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

• Main Authors: WANG Min, LIU Shi-lei, ZHANG Shuai, ZHANG Qiang, MU Kang-guo, CHEN Qing
• Format: Article
• Language: zho
• Published: Agro-Environmental Protection Institute, Ministry of Agriculture 2020-03-01
• Series: Journal of Agricultural Resources and Environment
• Subjects: potassium humate, phosphate fertilizer, application method, phosphorus migration, leaching risk
• Online Access: http://www.aed.org.cn/nyzyyhjxb/html/2020/2/20200208.htm

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.