Rapid Assessment of Soil Available Phosphorus and Exchangeable Potassium Content Using Portable Near-Infrared Sensors: A Non-Destructive Approach

Abstract

The I-DIN portable near-infrared sensor was developed by ScaNxt Scientific Technologies Pvt. Ltd. in collaboration with Global-Crops Co., Ltd. to assess soil nutrients, including organic carbon (OC), available nitrogen, available phosphorus, exchangeable potassium, and cation exchange capacity (CEC), directly in the field. This sensor provides a rapid, non-destructive method for soil sample analysis. This study aimed to evaluate the potential of the I-DIN portable near-infrared sensor in predicting available phosphorus and exchangeable potassium contents in soil. The results indicated that the sensor performed moderately well in estimating available phosphorus, with a coefficient of determination (R²) of 0.50, a root mean square error (RMSE) of 0.20, a ratio of performance to deviation (RPD) of 1.17, and a correlation coefficient (r) of 0.71. However, the sensor exhibited unreliable performance in predicting exchangeable potassium. Additional research is required to enhance the effectiveness of the I-DIN portable near-infrared sensor in evaluating soil Pavai and Kexch contents. Future studies could investigate factors such as adjusting the soil sample particle size (e.g., to 1 mm or 0.5 mm) and expanding the number of soil samples to improve test accuracy.