Abstract
Remote sensing observations that vary in response to plant growth and senescence can be used to monitor crop development within and across growing seasons. Identifying when crops reach specific growth stages can improve harvest yield prediction and quantify climate change. Using the Level 2 vegetation optical depth (VOD) product from the European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) satellite, we retrospectively estimate the timing of a key crop development stage in the United States Corn Belt. We employ nonlinear curves nested within a hierarchical modeling framework to extract the timing of the third reproductive development stage of corn (R3) as well as other new agronomic signals from SMOS VOD. We compare our estimates of the timing of R3 to United States Department of Agriculture (USDA) survey data for the years 2011, 2012, and 2013. We find that 87%, 70%, and 37%, respectively, of our model estimates of R3 timing agree with USDA district-level observations. We postulate that since the satellite estimates can be directly linked to a physiological state (the maximum amount of plant water, or water contained within plant tissue per ground area) it is more accurate than the USDA data which is based upon visual observations from roadways. Consequently, SMOS VOD could be used to replace, at a finer resolution than the district-level USDA reports, the R3 data that has not been reported by the USDA since 2013. We hypothesize the other model parameters contain new information about soil and crop management and crop productivity that are not routinely collected by any federal or state agency in the Corn Belt.
Highlights
The United States Department of Agriculture (USDA) National Agricultural Statistics Service (NASS) produces weekly growing-season Crop Progress and Condition reports
How can we model the seasonal pattern of crop development as measured by Soil Moisture and Ocean Salinity (SMOS) and estimate key model parameters? Two, how do estimates using SMOS satellite data compare with ground-based USDA NASS estimates of crop development, the only alternative source of information? This is especially important because the USDA stopped reporting the R3 corn stage after the 2013 growing season
SMOS vegetation optical depth (VOD) in the US Corn Belt has potential for monitoring crop growth and development because it is directly proportional to plant water, the mass of water contained within vegetation tissue per ground area
Summary
The data are collected by “enumerators” or human volunteers who make visual observations from roadways Despite inherent inaccuracies, these reports are important in the United States Corn Belt, a large region of corn and soybean production covering more than 10 different states and worth more than $100 billion annually, because they influence marketing decisions as measured by variance in close-to-open crop trading values and changes in market prices when new crop progress information becomes available [1]. The infrared radiation emitted by vegetation is a function of its temperature, which can be used to infer evapotranspiration (ET) and crop stress that can either accelerate or retard development and reduce yield. Both microwave backscatter and emission can be used to observe vegetation. Since liquid water contained within plant tissue is the primary cause of this attenuation [4], VOD is correlated with vegetation biomass
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
