Soil Properties

This page explains every soil property in the report: what it is, what unit it’s reported in, and how the Very Low to Very High classification works. It also covers regional calibration: why the same number can mean different things in Bulgaria vs Hungary vs the European default.

All values represent topsoil: the upper layer of soil where root activity, microbial life, and most agronomic decisions live.

Quick reference: what’s measured

Total Nitrogen (N)

Nitrogen drives almost all crop growth. The report shows total nitrogen, displayed as a percentage in lab mode (or 0:100 in index mode).

Very Low: < 0.10% : nitrogen-deficient, expect poor growth without input. Low: 0.10:0.13% : sub-optimal, will likely need supplementation. Good: 0.13:0.20% : healthy range for most arable crops. High: 0.20:0.33% : abundant, watch for excess application. Very High: > 0.33% : possibly over-fertilised, risk of runoff and lodging.

Phosphorus (P)

The plant-available form of phosphorus, critical for root development and energy transfer in plants. Phosphorus thresholds vary by region because soil chemistry and the lab methods used to validate them differ:

European default (mg/kg) Very Low < 8 : Low 8:15 : Good 15:25 : High 25:40 : Very High > 40

Bulgaria (mg/kg) Very Low < 40 : Low 40:80 : Good 80:150 : High 150:220 : Very High > 220

Hungary (mg/kg) Very Low < 50 : Low 50:150 : Good 150:250 : High 250:400 : Very High > 400

The system applies the right scale automatically based on where the field is located. In the report header, you can switch between mg/kg and ppm: numerically they’re equivalent.

Potassium (K)

The plant-available form of potassium, important for water regulation, disease resistance, and grain quality. Like phosphorus, potassium has regional calibration:

European default (mg/kg) Very Low < 85 : Low 85:170 : Good 170:220 : High 220:500 : Very High > 500

Hungary (mg/kg) Very Low < 50 : Low 50:150 : Good 150:250 : High 250:400 : Very High > 400

pH

Soil acidity, on the standard 0:14 scale. Most crops grow best in mildly acidic to neutral soils.

Very Low: < 5.5 : strongly acidic, many nutrients lock up. Low: 5.5:6.0 : acidic, possible aluminium toxicity for sensitive crops. Good: 6.0:7.5 : ideal for most arable crops. High: 7.5:8.5 : alkaline, micronutrients (iron, zinc) become less available. Very High: > 8.5 : strongly alkaline, often associated with sodicity.

Soil Organic Matter (SOM)

The organic component of the soil: decomposed plant material, microbial biomass, humus. It drives water retention, structure, and long-term fertility.

SOM thresholds depend on the soil’s clay content because heavier clay soils naturally hold more organic matter than sandy soils. The system selects the right threshold automatically:

Sandy soils (Clay < 15%) Very Low < 0.8% : Low 0.8:1.5% : Good 1.5:2.5% : High 2.5:4.0% : Very High > 4.0%

Loamy soils (Clay 15:35%) Very Low < 1.2% : Low 1.2:2.2% : Good 2.2:4.0% : High 4.0:6.0% : Very High > 6.0%

Clay soils (Clay > 35%) Very Low < 2.0% : Low 2.0:3.5% : Good 3.5:6.0% : High 6.0:10.0% : Very High > 10.0%

Cation Exchange Capacity (CEC)

A measure of how much nutrient charge the soil can hold and exchange with plant roots. Higher CEC means the soil retains nutrients better instead of leaching them.

CEC is shown in the data table but not as a heatmap layer. It’s most useful as context for the other values: a low-CEC sandy soil will need different management than a high-CEC clay soil even at similar nutrient levels.

Soil texture: Sand, Silt, Clay

The three texture components add up to 100% and together define the USDA texture class of the soil (Sandy Loam, Clay Loam, Silty Clay, etc.). The Overview tab shows you the dominant class with a pie chart.

Texture is structural, not something you can change with management, but it sets the context for everything else: water retention, workability, nutrient holding capacity, and the right SOM threshold band.

Organic Carbon (OC)

The raw organic carbon content in g/kg. SOM is derived from OC (multiplied by 1.724, the standard conversion factor). OC appears in CSV and shapefile exports for users who prefer to work with the raw value.

Index mode vs Lab mode

Every property is shown in two modes, switchable from the header:

• Index mode (0:100): a unitless score that compresses everything to a common scale. Below 30 is treated as Very Low, 30:80 is Good, above 80 is Very High. Useful for quick visual comparison and for non-specialist audiences.
• Lab mode: the actual chemical readings, with proper units (% for N and SOM, mg/kg or ppm for P and K, 0:14 for pH).

Both modes use the same underlying data: the index is just a normalisation of the lab values against the regional thresholds.

Why classification matters

A raw nutrient number in isolation isn’t always useful. The Very Low to Very High classification translates the value into a decision-relevant signal: is this field nutrient-deficient, on track, or over-supplied? The colour bands on the heatmaps and distribution charts make spatial variability obvious at a glance.

When sharing the report with someone non-technical (a buyer, a partner, a manager), the index view plus the labels usually communicates more clearly than raw chemistry.

Next steps

• The report: where each value is shown in the interface.
• AI Insights: a written interpretation that uses all of these properties together.
• Methodology: how the values are derived from satellite data and what we calibrate against.