All growers want to see their crops, gardens, and landscapes flourish. Competition among manufacturers of irrigation controllers, sensors, and flow meters is driving innovation at high speed in this digital age, to satisfy the market.
Diganta Adhikari, an expert on soil moisture sensors and controllers and director of engineering at Irrometer—a California-based manufacturing company of soil moisture measuring, controlling, and sampling instruments—says that the innovations in soil moisture sensor technology have been numerous, but advances in remote access of sensor data have been significant.
In the past, for example, Adhikari points out that one monitoring station would be located in a 100-acre field that was not a true representation of the whole field. The farmer would have to buy two or three independent systems to cover the field adequately. Now, with the development of mesh network-based telemetry for soil moisture sensors, data from multiple locations in the field can be transmitted wirelessly to the cloud or be available for downloading at one central location. This gives a better view of the spatial variability in the field, Adhikari says.
Other innovations are driving down the cost of electronics, Adhikari says. The technology has become relatively cheap, compared to five years ago, when a system cost thousands of dollars. Irrigation systems today cost a fraction of that.
Brian Vinchesi, president of Irrigation Consultants, agrees that the major developments in irrigation technology continue to be in the area of monitoring and sensing via controllers—usually wireless—to see what’s happening in the soil. Valves are standard, he says, and haven’t changed.
Vinchesi says he has seen the greatest growth in Internet-based wireless controllers that are available in the big box stores for the residential market. The controllers are small and very technical, although they don’t have much of an interfacing capability. A contractor or homeowner can rewire them to the sprinkler system already installed and hang the controller on the wall. The wireless controller, with an app on the homeowner’s iPhone, will allow him or her to monitor and change sprinkler schedules from the kitchen table, he says.
Vinchesi is also seeing another development: the addition of built-in pressure regulators on rotary sprinklers in the landscape market. Pressure regulators have been a presence for many years in the agricultural market and the movement to new applications is saving water and making them less expensive in the marketplace.
What’s Pushing Innovation?
Regulations and green building codes are propelling innovation, says Vinchesi. The State of California is now requiring meters to be installed both in the agriculture and landscaping businesses to monitor water use—a result of the State’s drought. National green building codes like Leadership in Energy and Environmental Design (LEED) certifications and several green building organizations offering alternate certifications are now in place.
Vinchesi was the Smart Water Application Technology (SWAT) chairman for the Irrigation Association when it created the committee to develop the SWAT protocol for weather-based smart controllers—a national initiative to promote landscape water-use efficiency through the application of state-of-the-art irrigation technologies. The SWAT protocol led to the US Environmental Protection Agency’s “WaterSense” label for weather-based controllers.
Vinchesi says the committee has since developed a SWAT protocol for soil-based smart controllers, but EPA is still beta testing it before it develops WaterSense labeling for these controllers. Instead, he says, EPA is developing WaterSense labeling for pressure-regulated sensors first.
Adhikari was also a member of the original group that developed the SWAT protocol. He is now working with the Precision Ag Irrigation Leadership (PAIL) project, which AgGateway has created, to develop a universal dashboard on the software level that will allow field data from various manufacturers’ controllers, sensors, and flow meters to be read on one dashboard. Currently, manufacturers of sensors and controllers develop their own dashboards that do not talk to other manufacturer’s tools.
In a collaborative effort of more than 20 manufacturers, PAIL’s purpose is to provide a common set of data standards to convert weather, soil moisture, and other relevant data from a variety of manufacturers’ hardware and software programs into an industry-wide format. That format can then be downloaded and used by an irrigation data analysis and prescription program.
Adhikari envisions manufacturers coming together to plug all data into the one-stop dashboard. “You can see all data on one dashboard or screen on your computer or smartphone, and then it will generate a prescription that could be sent to the controller if the operator chooses that prescription,” he says.
Currently, PAIL is field-testing and verifying the data exchange standard, Adhikari says. “We are working on the specification and language of the standard and PAIL will submit it to the American Society of Agricultural and Biological Engineers [ASABE] in the next two months where it will go through a review process and public comment for 60 to 90 days.”
Eventually, the proposed PAIL standard will advance through the International Organization for Standardization (ISO) process toward becoming an international standard.
Aqua Spy’s map view pinpoints all fields currently under AgSpy management.
A Green Market Application
California-based food company, Amy’s Kitchen, has a drive-through vegetarian, organic fast-food eatery called Amy’s Drive Thru in Rohnert Park, which has become a landmark in the area. It hired Symbios Ecotecture to design a roof garden to match the exterior theme of the barn-like building.
Symbios selected HydroPoint’s Weathertrak system to irrigate the roof garden. A mix of Californian and Mediterranean plants grow in engineered soil—a light-weight compound of 75% mineral-based soil and organics, much lighter than normal soil, says Kevin Falkerson, principal and owner of Symbios. The engineered soil creates stone mulch and the minerals present help the soil retain water.
There was no plan for “roof-to-table vegetables,” says Falkerson. He chose 13 to 14 drought-tolerant perennials such as salvia, seaside daisies, and bunchgrass. “The engineered soil needs a detailed smart irrigation system to deliver the water, and WeatherTrak allows this,” he says. It delivers water very precisely on top of the root zone.
A four-story water tower collects rainwater coming off the roof, which is stored to irrigate the roof garden. When the stored water runs out during summer months, the facility switches to reclaimed water, supplied by the City of Santa Rosa Water Department. Falkerson says using rainwater for the roof needed to be very efficient, especially for the plants growing on the roof.
Parameters are customized in the weather-based control management system with automated settings that turn the system off when it rains. The controller and flow sensor are located just under the eve of the roof and installed on the water line that goes to the roof.
“The controller tells us how much water is being used and will send messages if something goes wrong,” explains Falkerson. “A leak on the roof would be more dramatic than on the ground.” It can also produce a water budget report, he adds.
Symbios also maintains the system for Amy’s Drive Thru, and Falkerson says he can do 90% of any needed controller schedule modifications from his desktop.
The roof garden is now one year old. Some dead-headings and weeding of the plants may need to be done during winter months, Falkerson says. Perennials have come back and are blooming.
“We don’t have data points for water efficiency,” he says, meaning the building does not have drought restrictions. Amy’s is lucky to have access to reclaimed water. “In many other projects we don’t have reclaimed water and we have to not use up the rainwater supply. That’s why we look for smart irrigation systems,” concludes Falkerson.
Controllers Become Sophisticated
HydroPoint Data Systems, headquartered in Petaluma, CA, manufactures controllers. When an owner or operator purchases the controller, they also purchase the company’s cloud-based management services. Its all-in-one product, “WeatherTrak,” came on the market in 2004 and has been regularly upgraded, including the announcement of a new mobile app this year. HydroPoint became a US EPA “Water Sense Partner” in 2014.
Clients include large industrial companies, municipalities, residential communities, commercial businesses, and school districts. It does not serve the agricultural market.
Meg Mason, HydroPoint’s marketing director, says WeatherTrak downloads weather data every night into controllers for its customers’ specific irrigation schedules. The controller can calibrate how much water is needed going forward using an algorithm to calculate evapotranspiration.
Each controller, which can be remotely controlled, is assigned a specific microzone representing approximately one square kilometer with 12 to 96 stations, depending on the landscape being irrigated. The operator does not need a weather station nearby, thereby avoiding maintenance and calibration, Mason explains. The controller can also be adjusted so that the water schedule is assigned to the type of landscaping—grass, a flowerbed, or a soccer field—and whether or not the area is shaded.
Weather data is collected from over 40,000 government-regulated and privately owned weather stations across the US, according to HydroPoint. These data sets are combined with local wind, temperature, solar radiation, and humidity variables, and calculated to serve a particular zone and its soil type.
WeatherTrak has had a mobile app since 2012, and HydroPoint introduced its version 2.0 in January 2016 for advanced reporting, says Mason. It adds features for remote control, Spanish language localization, Google map integration, and central management for Apple iOS or Android devices.
When WeatherTrak was first developed, it had one-way communication, Mason explains. The weather data was downloaded but couldn’t talk back. Now the system has two-way capability. Features include water budget management and a drought manager. In this latter instance, if there are mandatory water reductions, or if irrigation is limited to a specific day and time, HydroPoint managers will verify that the controller is compliant with the drought mandate, says Mason.
If a sprinkler head breaks, Mason explains, the controller can remotely turn off that zone until the sprinkler head is repaired or at the master water meter valve. A zone sensor can also be shut off remotely by setting the condition with the controller—for example, if the water has been flowing for an hour.
HydroPoint does not manufacture its own flow sensors and flow meters. It does manufacture FlowLink, a sensor-water valve, and FlowShare that are accessory products “for complex sites to use to provide the ability to add flow sensors to current sites,” says Mason. HydroPoint sells Flow3 and FlowHD, both flow sensors and water meters manufactured by another company, she says. The controllers become the brain behind the sensors, “its eyes and ears,” says Mason.
Innovations in Sensors
Acclima, headquartered in Meridian, ID, has concentrated for the past 15 years on turf irrigation, commercial and municipal landscaping, and is now expanding into research and agriculture areas.
Kingsley Horton, Acclima’s sales and marketing manager, says that researchers from the US Department of Agriculture find the soil moisture sensors the company develops and manufactures to be useful, accurate, and affordable. Acclima is currently marketing them to researchers and agricultural equipment companies.
Horton says Acclima’s 24-volt closed-loop version of the Time Domain Transmisometry (TDT) soil moisture sensor, has been approved by the Irrigation Association using its SWAT protocol. The company also has a cooperative research and development agreement with the USDA. Acclima shares an award for excellence in technology transfer with the USDA Agricultural Research Service given by the Federal Laboratory Consortium for Technology Transfer for one of its Time Domain Reflectometer (TDR) technologies.
Acclima markets two types of soil moisture sensors, both of which yield readings of volumetric water content in the soil that are unaffected by salts and other ionic content, and which provide more accurate readings than the commonly used capacitance and impedance probes, Horton says. In 2002, it produced the digitized TDT sensor. When buried in the root zone of turf, trees, or shrubs, the sensor measures the moisture level of the surrounding soil and provides an absolute soil moisture reading in the percentage of volumetric water content.
In 2015, the company released a breakthrough technology—its integrated, digitized TDR-315 sensor, which is “innovative, easy to use, and very accurate,” says Horton. This sensor circumvents the problem of maintaining a high-frequency signal over long coaxial cable distances that conventional TDRs experience. A microcomputer is embedded in the sensor head with waveform-interpreting software preloaded. There is no bandwidth-constraining coaxial cable between its electronics and the waveguide.
The TDR sensor enables accurate monitoring of EC (a marker for nitrogen), nutrient flows, and microbiological activities. “The biggest factor is knowing what is going on underground,” says Horton. Knowing the value of the volumetric content of moisture can help farmers irrigate to save water and increase crop yields. The technology also has the capability to help scientists accomplish tasks such as more accurately prognosticating tornadoes and providing information about potential flooding or landslides, he says.
The TDR sensors are pushed into undisrupted soil at discrete depths of 6, 12, 18, and 36 inches. Horton says, “This is very important for soil scientists. Disturbance of soil around rods can distort the results.” An electrical pulse travels down the sensor and the sensor measures the amount of time the pulse takes to travel. Dr. Steve Evett from the USDA ARS explains that these measurements are directly related to how well the water is taken up from the soil and how nitrogen affects the depth of rooting.
Acclima also produces commercial controllers and two-wire system devices to communicate with valves, pumps, and other irrigation system equipment, as well as communication devices for controllers and irrigation manager software to access and analyze the data, performance, and efficiency of the information obtained from the sensors. The software is free of charge. A separate set of equipment: SDI-12 TDT and TDR sensors, and the DataSnap portable data logger are available for agriculture and research.
Acclima also offers radio, internet, and modem communications devices for remote control of irrigation with the commercial controllers.
A research report published in the July 2015 issue of the Journal of Irrigation and Drainage Engineering found that Acclima’s digital TDT performed best of seven soil moisture sensors tested in reclaimed wastewater. The study reports that, “Acclima resulted in the most robust and reliable system, with no practical reading variations when exposed to different combinations of temperatures and salinities.” Read more at http://bit.ly/2bVSSBr.
Ground View In Three Dimensions
A fairly new entrant in the business, AquaSpy has been in business since 2010 and serves the agricultural industry in the Mid West, Southeast, California, and internationally. It manufactures all of its equipment, including sensors, probes, and telemetry units in San Diego, but considers itself a data company, says Stephen Quindlen, vice president of marketing.
Quindlen says the company started out with bare bones technology and took about four years to get to where it is today. “By 2014 we think we had what we wanted and have been making refinements for the last three years,” he says.
AquaSpy’s 48-inch probe, which houses 12 sensors, covers a 4-foot profile. Sensors are placed every 4 inches at a depth of 4 inches.
Seametrics launched its pilot ultrasonic flowmeter, the jWAVE, in 2015. It is portable and clamps onto a pipe in under five minutes.
The probe sends data received from the sensors every 15 minutes to a telemetry unit that covers one irrigation pivot, or one zone in an orchard. The telemetry unit then sends the data collected to the cloud-based website every hour. The farm owner or manager can view the information on his or her smart phone and “determine in one and a half minutes what he or she has to do,” says Quindlen. “This is a level of agronomy not available from any other system.”
This data provides a vertical view of the ground—length, width, and depth, he explains. “Historically, the view was that you could make decisions in two dimensions. Unless you know what moisture and nutrients the plants are taking up, you won’t know that you’re feeding it,” says Quindlen.
Flow Meter Technology Jumps Ahead
Seametrics, headquartered in Kent, WA, manufactures flow meters for municipal, industrial, and agricultural markets. Katie Englin, business development manager for agriculture, says the company’s flow meters, which have no moving parts, are designed for specific markets to keep price points low.
Flow meters for municipal and industrial markets usually require more features in the meter’s electronics. Agricultural markets require fewer features.
Innovations in flow meter technology in the last five years has led electromagnetic meters to replace mechanical meters. The latter require maintenance and lack the capabilities of the electromagnetic meter technology. “The problem is that mechanical propeller meters have moving parts, says Englin. “Moving parts wear over time, and if the meter is not maintained and calibrated on a regular basis, there is a good chance it is not recording water use accurately.” Electromagnetic meters don’t have moving parts that wear out. They are maintenance-free, she adds.
Englin says when electromagnetic meters were first introduced, they were more expensive than mechanical meters, which provide only rate and total volume data. However, demand for electromagnetic meters grew due to their many capabilities. Today, prices for the two types of meters are comparable.
Features can be built into electromagnetic meters. For example, a grower can read water action remotely and with pulse output, additional features can be added to the flow meter for checking the health of plants, says Englin. With added features, the flow meter can also identify bidirectional flows. Furthermore, the operator can use the alarm function to detect when something is not quite right in the pipes.
Seametric’s electromagnetic meters can operate over large flow ranges. For example, standard mechanical propeller flow meters will register minimum flow at 50 GPM for a 4-inch pipe and a maximum flow of 150 GPM. The minimum flow rates for Seametric’s AG2000 electromagnetic flow meter registers 12 GPM for a 4-inch pipe, and registers a maximum flow rate of 1,000 GPM. Flow rates increase across the board in larger pipes.
Mechanical flow meters that register water-low flow rates below recommended levels won’t register accurately, Englin says. Propeller flow meters operated at high velocities can produce premature bearing wear or damage.
“We think the future is going to ultrasonic meter technology,” says Englin. It measures the sound waves water makes as it runs through the pipe. Its advantage is that meters are mounted on the outside of the pipe to avoid cutting into the pipe, to install as is necessary with mechanical and electromagnetic meters.
Seametrics launched its pilot ultrasonic flow meter, called the jWAVE, at the Irrigation Association show in 2015. It is portable and clamps onto a pipe in less than five minutes, according to the company, allowing an irrigation district operator to move from line to line to check them. It works on pipe sizes ranging from 2 to 20 inches. Furthermore, the operator can read the meter on a cell phone with the use of a mobile application that can be downloaded free on the Google app store.
The software uses Bluetooth technology and updates are automatically uploaded in the jWAVE app, making it always up-to-date, says the company.
Englin says Seametrics is working on an ultrasonic meter that can be installed permanently.
“The need for cutting-edge technologies that operate over large ranges is growing in light of the need for more efficient water use,” says Englin. “We’re seeing a trend as mechanical meters age. Instead of repairing them, users are replacing them with electromagnetic meters.”Englin acknowledges that other companies manufacture electromagnetic and ultrasonic flow meters but asserts that, “We think we have mastered the Bluetooth technology that is embedded in our app, and it is unique.”