Talk to me about Drip Irrigation

[jflournoy]

My son and I are doing a somewhat large planting of tomatoes this year (300+ plants), and while in the past I have planted in black plastic and have rarely needed to water my tomatoes, because we're planting so many this year, I want to have the option to easily water them if necessary. They are not close to my house, so a water hose connected to a hose bib at my house for the water supply line is out of the question. My plans are to use a rain barrel and gravity or a 100-gallon tank I have and pump it out of there with a small sump pump to get it started and then let gravity take it from there.

I'd like to get something with poly/rubber tubing that is flexible and doesn't have emitter holes already pre-set at regular intervals. I'd like to get the kind that I can use a punch to make holes and insert the emitters where I want them.

I've been searching on the web for the better part of the day and there are just so many different options that I am quite overwhelmed. I thought about rigging up a home-made drip set-up out of cpvc pipe like I did with my small apple orchard last year, but there are going to be 300+ feet of tomato row to irrigate (made up of several rows) and I don't think the cpvc is the practical way to go for this project (probably not as cheap, either).

Any help from personal experience, or some web site you can direct me to that explains the different options really well?

Thanks!

[taboule]

I know you said you don't want the pre-set emitter holes and want to "do your own", but with 300 ft /300 plants, that's a lot of additional, unneeded labor, and $$. Pro growers who do it on such a large scale typically use the ready made tape or tubing. They come with different spacing intervals from 6 in to 3 ft.

If you want to use rain water from a barrel, be especially careful with filtering before sending the water down to the emitters. Gravity feeding also presents a special set of challenges as the pressure may not be enough for such high volume and long runs.

You may want to setup separate "zones" that you can water independently from each other, especially if you have different veggies and other than maters.

For shopping, I use dripworks.com, no affiliation or special interest.

Good luck and let us know how you make out.

[jflournoy]

Originally Posted by taboule

I know you said you don't want the pre-set emitter holes and want to "do your own", but with 300 ft /300 plants, that's a lot of additional, unneeded labor, and $$. Pro growers who do it on such a large scale typically use the ready made tape or tubing. They come with different spacing intervals from 6 in to 3 ft.

If you want to use rain water from a barrel, be especially careful with filtering before sending the water down to the emitters. Gravity feeding also presents a special set of challenges as the pressure may not be enough for such high volume and long runs.

You may want to setup separate "zones" that you can water independently from each other, especially if you have different veggies and other than maters.

For shopping, I use dripworks.com, no affiliation or special interest.

Good luck and let us know how you make out.

My plants are going to be set 2' apart, and I hadn't seen any drip lines with that big of interval, guess I didn't look hard enough. Most of the ones I saw were 6-12" apart. Since my plants are going to be in black plastic, I just want to make sure I don't have a bunch of water just sitting on top of the plastic because some of the emitter holes happened to be between 2 plants.

I'm hoping, based upon my experience with the apple orchard last year, that pressure won't be a problem. I live on a hill, and even though my garden is on the "flattest" part of the hill, it is still a bit of a grade, and the rain barrel or water tank will be at the top of the garden and the hoses will all be going downhill. That is an interesting idea on the zones, though, I will think about that some more.

[huntoften]

300 plants and 100 gallons of water from rain barrels won't have much of an impact from my experiences. I have two 55 gallon barrels by my house and they do a fair job of handling 50-60 plants with a deep weekly watering. When it doesn't rain enough to fill the barrels, I fill them with the garden hose and let them sit a day for the water to warm up and the chlorine to evaporate a bit.

I use soaker dripline under silver reflective plastic film and have excellent results. The T-tape is a cheaper alternative, but it's better for straight rows. You can also run mainline tubing on top of your plastic and insert a 1gph emitter at the base of each plant to make sure the water goes directly to the root system.

Like others said...filtering rain barrel water is a must. You'll need to clean the filters every one or two waterings or the filters will stop allowing water into your system.

Drip systems are a pain to install, but if you do it right it is the most efficient way to water and saves you a lot of time during the summer months.

[Cole_Robbie]

My high tunnel plants are 3' apart, and I still use the drip tape with 1' spacing. It works fine. The water spreads out a great deal when it soaks into the ground.

Drip tape needs pressure, though. You would want a low-pressure gravity fed system. Dripworks has everything. There are a lot of different emitters. If your ground is not level, I think you'll need pressure compensating emitters. Connect them with tubing, and you can have whatever spacing you want.

[jflournoy]

Originally Posted by huntoften

300 plants and 100 gallons of water from rain barrels won't have much of an impact from my experiences. I have two 55 gallon barrels by my house and they do a fair job of handling 50-60 plants with a deep weekly watering. When it doesn't rain enough to fill the barrels, I fill them with the garden hose and let them sit a day for the water to warm up and the chlorine to evaporate a bit.

I use soaker dripline under silver reflective plastic film and have excellent results. The T-tape is a cheaper alternative, but it's better for straight rows. You can also run mainline tubing on top of your plastic and insert a 1gph emitter at the base of each plant to make sure the water goes directly to the root system.

Like others said...filtering rain barrel water is a must. You'll need to clean the filters every one or two waterings or the filters will stop allowing water into your system.

Drip systems are a pain to install, but if you do it right it is the most efficient way to water and saves you a lot of time during the summer months.

I can re-fill the water tank as necessary if more water is needed.

I'm not familiar with soaker dripline. I've used soaker hose where water soaks out of the entire hose, but what is soaker "dripline"?

Tell me more about the mainline tubing on top of the plastic and putting an emitter at the base of each plant. Is that something where you'd use a "punch" to make an individual hole in the main line where each plant is? Is that something that would work with a low-pressure, gravity system?

Is a filter just something that screws on between the rain barrel and the main drip supply line? I water a small apple orchard with water from a rain barrel and don't use a filter, but I've got a water hose as the main supply line and 3/4" cpvc as the drip-line's. So far, it hasn't been a problem.

[jflournoy]

Originally Posted by Cole_Robbie

My high tunnel plants are 3' apart, and I still use the drip tape with 1' spacing. It works fine. The water spreads out a great deal when it soaks into the ground.

Drip tape needs pressure, though. You would want a low-pressure gravity fed system. Dripworks has everything. There are a lot of different emitters. If your ground is not level, I think you'll need pressure compensating emitters. Connect them with tubing, and you can have whatever spacing you want.

I just want to make sure the water gets to the ground and I don't want wasted water from a drip emitter that is spaced between plants where the water sits on top of the plastic, since my line will be laying on top of the plastic, not underneath.

[heirloomtomaguy]

The driptape i use only uses 10 to 15 psi of water pressure.Low pressure will not be an issue with driptape however lack of flow will. If you have plenty of water flowing to your irrigation from the rainbarrels you will be fine.

[jflournoy]

Originally Posted by heirloomtomaguy

The driptape i use only uses 10 to 15 psi of water pressure.Low pressure will not be an issue with driptape however lack of flow will. If you have plenty of water flowing to your irrigation from the rainbarrels you will be fine.

How does one define "plenty of water"?

[Cole_Robbie]

The rain barrel would need to be on top of a 23' tower to create the 10 psi that drip tape requires.

http://www.nmenv.state.nm.us/swqb/FO...athematics.pdf

A column of water 2.31 feet high creates a pressure of 1 psi.

[jflournoy]

Originally Posted by Cole_Robbie

The rain barrel would need to be on top of a 23' tower to create the 10 psi that drip tape requires.

http://www.nmenv.state.nm.us/swqb/FO...athematics.pdf

A column of water 2.31 feet high creates a pressure of 1 psi.

I don't have that much elevation, so I guess that rules out using drip tape, unless I was going to pump it out with my 1/4 hp sump pump instead of just gravity feed it?

[lexusnexus]

Since you have no problem with the amount of labor that would be required to punch holes, what about buying the pre-punched tubing and tape (or otherwise close up) the outlets you don't want to use.

Dan

[heirloomtomaguy]

Originally Posted by jflournoy

How does one define "plenty of water"?

The amount of water needed to supply your system is dependent upon your system demand. For example say you have 10 psi supplying 300 feet of drip tape and the emitters are spaced 1 foot apart. If the drip emitters are rated at 0.25 gallons per hour you would need 75 gallons of water per hour to run your system....in a perfect world. However we do not live in that world so other factors such as the supply line diameter, linear feet of drip tape per zone, and water flow friction loss are also factors you will need to take into consideration when choosing your system. For your system i would not worry to much about friction loss because the system is relatively small. As stated your water tank is not on a 23 foot tall hill (1 psi = 2.31 ft) so you would definitely need a pump to boost pressure to the recommended 10 psi.

[Cole_Robbie]

A sump pump is a transfer pump. It does not make pressure, or at least any more pressure than is required to move the water. If you wanted to make pressure, you'd need a well pump. They're about $160 and will make 30-50 psi, similar to the pressure of tap water. Drip tape typically uses a pressure regulator.

[heirloomtomaguy]

For sure a pressure regulator is a must.