Soil Health Scorecard & One Score, One Thing to Fix
Scores organic matter
Single tools score one thing; soil health is a system. Enter eight indicators for your texture to get a 0–100 composite score, every sub-score, and the one indicator dragging it down — with the practice that lifts it most.
Enter your soil-health tests
| Indicator | Value | Score | Rating |
|---|---|---|---|
| Organic matter | 3.2% | 62 | medium |
| Active carbon (POXC) | 600ppm | 48 | medium |
| Aggregate stability | 42% | 51 | medium |
| Soil respiration (CO₂-C) | 55mg/kg | 50 | medium |
| ACE soil protein | 6.5mg/g | 48 | medium |
| Bulk density | 1.4g/cm³ | 64 | medium |
| pH (water) | 6.2 | 73 | good |
| Water infiltration | 28mm/hr | 52 | medium |
Next: prioritise the limiting indicator — active carbon (poxc) at 48/100 is dragging the composite down the most. Feed soil biology with cover crops, living roots and reduced disturbance to raise labile carbon. Re-test in 1–3 years; soil health moves slowly but the limiting factor responds first.
Composite is a weighted average of eight indicators scored on texture-specific Cornell-CASH curves (more-is-better, optimum, or less-is-better). Sources: Cornell Comprehensive Assessment of Soil Health (Moebius-Clune et al. 2016), USDA-NRCS soil-health indicators, Haney test. A planning estimate; use a certified soil-health lab for management-grade numbers.
Soil-health scoring — key facts
- Composite
- weighted average of 8 sub-scores
- Good
- ≈ 70–100 (functioning well)
- Medium
- ≈ 45–70 (has constraints)
- Poor
- < 45 (degraded, act now)
- Master indicator
- soil organic matter
- Earliest mover
- active carbon (POXC)
- Texture-specific
- bulk density, infiltration
- Privacy
- Runs in your browser; nothing uploaded
Soil-health indicators & what they measure
Indicator set and scoring approach from the Cornell Comprehensive Assessment of Soil Health (CASH) and USDA-NRCS / Haney soil-health tests. Each is weighted in the composite; bands shift by texture for the physical indicators.
| Indicator | Unit | Scoring | Weight | What it tells you |
|---|---|---|---|---|
| Organic matter | % | more is better | 1.4 | The master indicator — drives nutrients, water-holding, structure and biology. |
| Active carbon (POXC) | ppm | more is better | 1.2 | Permanganate-oxidizable carbon — the food source for soil microbes; an early-warning indicator. |
| Aggregate stability | % | more is better | 1.2 | How well soil clumps resist breaking apart in water — governs crusting, infiltration and erosion. |
| Soil respiration (CO₂-C) | mg/kg | more is better | 1.0 | 4-day CO₂ burst (Haney/CASH) — a direct measure of biological activity. |
| ACE soil protein | mg/g | more is better | 1.0 | Autoclaved-citrate-extractable protein — the pool of organically held nitrogen. |
| Bulk density | g/cm³ | less is better | 1.3 | Mass per volume — high values are root-restricting (texture-dependent thresholds). |
| pH (water) | — | optimum (peak) | 1.1 | Drives nutrient availability; most crops peak near 6.3–6.8. |
| Water infiltration | mm/hr | more is better | 1.1 | How fast water enters soil — controls runoff, erosion and how much rain is captured. |
Texture bands (good values): Coarse bulk density ≤ 1.5 g/cm³ · Medium bulk density ≤ 1.35 g/cm³ · Fine bulk density ≤ 1.25 g/cm³.
Soil health is a system, not a single number
You can measure organic matter, bulk density or infiltration on their own, but none of them alone tells you whether your soil is functioning. A high organic matter on a compacted, acidic soil still grows a poor crop. Soil health is the combined capacity of the soil to cycle nutrients, store and release water, support roots and resist erosion — and it is limited by its weakest link. That is why a scorecard rolls several biological, chemical and physical indicators into one weighted score and then points to the constraint.
This tool scores eight indicators on texture-aware Cornell-CASH-style curves, fills a radar as each one scores, feeds a single 0–100 composite gauge, and flags the limiting indicator in red with the management practice that lifts it most. Use it to benchmark fields, track whether reduced tillage and cover crops are working, and put your effort where it moves the needle. Pair it with the Soil Organic Matter Buildup, Cover Crop Nitrogen Release and Soil Bulk Density calculators.
How to use it — 5 steps
- 1
Pick the texture
Choose coarse, medium or fine — this sets the texture-specific scoring bands for bulk density and infiltration.
- 2
Enter the indicators
Add your lab or field values for all eight indicators; defaults show a typical medium soil.
- 3
Read the composite
The gauge gives a 0–100 weighted score and a good / medium / poor rating.
- 4
Find the limiting factor
The radar's red spoke is the weakest indicator — the one constraining overall health.
- 5
Act and re-test
Apply the named practice for the limiting indicator, then re-score the same field in 1–3 years.
Frequently Asked Questions
How is the soil-health score calculated?+
Each indicator (organic matter, active carbon, aggregate stability, respiration, ACE protein, bulk density, pH, infiltration) is scored 0–100 against texture-specific good/medium/poor bands using a Cornell-CASH-style scoring curve. The composite is the weighted average of those sub-scores. The result is one 0–100 number plus the individual scores so you can see exactly what is strong and what is weak.
What is a good soil-health score?+
On this 0–100 scale, roughly 70+ is good, 45–70 is medium with constraints, and below 45 is degraded and needs intervention. Cornell CASH uses a similar interpretation: the absolute number matters less than which indicators are constraining, because that tells you where to act.
Why does soil texture change the score?+
Several indicators have texture-dependent thresholds. A bulk density of 1.55 g/cm³ is root-restricting on a clay but only moderate on a sand, and good infiltration is far higher on sand than on clay. The calculator switches the scoring bands by texture so the same measurement is judged fairly for your soil type.
What is the limiting indicator?+
It is the lowest-scoring indicator — the one dragging your composite down the most. Soil function is constrained by its weakest link, so fixing the limiting indicator usually lifts overall health more than improving an already-strong one. The tool flags it in red on the radar and names the practice that targets it.
What is active carbon (POXC) and why measure it?+
Permanganate-oxidizable carbon is the small, labile fraction of soil organic matter that microbes feed on. It responds to management years before total organic matter shifts, so it is an early-warning indicator: rising active carbon means your soil biology is improving even if the organic-matter percent has not moved yet.
How do I improve a low aggregate-stability score?+
Aggregate stability — how well soil clumps resist breaking apart in water — is built by living roots, fungal hyphae and organic glues. Minimize tillage, keep continuous living cover and add organic matter. Better aggregates mean less crusting, faster infiltration and far less erosion.
Is this the same as a soil fertility test?+
No. A fertility test reports nutrient levels (N, P, K) for this season's fertilizer. A soil-health scorecard measures the soil's biological and physical condition — its capacity to cycle nutrients, hold water and resist erosion over the long term. They are complementary: fertility for this crop, health for the system.
How often should I re-score my soil?+
Soil health changes slowly, so every 1–3 years is usually enough to track a trend. Re-test the same fields at the same time of year for comparability. Biological indicators like active carbon and respiration move first, so they show whether a new practice is working before organic matter does.
What is bulk density and what is a bad value?+
Bulk density is dry soil mass per unit volume; high values mean compaction that restricts roots and water. Root-restricting thresholds are texture-specific — roughly above 1.45 g/cm³ on clay, 1.55 on loam and 1.75 on sand. The tool scores it against your texture's limit and suggests compaction relief.
Does pH count as a soil-health indicator?+
Yes — pH drives nutrient availability and biological activity, and it is scored as an 'optimum' curve peaking near 6.5. Both low (acidic) and high (alkaline) pH lower the score. The practice is to lime up a low pH or use sulphur/acidifiers to bring a high pH back toward the optimum.
Can I score soil health without lab tests?+
You can run the tool with field estimates (an infiltration ring test, a slake test for aggregates, a probe for bulk density and a strip test for pH), and it will give a useful directional score. For management-grade numbers, send a sample to a soil-health lab that reports the CASH or Haney indicators.
Which practice lifts soil health the most?+
It depends on your limiting indicator, which is why the tool names it. In general, the practices that lift multiple indicators at once are reducing tillage, keeping the soil covered with residue and cover crops, and adding organic matter — they build organic matter, biology and structure together.