Eyes in the Sky, Boots on the Ground: Assessing Satellite- and Ground-Based Approaches to Crop Yield Measurement and Analysis in Uganda

29 Pages Posted: 27 Mar 2018

See all articles by David B. Lobell

David B. Lobell

Lawrence Livermore National Laboratory

George Azzari

Stanford University - Department of Earth System Science and the FSE

Marshall Burke

University of California, Berkeley; Stanford University - Freeman Spogli Institute for International Studies

Sydney Gourlay

World Bank - Development Data Group

Zhenong Jin

Stanford University - Department of Earth System Science and the FSE

Talip Kilic

World Bank - Development Data Group (DECDG)

Siobhan Murray

World Bank

Date Written: March 26, 2018

Abstract

Crop yields in smallholder systems are traditionally assessed using farmer-reported information in surveys, occasionally by crop cuts for a sub-section of a farmer's plot, and rarely using full-plot harvests. Accuracy and cost vary dramatically across methods. In parallel, satellite data is improving in terms of spatial, temporal, and spectral resolution needed to discern performance on smallholder plots. This study uses data from a survey experiment in Uganda, and evaluates the accuracy of Sentinel-2 imagery-based, remotely-sensed plot-level maize yields with respect to ground-based measures relying on farmer self-reporting, sub-plot crop cutting (CC), and full-plot crop cutting (FP). Remotely-sensed yields include two versions calibrated to FP and CC yields (calibrated), and an alternative based on crop model simulations, using no ground data (uncalibrated). On the ground, self-reported yields explained less than 1 percent of FP (and CC) yield variability, and while the average difference between CC and FP yields was not significant, CC yields captured one-quarter of FP yield variability. With satellite data, both calibrated and uncalibrated yields captured FP yield variability on pure stand plots similarly well, and both captured half of FP yield variability on pure stand plots above 0.10 hectare. The uncalibrated yields were consistently 1 ton per hectare higher than FP or CC yields, and the satellite-based yields were less well correlated with the ground-based measures on intercropped plots compared with pure stand ones. Importantly, regressions using CC, FP and remotely-sensed yields as dependent variables all produced very similar coefficients for yield response to production factors.

Keywords: Food Security, Crops and Crop Management Systems, Climate Change and Agriculture, Inequality, Nutrition, Educational Sciences

Suggested Citation

Lobell, David B. and Azzari, George and Burke, Marshall and Gourlay, Sydney and Jin, Zhenong and Kilic, Talip and Murray, Siobhan, Eyes in the Sky, Boots on the Ground: Assessing Satellite- and Ground-Based Approaches to Crop Yield Measurement and Analysis in Uganda (March 26, 2018). World Bank Policy Research Working Paper No. 8374. Available at SSRN: https://ssrn.com/abstract=3150087

David B. Lobell (Contact Author)

Lawrence Livermore National Laboratory ( email )

P.O. Box 808
Livermore, CA 94551
United States

George Azzari

Stanford University - Department of Earth System Science and the FSE ( email )

Stanford, CA 94305
United States

Marshall Burke

University of California, Berkeley ( email )

310 Barrows Hall
Berkeley, CA 94720
United States

Stanford University - Freeman Spogli Institute for International Studies ( email )

Stanford, CA 94305
United States

Sydney Gourlay

World Bank - Development Data Group ( email )

1818 H Street, NW
Washington, DC 20433
United States

Zhenong Jin

Stanford University - Department of Earth System Science and the FSE ( email )

Stanford, CA 94305
United States

Talip Kilic

World Bank - Development Data Group (DECDG) ( email )

Via Labicana 110
Rome, Lazio 00184
Italy

Siobhan Murray

World Bank ( email )

1818 H Street, NW
Washington, DC 20433
United States

Register to save articles to
your library

Register

Paper statistics

Downloads
59
Abstract Views
267
rank
363,076
PlumX Metrics