砂页岩赤红壤磷肥活化效果及其机理研究

应用不同活化剂处理不同性质的磷肥，并对其在砂页岩赤红壤中的生物效应及作用机理进行了研究。结果表明，在砂页岩赤红壤上，施用供试的儿种经活化剂处理的磷肥均能显著提高蔬菜生物量。砂页岩赤红壤中的铁、锰质量分数与磷素的有效性有密切的关系，且在还原条件下，土壤铁、锰对磷的固定作用更大；硅、钙可促进土壤中磷的释放。供试活化剂不仅可促进难溶磷的释放，还可控制水溶性磷的释放，使土壤供磷性能平稳；有机活化剂的用量，用于难溶性磷促释时其质量分数为3％，用于水溶性磷控释时其质量分数约为14％。在土壤-植物体系中，活化剂对磷的促释和控释机理是它通过对土壤铁、锰、铝质量分数的调节而实现对磷的活化。

Activating effects and mechanisms of phosphatic fertilizers in lateritic red soil derived from arenaceous shale

Several activation agents were used to treat various phosphate fertilizers, and their biological effects and mechanisms in lateritic red soil derived from arenaceous shale were studied. The results showed that the growth of vegetables increased markedly in lateritic red soil when phosphatic fertilizers via the treatment of several activation agents were applied to them. The mass fraction of Fe and Mn elements in the soil are closely correlated to the efficiency of P elements, and the soil Fe and Mn have greater fixation effect on P under the condition of reduction. Si can benefit the release of P in soil, and proper Ca mass fraction also increase the activity of P element. The activation agents can not only promote the release of hard-soluble P, but also control the release of water-soluble P so as to stabilize the P supply from soil. The feasible mass fraction of organic activation agent is 3% for hard-soluble P but 14% for water-P. In the soil-plant system,the promotion and control mechanisms of activation agents to P is to adjust the mass fraction of Fe, Al and Mn in soil so as to realize the activation of P.