砖红壤磷的有效性研究

研究生长在两种不同母质的砖红壤上的作物的P营养与土壤有效P的关系，以及土壤有效P与Fe、Al、Mn等元素的关系。结果表明，玄武岩砖红壤的全P含量虽比浅海沉积物砖红壤高，但其有效P含量却不如后者高，生长在后种土壤上的香蕉、辣椒、桉树的P含量也高于生长在前种土壤上；玄武岩砖红壤的活性Fe、Al、Mn含量显著高于浅海沉积物砖红壤；同一种母质的土壤其有效P含量随土壤活性Si和交换性Ca、Mg的提高而增加；土壤中活性Fe、Al、Mn含量越高，土壤对磷的固定越强，土壤有效P含量越低。同时，植物体内Fe、Al、Mn含量的增加也抑制了植物对磷的吸收，使植株中P含量降低。

Study on phosphorus availability in latosols

Phosphorus nutrition of crop and phosphorus availabilities in latosols derived from differ mother material and their relationship to soil Fe, Al, Mn, etc., were studied in this paper. Results show that, even though the soil total P content in latosol derived from basalt is higher than that in latosol derived from shallow-sea deposit but available P content in latosol derived from shallow-sea deposit is higher. The P content of banana, capsicum and eucalyptus in latosol derived from shallow-sea deposit is higher also than that in latosol derived from basalt. The concentration of active Fe, Al, Mn in latosol derived from basalt is higher than that in latosol derived from shallow-sea deposit. The concentration of soil available P in same mother material was increased along with concentration of soil active Si and exchangeable Ca and Mg. When concentration of active Fe, Al, Mn in soil were high, fixation of P were stronger, and available P in soil was decreased. When concentration of active Fe, Al, Mn in crop were higher, absorption of P by crop was inhibited, and the concentration of P in crop was decreased.