Deep root fertilization

[TreeJunkie]

While working for Hendrickson Tree Care we primarily used the Liquid Injection method of fertilization. Now that i'm working on my own however i do not possess the expensive spray rig. However i still get requests for deep root fertilization.

What is everyone's thoughts on Drill Hole Method of Fertilization vs. Liquid Injection Fertilization?

I know when compaction is an issue that the drill hole method would be preferred.

From what i've read, one of the major benefits of the Liquid Injection method is the availablilty of needed water.

If you were using the drill hole method and watering in after the fact would this make this an equally successful method of fertilizing?


What are everyones thoughts.

 

[Lumberjack]

I would think that they would be similar assuming the appropriate high quality fert (granular) was used. It will still leach out like the liquid IMO, and perhaps it will stay around longer too (depending on what fert is used).

Would a heavy watering/rain be good after a granular application to get the minierals in the soil and start the process?

The soil is normally is compacted to some degree around the trees we arborist normally see, IMO.

Then again I am a noob at this, hopefully Guy and Mass will get on here and speak their minds and I can learn something too.

 

[treeseer]

Drill Hole Method of Fertilization vs. Liquid Injection

I use a hybrid method called Soilbuilding (tm). Just did a ~30" pecan today. I'll take pics and le tthem talk. I agree with most all of what you guys are saying.

 

[murphy4trees]

Why are u ferilizing?amd with what???
How big are the trees???
I know I know.......... For the $$$

 

[Kneejerk Bombas]

The greatest benefit of Deep Root Fertilizing is the tree gets a drink of water. If they could figure out how to get the un-needed fertilizer out of the tank, but leave the water, the trees would really do well.
The other obvious problem with DRF, is tree roots are shallow. In many cases, 90% of tree roots are in the top 12" of soil. If they could figure out how to add the water, without fertilizer, to the surface of the soil, where it could slowly run into the soil, then they'd really have something.
There just isn't funding to do the research to come up with such a method.

One problem with discussing tree fertilizer is the levels of understanding about soil science on a board like this. We need to separate soil fertility, structure, biological activity, pH, and now we also have the commercial hormones that can be added.
Daniel says, "Why are u fertilizing? And with what???"
He may be thinking about 10-10-10 or whatever, and I'm thinking Sulfur-compost-Cambistat. Big difference!

 

[Stumper]

As Mike pointed out-most tree roots are shallow and we often are thinking( or not thinking) about different treatments and or soil ammendments when we say fertilize. The drill hole method works quite well if: A. You determine what if anything the tree needs and what the soil is deficient in. B. You make the holes shallow ( 8-10 inches means that at least the leaching process starts in the root zone)

Think hard about incorporating Vertical mulching. If the soil is so good that it won't benefit from additional organic matter then it doesn't need fertilizer. If it "needs" fertilizer you will probably do as much or MORE good by making more holes and filling them with composted material. The customer asks for fertilizer, you offer them fertilizer plus something "wonderful" they have never heard of. You'll know that the compost is more important than the chemical fertilizer, they'll just be happy with the results. :angel:

 

[Lumberjack]

Excuse my ignorance, but I know that the roots are normally in the top 12". How deep is normal deep fert? I never woulda guessed deeper than 12", is that the case with the common practice?

 

[Treeman14]

If they could figure out how to get the un-needed fertilizer out of the tank, but leave the water, the trees would really do well...
If they could figure out how to add the water, without fertilizer, to the surface of the soil, where it could slowly run into the soil, then they'd really have something...
There just isn't funding to do the research to come up with such a method.

Actually, Mike, I've been doing my own self-funded research into these very same problems. I feel I'm on the verge of a breakthrough, but the recent afternoon rains have skewed my latest results, so I'll have to begin again when things dry out a bit.

 

[Kneejerk Bombas]

Don't feel bad, I was preparing a site for a research project, and my wife put a lawn sprinkler out under the tree. Now I too am unable to work on my ideas until it dries out.

Tree roots grow out from the tree, then they grow up to the surface. Most tree roots grow up. The deeper roots are thick and mostly transmission lines, while the roots that grow toward the surface are small and do most of the absorbing. Many very fine roots grow right up to and through the surface and die back all in one day.
When you stick a probe down into the soil, you not only compact a small area of soil, you also drive much of the product down past these small "feeder" roots.
Water and water soluble products, tend to move downward. If you are trying to apply water or water soluble products, the most efficient method is a surface application. You get a much more even distribution, and you hit the small absorbing roots at the surface.

 

[Kneejerk Bombas]

On a positive note, most of what is being applied with a DRFertilizer is bad for the tree, by getting the stuff down below the roots, you minimize the damage all the un-needed fertilizer can do.

 

[Kneejerk Bombas]

It seems like a hard way to achieve the goal, I mean, you need to make a lot of holes to be effective. I kinda like the core aerators that are used for lawns. Then rake compost over the surface. Horizontal mulching affects much more surface area with much less work. Try and get the volume of organic matter in a mulch bed, into vertical holes, not easy.
If you are going to make the commitment to help a tree, an airspade is the way to break up compacted soil.

 

[TreeJunkie]

Currently i've been using a 3" auger bit drilling down 8-10", adding a Doggett slow release 32-7-7 and the filling back w/ a mixture of peat and of the extracted soil. Then watering in. Holes are being drilled approx. 18-24" apart. Holes are started between 6-12 feet away from the trunk depending upon size of the tree, holes are extended out to just beyond the drip line, or at least as far as possible.


I didn't start this thread to have people tell me how bad traditional fertilization is on trees. I merely want opinions on whether it is worth the extra $ to be using liquid injection or to continue using the method i currently use.

How does everyone bill fertilization? Hourly product cost x ?, or $ x Square footage, $ x dia. inch ?????

 

[Stumper]

Brandon, I'm definitely NOT trying to pick a fight or criticize. As I mentioned previously-drill hole works quite well. It is the method I use. I believe it is superior from the standpoint of utilising slow release products allowing for long term results from infrequent treatments. Dilute liquid injection on the other hand offers ease of application and very minimal root damage-each have their strong and weak points.
Regarding the formulation you are using........I don't like it. The "authorities" are split on the subject. The ISA Arborist Certification Study Guide promotes the same research as Dr. Richard Harris reguarding adding nitrogen. Even Harris took the trouble to mention that Shigo's research caused him (Dr. Shigo) to oppose high Nitrogen applications. The idea that high doses of N can be harmful fits with my own observations and gut instincts. N will push lush growth but it may be 'false growth' -a depletion of reserves that aren't fully replaced by the new growth prior to the end of the growing season. High N apps also turn trees into sucking insect magnets-kind of like a dessert buffet attracts me.. My opinion (which I know you didn't ask for) is that N percentages should stay below 16 and we should concentrate on trace minerals and soil pH more. :angel:

 

[TreeJunkie]

Stump,

Sorry if i came off wrong. I didn't take any offense to anything you or anyone else said. More like trying to get my original question answered. I like your input though. The doggett's mix is what my uncle had always used and is also what Helena chemical recommended to me. Can you point me to a better product in a similar price range. What would you use?

 

[Stumper]

Brandon, You didn't come off wrong-I just wanted to not come across wrong myself. I don't know about the precise needs of your local soils but what I am using here is a locally available organic(partially) called Pro Rich. it is made from Dehydrolyzed Poultry Waste (Chinese man say Poo Poo make prant glow) and has a 14-5-5 analyisis with sulfer and Iron. I also use a Ferti-lome product called Iron plus-(11% N with lots of sulfer for acidifying the soil and some iron). My view of chemical ferts is that they are useful for treating trees that are exhibiting symptoms of deficiencies and are "Okay" for stimulating rapid development of young trees an moderate doses. Mostly I promote mulch, compost and good irrigation.

 

[John Paul Sanborn]

I'm with Erik on the fish soup. There are seaweed products out there, but application rates come to $1 or mere per gallon. That's not real good for a small operator.

Look into the Kioritz manual probe, it takes a lot more time, but not as much as auger ferting.

Auger ferting will also glaze the app holes, there was some studies that showed no net benefit from vert. mulch due to this. Louie Hampton had some pictures of this a year or so ago too.

On Mikes methodology the best way is a low N "organic" product applied with a broadcast machine after a thourough watering that has dried out a bit, the subsequent breif waterings to allow the product to leach down w/o running off.

 

[Kneejerk Bombas]

An air spade is a real easy way to make holes.

Putting 32-7-7 in the holes seems really bad for the tree, the tree roots, and the environment (because 90% of it will just leach into the sub-soil).
What you are doing is comparable to fertilizing your lawn buy putting 5 pound piles of lawn fertilizer in ten spots on your lawn. You will burn the crap out of any grass that is close, down hill, or under the fertilizer. Then a short distance from the pile you'll have real green healthy grass, and finally most of the lawn will be unaffected.
Trust me, even if the soil and tree are suffering a nitrogen deficiency, this fertilizing method is doing more harm than good.

It seems like you are trying to duplicate the action of tree fertilizer spikes (solid spike shaped nitrogen, you pound into the ground with a hammer), possibly ther worst product that ever hit the market. If you disagree, and like this methodology, why not just use the spikes?

 

[John Paul Sanborn]

32-7-7 i did not catch that skimming the thread. I do agree, maybe "slow" release mixed with a sandy loam would be OK since Brandon allready has the product.

The big problem is that most of the research to date is based on annual crops, such as corn and wheat. In these plants they want fast growth with large cells. That causes a problem with perennial plnats because those large cells do not contain the chemicals used to fight off pests and pathogens.

So people have said, hmm works for corn, lets see what it does for trees. Sure enough it increases terminal growth, makes longer internodes. Sounds good to me. So in the past few years you've only started to see good research on the long term effects.

There has been a vocal minority in the industry who have been expressing concern about anicdotal evidance that there are higher pest problems on trees that get a regular dose of high N.

Now they are becoming vindicated and the fert squirters are trying to supress or spin the data. That was for you Reed if you still come here at all

 

[Kneejerk Bombas]

I don't know of anybody that thinks high Nitrogen is good for the long term health of the tree. It's mostly used in nurseries to push growth and get the tree to market.
What I'm even more critical of is the delivery method being discussed. The only method that might be worse is to drill it into the trunk.
I hope I didn't give you any ideas.

 

[John Paul Sanborn]

No, I had to read back to find Brandon's comment on the product he's buying. You and I have discussed this here, there and in person. So I know where you stand. Your past prefered method is to topdress with a composted manure.

don't know of anybody that thinks high Nitrogen is good for the long term health of the tree.

most will defend there practice by trying to define high N as more then they use. What is antural N, around 4-8% ?

Going back to the core aerators, I'm not particularly fond of them due to the root damage I've seen.

If the compressor were not so darned expensive I would say that vert mulch with an airtool (AirSpade is a product name) then topdress, would be the best route to go.

But we are trying to help Brandon do the best with what he has, for the trees and for himself. He is in it to make money after all, just doing something he loves and providing a service.

if the fert he has is a fine granular, then i would mix it with a sandy loam to fill the holes, then broadcast some more it. If it is a large granule that can be broadcast by it'self then i would jsut vert mulch with the sandyloam and apply the fert with a spreader.

If the auger were my only option right now, I would vert mulch and apply a fish emulsion in the holes and if possible a topdress of a composted product.