Regenerative Ag SHAPE Curves — SDA & WSS Metrics

1

Chapter One

The SHAPE Framework

Regenerative Ag · SHAPE Scoring Framework

Six indicators.
One score for your soil.

SHAPE is a standardized framework for measuring, scoring, and tracking regenerative agriculture's impact on your land. It translates Kellogg Soil Survey Laboratory analyses and field measurements into straightforward 1–10 scores — comparable across fields, states, and management practices.

🌱

Soil Organic Matter

The foundation of every regenerative ag assessment. Organic matter drives nutrient cycling, water-holding capacity, and biological activity. KSSL measures total organic carbon (TOC) and loss-on-ignition (LOI) at every horizon.

KSSL: org_c · loi

⚡

Active Carbon (POXC)

Permanganate oxidizable carbon is the labile organic matter fraction that feeds soil microbes today. High POXC means an actively cycling ecosystem — the first to respond (positively and negatively) to management changes.

KSSL: c_tot · moist_1500

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Biological Activity

CO₂ burst respiration — carbon dioxide released by soil microbes after rewetting dry soil. Healthy soils exhale more because they support larger, more diverse microbial populations. Measured as CO₂-C in the KSSL soil measurement protocol.

KSSL: CO₂-C lbs/acre/day

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Aggregate Stability

Soil structure that resists erosion and compaction. Wet aggregate stability (WAS) measures the percentage of aggregates that remain intact after simulated rainfall. Directly queryable through KSSL's lab_agg_stab table in SDA.

SDA: lab_agg_stab table

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Available Water Capacity

Volume of water held between field capacity (−33 kPa) and wilting point (−1500 kPa). Critical for drought resilience and irrigation scheduling. KSSL measures water retention curves for every characterized pedon.

KSSL: moist_33 · moist_1500

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Regenerative Ag Composite Score

A weighted composite 1–10 score combining all indicators against regional benchmarks. Compare across fields, management practices, and years to track your soil quality trajectory over time.

Score My Soil ↓

How SHAPE Uses KSSL + SDA

The Kellogg Soil Survey Laboratory (KSSL) at the National Soil Survey Center in Lincoln, Nebraska has analyzed soil samples from tens of thousands of pedons across all 50 states since the 1950s. These characterization data — organic carbon, water retention, aggregate stability, and more — flow directly into Soil Data Access and underpin both SSURGO and SHAPE.

Every SHAPE assessment compares field measurements against regional benchmarks derived from these KSSL analyses. The same data that powers the national soil survey also powers the regenerative ag score on your operation.

Score My Soil Now ↓

Healthy Soil Benchmarks

Organic Matter

3%+

Active Carbon

450+

CO₂ Respiration

25 lb

Agg. Stability

80%+

Avail. Water

0.18"

SHAPE Score

7+ / 10

Benchmarks are generalized national targets. SHAPE uses regionally calibrated values. Score in the SHAPE App for location-specific results.

"Healthy soil is not a destination — it is a trajectory. SHAPE gives every producer a compass, powered by the same national data platform that maps every soil type in America."

★

Live Calculator · KSSL Data

Score Your Soil Against Real Lab Data

Live KSSL · Better Than Shiny

Where does your soil
rank?

Enter your soil's organic carbon %, select its texture group, and this calculator queries actual KSSL lab-measured SOC values from the Soil Data Access database to show exactly where your soil falls in the real distribution — not a static model, but live national data.

Texture Group Not sure? See the texture guide in "How Scores Work" below, or check Web Soil Survey for your field

Your Soil Organic Carbon (%) Enter the lab-measured SOC % for your surface horizon

Reference Dataset Percentile calculated against KSSL lab-measured values

SOC Distribution — KSSL Surface Horizons

Select a texture group to auto-score — or enter your SOC % and press Enter

Data: lab_layer + lab_chemical_properties + lab_physical_properties via SDA · Surface mineral horizon only (no-duff) · SOC via 4-method cascade ·

Platform Usage Metrics

Soil Data Access & Web Soil Survey usage metrics have moved to their own page.

Annual trends, state-by-state breakdowns, seasonal patterns, and interactive metric explorer — all live data from the Soil Data Access API.

📊

View Soil Data Metrics →

soil-application-metrics.html

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Chapter Two

KSSL Lab Data

Kellogg Soil Survey Laboratory · NCSS Characterization Database · All States & Territories

Lab reports at your
fingertips.

The National Cooperative Soil Survey (NCSS) characterization database contains lab analyses from the Kellogg Soil Survey Laboratory in Lincoln, Nebraska and cooperating state universities. Each pedon includes links to primary lab reports, taxonomy, water retention, and soil profile descriptions — all queryable live via Soil Data Access.

Full Pedon Explorer

All 50 states, territories, and protectorates — with map.

Filter by series name, see pedon locations on a live map, and access lab reports, taxonomy, water retention curves, and soil profiles. Up to 500 pedons per state.

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Open KSSL Lab Data →

kssl-lab-data.html — map + table + filter

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Chapter Three

SHAPE Scoring Infrastructure

Soil Texture Groups · Soil Type Groups · SOC Estimation

How your soil score
gets calculated.

Not all soils are created equal — and SHAPE doesn't score them equally. A sandy soil and a clay-rich soil have different natural limits for organic matter. SHAPE compares your soil against others with the same texture and the same natural soil type for a fair, meaningful score. Two simple questions determine which benchmark applies: What does your soil feel like? And what kind of soil is it naturally?

Your Soil's Texture — Choose the Best Match

Sandy Soil

Light and gritty. Drains fast, warms up early. Lower organic matter targets — soil can't hold as much.

Sandy Loam

Mix of sand and finer particles. Good structure and moderate drainage — the most common US cropland soil.

Silty Soil

Smooth and floury texture. Holds water well but can crust over when dry. High erosion risk when bare.

Clay Loam

Rich in clay. Excellent at holding nutrients and water — the highest organic matter potential of any texture.

Heavy Clay

Sticky when wet, cracks when dry. 60%+ clay — strong nutrient holding but slow drainage and compaction risk.

Not sure of your soil texture? Check your field on Web Soil Survey ↗

Your Soil's Natural Type — Sets the Comparison Group

Different soils form under different climates and vegetation over thousands of years — a prairie soil naturally holds more organic matter than a desert soil. SHAPE compares your soil only against others of the same natural type, so your score is always fair.

Peat & Wetland

Organic soils, bogs, and marshes. Naturally very high organic matter — these soils are always wet or saturated.

Wet or Volcanic

Poorly-drained or volcanic soils. Formed under unique flooded or ash-rich conditions — Pacific Northwest and Alaska.

Prairie & Forest

Rich Corn Belt prairie soils and acidic forest soils. Naturally high organic matter — most productive soils in the US.

Temperate Farmland

Forest-derived and shrink-swell farmland soils. Moderate to good productivity — covers much of the eastern US.

Dry or Thin Soils

Desert, eroded, or shallow soils. Low organic matter is expected — these soils are fragile by nature.

SOC Estimation — 4-Method Cascade

Not every KSSL pedon has all measurements. SHAPE uses a waterfall of SOC estimation methods, falling through to the next when the preferred method is unavailable:

① estimated_organic_carbon -- KSSL direct
② total_carbon_ncs − (caco3_lt_2_mm × 0.12) -- subtract CaCO3
③ total_carbon_ncs -- total C, no CaCO3 data
④ 0.25 + walkley_black × 0.86 -- WB correction

SQL source: Top_Combined_Estimated_Organic_Carbon.sql ↗

SQL Reference Scripts

KSSL_SOC_Characterization.sql

Full KSSL SOC characterization query — joins lab tables and returns all SOC estimation fields for SHAPE scoring.

View in repo ↗

Point_SDA_Intersect.sql

Given a lat/long point, intersects SSURGO polygons and returns SHAPE texture groups, suborder groups, surface texture, and dominant soil suborder.

View in repo ↗

All SQL Scripts →

SHAPE scoring, KSSL SOC, SDA intersects