Solar LoRaWAN multi-depth soil moisture and EC monitoring system

Solar LoRaWAN multi-depth soil moisture and EC monitoring system

This profile defines a sourcing requirement for multi-depth soil moisture and EC monitoring system. Suitable suppliers, origin, availability, and commercial terms are confirmed for the buyer’s project. The sourcing brief is structured around capacity, application, operating environment, required standards, destination, and delivery scope; the exact configuration requires supplier confirmation.

For farms, orchards, vineyards, and irrigation teams comparing wireless soil moisture sensors in Türkiye, successful field deployment depends on whether measurements represent the active root zone, whether the sensor response is understood in the local soil, whether the LoRaWAN network remains available across the production block, and whether the data can be converted into a repeatable irrigation decision.

The solar-powered root-zone monitoring system uses three- or four-depth probe configurations, LoRaWAN communication, a 5000 mAh rechargeable battery, integrated solar charging, IP68-rated field hardware, and mobile or web data workflows. The four-depth configuration can also include electrical-conductivity measurement. Probe depth, sensing principle, soil calibration, gateway coverage, reporting interval, alarm rules, and API scope are selected for the crop, rooting profile, irrigation method, and management zones.

The product should be evaluated as a root-zone monitoring and irrigation decision-support layer. Sensor readings do not automatically prove how much water a field needs, and a point sensor does not automatically represent an entire irrigation block. Probe placement, soil texture, salinity, root depth, crop stage, irrigation method, threshold design, and maintenance all influence whether the data becomes useful.

Technical configurations and specifications

The wireless node uses LoRa modulation and LoRaWAN in the EU-868 band with a multi-channel gateway, internal or external antennas, encrypted onboarding, and up to four probe connections per field unit. Nominal point-to-point range can reach 5 km under suitable conditions, while the field enclosure is designed for approximately -40°C to +85°C operation. Final radio settings and coverage follow the site survey and acceptance test.

Each project uses a revision-controlled technical schedule covering probe construction, sensing principle, channel count, measurement depths, battery and solar package, enclosure, gateway, radio band, reporting interval, platform version, API scope, and warranty. The approved schedule and installation guide are attached to the order and become part of commissioning and acceptance.

Why multi-depth root-zone sensing matters

A single surface reading can show that irrigation or rainfall has wet the upper soil while deeper roots remain dry. The reverse can also occur: the surface may dry quickly while usable water remains deeper in the technical specification. Multi-depth monitoring can help an irrigation team observe wetting-front movement, root-zone depletion, deep percolation risk, and the timing between irrigation events.

Probe depths such as 30, 60, 90, and 120 cm provide a useful multi-level root-zone profile, but the correct sequence depends on crop, plant age, soil horizons, irrigation geometry, and management objective. Shallow-rooted vegetables, young and mature orchards, maize, cotton, grapevines, and greenhouse substrates require different sensing depths and representative installation positions.

USDA Agricultural Research Service work on soil-moisture sensor placement also illustrates why depth selection is site-specific. In one seven-season sandy-loam study, a 30 cm observation was able to represent root-zone soil-water deficit at that research site, but the researchers explicitly identified transferability to other locations as a subject for further work. The practical lesson for buyers is not “install every sensor at 30 cm”; it is validate whether the selected depths represent the crop and soil technical specification in the actual field.

VWC, field capacity, and irrigation thresholds

The sensing package covers a 0–100% VWC reference range. VWC is volumetric water content—the volume of water relative to a volume of soil—and becomes operationally useful when the sensor response is calibrated to local soil-water retention, active root depth, irrigation method, and management thresholds.

A practical commissioning workflow should establish or validate:

1. The sensor response after a well-documented irrigation or wetting event.
2. The field’s approximate field-capacity condition for the monitored zone.
3. The depletion pattern during normal crop water use.
4. The lower threshold or management trigger used by the irrigation team.
5. The relationship between each probe depth and the crop’s active rooting depth.
6. The response of the technical specification after irrigation: how quickly upper probes rise, whether deeper probes respond, and whether water appears to move below the intended root zone.

Wireless soil-moisture research from USDA ARS has used root-zone measurements and soil-water characteristic information to define irrigation thresholds in sandy-loam and clay-loam soils. That research used a different sensor technology and must not be presented as product validation for the multi-depth soil moisture and EC monitoring system; its relevance is the irrigation-management principle: thresholds depend on soil, crop, root depth, growth stage, and the water-retention relationship rather than on one universal moisture percentage.

Calibration and soil-texture risk

Three-probe and four-probe solar configurations can be specified with a ±2% moisture-sensitivity reference value. The project data sheet must define whether this value represents accuracy, repeatability, resolution, or full-scale error, together with the calibration medium, soil conditions, temperature range, and test method.

Electromagnetic soil-moisture measurements are affected by soil texture, bulk density, salinity, temperature, installation contact, and calibration. USDA ARS evaluations of commercial sensors show that factory calibration can perform differently in saline or clay-rich soils. The project therefore states the sensing principle and uses a soil-specific field check against an agreed gravimetric, laboratory, or calibrated-reference method before irrigation thresholds are accepted.

The optional 0–20 mS/cm electrical-conductivity channel in the four-depth configuration can add salinity or nutrient-management context when its measurement basis is explicitly defined. The project specifies bulk-soil versus pore-water EC, electrode method, temperature compensation, moisture dependence, calibration, cleaning, units, and the agronomic interpretation used for decisions.

Root-zone and drip-irrigation context. Photo by Sercan Naya on Unsplash. Image source · Unsplash License.

LoRaWAN coverage and field radio planning

The three-probe solar configuration has a 5 km LoRaWAN reference range, while the four-probe solar configuration has a 10 km reference range; open-area communication is engineered in the 5–10 km class with EU-868 operation, gateway selection, antenna placement, terrain, and link budget.

LoRaWAN uses regional radio parameters; the LoRa Alliance maintains the regional-parameter specifications that define region-specific radio settings. A device saying “EU-868” is therefore only one part of network fit. Buyers still need to confirm the gateway, network server, device onboarding method, antenna configuration, local radio design, and actual field coverage.

For an agricultural deployment, conduct a coverage survey at the intended sensor locations. Test during the season if crop canopy changes substantially. Record packet delivery or missing-data behavior at the farthest points, low areas, behind terrain, and around metal structures or greenhouse infrastructure. Ask what happens when connectivity is lost: whether measurements are buffered locally, how much history is retained, and how data is backfilled after reconnection.

Nominal 5 km and 10 km LoRaWAN design ranges are planning references, not guaranteed circles around a gateway. The radio design accounts for antenna height, terrain, canopy, greenhouse structure, soil-sensor placement, interference, duty cycle, spreading factor, and gateway diversity. Acceptance requires successful data delivery from every named installation point at the selected reporting interval.

Solar power and battery behavior

The three- and four-depth configurations combine an integrated solar panel with a 5000 mAh rechargeable battery. A 45–60 day no-sun autonomy target can be used as a reference design condition; final autonomy is calculated from reporting interval, LoRaWAN airtime, signal quality, winter irradiance, shading, temperature, battery chemistry, aging allowance, and low-voltage behavior.

Before deployment, ask for:

• Battery chemistry, nominal voltage, expected cycle life, and replacement part number.
• Solar-panel output and charging-control specification.
• Minimum recommended daily solar exposure.
• Low-battery alarm and remote battery-health visibility.
• Data interval and radio settings used for the 45–60 day no-solar statement.
• Behavior in orchards with dense canopy, greenhouse shade, winter conditions, dust, and panel contamination.
• Field replacement procedure and whether opening the enclosure affects sealing or warranty.

Power autonomy is calculated from the 5000 mAh battery, solar-panel rating, reporting interval, radio airtime, winter irradiation, shading, battery chemistry, temperature, and aging allowance. The project defines a no-solar autonomy target, replacement interval, low-voltage alarm, panel-cleaning routine, and field procedure for safe battery replacement.

Mobile, web, alerts, reports, and irrigation workflow

The platform provides web and mobile access to real-time sensor data, soil-moisture graphs, analysis and comparison tools, history, alarm thresholds, and automated-irrigation planning.

Platform functions include:

This distinction matters: monitoring, irrigation advice, scheduling, and closed-loop automatic irrigation are different technical layers. A soil-moisture sensor may provide the measurement input, but automatic control also requires compatible field-control hardware, valve or pump interfaces, decision rules, network availability, fail-safe behavior, and manual override.

Water-saving and yield performance validation

Water-saving and yield targets are established against a measured baseline for the actual farm. Results depend on the previous irrigation practice, climate, crop, soil, hydraulic uniformity, operator behavior, irrigation method, threshold strategy, and measurement method.

A serious field evaluation should record:

1. Baseline irrigation volume using a water meter or reliable flow-and-runtime calculation.
2. Irrigation date, start/stop time, zone, and applied volume.
3. Rainfall and relevant weather data.
4. Moisture trends at each monitored depth before and after irrigation.
5. Crop stage and visible stress observations.
6. Pump energy where energy savings are claimed.
7. Yield and quality measurements using the same area and method as the baseline.
8. Sensor outages, maintenance events, calibration checks, and changes to irrigation rules.

The strongest result is not “the dashboard looked drier.” It is a documented chain from sensor observation → irrigation decision → applied water → root-zone response → crop and operating outcome.

Project definition checklist

1. Choose the crop and irrigation block first. Record crop, variety, crop age, rooting pattern, soil layers, irrigation method, emitter or sprinkler layout, and management zone.
2. Map soil variability. Do not place one sensor in a convenient location and assume it represents the whole farm. Identify different soil textures, slopes, low areas, and irrigation-pressure zones.
3. Select the probe configuration by root-zone need. Compare the 30/60/90 cm and 30/60/90/120 cm profiles against the crop and wetting depth; do not buy a fourth probe only because “more data” sounds better.
4. Clarify the ±2% figure. Request the measurement principle, calibration basis, accuracy or sensitivity definition, resolution, repeatability, temperature effects, and salinity/clay limitations.
5. Clarify EC on the four-probe solar configuration. Ask exactly what EC is measured, the electrode and compensation method, and how the value should be interpreted in changing soil moisture.
6. Run a LoRaWAN coverage test. Verify the exact gateway and antenna design, EU-868 configuration, device onboarding, reporting interval, missing-data behavior, and coverage at every intended sensor location.
7. Check the solar budget. Review canopy and shade, panel orientation, winter operation, battery-health alerts, replacement, and the specified conditions behind the 45–60 day no-sun autonomy target.
8. Inspect data portability. Request CSV or JSON examples and the contracted REST API specification. Confirm timestamps, units, depth labels, device identifiers, data ownership, retention, and account termination/export procedures.
9. Separate sensing from automation. Document the valve, pump, or controller hardware and the fail-safe logic if irrigation will be automated from moisture thresholds.
10. Define the warranty scope. Record warranty duration, probe and battery coverage, water-ingress exclusions, replacement procedure, and service turnaround in the signed quotation or contract.
11. Approve the project data sheet. Attach the selected sensor, gateway, battery, solar panel, reporting interval, API, enclosure, and warranty specifications to the order.
12. Design a field acceptance test. Compare readings with a documented manual or laboratory reference method, irrigation events, rainfall, and root-zone observations before scaling the deployment.

Where this solution can fit

The strongest fit is a farm or irrigation team that wants continuous root-zone trends and is prepared to build irrigation rules around the data. Relevant use cases include orchard and vineyard irrigation, field crops such as maize or cotton, greenhouse soil monitoring, and distributed agricultural IoT networks where cabling and mains power are difficult.

For complex soil profiles, salinity conditions, large irrigation blocks, or automatic valve control, AgriTech.tr recommends defining the measurement, network, and irrigation-control architecture before comparing quotations.

For a soil-moisture, LoRaWAN, irrigation-automation, VWC/EC, or sensor-placement project in Türkiye, contact AgriTech.tr at info@agritech.tr. The sourcing brief can structure the technical requirement, network and sensor architecture, comparison fields, and site-acceptance criteria.

Image source and reuse note

The cover and in-article photographs provide irrigation and root-zone context and are used under the Unsplash License. Photographer and source credits are retained in the reference section.

Procurement and project delivery

AgriTech.tr can structure the technical requirement and compare current supplier responses for the buyer’s project. Installation, commissioning, operator training, warranty, spare-parts, and after-sales scope must be confirmed in each supplier quotation. The final scope should be documented against the approved application, capacity, site conditions, destination, and delivery schedule in the selected supplier quotation and contract.