Data-driven, spatially explicit, economics-aware evidence for managing acid soils in smallholder farming systems of sub-Saharan Africa.
GAIA is a CIMMYT-led research project (2021–2025) funded by the Bill & Melinda Gates Foundation. It generated the data, analytical workflows, and decision-support tools that reframed soil-acidity management in East Africa — showing that soil pH alone is not enough: the kind of acidity, the crop, the geography, and the economics of lime all determine where liming actually pays. The project's analytical agenda now continues under the CGIAR Sustainable Farming Program (SFP).
This organization is the single home for GAIA's reusable workflows, tools, and analytical assets. 🌐 Public products: acidsoils.africa · 📚 Knowledge hub (coming soon).
| If you are a… | Go to |
|---|---|
| Policymaker / investor | The Acid Soils Dashboard and its Profitability Explorer → and the Ethiopia scenario notebook (app-ethiopia-notebook) to test "what if" liming scenarios. |
| Researcher / analyst | The framework-* ex-ante engine, data-* evidence bases, trials-* analyses, and protocols-* for instruments & field protocols. |
| Replicator (new country / new input) | templates-exante + the regional handbook — step-by-step guidance to stand up the GAIA analysis in a new geography. |
| Repo | What it does |
|---|---|
| framework-exante-lime | Reproducible lime yield→economics framework (response curves, NPV, sensitivity, Monte Carlo) + Shiny app. Templated for reuse across inputs. |
| framework-report-generator | Auto-generates per-country ~25-slide technical briefs from framework outputs. |
| framework-risk-uncertainty | Site-specific profitability under joint climate + price uncertainty (spatial copula Monte Carlo). |
| framework-erw | Enhanced Rock Weathering economic viability across 47 countries × 23 crops. |
| Repo | What it does |
|---|---|
| data-source-pipeline | Sources & standardizes open data (CHIRPS, NASA POWER, Google Earth Engine, iSDA). |
| data-era | R package wrapping the ERA evidence base (>100k observations from >2k African studies). |
| Repo | What it does |
|---|---|
| trials-kakamega-agronomy | Kenya Lime×P and Lime×N×P factorial trial analysis. |
| prices-tanzania | Crop and lime price prediction workflows for Tanzania. |
| methods-multiloc-design | Simulation framework for designing predictive multi-location experiments. |
| Repo | What it does |
|---|---|
| app-dashboard | Code behind acidsoils.africa: spatial explorer + Profitability Explorer + shotgun-trial analyzer. |
| app-lime-profitability | Multi-country lime profitability explorer (Shiny). |
| app-ethiopia-notebook | Layered Ethiopia policy tool — point-and-click web UI + runnable analyst notebook. |
| tool-climate-prioritization | Interactive tool mapping climate hazard × agricultural exposure. |
| tool-dc-monitor | Data-collection monitoring dashboard. |
| Repo | What it does |
|---|---|
| protocols-trials | Shotgun + Component Trial protocols, field books, ODK/Kobo survey instruments, sampling designs. |
| docs-knowledge-hub | Source for the public knowledge hub (data, tools, protocols, publications, policy by country). |
| templates-exante | "Use this template" starter for running the GAIA analysis in a new geography. |
| .github | This profile, shared issue/PR templates, and reusable CI workflows. |
GAIA datasets are openly deposited on CIMMYT's Dataverse under FAIR principles (soil properties, on-farm agronomic trials, socioeconomic surveys for Ethiopia, Rwanda, Tanzania, Zambia, Kenya). Repos point to these DOIs rather than vendoring raw data — see each repo's data/README.md.
Every repo is labelled with the GAIA outcome it serves — filter the org by topic:
po-1 depth & utility of evidence · po-2 support to govts & private sector · po-3 access to & use of data · plus country-* and function tags (framework, data, app, protocols).
Code is released under a permissive OSI license (see each repo's LICENSE); data & docs under CC-BY-4.0. Every repo carries a CITATION.cff — use the "Cite this repository" button. Tagged releases are archived with DOIs via Zenodo.
CIMMYT · Bill & Melinda Gates Foundation · EIAR (Ethiopia) · RAB (Rwanda) · TARI (Tanzania) · ZARI (Zambia) · KALRO & University of Nairobi (Kenya) · UC Davis · CGIAR Sustainable Farming Program.