Tree Fertilization

[Mikecutstrees]

I'm thinking of getting into tree fert. a little. I see quite a few large trees on lawns with no input of nutrients. They pick up all of the leaves, sticks etc. and leave nothing to decompose. I think some fertilization would be a benefit to these mature trees. I don't want to buy alot of equipment right now for this. I have a Toro Dingo and I thought I could tow a small trailer with a tank on that and make a pump for it too. Or maybe just spread a dry fert. on the root zone before a rain? What would people on here recommend?..... Thanks... Mike

 

[derwoodii]

A simple PH soil test kit would help, you can do the test as sell your skills to the client. Broad spec long lasting with trace elements fertilizer is usually best augment it with mulch as seen required.
I'm a fan of stressed trees treated with just sugar and water. I have had good results, some have argued not repeatable but I say what the hell costs little has no cons and could help.

Read below a few extracts & try the link good luck

Journal of Arboriculture 30(6): November 2004

http://www.treelink.org/joa/2004/nov/percival11-04.pdf

Abstract. The influence of sugar (sucrose) applied as a root drench
at 25, 50, or 70 g (0.9, 1.8, or 2.7 oz) per liter of water on root and
shoot vigor, leaf chlorophyll fluorescence, photosynthetic rates,
and chlorophyll content in silver birch (Betula pendula)

In conclusion, applications of sugars at 25 and 50 g (0.9 and 1.8 oz) per liter of water improved root vigor of the majority of trees tested and may be useful in reducing transplant shock in landscape plantings. Although further studies are required to understand the mechanistic basis by which improvements in root vigor occurred, sugar feeding may be an area worthy of further research given the fact that sugars are water soluble, nontoxic, environmentally safe, and inexpensive to purchase

The application of soluble carbohydrate could encourage mychorrizal associations to form in a number of ways. They could act as an initial source of energy for the mychorrizae, i.e. as a biostimulant, causing those fungi already present in the soil to become active.

Keep this A Shigo thought in mind.

Myth 11: "Fertilizer is tree food."
This is a half truth were the wrong half has become the accepted part. Fertilizers provide elements that are essential for growth. Fertilizers do NOT provide an energy source for trees and other plants.

A food is any substance that provides the essentials for life; an adequate source of elements that are essential, but do not provide energy, and other types of elements that do provide energy (carbohydrates). Unlike animals, trees are able to trap the energy of the sun in a molecule called glucose. THIS is the essential energy source for the tree.

From the soil, trees obtain water and other elements that are essential for life. These do not provide an energy source for the tree.

Yes, soil elements in many chemical combinations can and do provide energy for bacteria and bacteria-like organisms. But trees do not work that way. Correct fertilization should consider the tree and its age and condition, the soil type and pH, the elements lacking in the soil, and the desires of the tree owner. The variables are almost endless.

The entire subject of fertilizers needs a thorough "clean up." Many people do not understand the numbers given to N, P, and K on bags of "plant food!" It is beyond the scope of this publication to try to clarify the subject here. (For more information, see Modern Aboriculture p.232-245.)

 

[Ed Roland]

Nice post, derwoodii.

MCT,
Adding that big bag-O-macros to the soil disrupts the mycorr. relationship.
"Generally, mycorrhizae are only helpful to plants on soils that are extremely low in P. On soils heavily fertilized with P. the fungi do not provide sufficient P to the plants growing theron to be be effective."
- Keefer
So whats more important? Pumping the soil full of elements and flushing unhealthy growth or ensuring healthy growth through a healthy soil.

And why are we so caught up on mycorr anyway?
"Mycorrhizas are symbiotic association of fungi with the roots of higher plants which help in the uptake of mineral nutrients such as P, Zn, Cu, Fe and K from soil. Besides this, mycorrhizas have been reported to be an important tool in the management of soilborne plant diseases, especially root rots and wilts." - Department of Mycology and Plant Pathology, Dr Y.S. Parmar University of Horticulture and Forestry

Use that dingo to bring in the correct mulch.

 

[Urban Forester]

"Mike",
As you can see by the 2 previous posts tree "fertilization" is a rather complex topic. The use of macro fert (NPK) is (in my opinion) one of the most over used and misunderstood areas of tree care. If interested in fertilization I recommend going to the ISA website store and get a copy of ANSI A300 part 2-Tree Fertilization. It will explain alot. The use of soil testing cannot be understated. Without knowing what the soil is lacking the application of anything is only guess work. Dr. Shigo said when a tree is in decline there is almost always something wrong in the rhizosphere. Learning what the rhizosphere needs is more important than knowing what the tree needs, since the relationship is symbiotic. Also getting an understanding of biological nitrogen fixation is very important in knowing how fertilizer works in the soil. The bottom line is "Soil Health" is the key to tree vitality. Sometimes what may appear to be a lack of "nutrients" is merely a lack of oxygen or other benefical soil organisms. Accurate diagnosing is the starting point...

 

[treeseer]

I recommend going to the ISA website store and get a copy of ANSI A300 part 2-Tree Fertilization. It will explain alot. .

Actually you can review the current draft version for free, online at the tcia site. Maybe you guys want to submit comments...

 

[Mikecutstrees]

Thanks for the great advise. I went to college and took a whole class in soils. That doesn't mean I remember too much though. What everyone is saying makes alot of sence though. I'm going to get a soil kit and start testing some tree soil. Finding out what is needed and then fixing the problem is definately the professional thing to do. Can you do soil tests in the winter?. Thanks.... Mike

 

[Castenea]

Can you do soil tests in the winter?. Thanks.... Mike

Depends on how solidly frozen the soil is. If you can dig the soil with a trowel you can do a soil test. If you need a jackhammer, wait untill the soil thaws in the spring.

 

[treeseer]

Portable pH meters are great. Mine was $50, very well spent.

What is a Castenea? opcorn:

 

[Ed Roland]

This is the cheapest meter. Spend more to get a meter that works. Guy, brand suggestion? What u usin? My clients appreciate a lab report. I like to hand them the raw copy and watch their eyebrows wrinkle. I make $ off generating that report. I make $ off explaining that report. I make $ performing recommendations based on that report.

The refractometer is a gift. The supplied brix scale is enemic.

 

[MCW]

So whats more important? Pumping the soil full of elements and flushing unhealthy growth or ensuring healthy growth through a healthy soil.

What you are saying makes sense on household trees but by keeping elements in balance in fruit trees you can limit vegetative growth despite massive amounts of Nitrogen. Tissue testing is another tool you can use as well, as long as a set of nutrient standards are available for that particular species/variety.
You can have a healthy soil and add a lot of fertiliser at the same time, providing it is balanced and getting used.
I am a Horticultural Consultant and do heaps of soil and tissue tests in Agriculture and the most unhealthy ones I see are those in organic farming funnily enough.

 

[D Mc]

You can have a healthy soil and add a lot of fertiliser at the same time, providing it is balanced and getting used.
I am a Horticultural Consultant and do heaps of soil and tissue tests in Agriculture and the most unhealthy ones I see are those in organic farming funnily enough.

Define healthy soil.

Dave

 

[S Mc]

As WW pointed out, if you add nutrients to the soil to "feed" the fungi that develops mycorrhizal relationships with trees, you are going to inhibit or interrupt the establishment of this important symbiotic relationship. This relationship builds as the need dictates. Take away the need...and it will not establish. Feeding takes away the need.

James Urban states numerous times in his book Up By Roots, that you can amend the vast majority of soil nutrient problems by adding organic matter.

The pH of the soil is of primary importance. If it is "off" it won't matter WHAT you put on if the tree cannot access it. Testing the soil and perceiving that there is an element that is "out of balance" and then trying to "amend" that by augmentation may be futile if the pH is limiting.

If you have people with highly maintained lawns with trees that are struggling, encourage them to dispense with the chemicals they might be using and mulch the trees. You can add 1/4" of organic matter as a top dressing to the lawn and it will like it as well.

The possibilities of why the trees are struggling can be a long list: Lack of aeration, compaction, irrigation water that has a high saline content, too much water, too little water (most people we know water with a "one-size-fits-all" mind set), and on and on.

Most people are very prepared to accept fertilization as a natural course of action and, therefore, this is an easy sell. However, it is not always in the trees' best interests.

With all due respect, recommendations on a high production orchard should NOT be brought across the board to landscape trees. The desire for maximum yield of a commodity is a distinct goal. Artificially pumping trees full of chemicals/nutrients to produce that yield may satisfy a human-based desire, and I won't go into the pros and cons of that mentality here, but bringing this mindset over to landscape trees is not warranted or healthy.

"Justus van Liebig, 19th-century German chemist, is credited with discovering the link between nitrogen and plant growth, and along with it much of the chemistry that created modern synthetic fertilizers. Toward the end of his life, he recognized that synthetic fertilizers had created an agricultural system that robbed the soil of important recycling functions needed to keep soil healthy. He then championed the beginnings of the principles of organic farming: 'After I learned the reason why my fertilizes were not effective in the proper way, I was like a person that received a new life.'"

Quoted from pg 59 of James Urban's book.

Sylvia

 

[MCW]

Define healthy soil.

Dave

Sorry to bring a commercial argument over here, not my intention to upset anyone.

If you guys do a soil test, even in a backyard application, do you get down to the nitty gritty of cation exchange etc?

I do work for commercial orchards that would pass any healthy soil test you'd care to throw at them. Nothing wrong with synthetic fertilisers IF used at the correct ratios. A plant cannot distuinguish between a Potassium ion from pig manure or a Potassium ion from Potassium Nitrate for example.

In saying that I also do work for the odd commercial orchard where their soil has been whipped through inproper use of synthetic fertiliser. However, soils from organic orchards where I've done tests have been in even a worse state. Where they use excessive manure they always tend to end up with a bad N ratio. These guys are trying to gain a yield where they can actually afford to eat but it is very hard to do. This is where marketing comes into play which is what organics is all about.

You are also right about soil pH. The ideal pH for a broad range of nutrient availability is around 6. We have alkaline soils in my area from a lot of Calcium Carbonate. Our pH is generally around 8.2 from areas untouched. We have a lot of Zn, Mn, B and Fe deficiencies.

By the way, the quote above is from a 19th century chemist. Hardly valid anymore. The earth may have even still been flat

 

[S Mc]

Sorry to bring a commercial argument over here, not my intention to upset anyone.

Nothing wrong with synthetic fertilisers IF used at the correct ratios. A plant cannot distuinguish between a Potassium ion from pig manure or a Potassium ion from Potassium Nitrate for example.

By the way, the quote above is from a 19th century chemist. Hardly valid anymore. The earth may have even still been flat

This is certainly not an argument but a legitimate discussion relevant to this post, as the OP is debating offering commercial fertilization.

Both synthetic and natural fertilizers can be misused. Citing an example comparing a well-managed orchard that "properly" uses synthetics to an organic orchard that misuses organic fertilizers is the equivalent of comparing apples and oranges.

Your argument of saying that a plant can't distinguish between an organic and synthetic substance is often used as justification for the use of synthetic fertilizers. But this bypasses an important organic function within the soil. That of the breakdown of organic matter by the microbial life within. That function has not changed with the ages. It was not determined by the world being flat but by the realization that it is a necessary part of a healthy biosphere. You never get something for nothing. If you disrupt a function, there is a cause and effect. Just because you have found a way to mask the results, does not mean the consequences aren't occuring.

Hence David's comment regarding healthy soil. The diversity and density of active and properly functioning biological life. This is the symphony of activity that allows things to grow properly and continuously as they have been for thousands and thousands of years.

There is the fact that not all things are meant to grow everywhere. This is an issue that we, people in general, are constantly struggling against, because we want what we want where we want it, with little to no regard to how realistic that is.

Sylvia

 

[Ed Roland]

Sorry to bring a commercial argument over here, not my intention to upset anyone.

No arguments here. Lets hope they are isolated to the commercial tree care threads.

If you guys do a soil test, even in a backyard application, do you get down to the nitty gritty of cation exchange etc?

of course, whats your point?

I do work for commercial orchards that would pass any healthy soil test you'd care to throw at them. Nothing wrong with synthetic fertilisers IF used at the correct ratios.

MCW, I see from your profile that you are an agronomist. Stressing a tree to produce as much fruit as possible is a far cry from the optimum health arborists strive to achieve for client trees.
[friendly jest]

 

[MCW]

There is the fact that not all things are meant to grow everywhere. This is an issue that we, people in general, are constantly struggling against, because we want what we want where we want it, with little to no regard to how realistic that is.

Sylvia

I agree Sylvia. The problem is that, for example, our soils are more suited to natives such as Eucalypts. Unfortunately too many gardens in our area have trees planted that are not suited to our conditions, even from other countries - I'm sure it is the same in your area. My experience is not only limited to commercial fruit crops, I also have quite a bit of experience in domestic applications. Quite often I have had to recommend Zn, Mn, but particularly Fe supplements to home gardeners as that pretty tree they've planted doesn't look so pretty anymore.
What has happened in the past regarding synthetic fertilisers is not necessarily happening anymore, hence the reason why more and more organic "type" inputs such as Humic and Fulvic Acids are being utilised.
I am not 100% anti organic, far from it, but I can also see the benefits from synthetic inputs where needed. Unfortunately my dealings with organic orientated people show that they rarely accept both sides of the fence.
The only problem I have with organics (or more so some of the people associated with organics) is that there is too much snake oil around and very few facts to back it up. For example in my job, and my previous job as a consultant in the industry, if a new product entered the market we demanded non biased trial results. If I am to recommend some new Diazotroph formulation that "claims" to add 100 units of N per hectare then I demand proof of this - none was available in this case.
If I was to recommend this to someone and their crop goes backwards, I open myself up to a legal case.
As far as commercial organics go in many crops it is a simple case of nutrient removal. A certain amount of nutrient are removed with the crop, and these have to be replaced. Unfortunately without smart marketing and asking a super premium for their produce, by the time this "balance" has been reached the tree is suffering badly and the farmer is broke.

The quote used earlier regarding a German Chemist from the 19th century would most certainly have been relating to Urea as the synthesised fertiliser - one that I very rarely recommend as it has a habit of creating acid soils and purely vegetative growth. The people that tend to want a lot of it are also the ones more likely to misuse it. Better growers rarely touch urea.

As you mentioned though what works in a home garden may not be relevant to a commercial orchard, however the soil science remains the same, it's just the amount and types of inputs that vary.

of course, whats your point?

It was just a question, that was my point. I have seen some pretty lame soil tests in my time claiming they are something they are not.

MCW, I see from your profile that you are an agronomist. Stressing a tree to produce as much fruit as possible is a far cry from the optimum health arborists strive to achieve for client trees.
It would be interesting to hear your definition of a "healthy" soil.

Are you saying stressing a tree produces fruit? Stressing a tree produces excessive flowering as a rule, quite often leaf drop, which results in dropped fruit if they even set to start with. To say that synthetic fertiliser stresses trees comes as a bit of a surprise to me.
I am sure that commercial horticulture is a far cry from Arboriculture, but as I said above, the soil science remains the same.
The proof is also in the pudding, I'm sure what you do works, and I know what I does works, so that shows there are many ways to skin a cat. Unfortunately this is what I am talking about above as far as dealing with people involved in purely organics - in their eyes I am doing nothing but wrecking the soil and poisoning the earth.
My definition of a healthy soil is one that can sustain whatever plant/crop is growing on it. Some people's idea of soil health may relate only to soil organisms which I agree on, however properly used synthetic fertilisers at the right ratios will not kill these beneficials.
What tests do you get done to determine microbe activity and numbers in a soil? Once again, not a trick question, but an honest one.

 

[Ed Roland]

Are you saying stressing a tree produces fruit?

If not then how do we get our food? Perhaps the better question here is: do you believe our fruit comes from trees that are stress free? Mine does not and I'm not sure i could afford it otherwise.

My attempt to be humorous rarely ever takes here and one of these days i will learn my lesson. :monkey: My post prior was a poke in the ribs and knot a red face fury.

I'm no treehugger. I'm that rare individual that understands these two things: the e-coli outbreak 2 years back was from uncomposted material on the product. If the grower had used synthetic then those individuals would be alive today. And while the plant may not know the difference the soil certainly does.

ok, fine. The soil needs it, we give it. Does adding greensand to amend K alter mycorr popuations? Does squirt and fert of a big bag-0-micros alter mycorr populations? Some common sense is endemic to the process.

 

[MCW]

If not then how do we get our food? Perhaps the better question here is: do you believe our fruit comes from trees that are stress free? Mine does not and I'm not sure i could afford it otherwise.

My attempt to be humorous rarely ever takes here and one of these days i will learn my lesson. :monkey: My post prior was a poke in the ribs and knot a red face fury.

I'm no treehugger. I'm that rare individual that understands these two things: the e-coli outbreak 2 years back was from uncomposted material on the product. If the grower had used synthetic then those individuals would be alive today. And while the plant may not know the difference the soil certainly does.

ok, fine. The soil needs it, we give it. Does adding greensand to amend K alter mycorr popuations? Does squirt and fert of a big bag-0-micros alter mycorr populations? Some common sense is endemic to the process.

Sorry if I misread you mate. As mentioned sometimes the humerous poke in the ribs doesn't come across on the internet

You're right, common sense should always prevail. You don't go dosing up a plant in it's natural environment with fert as it shouldn't need it. To get a viable crop (people's perception of viable can vary) from a tree in a non native environment where nutrient availability and soil pH are different to ideal you will have to add synthetic fertiliser. Apart from micros in some situations backyard "ornamental" trees shouldn't need much fertiliser at all, in fact it can sometimes be counter productive, depending on the species. I've lost count of how many people I've done work for that have killed backyard trees because old Fred the fruit grower has given them a bag of Urea to pour on it because it "made his grapevines greener". Some trees can use as much as you give them, others will roll over and die.

I suppose I joined in this thead because the OP asked about adding synthetic nutrients/micros to ammend any deficiencies and a few chimed in with an organic approach, basically condemning the addition of synthetic nutrition. I couldn't help myself!

There are all sorts of issues regarding public health as far as manure and E. coli goes. There is an area with Almonds (I think in California?) where this bacteria is now established in their soil and every nut has to be heat treated (this may be the case you are talking about?). When I was doing nutrient, pest, and disease programs for organic almond orchards they thought their throat was cut when I told them they HAD to use heat treated manures. This is actually a food safety legality but they complained that the heat treatment would lower nutrient availability. The temperatures used for pasteurising is unlikely to have caused any nutrient loss but one grower in particular just wouldn't accept that it had to be done. Because almonds are a ground harvested crop this is a very important thing he had to do. It was against "his" principles of organics.

I just found something very strange at work - some Sumitomo Giberrellic Acid that is certified for organic use in Australia! Now that amazed me. Anyway...

Also let me know what greensand is mate, I've never heard of it out here. I'm not sure if it affects Mycorrhiza populations as I don't even know what it contains. Is the "bag-O-micros" an actual product or a generic term that you use?

I'm not even sure if we have tests available here to determine numbers of Mycorrhiza or what the standard number per gram of soil would be? One thing I do know is that certain micros in large doses such as Cu and Boron are extremely toxic to soil flora and fauna. Other micros such as Selenium can have a negative affect too although rarely needed here. Naturally occurring Selenium toxicity to some grain crops is more likely in our soils from what I'm told.

By the way, I very rarely deal with shotgun aproach nutrition as in one bag does everything. Calcium Nitrate, Potassium Nitrate, chelated liquid elements, liquid UAN to a lesser degree (contains Urea but unfortunately after 9/11 anything with a reasonable % of Ammonium Nitrate is restricted) plus a few others depending on the crop.

Please don't think that I'm not looking at both the organic and "conventional" side of the coin, I am and have had a lot to do with both. I think that ideally in many situations a blend of both is perfect. I have had my fair share of discussions (quite often heated) with some of the 100% organic people I've dealt with. They ask me why they can't get 40 tonne of citrus per hectare like their conventional mate down the road. Fact is they can't and they never will. What is taken out has to be put back in otherwise all you are doing is mining the soil - this always comes around and kicks you in the butt at some stage. To put back 130 units of N per hectare in an organic situation cannot be done in a practical sense, that'll own economically. One common misconception from the old days is that our soilsare high in Potassium. Indeed they are. It's just people don't realise that less than 1% of it is available. This mentality has led to a lot of Potassium deficiency and poor fruit quality as market price is poor or it goes rotten in transport.
Interesting - New studies from South Africa are showing that by coating granular, synthetic fertiliser with humates has the ability to reduce fert inputs by up to 20% on citrus with no yield or quality decrease - some areas in organics can't be ignored

As far as getting fruit from stressed trees are you getting all hormonal on me? Heh heh, only kidding. If every tree was 100% stress free at a hormone level we'd never get any fruit and as a consequence no fruit trees (there would be no fruit to get seeds from) as quite often it is the same hormones that cause tree stress that are involved in flowering and fruit set to a small degree (ie: auxins). Auxins are necessary for both plant growth (at low levels) and in herbicides (at high levels). Its been 17 years since I studied plant science at uni down to a hormonal level. It did my head in - very complicated.

Please fill me in on what you guys do though, I find it interesting as its always good to hear what goes on on the other side of the world! Even if I don't always agree 100% For example what are your soils like? Ours are generally a sandy loam, with areas of clay loam on the river floodplains. Our soils are what many would call "gutless" which may explain why I do a lot of fertilising

Sorry for dribbling on for so long. I normally stick to the chainsaw section

 

[Ed Roland]

Great stuff, MCW. We agree on much more than we disagree. I've a few questions and a few points to try to express but today i have to hit the road. Snow = work! I look forward to continuing our conversation when i get back this weekend.

 

[S Mc]

I stand by my words that you can not and should not relate a management regimen that is designed for a high-production orchard to a landscape ornamental. I'm not even insisting go organic over synthetic, even though I firmly believe in the landscape setting this can be achieved the vast majority of times.

What I am saying is that taking a soil test that shows the nutrients in the soil is not going to give you the full and accurate picture. It does not show what the tree is uptaking. If you start putting nutrients in they may or may not be available to the tree due to pH.

With the micronutrients you applied in your backyard landscape in your reference above, MCW, how did you address the pH first in order to make them available?

We, and I am speaking of my husband and my's business, are constantly trying to educate our client's that fast growth is not the determining factor to health in a large, woody perennial. They have been bombarded with advertisements that show exaggerated growth and beautiful fruit or flower crops and feel that, therefore, this is how their tree should respond as well. That mindset is not in the tree's best interest for longevity.

All plant life put exudates back into the soil to feed and develop the biological, living portion of the soil. This mandatory web exists. Ignoring the consequences that we create because of synthetic or mismanaged organic amendments is at the expense of healthy soil...which is a large portion of our Earth's surface. A surface that should be able to sequester a large amount of carbon...and I am not talking about trees here, but the soil itself.

MCW, you are obviously very knowledgeable for the business you are in and I mean no disrespect and have no argument towards that. I just feel your orchard-oriented mindset is not the best recommendations to follow for arboriculture. The illustration of the 19th century chemist was to point out his realization of the important process that synthetic fertilization bypassed...not that one product worked better than another.

Ed, citing an example of misused organics that had tragic consequences undermines all the documented evidence of where the use of chemicals have caused devastation with as tragic results. No synthetic fertilized orchard, that we are aware of, uses synthetic fertilizers without the aid of tremendous amounts of chemicals to keep these synthesized products marketable.

But at this point we have digressed. This is not a thread on how to manage an orchard...which if you want to discuss that in another thread, I will link an article you should read, MCW.

James Urban stresses over and over again the ability of organic matter to manage the vast amount of landscape issues. I firmly agree with this statement.

I have no problems with using non-native species. I do recommend that people select SUITABLE species for their microclimate. A lost cause is a lost cause...whether you opt for organic solutions or synthetic.

Sylvia