Publication: Eyes in the Sky, Boots on the Ground: Assessing Satellite, and Ground-Based Approaches to Crop Yield Measurement and Analysis
Date
2022-07-15
ISSN
Published
2022-07-15
Author(s)
David B. Lobell
George Azzari
Burke,Marshall Benajah
Gourlay,Sydney
Zhenong Jin
Kilic,Talip
Murray,Siobhan
Abstract
Understanding the determinants of
agricultural productivity requires accurate measurement of
crop output and yield. In smallholder production systems
across low- and middle-income countries, crop yields have
traditionally been assessed based on farmer-reported
production and land areas in household and farm surveys,
occasionally by objective crop cuts for a sub-section of a
farmer’s plot, and rarely using full-plot harvests. In
parallel, satellite data continue to improve in terms of
spatial, temporal, and spectral resolution needed to discern
performance on smallholder plots. This study evaluates
ground and satellite-based approaches to estimating crop
yields and yield responsiveness to inputs, using data on
maize from Eastern Uganda. Using unique, simultaneous ground
data on yields based on farmer reporting, sub-plot crop
cutting, and full-plot harvests across hundreds of
smallholder plots, we document large discrepancies among the
ground-based measures, particularly among yields based on
farmer-reporting versus sub-plot or full-plot crop cutting.
Compared to yield measures based on either farmer-reporting
or sub-plot crop cutting, satellite-based yield measures
explain as much or more variation in yields based on
(gold-standard) full-plot crop cuts. Further, estimates of
the association between maize yield and various production
factors (e.g., fertilizer, soil quality) are similar across
crop cut- and satellite-based yield measures, with the use
of the latter at times leading to more significant results
due to larger sample sizes. Overall, the results suggest a
substantial role for satellite-based yield estimation in
measuring and understanding agricultural productivity in the
developing world.
Citation
“David B. Lobell; George Azzari; Burke,Marshall Benajah; Gourlay,Sydney; Zhenong Jin; Kilic,Talip; Murray,Siobhan. 2022. Eyes in the Sky, Boots on the
Ground: Assessing Satellite, and Ground-Based Approaches to
Crop Yield Measurement and Analysis. © Washington, DC: World Bank. http://hdl.handle.net/10986/37749 License: CC BY 3.0 IGO.”