USDA · SSURGO · SDA REST API · SQL Training

Learn to Query
America's Soil Database

From your first SELECT to production-grade soil carbon calculations — a complete guide to SSURGO and the Soil Data Access REST API. Live examples run against real data.

Start Beginner Track → Try the Query Lab Explore Data Model
Curriculum Overview

What You'll Learn

Three SQL tracks, two API tracks, one live query sandbox — everything built around real SSURGO data.

🔍
The Foundation

The SSURGO Join Chain

Every SSURGO query follows this four-table spine. Learn it once, use it in every query you write.

Survey Area
legend
lkey PK
areasymbol
areaname
saverest
lkey
Map Unit
mapunit
mukey PK
lkey FK
musym
muname
muacres
mukey
Component
component
cokey PK
mukey FK
compname
comppct_r
majcompflag
cokey
Horizon
chorizon
chkey PK
cokey FK
hzname
om_r
awc_r
Try It — Full Join Chain (Live SDA Query)
Your Path

Five Steps from Zero to Expert

1

Beginner SQL

SELECT · FROM · WHERE · ORDER BY · dominant component. Get data out of SSURGO in 30 minutes.

2

Intermediate SQL

JOINs · GROUP BY · CTEs · CASE WHEN · Available Water Storage calculation.

3

Expert SQL

Soil organic carbon formula · NCCPI · interpretations · temp tables · spatial AOI queries.

4

Python API

requests · pandas DataFrames · batched queries · soilDB-style wrappers · matplotlib charts.

5

JavaScript API

fetch() · live HTML tables · MapLibre GL integration · reusable SDA client module.

Companion Resource

Soil Intelligence Platform

A separate maintained repository with 254 production SQL scripts, interactive maps, and data journalism — all built on SSURGO. Links below are live and maintained independently.

Note: These links point to the live Soil Intelligence GitHub Pages site — maintained as a separate repository. If a link doesn't resolve, the companion site URL may have changed; check github.com/jneme910/NRCS-Soil-Data-Access.