Is satellite Sun-Induced Chlorophyll Fluorescence more indicative than vegetation indices under drought condition?

Droughts represent one of the most severe abiotic stress factors that could result in great crop yield loss. Numerous vegetation indices have been proposed for monitoring condition under and assessing drought impacts on However, understanding comparison between traditional (VIs) newly emerging satellite Sun-Induced Chlorophyll Fluorescence (SIF) is still limited especially at multiple spatial scales. In this study, potential observation SIF corn response to was investigated based 2012 US Corn Belt. The standardized precipitation evapotranspiration index (SPEI) used here quantify drought. We found all SPEI were above −1, except July (−1.27), August (−1.39) September (−1.14) 2012, indicating severity examined relationship measurements SIF, SIFyield, VIs (e.g., NDVI EVI) SPEI. Results indicated SIFyield sensitive captured more accurately both regional state scales Quantitatively, had a high correlation with (r = 0.987, p < 0.05) over entire Belt, it losses approximately month earlier than SIF/NDVI/EVI. Furthermore, our results demonstrated be trusted as an effective indicator study GPP (R2 ≥ 0.8664, 0.01) conditions across This highlighted advantage using observations monitor growth scale.