Comparative analysis of spectroradiometric and chemical methods for nutrient detection in black gram leaves

Abstract

This study evaluated the nutrient content in Vigna mungo leaves using a visible near-infrared spectroradiometer (VNIR 650–900 nm) and compared it with traditional chemical analysis. Nutrient deficiencies were induced in a controlled environment, focusing on Nitrogen (N), Phosphorus (P), and Potassium (K). The VNIR spectroradiometer measured the spectral reflectance of the leaves at different intervals. Peak reflectance for N, P, and K deficiencies occurred at 716 nm, 737 nm, and 720 nm, respectively. A 30 % deficiency in N, P, and K resulted in reflectance values of 45 %, 42 %, and 41 %, respectively, while a 40 % deficiency increased these values to 48 %, 46 %, and 43 %. Results showed a strong correlation between nutrient deficiency and spectral reflectance, providing a quicker, more economical method than traditional chemical analysis. The study concludes that VNIR spectroradiometry is an effective tool for non-destructive, real-time assessment of nutrient status in Vigna mungo, which could lead to optimized fertilizer application and improved crop management.

Keywords

• Nutrient deficiency
• Vigna mungo
• VNIR spectroradiometer
• Spectral reflectance
• Non-destructive testing