How to use USDA Web Soil Survey (and an easier way to read your soil)

What Web Soil Survey is

Web Soil Survey is the public tool the USDA Natural Resources Conservation Service (NRCS) runs to deliver the national soil survey to anyone, free. Behind it sits SSURGO, the Soil Survey Geographic Database, the most detailed soil map the federal government publishes. When you draw an area on Web Soil Survey, it looks up the soil map units under that area and lets you generate reports on their properties. It is the authoritative source, and it is genuinely useful once you know the four steps.

One expectation to set first: a soil survey describes the ground you have, using data mapped by soil scientists over decades. It is not a lab test of your field and not a yield guarantee. It tells you the kind of soil, how well it drains, how erodible it is, and how productive its class makes it, which is exactly what you need before a lease, a purchase, or a conservation decision.

How to pull a soil map, step by step

The tool follows the same four moves every time.

1. Set your Area of Interest (AOI). Open Web Soil Survey and use the Area of Interest tab. Navigate to your land by address, county, or latitude and longitude, then draw a rectangle or polygon over the parcel. Everything the tool reports is clipped to this shape, so draw it to match your ground.
2. Open the Soil Map tab. This overlays the soil map units on your AOI and lists each one by name with its acreage and percent of the area. This is the answer to "what soil types are on my land."
3. Open the Soil Data Explorer. This is where the properties live. Under its sub-tabs you can pull land capability class, drainage class, available water capacity, organic matter, hydric rating, and dozens of other ratings and interpretations for each map unit.
4. Generate the Soil Report or shopping cart. Web Soil Survey builds a custom PDF of the reports you selected for your AOI, which you can download and keep. That PDF is the document to bring to a lender, an appraiser, or a lease negotiation.

That is the whole workflow. The friction most people hit is the interface, not the data: the AOI tools are fussy, the reports are buried under nested tabs, and the output is dense. The next section decodes the fields that actually matter so the report reads in plain English.

How to read what you get

A soil report has a lot of fields. For a land decision, a handful carry most of the signal. These are the same four SSURGO attributes AgriTerra reads to compute a parcel's productivity index, and the table below shows what each one is and how much weight it carries.

The four SSURGO soil fields that drive productivity

What to read	SSURGO attribute	Weight in the AgriTerra index
Land capability class	Non-irrigated capability class (I through VIII)	40%
Drainage class	Natural drainage class	25%
Organic matter	Organic matter (percent)	20%
Available water capacity	Available water capacity (inches of water per inch of soil)	15%

These four fields are read straight from USDA SSURGO for a parcel; the weights are how the AgriTerra productivity index combines them into a single 0 to 100 score. Web Soil Survey reports each of these fields under its Soil Data Explorer tab. The index itself is modeled, not a USDA-published rating.

• Land capability class is the headline. Classes run I (few limitations) to VIII (unsuited to cultivation), often with a letter for the main limitation: e for erosion, w for wetness, s for a soil limitation, c for climate. Class I and II ground is your best cropland; V and up rarely justifies row crops.
• Drainage class tells you how wet the soil sits, from very poorly drained to well or excessively drained. It moves yield, workability, and whether the ground is a candidate for tile or a wetland concern. See our guide to hydric soils for the wettest end of this scale.
• Organic matter is a proxy for natural fertility and structure. Higher percentages generally mean more productive, more resilient soil.
• Available water capacity is how much plant-available water the soil holds, which matters most in a dry year, when high-capacity soils carry a crop and thin ones do not.

One more field worth pulling in Web Soil Survey is the hydric rating, which flags soils that formed under saturated conditions. A hydric flag does not by itself mean a regulated wetland, but it is a signal worth understanding before you drain or convert ground. We cover it in the hydric soils guide and the regulatory side in wetlands on your land.

The easier way: the same federal data, read for you

Web Soil Survey is the official source, and there is nothing wrong with using it directly. But if you want the answer without the interface, AgriTerra reads the same SSURGO database for a parcel and turns those fields into one plain-language read: the soil map units, the capability class, drainage, and a single 0 to 100 productivity index, free, in under a minute. You get the government data, decoded, with the source and date on every figure. It is the government tool, explained, plus a shortcut to the same numbers.

For the exact formula behind that score, see the soil productivity index guide, which publishes the weights above and the reasoning. For how every figure on this site is sourced and labeled, see how we get our numbers.