晚近的研究表明,土壤养分供应大致通过三个途径:即质流、扩散和根系截获。并认为NO_3~-、Ca~++、Mg~++等营养离子主要通过质流,而磷、钾、铵则主要通过扩散。因此,土壤中磷的扩散是判别土壤磷素供应和提高磷肥效率的重要指标。然而,由于影响磷扩散的土壤因素很多,所以在鉴别某一土壤的磷素供应,或研究如何进一步发挥磷肥肥效 Recent studies have shown that nutrient supply to soils passes through roughly three paths: mass flow, diffusion and root interception. It is considered that nutrient ions such as NO_3 ~ -, Ca ~ + +, Mg ~ + + mainly pass through the mass flow and phosphorus, potassium and ammonium mainly diffuse. Therefore, the diffusion of phosphorus in soil is an important index to judge the supply of soil phosphorus and improve the efficiency of phosphate fertilizer. However, due to the large number of soils that affect phosphorus uptake, it is important to identify the availability of phosphorus in a particular soil or to study how to further