A Portable Determination Method for the Soil Rapid Available Potassium via Enhanced NaBPh4 Turbidimetry

• Published in: Communications in Soil Science and Plant Analysis 2024-09, Vol.55 (16), p.2478-2487
• Main Authors: Lu, Qinwen, Wang, Ruijing, Li, Mengya, Wei, Liman, Chang, Yongjia, Guo, Hongyan, Cao, Qiao, Chen, Xiangyu
• Format: Article
• Language: English
• Subjects: Accuracy; Acetates; Acetic acid; Ammonium; Ammonium acetate; Ammonium acetate-flame photometer method; Ammonium compounds; Calibration; Environmental monitoring; Fertilizers; Photometers; Portability; Potassium; Sodium; sodium tetraphenylborate turbidimetry; Soil; soil nutrients detection; soil rapidly available potassium; Soils; Spectrophotometers; Turbidimeters; Turbidimetry
• ISSN: 0010-3624; 1532-2416; 1532-4133
• DOI: 10.1080/00103624.2024.2365743

Monitoring soil rapidly available potassium (RAK) reserves is extremely significant for developing precise fertilizer recommendations. The sodium tetraphenylborate (NaBPh 4 )-spectrophotometer method is applied to the detection of soil RAK content as a speedy, efficient and portable approach. However, the detection accuracy of this method is inferior to the ammonium acetate (NH 4 OAc)-flame photometer method. Here, the detection processes of the NaBPh 4 turbidimetry were optimized to find the correlation with the NH 4 OAc method, further discussed the reasons for the different results by the two methods. The maximum relative error is 13% after conversion through the calibration curve. In addition, the accuracy of the calibration curve was verified by selecting non-fitting soil samples from two experimental sites. Therefore, our work proposes that the NaBPh 4 turbidimetry, more convenient and rapid, can accurately detect the soil RAK content in the field. It provides an experimental guidance for the detection method of soil RAK content based on ultraviolet detection and on-site rapid detection devices.