a relatively high availability and it produces mainly the residual effect.The most optimum application is 4kg P2O5/mu yearly. Instead of a big dosage at one time,suitable ones yearly are recommended.

Key words: Calcarious soil, Residual effect of phosphorus fertilizer, Forms and transfomation of phosphorus, Fertilization