Improving the monitoring of crop productivity using spaceborne solar-induced fluorescence.
Large-scale monitoring of crop growth and yield has important value for forecasting food production and prices and ensuring regional food security. A newly emerging satellite retrieval, solar-induced fluorescence (SIF) of chlorophyll, provides for the first time a direct measurement related to plant photosynthetic activity (i.e. electron transport rate). Here, we provide a framework to link SIF retrievals and crop yield, accounting for stoichiometry, photosynthetic pathways, and respiration losses. We apply this framework to estimate United States crop productivity for 2007-2012, where we use the spaceborne SIF retrievals from the Global Ozone Monitoring Experiment-2 satellite, benchmarked with county-level crop yield statistics, and compare it with various traditional crop monitoring approaches. We find that a SIF-based approach accounting for photosynthetic pathways (i.e. C3 and C4 crops) provides the best measure of crop productivity among these approaches, despite the fact that SIF sensors are not yet optimized for terrestrial applications. We further show that SIF provides the ability to infer the impacts of environmental stresses on autotrophic respiration and carbon-use-efficiency, with a substantial sensitivity of both to high temperatures. These results indicate new opportunities for improved mechanistic understanding of crop yield responses to climate variability and change.
Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA.|Center on Food Security and the Environment, Stanford University, Stanford, CA, 94305, USA.
Kaiyu
K
Guan
Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, USA.
Joseph A
JA
Berry
International Institute for Earth System Sciences, Nanjing University, Nanjing, 210023, China.|Remote Sensing Section, German Research Center for Geosciences (GFZ), Telegrafenberg A17, 14473 Potsdam, Germany.
Yongguang
Y
Zhang
Laboratory for Atmospheric Chemistry and Dynamics (Code 614), National Aeronautics and Space Administration Goddard Space Flight Center, Greenbelt, MD, 20771, USA.
Joanna
J
Joiner
Remote Sensing Section, German Research Center for Geosciences (GFZ), Telegrafenberg A17, 14473 Potsdam, Germany.
Luis
L
Guanter
Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA.|Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, 94305, USA.
Grayson
G
Badgley
Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA.|Center on Food Security and the Environment, Stanford University, Stanford, CA, 94305, USA.
David B
DB
Lobell
D002734:Chlorophyll / Q000378:metabolism; D002980:Climate; D018556:Crops, Agricultural / Q000254:growth & development* / Q000378:metabolism; D005453:Fluorescence; D010788:Photosynthesis; D011891:Rain; D017215:Satellite Communications; D013472:Sunlight; D013696:Temperature; D014481:United States
D002734:Chlorophyll
carbon use efficiency; crop monitoring; fluorescence; gross primary production; net primary production; respiration