Need advice on organic fertilizing with drip irrigation

I’m in CA where my (stone fruit) orchard relies on irrigation for most of the growing season. I’m trying to figure out the best way to fertilize, given these three factors:

  1. Using inline emitter drip irrigation
  2. Using organic practices
  3. The ground is mulched with 3-4" of wood chips.

If I apply dry fertilizer (e.g. composted chicken manure) I don’t see how it’s going to get moved into the soil by the drip system. And even if that’s weren’t an issue, getting it under the mulch would be a lot of work (i.e. moving the mulch aside, applying the fertilizer, replacing the mulch).

I’ve looked into fertigation, but there’s not a lot of information out there about organic fertigation and not many products available, and it also seems to me that for the long term health of the soil it would be better to be adding solid organic material, rather than just nutritious liquid.

Does anyone have experience to share and advice to give regarding fertilizing an orchard in this kind of situation?

(BTW, in case it’s relevant, I’m using Backyard Orchard Culture, with 16 trees in a 20x20 area.)

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The problem you are likely to encounter with organic fertigation is your lines getting clogged. You might try organic fertilizer spikes or tablets. You would be limited to the area right below the drip. The problem with organics is maintaining a rich microbial environment to break down the nutrients. Organic fertilizers usually leave residues in irrigation lines that will grow microbes and clog. K-mag (langbeinite, sul-po-mag) can be fertigated without much problem, but the nitrogen and phosphorous are problematic. I tried organic hydroponics years ago, but gave up on it due to the cleaning headache. It clogs your gear beautifully.


I started using spot spitters to water in top dressed fertilizer. my drip valves can do either 80 or 120 gph and there are spot spitters available at 3.6, 4.8, 7.2gph, etc. So, using those I can have tens of trees on one valve even though the rates are higher than regular drip emitters


I do not have any fertigation experience, however, I once got interested in it and ordered Venturi Mixer nozzles from ebay. Let me tell you, I never used them - lol. What I can tell you from my experience of backyard gardening in the last 3 years of composting, wood chips, organics, etc. if it’s too time consuming and high maintenance you won’t be able to keep up and it will be another expense. The key is to keep things simple. If it’s just 16 trees, just hire someone to fertilize for you every season. It will be less headache with no maintenance.
EDIT: If you’d like you can do the math of such a system + maintenance vs. hiring someone to do.

Digging in organic fertilizer would be tough in that condition. You could add organic fertilizer to your compost pile if you have one and top dress with finished compost then a heavy layer of fresh tree chippings say from a tree cutting service. You want material that has the branches and leaves all chipped together this should give your trees all the nutrition they can use as the finished compost and freshly decomposing wood chips release the nutrients over the year. In addition to this a few buckets of AACT (compost tea) poured on top once or twice a year will help. If after following this practice if you see evidence of a nutritional problem that might need to be corrected with a non organic approach for faster results following the recommendation of a soil test. I hope this helps

I am putting together a densely planted orchard. Ten foot between trees and 15 foot between rows and will maintain the height to under 12 foot.
I am also looking for drip irrigation system to hook up to a well pump that has low pressure. It is designed to fill tanks. I am looking at Netafilm UniRam that may have the capability as along as you use a 120 mesh filter. Need to find out how to connect these to a thick wall poly pipe that is 3/4 inch. I will use JADAM solutions to build up the soil biology and also fertilize.
I will use a two stage filter to ensure the nutrient particles are small so it will not create a problem. Each time I fertilize I will run plain water through the lines to clean them out.

I have virtually the same environment - I’m using Dave Wilson’s Backyard Orchard Culture with wood chips, 1gph drip emitters, and organic fertilizer. I simply dig into the wood chips below the emitters and pour my fertilizer in there, then put the wood chips back on top.

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Thanks! I have a few questions, please:
How many emitters do you have per tree, and do you do this with every emitter?
What kind of organic fertilizer are you using?
How often do you apply?
How long have you been using this application technique?

How many emitters do you have per tree, and do you do this with every emitter?

  • My plums/pluots/nectarines are spaced very close together, about 4 feet apart, so many emitters are providing water to trees on either side (see attached, left). But roughly 6 1gph emitters per tree. My cherries/pears/asian pears are spaced about 6-8 feet apart (right), and I use 6 emitters per tree. My citrus have 6-10 emitters per tree (depending upon age), and my blueberries have 6 emitters each (bottom). I do try to pour some fertilizer under each emitter.
    acacia backyard irrigation map.pdf (227.8 KB)

What kind of organic fertilizer are you using?
I’m using EB Stone 7-3-3 for all my fruit trees, although I just swapped to non-organic Master Nursery 12-8-4 per @brownmola’s advice. The EB wasn’t providing enough green on my citrus, so I’m switching it up.

How often do you apply?
See my chart here (feel free to copy and use it for yourself). I apply monthly for citrus, 2-3 times a year for other fruit trees, and 4-5 times for blueberries.

How long have you been using this application technique?
About 5 years, although I’m re-doing my citrus technique (as noted above, the nitrogen / application amount was too low in previous years, and watering was too high – of all my citrus, the lemon has been the only one that’s been healthy and green, and it’s also doing well with EB Stone and with MUCH less water than the others, so perhaps it’s not the fertilizer but just my over-watering – I also have a huge gopher problem, so perhaps it’s that also).

Hope it helps! Feel free to ask anything else, I’m learning just like you :wink:

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Thanks for the extensive explanation and info! I have even more emitters per tree. I’ll have to give serious thought as to whether I’m willing to go to this much (ongoing) trouble to fertilize my trees.

Are you folks considering the amount of nutrients contributed by the mulch? Initially mulch should provide all the K the trees need and P as well, given contributions from mycorrhizal relationships. AS the mulch breaks down it will gradually add increasing amounts of N, some as the result of N fixing bacteria.

I can see the idea of adding N automatically if trees seem to be growing in insufficient vigor, but I never add P or K to mulched trees and have never witnessed any signs of nutrient deficiency as a result. This is at many sites in many soil types but in Northeastern weather. I have created a situation of excess K from wood chip mulch over time that seems to contribute to corking in apples.

My problem with most organic N sources is that they tend to release the most N when mature fruit trees don’t need it. Once trees reach adequate size, one wants to stimulate growth in spring, but not in summer and fall.


Great notes. We have clay soil where I live in SF Bay Area, where P and K are readily available. So yes, I agree that N is really the only thing that’s needed. What’s really neat with using live wood chips is the amazing amount of fungi that grows, it’s grows like spider webs throughout the yard, amazing!

In the humid zone, wood chips over time can be problematic by making the soil too good and providing too much available water, potentially driving down brix. But where the sky seldom drops water during the ripening season this probably isn’t an issue and only an advantage when winter happens to bring skywater. OM can store some of it for spring growth. Spring is the only time I want growth of bearing trees stimulated.

I had my soil tested by sending a sample off to a service (having found the home-test kits completely useless) and learned that my soil has high levels of P and K, but relatively low N. My understanding is that the high levels of P and K actually exacerbate the low levels of N by making it harder for the trees to absorb the N. I’d like to try adding just some organic N, perhaps in the form of blood meal. Maybe I’ll try adding by digging holes under some of the emitters.

I use my own urine for my orchard trees. but the problem is its high K content. However, that has only been an apparent problem for a few of the apple varieties I grow which are prone to corking. High amounts of K has never seemed to interfere with N absorption and I have never read that it does.

That said, I’ve never understood the reluctance to use N that has been extracted from the atmosphere via natural gas- I understand the environmental issues in its large scale agricultural use but even that has to be weighed against the increased productivity of agricultural land, thereby reducing the need to turn wilderness into farm land. Some aspects of organic orthodoxy seem more religious than scientific to me, although I’m entirely sympathetic to the desire to produce food without using poisons.

I started growing my vegetables organically back in about 1968, when it was a hippy religion. I still do today besides using some synthetic fertilizer in the greenhouse when starting my plants. Funny how things change- like rock and roll, it was once part of youth counter-culture but ORGANIC is now mainstream and embraced as being the only sensible way to grow food by many.