Soil Health Scorecard & One Score, One Thing to Fix

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.