Open Source Automated Irrigation System for Small Farms, Urban Farms or Specialty Crops
The goal of this project was to build an irrigation system using irrigation components available to all consumers, including the use of an open-source irrigation controller. I spent this year designing, preparing, building, installing, configuring and testing this system. A lot of work went into this system and I am very proud of the results so far.
To make sure the system was installed by our first planting on June 1st, I began work in late April, 2016. I purchased all of the valves, irrigation tubing, piping, irrigation controller, filters, drip tape, and other materials early so I could inventory everything and make sure I was not missing any crucial items. This was the bulk of the expenses and a detailed expense sheet is located on the budget form. I contacted the local land surveying company who originally surveyed our neighbor’s land to get a report and verification of the existing property line. I wanted to make sure that I was installing my water line within my property to prevent any possible future disputes. They provided this at no charge. After verifying the property line, I made sure that the water line was more than 15 feet from the property line for a personal level of comfort. I laid out and marked the proposed waterline path with string, posts and ground-marking spray paint. I submitted a MISS DIG inquiry to verify there were no underground utilities on my proposed path. The various utility companies marked their underground items and none of them conflicted with my proposed path. Next, I contacted a local well drilling company and had them upgrade my well pump and bladder to support the irrigation requirements for the drip system that I had calculated based on manufacturer information. They also split the main line properly for me to tie in the irrigation system. Upgrading the well was an alternative solution to running electricity 1,300 feet to the back of our property to power a pump and take water from a stream. The cost of running power to the stream was double that of upgrading our well.
I installed an underground main shutoff valve for the irrigation system 5 feet from the well. This allows me to shut off the water to the irrigation system directly at the well for maintenance and winterization. I also added a blowout valve for winterization purposes. Rather than running PVC from the well to the field, I opted for polypipe and purchased a grade that was recommended by a local irrigation company. A trench was dug from the well to the back of the field to accommodate the main irrigation line. A few issues arose while digging the trench. The first issue was abandoned non-commercial electrical wires. As soon as the wires were discovered, an electrician friend was consulted to determine if they were live. They were not live so digging was resumed. The second issue was a hidden tree trunk and root system. The trench digger was unable to cut through the massive root so it was hand dug and removed with our tractor. Once the entire trench was dug, the irrigation pipe was laid in the trench and valve stand pipes were installed using a “T” connector. The standpipes were constructed out of PVC and subsequently painted white to increase their UV resistance. Along with the irrigation pipe, irrigation wire was run from our garage and followed the irrigation pipe to the back of the field. Appropriate gauge wire was used to allow for the distance needed.
An irrigation valve was installed at the top of each valve standpipe. Each irrigation valve has its own anti-siphon feature to prevent water from going through the system in reverse. This was important to maintain water safety and prevent any contaminants introduced at the drip line from entering the water supply. A backflow prevention device, as required by code and for Michigan MAEP verification purposes, was installed at the beginning of the system. Each irrigation valve was connected to the irrigation wire using outdoor waterproof splicing nuts. I further waterproofed each wire connection by wrapping it in outdoor electrical tape, enclosing each bundle of wires in a plastic bag and finally we will be installing a white, above ground valve box over each valve and standpipe in the coming year. A filter is attached to the outlet of each valve to catch debris and prevent it from clogging the downstream driptape. From the filter a smaller diameter irrigation piping was connected, also called a “sub main line”, which was then connected to drip tape at the “plot” of land within the field.
All of the vales are wired to the OpenSprinkler Open Source irrigation controller that was installed in my garage. The controller is connected wirelessly to our network and the internet. After connecting each of the irrigation wires to the unit, a test was performed. Each valve was signaled to turn on and I would verify that the valve actually opened and let water through. This system can be activated manually or using a mobile website. I was able to test the valves from my cellphone while I was in the field, between 100 and 1000 feet from the well and the irrigation controller. The commands were instantly sent to the valves each time. Within a few weeks of installing and testing the irrigation controller I had set up irrigation schedules and weather related irrigation delays. The irrigation schedule was based on each plot’s plant types and the water flow as measure at the drip tape itself. I wanted to water as infrequently as possible but still maintain proper soil moisture. I was unable to take moisture readings this year but plan to next year. Everything this year was based on estimates.
RESULTS AND WHAT WAS LEARNED SO FAR
The project so far has opened my eyes to irrigation and its many intricacies – whether you are pumping it from surface water vs. ground water or using a municipal source, there are many different variable to consider to get water from its source to your crop.
As for the results of our project, we have not taken precise measurements of the water being utilized at this point. We have however cataloged the process and materials that can be used to universalize our setup for small and urban farms. Our idea was to “open source” an irrigation system that any urban, micro, or small farm could replicate affordably and with little learning curve. We believe our system is intuitive enough to be reproduced by others with similar circumstances. The addition of the internet connected irrigation controller also adds “smart” functionality to the system that allows for more time to do other things than worrying about the actual task of irrigating. It also gives the farmer more control if they want to cancel or start an irrigation cycle while away from the farm.
We believe that by the end of this project we will have seen the typical benefits of utilizing drip irrigation – such as reduced water use, increased nutrient uptake via fertilizer injection at the soil bed vs. broadcasting, less erosion, and also the benefits of our “smart” system. We also believe that we can deliver a reproducible, affordable urban and small farm irrigation plan. We are very excited for the second half of this project.
WORK PLAN FOR 2017
Next year will include general maintenance of the system which should include the following items:
- Reinstall winterized items (some items removed to protect from winter)
- Verify all wiring connections, fix any that may be disconnected
- Test all valves, replace any that may have failed
- Run an organic acid-based solution through irrigation system to clean any calcium or mineral deposits.
- Check all sub-main and drip tape lines for leaks, fix all leaks
Along with general maintenance tasks above, a few news items will be installed that were outside the scope of the original budget and were determined useful after running the system for a year:
- White, above-ground valve boxes over each zone valve
- In-line Water flow meter
Last year all of the water output was an estimate based on measured flow at one zone, manufacturer flow rate estimates, and estimates based on the output and pressure of the well system. This year we intend to take actual water flow measurements from an inline flow meter. The meter will be hooked directly to the irrigation controller and log all water that passes through the system. We can then take the data and cross-reference our scheduling data to even determine how much water was used on each crop and during what times of the season. We will also correlate these measurements with weather events to show decreased water use based on weather (temperature, sunlight, precipitation).
Impacts and Contributions/Outcomes
We have shared the irrigation project on various social media accounts include Facebook, Instagram, snapchat and through email as well. Our Facebook accounts have a combined audience of 2,500 people, our Instagram account has an audience of 500 people, and our snapchat has an audience of around 50 people.
We plan to install a page on our blog this February detailing our irrigation project for all to see. We shared our project with various small farmers at Farm Bureau events, and will be speaking about our irrigation project this February at a farming conference in Michigan. We are very excited to share not only the SARE grant process, but also the success of our project specifically.
We also share our irrigation story with anyone who visits the farm. We had around 25 visitors last year who we shared the story with. As the farm becomes more and more established we intend to host groups of people and as part of the tour they will see the irrigation system and how it functions.