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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Water Quality and Ecology Research » Research » Publications at this Location » Publication #390936
Research Project: Strategic Investigations to Improve Water Quality and Ecosystem Sustainability in Agricultural Landscapes

Location: Water Quality and Ecology Research

Title: Relationships among vegetation indices for different crops in the Northern Great Plains

Author
item Chatterjee, Amitava

Submitted to: Crop, Forage & Turfgrass Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Sensors for the measurement of chlorophyll content and canopy reflectance are becoming essential tools for fertilizer nitrogen management. Wide application of these requires understanding of associations among sensors for different crops. Chlorophyll content and canopy reflectance were measured with SPAD and RapidSCAN, respectively. Vegetation indices showed a strong relationship with SPAD and growing degree days; but the magnitude of association varied with crops. Spring wheat had the lowest and corn had the highest associations between SPAD and vegetation indices.

Technical Abstract: Wide-spread adoption of proximal sensors in crop health assessment requires understanding of changes in canopy reflectance during the growing season and associations among readings from different sensors. Chlorophyll meter reading (SPAD) and red normalized difference vegetation index (RNDVI) and red edge normalized difference vegetation index (RENDVI) were measured for crops, sugarbeet (Beta vulgaris L.), corn (Zea mays), sunflower (Helianthus annuus L.), soybean (Glycine max), and spring wheat (Triticum aestivum) throughout 2021 growing season. Cumulative growing degree days (GDD) had a significant relationship with SPAD, RNDVI, and RENDVI. The correlation coefficient indicated SPAD was more associated with NDRE (r = 0.73) than RNDVI (0.50). The R2 values of multiple linear regression of SPAD and GDD with RNDVI and RENDVI were the lowest for spring wheat (0.34 and 0.52, respectively) and the highest for corn (0.94 and 0.95, respectively). All three studied indices, SPAD, RNDVI, and RENDVI had a close association, but the relationship varied with crops.