Collecting the Dirt on Soils : Advancements in Plot-Level Soil Testing and Implications for Agricultural Statistics
Much of the current analysis on agricultural productivity is hampered by the lack of consistent, high quality data on soil health and how it is changing under past and current management. Historically, plot-level statistics derived from household s...
| Main Authors: | , , , |
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| Format: | Working Paper |
| Language: | English en_US |
| Published: |
World Bank, Washington, DC
2017
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| Subjects: | |
| Online Access: | http://documents.worldbank.org/curated/en/748621494523429244/Collecting-the-dirt-on-soils-advancements-in-plot-level-soil-testing-and-implications-for-agricultural-statistics http://hdl.handle.net/10986/26736 |
| Summary: | Much of the current analysis on
agricultural productivity is hampered by the lack of
consistent, high quality data on soil health and how it is
changing under past and current management. Historically,
plot-level statistics derived from household surveys have
relied on subjective farmer assessments of soil quality or,
more recently, publicly available geospatial data. The
Living Standards Measurement Study of the World Bank
implemented a methodological study in Ethiopia, which
resulted in an unprecedented data set encompassing a series
of subjective indicators of soil quality as well as spectral
soil analysis results on plot-specific soil samples for
1,677 households. The goals of the study, which was
completed in partnership with the World Agroforestry Centre
and the Central Statistical Agency of Ethiopia, were
twofold: (1) evaluate the feasibility of integrating a soil
survey into household socioeconomic data collection
operations, and (2) evaluate local knowledge of farmers in
assessing their soil quality. Although a costlier method
than subjective assessment, the integration of spectral soil
analysis in household surveys has potential for scale-up. In
this study, the first large scale study of its kind,
enumerators spent approximately 40 minutes per plot
collecting soil samples, not a particularly prohibitive
figure given the proper timeline and budget. The correlation
between subjective indicators of soil quality and key soil
properties, such as organic carbon, is weak at best.
Evidence suggests that farmers are better able to
distinguish between soil qualities in areas with greater
variation in soil properties. Descriptive analysis shows
that geospatial data, while positively correlated with
laboratory results and offering significant improvements
over subject assessment, fail to capture the level of
variation observed on the ground. The results of this study
give promise that soil spectroscopy could be introduced into
household panel surveys in smallholder agricultural
contexts, such as Ethiopia, as a rapid and cost-effective
soil analysis technique with valuable outcomes. Reductions
in uncertainties in assessing soil quality and, hence,
improvements in smallholder agricultural statistics, enable
better decision-making. |
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