Nitorgen 1Lb./1000 Sq' VS. 2lbs./1000 Sq'

[WillClimb]

Nitrogen 1Lb./1000 Sq' VS. 2lbs./1000 Sq'

I've been experimenting on my own live oaks which have been in decline ever since my father built the house.

Tree 1)
Sprayed Round-Up on the centipede turf around the tree (about a 40' radius). 2 weeks later covered the brown grass with wood chips. This was in the fall of last year. In one month I could easily dig down at least 6" with my hand in the soil underneath the tree. The turf underneath the mulch had disappeared. But where the turf surrounds the perimeter of the mulch bed...have fun trying to hand dig in that stuff.
So, hardwood mulch can bring soil back to forest conditions pretty quickly...at least as far as compaction is concerned. And with the hairy feeder roots being so important, I've learned not to underestimate compaction with trees.

Anyway, then at the beginning of this spring I fertilized with Growth Products (ArborCare 15-8-4, I believe...the spring stuff) NPK with micros, @ a rate of 1lb nitrogen/1000 sq'. Injected 4" - 8" into the soil on a 2.5' grid. The tree is now booming. Beautiful lime green colored leaves and more foliage than I've seen since living here.

Tree 2)
Same situation but it was worse off. Mulched as stated above and I can already see a positive change in the growth from the mulching alone. Fertilized this one with 2lbs nitrogen/1000 sq'. Waiting on the results but I can already see darker green leaves than with Tree#1.

So finally, the question: I've seen the mixing directions for both 1 lb. and 2 lb./1000 sq' rates on the product label. Is one considered more of the industry standard than the other?

JPS - when you said you liked low nitrogen did you mean low on the NPK ratio or low lbs. per sq' ?


Sorry for the romance novel. I'll try to be more succinct (suck what?!?) next time.

 

[Tim Gardner]

It has been a while since I did fertilizer work. Seems like we had a formula of X lbs per in DBH depending on diameter and type of tree.

 

[John Paul Sanborn]

The thread came up perfect for me, don't know what happend for you.

My problem with N in the picture is that it does stimulate top growth. Studies have shown that this is from making larger cells, not more of them. Maybe there is no increase in the net photosynthesis.

All the science out there is realy on annual crops like sorgum, corn wheat...not on perenial woody plants that we want to keep around in unnatural, highly competative envirnoments (turfgrass) for decades.

What I want to see is an increase in the whole spectrum of Mr. C Hopkins CaFe and all the other trace elements that do things we realy dont understand, but when missing cause problems. (They are finding that different sugars will help a stressed tree, but these are compounds, not elelments) Which is why I like seaweed emultion, it like injecting a green manure into the soil.

Making a stressed tree grow more is not a good thing. We are making it take the researves it needs to fight whatever problem and put them into top growth. All we want to do is give it what it needs to help build up those reserves and then it can increase terminal growth when it has the energy to do so.

So to answer your question

when you said you liked low nitrogen did you mean low on the NPK ratio or low lbs. per sq' ?

Yes, they are bothe the same in the end when you apply the mix. The ratio is just a measuring stick for misapplied science. What I want to know is what else is in the product, and get the N down as low as possible. I don't want to make it grow more, I want to help itlive better.

 

[underwor]

I will agree with JPS 100%. That scares you doesn't it John??? I think we concentrate too much on growing something faster rather than keeping it in good health. Every one should look at the series of articles in TCI in about the November issue of 2000 (it ran for 3 months). There is also one in May 2001 issue called "Fertilization and Tree Resistance to Insects" by Dr. Daniel A. Herms. Both of these show how much faster you can grow an insect or disease if you give it enough Nitrogen. I believ it said that you can grow tent catepillars 533% faster on a fertilized tree. It explains how N is bug food, not tree food. Very interesting reading. It helps to explain why some insects and diseases are problems in our landscapes, but not in the surrounding woods.

Bob Underwood, MSU-Bottineau, ND

 

[Reed]

It warms my heart that folks are dissing N in favor of common sense.

Years of the big Ag school's advice on row crops translated to tree science is crumbling.

Here we've had much experience on the end-results of N input to stress conditions - and we always assume now that stress is a fundamental base for all exacerbated tree decline.

I use my anhydrous now to grow pathogens in vitro - increasing time spent for more luxurious pursuits like fishin'.

All vascular inhibiting fungi and most sucking insects are parasitic, they scream for more N. I watched our county agent the other day showing his team the most effective way to kill Winter Vetch and other Legumes in a Coastal Burmuda field - lest they spread and choke-out the precious grass. Afterward he provided a list of high-Nitrogen ammendments to feed the range. Right.

We've totally eliminated N from tree treatments, unless a unavoidable remnant in Medina Plus (c) from sea kelp is kept to a 1 to 2 percentage point componant rate. People don't realize a lighting storm does more than irrigate. Phosphorous is elemental in water relationships, potassium is vital. We're looking to stimulate long term feeding, careful and slow root-growth rates, and minimizing canopy development to stay in sync with rhizosphere growth, including symbiotic organisms growing and thriving along with root tissue.

N is a quick fix, like steroid use for weightlifters. It'll promise headaches futher down the road however.

 

[John Paul Sanborn]

Originally posted by underwor
I will agree with JPS 100%. That scares you doesn't it John???

Just means that you can be right some times to Bobby m' boy.

 

[Paul O'Neill]

I have heard some convincing arguments from a seminar last summer talking about N uptake. It seems that tree needs to utilize carbon to process the N. It gets that carbon by breaking it off of the processed sugar chain. So, we end up breaking down the desired end product to process more N. If I recall correctly, it is something to the effect of using 53lbs. of carbon to process 1lb. of N. That really makes the argument for not appling fert to a stressed tree and apply only based on a soil test and then probably go a little low on the N/1000ft^2. That's my two cents.

Bob and JPS, maybe you guys can rework my gibberish ramblings into something that makes sense.

Paul.

 

[WillClimb]

OK, well on the topic of soil tests...do you all have your own test kits? If so, tell me what kit you like and shoot me an e-mail with a dealer that can get me a decent one at a good price. I looked at them in the Forestry Suppliers catalogue but some were pretty extensive/expensive.

So, as far as the mulch goes, don't you think that is an important step for stressing trees? We're basically mimicking the "leaf litter" of forest trees when we do this, right?

 

[WillClimb]

Oh yeah, JPS, what would you consider to be low nitrogen?

Thanks again!

- Will Allen

 

[John Paul Sanborn]

Originally posted by Paul O'Neill
maybe you guys can rework my gibberish ramblings into something that makes sense.

Who me!?!?

I guess this is a elaboration of the on going study.

Like with sucking insects feeding there is more C then N so they secreat the excess C in honeydew.

The tree gets it's C from the air through leaves.

So if the tree is in a stressed state it must get the additional C, at a 53:1 ratio, from storage.

This would be the starches it is saving up to use for stress responce, like walling off injury or killing boring insects. (which, incidently are very similar prosesses.)

So in this scenario, using N to make a small tree that is supposed to grow fast, has a high oercentage of dynamic mass and a low caloric reserve, is not nessesarily a very bad thing.



Now did I confuse matters any more?

 

[John Paul Sanborn]

Mulch is good if not over done and we do regular maintinance on the basal flair to ensure proper development of it and tha first order roots.

I don't advocate doing this on every tree, just the ones we want to live longer then 30-40 years. that's a different thread though.

I've heard anecdotal evidance of an 8 fold increase of macor-fauna onder mulched areas.

Now what about natural environments? would you find bur oak in 3 inches of duff? How about looking at native plantings under trees, you will also increase the water handling capasity of those sites and airation. Big blue stem, a native grass here will root down 18 feet ! that will help for deeper root penetration of the tree too.

My N preferance is ZERO, but that is not possible with organic products. So as low as feasable. I've used an 8% at a 100:1 dilution in water. What i use now is labled a 0.