Early season prediction of within-field crop yield variability by assimilating CubeSat data into a crop model

Journal Article · Mon Nov 29 00:00:00 EST 2021 · Agricultural and Forest Meteorology

DOI:https://doi.org/10.1016/j.agrformet.2021.108736· OSTI ID:1981532

Ziliani, Matteo G. ^[1]; Altaf, Muhammad U. ^[1]; Aragon, Bruno ^[2]; Houborg, Rasmus ^[3]; Franz, Trenton E. ^[4]; Lu, Yang ^[5]; Sheffield, Justin ^[5]; Hoteit, Ibrahim ^[1]; McCabe, Matthew F. ^[1]

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1. King Abdullah University of Science and Technology (KAUST), Thuwal (Saudi Arabia)
2. California Institute of Technology (CalTech), Pasadena, CA (United States)
3. Planet, San Francisco, CA (United States)
4. Univ. of Nebraska, Lincoln, NE (United States)
5. Univ. of Southampton (United Kingdom)

Accurate early season predictions of crop yield at the within-field scale can be used to address a range of crop production, management, and precision agricultural challenges. While the remote sensing of within-field insights has been a research goal for many years, it is only recently that observations with the required spatio-temporal resolutions, together with efficient assimilation methods to integrate these into modeling frameworks, have become available to advance yield prediction efforts. Here we explore a yield prediction approach that combines daily high-resolution CubeSat imagery with the APSIM crop model. The approach employs APSIM to train a linear regression that relates simulated yield to simulated leaf area index (LAI). That relationship is then used to identify the optimal regression date at which the LAI provides the best prediction of yield: in this case, approximately 14 weeks prior to harvest. Instead of applying the regression on satellite imagery that is coincident, or closest to, the regression date, our method implements a particle filter that integrates CubeSat-based LAI into APSIM to provide end-of-season high-resolution (3 m) yield maps weeks before the optimal regression date. The approach is demonstrated on a rainfed maize field located in Nebraska, USA, where suitable collections of both imagery and in-situ data were available for assessment. The procedure does not require in-field data to calibrate the regression model, with results showing that even with a single assimilation step, it is possible to provide yield estimates with good accuracy up to 21 days before the optimal regression date. Yield spatial variability was reproduced reasonably well, with a strong correlation to independently collected measurements (R² = 0.73 and rRMSE = 12%). When the field averaged yield was compared, our approach reduced yield prediction error from 1 Mg/ha (control case based on a calibrated APSIM model), to 0.5 Mg/ha (using satellite imagery alone), and then to 0.2 Mg/ha (results with assimilation up to three weeks prior to the optimal regression date). Such a capacity to provide spatially explicit yield predictions early in the season has considerable potential to enhance digital agricultural goals and improve end-of-season yield predictions.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). AmeriFlux
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1981532
• Journal Information: Agricultural and Forest Meteorology, Journal Name: Agricultural and Forest Meteorology Journal Issue: C Vol. 313; ISSN 0168-1923
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
APSIM
Crop modeling
Crop yield prediction
CubeSat
Data assimilation
LAI