A fully automated irrigation system has the potential to both reduce labor costs and improve irrigation efficiency. However, automation of drip irrigation systems is one of those technology options that has been around for awhile in theory but hasn’t seen widespread adoption.
There are several reasons for this limited adoption, but one important obstacle has been that the automation solution consisted of a collection of separate technologies, and the grower was responsible for making them all work together. This leads to a deeper discussion about what “fully automated” means and why system integration is so essential.
The word “automation” is used with different meanings depending on the context. The two most salient features of an automated system are remote control and system integration. Remote control is probably the most common and most immediately useful feature of an automated system. This is the feature that lets you turn on and off components of the system from the comfort of your living room, fishing boat or while on vacation. Remote control is such an essential part of automation that the terms are generally synonymous. A more robust view of a fully automated system is one where the operator tells the irrigation control system to apply a certain depth of water at a specific time, and the control system handles the details of starting pumps, opening valves and shutting down at an appropriate time. However, implementing this level of automation requires the second salient feature.
System integration is an often overlooked aspect of irrigation automation. There are robust theories of what system integration is and how it should work,1 but on a practical level, the definition is simple. Having a fully integrated irrigation system means all the various parts and pieces speak the same language, can “talk” to each other and have something useful to say. This benefit is often overlooked because the remote control feature can (and often is) applied separately to individual components of an irrigation system.
For example, booster pump controls can be acquired and managed separately from well pump controls, as can the controls for the fertigation system or the block level valving system. A fully automated and integrated irrigation system would enable the operator to run the entire system from a single platform. Unfortunately, this single platform benefit may not be available because the automated component of the system was acquired or designed separately, resulting in a mix of system components that don’t talk to each other. This situation results in the grower needing to use separate platforms (apps) to operate different parts of the overall system. In addition to the added time, expense and inconvenience, using multiple platforms can also lead to mistakes caused by context switching and insufficient attention.
Having a fully integrated irrigation system means all the various parts and pieces speak the same language, can “talk” to each other and have something useful to say.
It is also helpful to make a distinction between automated and autonomous. With an automated system, the human operator is making all the decisions. An autonomous system is one where the system itself decides when to turn on/off and how much water to apply. With full autonomy, the human operator is partially separated from the decision-making process but still “in the loop” via monitoring and feedback from the system. Autonomous irrigation control is an active area of research.
So, given these definitions, what can actually be automated? Simply put, everything. The most obvious and most common candidate is pump controls. Nearly every vendor of pumping systems offers some type of remote control option. Adding a newer variable frequency drive to an existing pumping plant opens the door to automation because most new VFDs have a ModBus interface, and there are a plethora of options for remote control of ModBus devices.
The next obvious candidate is the cornucopia of sensing systems. For these devices, automation means the data is delivered to you automatically, and this definition is synonymous with telemetry. Nearly every sensor system today has some type of telemetry option.
The third candidate for automation is the control valves that regulate which parts of the field receive water. Typical drip irrigation system designs subdivide the field into blocks, and each block has a valve to control flow to that part of the field. Often, when automation is not part of the initial design, the valve is manually controlled.
Typical operations in California will have a person (usually called the irrigator) whose main job is to drive around the farm opening and closing valves. This manual step in implementing irrigation is an obstacle to improved irrigation management because the irrigation schedule is limited by the time constraint of driving around the farm. Adding automated valves to an existing system is possible, and some options include solar power and telemetry integrated into single units, thus eliminating the need to run power to each individual valve. As described in the following example, automating block-level valve controls (and pump controls) enables both water and energy savings in addition to the obvious labor savings.
Take a look at the work being done by Texas A&M AgriLife Research in Amarillo at https://agrilifetoday.tamu.edu/2019/01/31/integrating-center-pivot-irrigation-control-technologies-goal-of-texas-am-study/.
Consider a typical drip irrigation system in an orchard. The grower’s options for set duration are limited by how long it takes the irrigator to visit all the valves twice, once to open and once to close. Crop water use changes from day to day, and when an irrigation system is designed for frequent applications (as many are in California), the grower should adjust the set durations based on the recent crop water use.
But, if labor constraints limit the system, those set durations can be difficult or impossible to implement. For example, if the irrigator needs eight hours to visit all the valves on the farm, then the farm can’t change sets more than three times a day (assuming they are running 24/7) and can’t run sets longer than eight hours without scrambling their labor schedule. The consequence is that the set durations are tuned to the labor constraint rather than the crop water use, and irrigation efficiency suffers. With a fully automated system, the farm can change set durations as needed, and the farm can change sets as frequently (or infrequently) as the farm’s water supply allows.
The second example involves energy savings. Many power companies have variable rate energy pricing where prices vary seasonally, weekly and by the time of day. Taking advantage of these programs requires shutting down or reducing pumping during the peak periods of the day. When labor limitations constrain a farm’s irrigation schedule, the farm may not be able to implement the additional shutdown and startups or adjust set durations to accommodate the times when prices are lower.
Another typical energy program is one where farms are asked to shut down pumping when the power provider expects high power demand, so-called demand response programs. For labor-constrained systems, it may be impossible to participate in these programs because the unplanned shutdown will disrupt the irrigation schedule and cause cascading disruptions that can last for days or weeks. Full system automation can make both of these energy programs easier to implement because the automation makes it easier to adjust the irrigation schedule.
One key obstacle to drip automation that must be considered is cost. The capital cost of whole system automation is a significant investment and can be discouraging. However, there is some help available to growers that want to adopt automation. The Natural Resources Conservation Service’s Conservation Stewardship Program and Environmental Quality Incentives Program-Conservation Incentives Contracts programs have some support for automation in certain circumstances. Contact your state NRCS about how it can assist with automation using information from irrigation water management sensor data.
The final and perhaps most impactful feature of a fully integrated system is the automated translation of sensor data into irrigation recommendations that the control system can implement. This critical feature has only recently started to appear in manufacturer’s products, but it can have a profound impact on irrigation management. One of the obstacles to using advanced sensor systems is the laborious cost of data integration: collecting all the data and turning it into actionable information. A fully automated and integrated system will (or should) substantially reduce this data integration burden and thus make precision management easier. With many manufacturers now offering fully automated solutions that are turnkey or nearly so, hopefully adoption will also be more common.
