Below is a guest blog shared from Cedar Hedge Farm in Ontario, Canada, looking at how they managed the unusually dry weather in 2021. These updates were written by Farmer Chris in July 2021 and January 2022.
From the different solar pumps they tried, to the impacts of irrigation on crop growth, this is a fantastic read into how solar powered irrigation and a bit of learning can change farming for the better in North America.
Off Grid Sunshine Watering System – July 2021
Rainy days are a vegetable farm’s days off. This is basically the first real rain event since March and my first real down day. With that I thought I would use some of the time to write an update about the Shine watering system. Thanks to your support, it has already made the difference between having a season and not.
I have never seen a spring like this. Because of where the farm is situated, we get less rain than some of the surrounding areas but this spring has been unbelievably dry. In total, up to today, we have received about 13cm (5 inches) of rain. On top of that, the very light snow levels over the winter meant there was very little water in the ground to start with.
So what’s happening with the watering system
The Basics: The pumps are here and in place and running. We have already had to receive 3 shipments of 15,144L (4000 gallons) of water, which means with the aid of the pumps we have moved 60,576L (16000 gallons) of water this season (Total includes water reserves from 2020). We have also laid 1737m (5700 ft) of drip irrigation lines with still more to do. We brought in 10 – 1000L (250 gallon) cubes to aid in water storage and are working on water collection plans.
For those that want a deeper dive
The Pumps: All the pumps we are using are solar driven low voltage. There is the small pump we started with, this is used for irrigating around and in the greenhouse. We can also use it to transfer water from a 1000L cube back to the pool or mount it on the water wagon for spot watering in the fields or if we are moving water to a cube further away on the farm. The submersible transfer pump is a pump that sits in the pool, it is high volume at low pressure. This is used mainly to fill the water wagon quickly. It can also be used with a garden hose to do some watering in a pinch. These 2 little pumps mean that we are not carrying water around the greenhouse in watering cans.
The most important pump in the group is the Futurepump
It’s the one that we purchased from India. This pump, if needed, can run all day as long as I’m not standing in front of the solar panel. Hooking it up was quite funny; being from another country the electrical set up was a little different.
Once I got it figured out and got it started I stepped back to admire my handy work and the pump stopped. I was like, “oh no, what’s wrong” but as I stepped forward to check the pump it started. Relieved, I stepped back, only to have it stop again. It was at this point I realized I was standing between the solar panel and the sun. The pump is direct to panel; there are no batteries, but the panel has to have light on it. It has been a bit of a learning curve, especially knowing when to go turn the panel based on the sun’s position. Nevertheless, the pump is moving water, at full power around 60L (16 gallons) per minute. We will run the pump for approx. 2.5 hours at a time per zone to get to the equivalent of 1 inch of rain.
Thanks to you and this pump, we have already moved more water and irrigated far better than we did in all of 2020.
The Irrigation Method
The main method of irrigation we are using is drip tape. I say main because we are still using watering cans and hose on occasion. The drip tape system works by providing water to only the areas and plants that we want to irrigate. This means we are not watering the walkways or areas to the side of a field that would be covered if we used sprinklers. It also means we are using 1/4 to 1/3 of the water that would be used in a sprinkler method.
Additionally, because each line has its own shut off, we can pick and choose what gets watered. If a crop is finished we can shut down those lines. If we have a crop that needs more water eg. cucumbers – we can focus our efforts with the turning of a valve. The system is not perfect but it’s already making a difference. Due to the lack of rain in the spring, we started setting up the system and the difference in the peas between the first zone set up and the second is visible. The peas that got less water are smaller in size, both the plant and the fruit.
The Plan and Management
With the pieces in place the next main thing is understanding how much and when the plants need water. There are times that we may want to reduce the amount of water to force the plant to look for it and build a better root system. Once the plant starts to bear fruit, there is an amount that it will need in order to be more productive.
To do this we have to monitor rainfall; this tells us how much water has been applied to the ground in a given week and we then know if we have to add more. We need to know three things: how much water each variety of plant needs, how much has fallen and how much the pump is delivering. The first step in this was putting a simple homemade rain gage in the field. After each rainfall I record the amount and from there can decide how much I need to add. The other is understanding the pump and how much it’s delivering and how many tape lines we are running. This allows us to know for how long to run the pump.
All in all I’m very pleased with the progress of the system and hope in August to have some Sunday tour/demonstrations of the pump and system.
The difference water makes
Due to the dry spring and me not believing we could have a spring drought. We got the irrigation in place a bit late. When we were setting up the system one section of peas did not get irrigation tape. Those are on the left the ones on the right got a small amount of water.
Year end update Jan 1 2022
It worked and worked well. When I started the project I was told by North American companies that the idea of a solar powered irrigation system sounded impossible and was financially prohibitive. North American companies are so tied to our grid system that they can’t see past it.
When I found the pump in South Africa and India and told a local solar company about it, the person I was speaking to said (not a direct quote, it’s been awhile), “yeah, you won’t find innovative stuff here.” I guess the idea here of being off the grid is frowned upon. I’m not sure why, but a 300-400 watt panel is almost cheaper than what I would pay on my hydro bill just for the delivery charge to the farm. But that’s another story.
The irrigation system was a success
We had the best cucumber crop we have ever had. This was directly due to the system and a simple mistake I made that turned out not to be a mistake.
As you will remember, we had a dry winter in late 2020 into spring 2021. Then there was the spring drought. From mid March until mid June the farm got 12.7 cm (5 inches) of rain, based on my little homemade rain gauge. The average vegetable plant needs 2.5 – 5 cm(1-2 inches) per week, so that’s quite a shortfall. Enter the irrigation system; by tracking the rain I was able to augment with irrigation up to the proper amount. With the fields broken into zones with crops of similar water needs grouped together, I was able to target water. Targeting was necessary due to the limited amount of water available. The pool was being filled every 5 days.
The importance of soil moisture
The mistake wasn’t a mistake but a big learning once I recognized it. As mentioned we had our best cucumber crop but probably our worst tomato year. The question I had was, why? First the cucumbers: the irrigation system draws water from a 4000-gallon above-ground swimming pool we use as a reservoir. The solar pump sits on the ground (some of you may see the issue). When the pump is turned on the water is pulled up over the side of the pool, and moves through the pump and into the field. Just after the cucumbers had been planted the pump was turned on – the pool was full – and the pump ran for about 4 hours. When the pool was just under 3/4 full – the pump was turned off. We water late in the day and this is because (if you remember the heat) we are trying to avoid evaporation and to allow the water to soak in as the sun sets and overnight.
The next morning I checked the pool to see about watering and it was down to less than a 1/4 full. My first thought was that it was a leak. I walked around the pool numerous times but could not find any water. Then I walked out to the cucumbers and the drip tape was still dripping. The pump was off but the water was still flowing. It hit me that I had syphoned the pool of a lot of water…luckily it went to some of the veg.
What does this one overnight watering have to do with a good cucumber and poor tomato crop? Simply, ground moisture. Because of the dry spring there was no water in the ground. You could dig 3, 4, even 6 inches and just have dry soil. When we only watered for the usual 3-4 hours (a typical feeding), the roots would move to the water. And along with that the sun was drawing the water up and the roots were following. How do I know this? When I pulled up a few tomato plants in the fall the root structure was awful. In past years the plants wouldn’t pull with two hands; this time they came out with ease. The overnight watering of the cucumbers put water down deeper than when we did our twice-weekly waterings; then, we were adding to the base. The tomatoes didn’t have the base.
One of the learnings is that I will spend the rest of my life learning. Also I’m in the process of ordering a long-shaft soil moisture meter. We will be doing tests this coming spring to make sure the moisture levels are correct before we plant. If that means emptying the pool many times over, that’s what we will do.
The irrigation system is all packed up for the winter. The solar panels have been re-purposed for the greenhouse over the winter but will be back to pumping water as soon as necessary. The pump is safe and warm; it’s actually covered and at the end of the bed in the spare bedroom so it will be safe over the winter.
The next steps for the system are simple : keep learning, and find or make a reliable supply of water. The plans for a small pond and a couple of cisterns are underway. 2022 is going to be a good growing year because with climate change the biggest learning is adaptability and that we can do.
Thank you so much for your help with this project. Please, once COVID is done, stop by the farm. I’ll be happy to show you the system, how it works and everything we are doing.
Have a great 2022!
Thank you Chris for sharing your experiences with us, and we can’t wait to see what 2022 brings for Cedar Hedge Farm.