How to set up a drip irrigation system?

[hetas]

Hi, I have just joined this platform and it is an amazing find. 

Last month, I installed a drip irrigation system at our weekender land near Kingaroy. However, it looks like I have messed up something. Even when my rainwater tank is going down drastically every week, whenever I check the raised beds, they look dry. Though the plants are surviving so not complaining about that. This was my first time doing anything of this sort. So please be kind if I have made some stupid mistakes.  

Here is the image attached to give some idea and context. 

Some specifics are below: 

1. Rainwater tank: We have a 22k litre tank which is about half empty now. 

2. Pump: I am using 12v, Ozito water pump that delivers about 600L per hour/10L per minute water. We don't have power onsite so using 12V battery and a solar panel. However, I can upgrade the pump if required. 

3. 13mm Polypipe: I didn't know that I should use 19mm initially and later 13mm. So I used all 13mm from the rainwater tank to pump to raised beds. 

4. 13mm drip irrigation pipe: Each bed is 3x1.5m in size and is 420mm high. So we spread about 21m of drip irrigation pipe on each bed (total 10 beds x 21m = 210m) in spiral motion to avoid putting a lot joints . Read somewhere that each join reduces the pressure. 

5. Each bed has 13mm barbed tap at the start. 

6. Automatic timer: I have GARDENA Flex Water Computer to water the beds every 48 hours for 40 minutes. 

7. From the pump to the beds, there is an elevation of about 2 to 3m. So the beds are sitting higher than the pump. 

Is this overkill/underkill? Do I need to upgrade the pump? Should I replace the initial run of 13mm poly pipe with 19mm or higher? Should I upgrade the pump? How much water roughly should I need every month looking at the current setup? Based on @Adam_W YouTube video, I can now understand that my pump is able to push 10L per minute, which is 400L each time my timer turns on for 40mins every 48 hours. 

But then the drip irrigation pipe can drip about 5.3L every hour per meter and looking at my current setup, I have about 200m length of drip irrigation pipe layed. So that comes up to be around 750L every 48 hours. Do I need to increase watering? Or decrease? 
We are getting bore drilled in a month's time but right now rainwater tank is all we have got. 

PS: We don't live there full-time. We visit every weekend and don't use water too much as we have composting toilet and no shower facilities currently. So this question is more about setting up right amount of water for the raised beds. 

[EricL]

Hello @hetas 

Welcome to the Bunnings Workshop community. It's a pleasure to have you join us, and thanks for sharing your drip irrigation system.

It looks to be very well laid out and based on the pump you mentioned, there should be sufficient pressure for your system to work. But just to be on the safe side, can you please confirm that you've seen the pump in operation and all the pipes are working properly? Does the water reach all of the the raised beds? 

If everything works properly, I don't see any reason to change your setup to 19mm. In regards to the amount of water being pumped out, it all depends on the type of plant you are looking after. Your soil composition also plays a factor on your watering schedule. 

Can you please tell us what you have planted in your garden bed? 

Let me call on @robchin and @Adam_W for their recommendations.

If you have any other questions we can help with, please let us know.

Eric

[hetas]

Thanks Eric. That's a relief 🙏😊. 

Yes I have seen everything in operation and seems to be working fine. I have seen water dripping in the most farthest raised bed too (of course a little slow drip but not too bad). 

Re what we have planted is different in all beds. We have planted heaps of plants. Watermelon, carrots, onion, cabbage, cauliflower, lettuce, spinach etc. We recently added shade cloth (30%) on top of all our raised beds to help when it gets too hot.

[MitchellMc]

Hi @hetas,

I'd agree with @EricL that if the system is irrigating adequately, then there is nothing to change. After a watering cycle, check to see that water is reaching down to the roots of the plants in the furthestmost location in the system.  

Mitchell

[hetas]

Thanks for your feedback. I will check this during the weekend and report back if any issues. 

[J-P]

@hetas @MitchellMc @EricL - is drip good for veggies garden beds? I feel that it drips and the area around 10cm radius gets wet and there are dry spots between them. I feel that it is more meant to be for trees than garden beds. What’s your thought?

[EricL]

Hi @J-P 

Thanks for sharing your question about drip irrigation. I believe that a drip line system is perfect for growing plants like fruit and vegetables as they are prone to overwatering, which can cause bad growth and even disease. 

Because drip irrigation systems apply the water slowly, it gives your plants a chance to absorb the water instead of drowning in it. It's very efficient and only applies water in accordance with the system that you've set-up.  

Eric

[tanveersattar]

Hi @hetas 
Watering via dripline may not be visible on the surface. You can tell by checking couple of cm of soil depth to see how much moisture it has. Also dripline irrigation takes longer as it drips through tiny holes, but as @EricL mentioned it is efficient as it does not flood the area, rather it helps soil to absorb water as it is being irrigated. One question though, to @EricL, do you think 600L/hr is enough water delivery for these many beds? I think it may be not enough (depending on what is the flow rate of the dripline used). So in this case longer irrigation cycles may be required?

[EricL]

Hi @tanveersattar 

I understand your concern about the volume of water being pumped out to the garden beds. Some of the factors that will affect your irrigation schedule are soil composition, evaporation levels, temperature and size of the garden bed. Your suggestion of longer irrigation cycles might be necessary, but I think a bit of observation will need to be conducted in order to see if the plants are getting enough water.

Dehydration and low watering levels are easy to spot. You'll notice that your plant is droopy and not vibrant. The tip of the leaves will start to go yellow and brown. Plants will often have their own water saving measures in order for them to survive. But as soon as you see these symptoms, you'll know that it's not getting enough water. 

Eric

[hetas]

Thanks for the comment. 

I had the same question in terms of whether 600L/hr is enough water or not. I am upgrading the pump though. I have just bought the Ozito 800W constant pressure pump that would offer me 3600L/hr.