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Japetos new 6 in 1 Soil Fertility Tester is out now!
Date Posted: 06 July 2026Japeto has just launched its new 6 in 1 Soil Tester & Monitor which is great news...
But...how do they work and what does each measurement mean? We take a look below in this handy guide.
Smart Soil Tester: Quick Start Guide
1. Soil pH (Acidity vs. Alkalinity)
Your soil's pH level dictates how efficiently plants absorb vital nutrients.
- Ideal (6.0 – 7.0): The optimal "sweet spot" for maximum nitrogen and phosphorus uptake.
- Low (< 5.5): Highly acidic soil, which frequently triggers calcium and magnesium deficiencies.
- High (> 7.5): Alkaline soil, which locks away iron and zinc, leading to yellowing leaves.
2. Soil Moisture
This tracking function monitors hydration levels directly at the root zone.
- Dry (< 25%): The ground is parched. Hydrate the soil gradually to revive the root system.
- Ideal (30% – 50%): Perfectly balanced moisture. Soil should feel like a wrung-out sponge.
- Wet (> 60%): Oversaturated ground. Stop watering immediately to prevent root rot and allow oxygen back in.
3. Soil Fertility (Nutrients)
This mode measures Electrical Conductivity (EC) to calculate the volume of dissolved mineral food.
- Low: Missing essential NPK (Nitrogen, Phosphorus, Potassium). Your plants require immediate feeding.
- Medium / Ideal: Perfectly balanced nutrition for steady, predictable growth.
- High / Excessive: Over-fertilisation warning. This can cause severe root damage and "salt burn."
4. Sunlight Intensity
Calculated via the top-facing light sensor rather than the subterranean probe.
- Low: Deep shade. Plants may become weak, structural "leggy," or fail to photosynthesise.
- High: Ideal conditions for sun-loving varieties. Delicate plants may need midday shelter.
5. Soil Temperature
- Purpose: Measures the exact thermal levels around the root network.
- Impact: Ambient cold below 10°C halts germination. Ground heat over 30°C causes thermal shock.
6. Ambient Humidity
- Purpose: Gauges moisture content in the air directly surrounding your plant's foliage.
- Impact: Crucial for indoor gardens. Dropping below 40% causes tropical leaves to turn crisp and brown.
Quick Reference: Soil pH Targets
- Blueberries & Azaleas: 4.5 – 5.5 pH (Thrive in highly acidic, "sour" soil)
- Most Garden Vegetables: 6.0 – 7.0 pH (Prefer a balanced, nearly neutral environment)
- Lawn Turf: 5.5 – 6.0 pH (Best maintained in slightly acidic conditions)
Understanding Soil Fertility Ratings
Soil fertility is displayed in µS/cm (microsiemens per centimetre). This metrics checks Electrical Conductivity (EC)—the ease with which an electric current travels through your soil.
Because primary plant nutrients like Nitrogen and Potassium are actually dissolved salt ions, they conduct electricity. Higher µS/cm readings indicate a richer volume of available plant food.
Reference Ranges
- 0 – 200 µS/cm (Very Low): Starved soil containing virtually zero accessible nutrients.
- 200 – 800 µS/cm (Seedling Safe): Gentle range ideal for cuttings and delicate sprouts vulnerable to fertiliser burn.
- 800 – 2,000 µS/cm (Standard Garden): The benchmark target for most established flora.
- Over 2,500 µS/cm (High Risk): Danger of acute "salt stress" which can scorch tips or kill sensitive species.
Crop Requirements by µS/cm Rating
| Plant Type | Target Range (µS/cm) | Management Notes |
|---|---|---|
| Lettuce | 800 – 1,200 | Light feeder. Excess nutrition turns the crop bitter. |
| Strawberries | 1,000 – 1,400 | Highly sensitive. Elevated salt spikes will stunt fruit growth. |
| Basil & Mint | 1,000 – 1,600 | Standard herbs thriving on steady, moderate nutrition. |
| Roses | 1,500 – 2,500 | Heavy feeders. Require rich ground conditions to generate full blooms. |
| Cucumbers | 1,700 – 2,500 | Demands dense nutrients to support rapid vine development. |