Greenhouse operators, landscapers, horticulturists, golf course managers, farmers, cannabis growing facility personnel and other commercial growers all need to manage irrigation. Remote monitoring can help use water more efficiently by measuring the amount of water in the soil and alerting when moisture conditions fall outside the desired range. This instant notification can prevent under- or overwatering, minimize water usage, promote growth and increase crop yield and quality.
Humidity and moisture control
Moisture is present in the air, in the soil and inside the plants. Soil moisture sensors provide data that can help operators develop the best irrigation plan for each growing area. This data helps determine how often the plants need to be watered and how much water is required. It also can help growers learn which plants are using the most water and which areas of soil retain the most.
Preventing stress and overwatering
Monitoring soil moisture helps growers learn what conditions are best for optimal crop production. You can detect plant stress before the signs are visible, which can increase growth, yields and crop quality.
It can also help prevent overwatering that causes roots rot and disease. And it can prevent nutrient leaching from the root zone and unnecessary water use.
Benefits of monitoring soil moisture
- Know how much water is at the root zone
- Reduce water costs
- Reduce fertilizer costs
- Maximize crop production
- Prevent over-irrigation
- Get alerts for low and high soil moisture
How soil monitoring works
Soil moisture monitoring sensors come in many shapes and sizes. Some are placed in the canopy and others are placed in the soil near the crop roots.
Sensors like the Sensaphone soil moisture sensor determine volumetric water content (VWC). This technology provides accurate readings in almost any soil or soilless growing media. The sensors operate in a wide range of temperatures and are highly accurate when calibrated for the growing media they support.
The moisture sensors are connected wirelessly or hard-wired to a monitoring unit that functions as the brains of the system. The monitoring unit communicates constantly with the sensors and collects and stores the sensor data.
Reviewing data over a period of time helps uncover patterns in environmental conditions. Many monitoring systems automatically save this data, recording tens of thousands of data points, dates and times. The Internet of Things (IoT) technology in agriculture has come a long way. Now, growers can be more directly connected to the environment and crop conditions that they oversee.
Cloud-based data logging makes it easy to securely log in from anywhere to view, graph, print and export data trends in real time. Growers don’t have to be on-site. Analyzing data samples may uncover larger issues and prevent problems before they arise. For example, the historical data could help identify specific growing areas that are more prone to frost or extreme heat during certain times of the day, week, month and year. See sample below.
More on water sensing
As mentioned above, Sensaphone’s soil moisture sensor offerings express soil moisture content in terms of volumetric water content (VWC). This measurement is the ratio of the volume of water in a sample to the volume of soil in a sample. Typically, the VWC is determined indirectly through another soil property that is easier to measure with electronic sensors. Listed below are the three methods commonly used to determine soil VWC:
Resistive measurement: This is the simplest and least expensive method of moisture content measurement. A resistive water content sensor consists of two probes. By measuring how much current passes between the two probes soil resistance is measured and the water content can be determined. Because resistive measurement sensors must have metal probes that are in direct contact with soil, over time these probes corrode and as a result the lifetime of these sensors is limited.
Dielectric measurement: Another way to determine a soil’s moisture content is by measuring its dielectric permeability. Sensaphone’s water content sensors measure the soil’s dielectric permeability through a method known as frequency domain reflectometry (FDR). Because the probes in a dielectric VWC sensor do not have to be in contact with soil, these sensors have a much longer life than resistive measurements devices. Further, dielectric measurement allows for accurate VWC measurements at a reasonable cost and size.
Neutron probe measurement: A neutron probe measures the presence of water in soil by emitting fast moving neutrons. As these fast-moving neutrons collide with hydrogen in water molecules present in soil they slow and return back to the probe. By measuring how many slow neutrons return to the probe the water content of the soil can be determined. A strength these sensors have is that they are not affected by soil with high salinity. However they are by far the most expensive type of VWC sensor.
Other monitoring for growing facilities
In addition to monitoring for moisture, growers can use remote monitoring systems to monitor for high and low temperatures. Positioning sensors in key growing areas and setting minimum and maximum temperatures will alert you to potential issues like power outages and HVAC problems before they severely impact plants.
Monitoring for humidity can alert you to issues with transpiration, poor photosynthesis, poor nutrient absorption, and increased mold and fungal growth. Some growers place sensors on ventilation equipment like vented roofs, side vents and electrical fans so that they get an alert if these systems stop running or are being operating outside of preset parameters. Remote monitoring systems can even perform physical security functions. Adding sensors to entrance doors, windows or gates can alert you to visitors entering growing areas after hours.
Remote monitoring systems provide vital protection for growing facilities. These systems can help optimize irrigation plans and protect against environmental threats, equipment failures and power loss. They provide an easy way to check on the status of these conditions any time from anywhere.
For assistance selecting the best soil moisture monitoring system for you, contact our technical sales support team.