腐植酸钾与磷肥施用方式对土壤磷素移动性的影响

为探明腐植酸与磷肥施用方式对土壤磷素移动性和淋失量的影响，通过室内土柱淋溶试验，分别设计了不施肥（CK）、基施腐植酸钾追施/不追施磷肥（HA-P、HA）、基施磷肥追施/不追施腐植酸钾（P-HA、P）和磷肥腐植酸钾共同基施（P+HA）共6个处理，来探讨将腐植酸水溶性肥料中的主要原料腐植酸钾与磷肥按照不同施用方式施入土壤后对土壤磷素剖面迁移能力和淋出的影响。结果表明：在相同的灌溉条件下，HA-P处理显著增加了土壤磷素的淋出，分别比P-HA、P和P+HA 3个处理的磷素淋出总量高244.08%、78.51%和35.34%，而P-HA则显著降低了土壤磷素的淋出量；P+HA和P-HA处理土壤剖面的速效磷和全磷含量均随土层深度的增加而显著增加，与P处理结果相似，而HA-P处理剖面各层土壤的速效磷和全磷含量差异较小；HA处理会使土壤磷素淋出略有增加。研究表明，腐植酸钾与磷肥等量输入时，以腐植酸钾为基肥、磷溶液进行追肥的施用方式对土壤磷素移动的促进作用最大，有较高的淋失风险，而基施磷肥、追施腐植酸钾则可以显著控制土壤剖面磷素移动，降低土壤磷素的淋出量。

Effect of potassium humate and phosphate fertilizer application method on soil phosphate mobility

With the popularization of humic acid functional water-soluble fertilizers, the risk of non-point source pollution caused by leaching of soil phosphorus has increased because humic acid has a significant effect on the mobility of soil phosphorus. It is particularly important to determine the influence of application methods of humic acid and phosphate fertilizer on the mobility and leaching of phosphorus in soil. The optimized application method of humic acid fertilizers may contribute to the reduction of phosphorus leaching and non-point source pollution. In the current study, the effects of the application method for potassium humate and phosphate fertilizer(the main raw materials of humic acid water-soluble fertilizer) on the soil phosphorus migration ability and leaching were investigated using a soil column leaching test. The results showed that under the same irrigation conditions, application of phosphate fertilizer topdressing with potassium humate as the base fertilizer significantly increased soil phosphate leaching, and was 244.08%, 78.51% and 35.34% greater than that of the treatment applications for potassium humate topdressing with phosphate fertilizer as a base fertilizer, phosphate fertilizer as a base fertilizer without potassiurm humate topdressing, and phosphate fertilizer and potassium humate as a base fertilizer, respectively. The content of available phosphorus and total phosphorus in soil increased with the increase of soil depth in the treatments of application of phosphate fertilizer and potassium humate as a base fertilizer and application of potassium humate topdressing with phosphate fertilizer as a base fertilizer, which was similar to that of the phosphate fertilizer as a base fertilizer without potassiurm humate topdressing treatment. There was little effect on the content of available phosphorus and total phosphorus in the different layers of soil when potassium humate was applied as a base fertilizer with phosphorus fertilizer topdressing. Phosphorus leaching slightly increased when potassium humate was used as a base fertilizer. In conclusion, the same input amount of potassium humate as a base fertilizer and phosphorus solution as topdressing fertilizer had the greatest promoting effect on soil phosphorus movement, which increased the risk of phosphate leaching. Phosphate movement and leaching in soil could be reduced when phosphorus solution and potassium humate were used as the base fertilizer and topdressing fertilizer, respectively.