中国几种典型农田土壤磷素固液相分配规律

土壤养分、污染物的生物有效性与其固液相分配规律密切相关。本研究通过室内模拟试验,设置不同的水、热、肥条件和培养时间序列,采用高速离心法对红壤、黑土、潮土、黑垆土、塿土5种典型土壤的磷素固液相分配规律及其影响因素进行了探讨。结果表明,质地不同土壤磷素固液相分配系数(Kd)值差别很大,整体变化趋势是红壤>黑垆土>塿土>黑土>潮土。不同培养条件下土壤磷素固液相分配系数(Kd)值变化特征表现出随着培养时间延长,土壤磷素Kd值增大,土壤磷素生物有效性逐渐降低。水吸力、浓度与之相反,随着水吸力的增加土壤磷素Kd值变小,随着施入磷素浓度的增加而Kd值降低。在整个温度梯度中,当温度处于20￣25℃左右时,土壤磷素Kd值达到最小值,液相磷素含量相对增多,养分有效性增强。

The bioavailabilityofsoil nutrient and pollutants is closelyrelated totheir distribution coefficient of solid-liquid phase. In a laboratory incubation experiment, the distribution coefficient in the solid-liquid phase( Kd) in five typical Chinese soils, namely red soil, black soil, fluvo-aquic soil, lou soil and black lu soil, were estimated byultracentrifugation method. The treatments included different water suction pres- sure, temperature, incubation period and addition of different concentrations of K2H...