Improving the monitoring of crop productivity using spaceborne solar-induced fluorescence

Kaiyu Guan, Stanford University, Stanford, United States, David B Lobell, Stanford University, Department of Earth System Science & Center on Food Security and the Environment, Stanford, United States, Joe A Berry, Carnegie Institution for Science Stanford, Stanford, CA, United States, Joanna Joiner, NASA GSFC, Greenbelt, United States, Luis Guanter, Institute for Space Sciences, Freie Universität Berlin, Berlin, Germany, Yongguang Zhang, Freie Univ Berlin, Berlin, Germany and Badgley Grayson, CarbonPlan, San Francisco, CA, United States; Carnegie Institution for Science, Global Ecology, Washington, DC, United States
Abstract:
Large scale monitoring of crop growth and yield has relied on empirical correlations between remotely sensed vegetation-indices and yield. However, the determinants of yield are complex with several processes including crop phenology, photosynthesis and respiration contributing to overall crop yield. It has not been possible to delve more deeply into environmental effects on these controls given the limitations of current remote sensing technology. Recent advances in the ability to monitor solar induced chlorophyll fluorescence (SIF) now provides a direct measurement of photosynthetic activity from space and opens up new approaches for understanding the controls on crop yield. Using county-level crop statistics in the United States, we find that spaceborne SIF measurements for 2007-2012 provided improved measures of crop productivity compared with various traditional crop monitoring approaches, despite the fact that SIF sensors are still not optimized for crop monitoring. We also demonstrate that SIF, when combined with other data, can be used to estimate light-use-efficiency and plant autotrophic respiration. SIF thus opens up an unprecedented opportunity for improved crop monitoring and mechanistic understanding of how crops respond to temperature and other climate drivers.
Back to: Remote Sensing of Vegetation Function and Traits III