Soil

15.12.2025 10:29:24

The goal is to create an IoT device for monitoring the movement of nutrients in the soil profile. Sensors for the analysis of soil properties are placed vertically in the soil profile every 100 mm. The first sensor is 70 mm deep, the second 170 mm, the third 270 mm and the fourth 370 mm deep. The device will make it possible to analyze the rate of seepage of water and nutrients during rain and to analyze the leaching of nutrients into the lower soil profile, where nutrients are no longer available to plants.

The measurement system is built on the basis of a five-electrode sensor of soil properties, which is connected to the ESP processor via the RS485 bus. The measuring system is powered by a photovoltaic panel and the accumulator is charged for device operation. Data is sent via WiFi to the database. The sensors measure temperature, humidity, content of nitrogen, phosphorus and potassium components, soil conductivity, pH, salinity, as a supplement for IoT devices it also sends battery voltage, PV panel voltage, battery capacity and WiFi signal.

Battery voltage 4.16 V
Panel voltage 3.98 V
Battery capacity 96.00 %
Battery temperature -2.59 °C
Photoresistor 3754.00 Ω
RSSI -55.00 dBm
Soil

70 mm

Temperature 3.88 °C
Moisture 33.02 %
Nko 15.00 mg/kg
Pko 81.60 mg/kg
Kko 74.00 mg/kg
Vodivost 258.60 mS/m
pH 5.20
Salinity 141.60 mS/m
TDS 129.00

170 mm

Temperature 4.74 °C
Moisture 27.70 %
Nko 12.00 mg/kg
Pko 74.60 mg/kg
Kko 67.00 mg/kg
Vodivost 244.60 mS/m
pH 7.50
Salinity 134.00 mS/m
TDS 122.00

270 mm

Temperature 5.46 °C
Moisture 27.74 %
Nko 18.00 mg/kg
Pko 87.80 mg/kg
Kko 80.80 mg/kg
Vodivost 272.20 mS/m
pH 9.00
Salinity 149.40 mS/m
TDS 135.80

370 mm

Temperature 6.20 °C
Moisture 28.10 %
Nko 16.00 mg/kg
Pko 84.00 mg/kg
Kko 77.00 mg/kg
Vodivost 264.00 mS/m
pH 8.60
Salinity 145.00 mS/m
TDS 132.00