Soil moisture sensors collect information about moisture and soil temperature, helping you make better water management decisions or automate watering itself. This article covers how to install, configure, and use Baseline soil moisture sensors with the BaseStation 3200 controller. Click any section below to expand.
Installing Soil Moisture Sensors on Two-Wire
Video originally published December 2020.
This section covers the physical installation of soil moisture sensors in a two-wire system, including proper placement, depth, orientation, and wire connection.
Sensor Types and Selection
There are two different sizes of baseline soil moisture sensors available. The large sensor is roughly 18 inches long, while the short sensor is 5 inches long. They're interchangeable and perform the same function, but are selected based on installation requirements. The large sensor fits into most landscape applications, while the short sensor works well for pots and green wall applications where space is limited.
Sensor Placement Guidelines
Where you place your soil moisture sensor is critical for accurate readings. Position sensors in the top one-third of the active root zone. For turf applications, this means approximately one to three inches of cover over the sensor. The depth varies for larger plant material, but should still be in the top one-third of the root zone.
Place the soil moisture sensor in a spot that's representative of the entire area you're measuring—not in the driest location and not in the wettest location. You'll have the option of adjusting individual zones up or down during programming.
Installation Steps
1. If working with existing turf, remove the sod and set it aside. For new installations without plant material, proceed directly to excavation.
2. Excavate the installation area, removing any large stones. Air pockets are the enemy here, and good soil contact with the sensor is essential.
3. Before installing, record the serial number and location. Each sensor comes with two additional stickers that match the device. Use one extra sticker on an as-built plan and place another on a list to document the sensor location. Keeping track of the sensor now will make assignment much simpler later.
4. Double-check the depth of the hole before installing the sensor. Use a straight edge to measure down from grade to ensure proper depth in the active root zone.
5. Set the moisture sensor horizontally and on edge. If it lies flat, it will trap water and cause inaccurate readings. The goal is to measure water as it passes by the sensor, not what collects on top of it.
6. Backfill the sensor, ensuring no rocks are against the sensor and there's good soil contact. Gently tap down the soil to eliminate air pockets.
7. If installing in an existing turf area, restore the sod.
Wire Connection
For a conventional wire installation, run the wire back to a valve box. Since this project uses two-wire, you can connect anywhere along the two-wire path as long as it's in a splice box. When connecting the sensor, use the DVRY6 splice included in the kit. Remember that industry standards require all splices to be in a box, not in the trench.
Post-Installation
Once installation is complete, water in the sensor. This helps remove air pockets that can impact sensor calibration.
Protecting Sensors from Aeration Equipment
If you use turf aeration equipment on your site, take steps to avoid damaging the sensor. Core aeration tools can go deep enough to damage soil moisture sensors, so the easiest prevention is to not aerate over the sensor.
Methods to locate and mark buried sensors:
1. Make note of the wire length and distance from the splice box during installation. This can tell you that a sensor is buried a specific distance (e.g., 23 feet north) of the box.
2. Set a grading feather or plastic marker in the soil close to the sensor, then avoid aerating in that area.
3. Use two measurements from buildings or trees to indicate where the sensor is buried. Later, use the location where those two measurements cross to find the sensor and avoid aerating there.
Installing Soil Moisture Sensors on Conventional Wire
Video originally published November 2021.
This section explains how to connect a soil moisture sensor to an existing conventional wire controller without running a separate 2-wire cable back to the controller.
Physical Installation
1. Install the soil moisture sensor in the appropriate location. Position it on edge so water doesn't pool on top of it, ensuring water moves past the sensor in the active root zone.
2. Bury the sensor at the correct depth for your plant material. For turf, use 2-3 inches of cover over the sensor. Other plant materials may require deeper installation—refer to online installation documentation for specific depths.
Wiring to the Nearest Valve
3. Using the included 50-foot wire from the sensor kit, run the wire from the sensor back to the nearest valve.
4. At the valve, use the DBR-Y6 splice kit (included in the sensor kit) to make waterproof connections:
• Connect the red wire to the station wire
• Connect the black wire to the valve common (often white, but not always—you may need to identify the correct wire)
The sensor kit includes the sensor, 50 feet of wire, DBR-Y6 splice kit, and location stickers for tracking serial numbers.
Controller Connection
5. At the controller, identify which station wire runs to the valve where you connected the sensor. This station wire connects back to the power biCoder board.
6. Connect the station wire to one of the designated soil moisture sensor terminals on the power biCoder. Only terminals A1, A2, B1, or B2 will work—the controller only checks these four terminals for soil moisture sensors.
You may need to identify the correct zone by toning the wire, disconnecting it to see which zone stops working, or testing different connections to ensure proper zone identification and polarity.
Sensor Detection
7. Press the small button on the power biCoder (located in the cutout area) to update and detect the sensor.
8. Verify that the LED light behind the connected terminal (A1, A2, B1, or B2) comes on and stays on. This confirms the controller has found and can communicate with the soil moisture sensor.
Configuration
Once physical installation is complete, configure the sensor through the controller interface as you would with any soil moisture sensor. Assign it as a primary sensor or use it to start a program (if using a BaseStation 1000), then set your soil moisture parameters according to your irrigation needs.
Soil Moisture Sensors for Data Collection
Video originally published July 2021.
This section explains how to set up soil moisture sensors for data collection and monitoring in your HydroPoint system, allowing you to track moisture content and soil temperature trends before implementing automated watering decisions.
1. Log into your App Manager account with your secure username and password.
2. Open Base Manager and verify you're working on the correct controller.
3. Navigate to the Devices tab.
4. If you haven't already assigned your moisture sensor, select the Assign Sensors menu to search for and find sensors attached to your system.
5. Click Edit next to your soil moisture sensor and name the sensor to help identify its location (for example, "Moisture Sensor 2 in Zone 17 Turf").
6. Be sure to save before leaving Devices.
7. Open the program that holds the zone with the installed soil moisture sensor. If you don't already have an existing program with the sensor, create one now.
8. Open the program, then select Edit to make changes.
9. Change the zone's current Timed mode to Primary mode. With Primary enabled, you can assign a soil moisture sensor to the zone.
10. Assign the soil moisture sensor to the zone. Naming the sensor makes this process much simpler; otherwise, you'll have to rely on the serial number to make this critical assignment.
11. Move to the Strategy field and set it to Timed. Later you may want to use a Lower Limit Strategy or an Upper Limit Strategy, but for now you're only collecting data in timed mode.
12. Save your work before leaving Schedules.
Viewing Collected Data
With the soil moisture sensor assigned to a zone, you can now collect usable data.
1. Navigate to Devices, then Moisture Sensors to view the current moisture content percentage and soil temperature in degrees Fahrenheit.
2. Select Chart Moisture to bring up an interactive graph that compares moisture content and soil temperature.
3. Change the interval to view the moisture and temperature trend over different time periods, such as the last month.
Viewing Zone Run Times with Moisture Data
1. On the Schedules tab, open a program for a different view of moisture content.
2. Select Chart Moisture for the zone with the associated soil moisture sensor. Initially, you'll see just the zone run times.
3. Select the gear icon to modify the report. Verify you have the correct moisture sensor selected and change the interval to reflect a different time period.
4. When you rerun the report, the blue bars show zone run times and the green line indicates the changing moisture content.
Information from this report can reveal changing weather patterns, heating or cooling trends, and rain events. This data can also be used to determine if run times are too long or too short, as well as helping determine optimal run day intervals. For example, you may notice moisture content increasing after irrigation and then decreasing over subsequent days as weather dries out the soil, or moisture content peaking with shorter run times during cooler weather conditions.
Soil Moisture Sensors for Lower Threshold Watering
Video originally published July 2021.
This section explains how to automate watering decisions using soil moisture sensors with a lower threshold strategy. This approach allows irrigation to occur only when soil moisture drops below a predetermined level and the start time condition is met.
Before You Begin
Ensure your soil moisture sensor is installed in an area that represents the other irrigation zones. It's recommended to first use the sensor to collect data before implementing automation.
Assigning Your Moisture Sensor
1. Log in to your App Manager account with your secure username and password.
2. Open BaseManager and navigate to the Devices tab.
3. If you haven't already assigned your moisture sensor, select the Assign Sensors menu to search for and find sensors attached to your system.
4. Click Edit on the sensor you want to use.
5. Name the sensor to help identify its location (for example, "Moisture Sensor 2 in Zone 17 Turf").
6. Be sure to save before leaving the Devices section.
Setting Up Primary and Linked Zones
1. Open the program that contains the zone with the installed soil moisture sensor. If you don't already have an existing program with the sensor, create one now.
2. Open the program and select Edit to make changes.
3. Change the current time mode on the zone with the sensor to Primary Mode.
With primary enabled, you can assign a soil moisture sensor to the zone. A primary zone influences other zones that are linked to it. When a primary zone is set to run for 20 minutes, all the zones linked to it will also run for 20 minutes. The tracking ratio allows you to adjust individual linked zones up or down by percentage to account for microclimates.
4. Change the remaining zones from Timed to Linked (linking them to your primary zone number).
This links the other zones to whatever the primary zone does. Since the soil moisture sensor influences the primary zone, all zones in this program are now influenced by a single soil moisture sensor.
Configuring Lower Limit Watering Strategy
1. Move to the Strategy field and set it to Lower Limit.
A lower limit watering strategy allows watering only when the soil has dried down to the predetermined moisture content and when the start condition has been met. Lower limit watering helps conserve water and encourages deeper root growth by stretching out watering days when the plant material doesn't need additional water.
The system will water when the current moisture drops below the start below limit and the scheduled start time is met.
Determining Your Start Below Limit
The default start below limit doesn't necessarily reflect the limit that you need to use. There are several methods for setting this threshold:
Calibrate Single or Calibrate Monthly: These methods allow the controller to run irrigation until it reaches the soil saturation point while looking for water holding capacity (field capacity)—how much water your soil type can hold before gravity drains it away. Anything more just drains out the bottom or runs off and is wasted. If you can't allow saturation for a zone, the calibration method may not be for you.
Review Sensor Data: If you've collected moisture data for a month or so, reviewing the soil moisture sensor graphs can be helpful. They offer a view into the soil profile and help you determine run times and how often to water. With some interpretation or help from Baseline support staff, this data can be used to find a good lower limit.
Site Observations Combined with Experience: Walk out into your landscape and observe. Is the plant material stressed or is the turf off color? Your experience indicates these are signs that it's time to water. Once your observations say that your landscape needs water, review the current moisture for the sensor and use that number as a starting point. Since the data from Baseline soil moisture sensors is repeatable, it'll look the same next time that moisture reading comes up.
Keep in mind that all soils are different and there are variations across the same site. Monitor your property closely to see if you need to adjust the start below threshold.
2. Enter your determined value in the Start Below Limit field.
3. Save your work.
How the System Works
Once configured, the primary zone with the sensor will influence all linked zones. Some linked zones can be adjusted for microclimates using the tracking ratio. When the scheduled start time is reached, the program will start if the current moisture is still below the start below limit. If it rains before the start time and there's enough moisture to raise the level above the start below limit, the program will be skipped until the next start day and time.
Best Practices
Don't share the soil moisture sensor across different programs. It could skip watering on one program even though the other program still needs watering.
Make sure your run times are long enough so they apply half to three-quarters of an inch of water each time they run.
Use the cycle and soak feature. This allows time for the water to soak in and reach the sensor. It's especially helpful in heavy soils where runoff might happen.
Allow as many program start days as practical. A program with just one start day that skips a day has to wait another seven days before its next water opportunity. Offering multiple start opportunities can lessen the impact of a skipped water day while still conserving water.
Soil Moisture Sensors at the Controller (Legacy Firmware)
Legacy Content
This procedure is based on legacy firmware. UI labels and screens may differ from current versions. For the current procedure, see the other sections of this article.
Video originally published May 2013.
Note: This procedure applies to legacy firmware on the BaseStation 3200. UI labels and screens may differ in current firmware versions.
This section explains how to configure moisture sensor-based watering using upper and lower threshold strategies on a BaseStation 3200 controller.
Assigning Moisture Sensors to Primary Zones
1. Turn the controller dial to the Smart Watering position.
2. Navigate to the Moisture Sensor Assignments box and press Enter.
3. On the assignment screen, the left column displays unassigned moisture sensors, and the right column shows available primary zones. (Primary zones are explained in a separate video.)
4. Use the Plus key to move up or down in the left column to highlight the sensor you want to assign.
5. Use the Next or Previous key to move up and down in the right column to select the primary zone.
6. Press Enter to assign the sensor. The moisture sensor will move from the unassigned list to the primary zone assignment on the right side of the screen.
7. Press the Back button when assignments are complete.
Configuring Moisture Sensor Watering Strategy
1. Press Next to highlight Moisture Sensor Setup and press Enter.
2. Select your primary zone using the Plus or Minus keys.
3. Choose a watering option:
Lower Limit: The controller starts the program when the moisture sensor dries down below the set threshold.
Upper Limit: The controller starts the program based on your configured start days and times, but adjusts runtime and turns off the program when it reaches the moisture threshold (upper limit).
For detailed information on both strategies, refer to the "Watering with Soil Moisture Sensors" document available at baseline-systems.com.
Setting the Moisture Threshold
1. After selecting your watering strategy (e.g., Lower Limit), configure the moisture threshold.
2. Choose a calibration cycle option:
Monthly: The controller performs a calibration cycle every month and automatically sets a new lower threshold for the sensor.
One Time: The controller runs the calibration cycle once, sets the limit, and leaves it unchanged unless manually adjusted.
Never: The controller relies on you to manually set and maintain the limit.
All three options are valid depending on your site needs. For specific information about calibration cycles and when to use each option, consult the "Watering with Soil Moisture Sensors" document at baseline-systems.com.
Note: The Limit Adjustment field is an advanced setting used primarily in upper threshold watering. For guidance on using this setting at your site, contact Baseline Systems.
If you have questions, here are 3 ways to get answers:
1. Search within this HydroPoint knowledgebase
2. Visit the HydroPoint support page
3. Call 800-362-8774 or email support@hydropoint.com, hours are Mon-Fri 3:00 AM – 6:00 PM PT and Sat 9:00 AM – 2:00 PM PT.