Bonsai in the tropics

[AussieBonsai]

Thought I may try to start a thread for bonsai in the actual tropics and the challenges, etc

I’m based in Singapore.

First topic.... given the enormous amount of lightning we have in the tropics (almost daily), I wonder if we even need to fertilise with Nitrogen, given that theoretically, it must be abundant It the rainwater, given the aforementioned lightning....?? Thoughts on the back of an envelope pls...

 

[Shibui]

I have noticed that plants in general seem to grow much better here in the days after a thunderstorm. I have assumed that is because of a dose of natural N in the rainwater because they have been watered well in the times between storms without that same response.
I am not convinced, however, that storm N would be enough to maintain maximum growth. Not being in a daily thunderstorm area I don't have any basis for that belief but it should be easy enough to set up some trials to prove one way or the other.
Some similar plants in the same location, some just watered, others watered and fertilised.
Now, on second thoughts, I am wondering that even if the rain was supplying enough N what about the other elements? The trouble may be finding a suitable no N fertiliser that would supply the P,K and trace elements the storms don't supply.

 

[AussieBonsai]

Agreed that finding a fertiliser which omits N, would be difficult, if not impossible, for amateurs, anyway. I Guess I was just thinking out loud. I’m interested to find out more though and will let you know if I can find any research

 

[AussieBonsai]

Another Tropics question.. when to re-pot? Most threads will say spring or winter, given the species, however considering we have no spring and winter, only wet and slightly less wet... when would be best? Plants (all evergreen here) seem to be actively growing year round.

 

[Shibui]

Some tropical growers will need to give experienced advice but I understand that repotting and root pruning most species can be done year round.
Down here we have found that repotting and root pruning Aussie natives in summer when they are actively growing gives far better results than traditional winter-spring dormant repotting.
Ficus do far better when root pruned in active growth mode.
Tropical Aussie growers around Brisbane have found that even some temperate species like Chinese elm that does not go dormant in their area can be repotted any time of year up there. Even in active growth.

I know there are active bonsai growers in Phillipines and Indonesia. If you can find some sites there may be some good tips from them. Otherwise Ausbonsai.com.au has some active Aussie growers from tropical areas of QLD.

 

[Crawforde]

I’ve never noticed a correlation between lightning and N.
Where I live we have daily thunderstorms all wet season long.
Background N and P levels are measured.
I’ll have to look up the N if you are interested, but the P levels fluctuate around 10 PPB. That’s a little lower than what you would have in purchased distilled water.

 

[Shibui]

It is no wonder you have not noticed if you have daily thunderstorms. It is only when we switch from stored water to thunderstorm rainfall that the difference is seen so clearly.

I will be interested to see your N and P levels. Are they soil or water levels? Water soluble nutrient levels are often low in high rainfall environments because the high rainfall leaches these nutrients from the upper soil profile.

 

[Tieball]

What you asked made me wonder also. I don’t have the abundant lightning storms that you have in the tropics. However, every spring, when I do get storms, I notice the grass, tree leaves, bushes, anything growing, is a brighter fuller green. So I lightly researched and found this commentary:

**********
“Air is comprised of 78% nitrogen and about 20% oxygen. Nitrogen is an element that plants need for chlorophyll production (which aids photosynthesis), foliage development, and overall growth. It is usually the main ingredient in fertilizers. However, the nitrogen in air is not in a usable form for most plants. So how do plants get nitrogen that is in the air?

From lightning.

The intense heat and electric charges produced by lightning causes the nitrogen molecules in the air to cling to the oxygen molecules. This bond forms nitrogen oxides. The nitrogen oxides will either fall from the sky, or be collected by the rain drops – bringing a form of nitrogen that can now be used by the plants.

The plants now receive a supercharged dose of available nitrogen, causing them to become brighter, healthier, and greener.”
**********
Several articles explained this natural occurrence. I just Google searched “Is lightning beneficial to plant growth”. Interesting reading. Some articles also discussed how to harness the electrifying effect with the collection of static electricity in gardens that is then released to the soil when watering.

The many articles I found clarified what was happening between plant life and lightning storms. I found an earth benefit I just didn’t know about.

 

[Crawforde]

I would assume that lightning abused NOX deposition, while measurable would be insignificant compared to that fixed in the soil by soil microbes. I’m just Just guessing based on old memories, so I could be convinced otherwise.
I think remember a study in Texas and another one in Florida that tried to quantity atmospheric deposition and one of them looked at possible additive lightning effects. From what I remember the amounts per acre were pretty low, compared to fertilizer or soil microbe fixing. But I haven’t looked at that stuff in years. It’s worth a google search.

 

[Anthony]

We use an N -0P - K fertilser for lawns during our Dry Season
[ Dec - May / June - no rain ]
1/3 strength.
Things stay green, but extensions are slow or zero.

The wet season once a month or so of Blaucorm
Sprinkle.
41 years.

Transplanting as suggested by the Phillipines
is April / May for Tropicals.
Good Day
Anthony

 

[Bnana]

N from lightning is very low levels, is also not deposited immediately. The NOx from traffic and factories will be much more significant in Singapore, that's far above the natural level.

 

[penumbra]

Granted that the level of nitrogen in thunderstorms is low, but I would argue that its effects are immediate. After 55 years of working in every facet of horticulture I have seen ample evidence of it. Most notably in lawns on commercial sites that get excellent irrigation. They do well as a rule but the actual color of the green deepens significantly within hours of a thunderstorm.
This is not textbook wisdom but pure observation over decades. Ask anyone into landscape maintenance.

 

[Tieball]

Granted that the level of nitrogen in thunderstorms is low, but I would argue that its effects are immediate. After 55 years of working in every facet of horticulture I have seen ample evidence of it. Most notably in lawns on commercial sites that get excellent irrigation. They do well as a rule but the actual color of the green deepens significantly within hours of a thunderstorm.
This is not textbook wisdom but pure observation over decades. Ask anyone into landscape maintenance.

My lawn and all the trees around me do the same...a thunderstorm leaves behind a really fresh and healthy green color after a thunderstorm rolls through. The fresh color lasts for several days. No science study on my part...just observation. And, I like the fresh green color. It’s a benefit of a thunderstorm no matter what time of the spring, summer or autumn.

 

[Bnana]

Could be true but I don't think it's got anything to do with NOx. A truck running idle next to the grass for a few minutes has a larger effect on NOx.

 

[AussieBonsai]

From NASA :
According to a new paper by Ott and Pickering in the Journal of Geophysical Research, each flash of lightning on average in the several mid-latitude and subtropical thunderstorms studied turned 7 kilograms (15.4 pounds) of nitrogen into chemically reactive NOx. "In other words, you could drive a new car across the United States more than 50 times and still produce less than half as much NOx as an average lightning flash," Ott estimated. The results were published July.

 

[leatherback]

From NASA :
According to a new paper by Ott and Pickering in the Journal of Geophysical Research, each flash of lightning on average in the several mid-latitude and subtropical thunderstorms studied turned 7 kilograms (15.4 pounds) of nitrogen into chemically reactive NOx. "In other words, you could drive a new car across the United States more than 50 times and still produce less than half as much NOx as an average lightning flash," Ott estimated. The results were published July.

Who wants to upscale this...

Fun Facts About Lightning

A few fun facts about lightning.

learn.weatherstem.com

100 strikes globally per second on average. 8M strikes globally per day. 3B per year
Earth surface is about 510M km2

So..
3B * 7kg = 21B kg NOx due to strikes per year. Over 510M km2. That makes about 40kg per square km per year. Or 0.36 pounds per acre.

Unfortunately that is in the air, and not what gets dissolved in the rain..

 

[AussieBonsai]

I’ve reached out to the Nat Uni of Singapore to see if they can settle this...

 

[leatherback]

I’ve reached out to the Nat Uni of Singapore to see if they can settle this...

Why not do a little research yourself? There is info on the web..

in 1960 there were already academic discussion: https://journals.ametsoc.org/doi/pdf/10.1175/1520-0469(1960)017<0681:LATOON>2.0.CO;2


And if you go here: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/JD094iD08p11089 and follow the citing literature, you will get a bunch of newer findings on the topic. Spend a few hours delving through those and You know all thre is available.

 

[AussieBonsai]

Thanks. I did have a look (little else to do here while in lockdown..) And found those same articles, however some were contradicting and couldn’t find anything specific to the tropics where the affect would presumably be amplified. The impression I have is that it is still being researched and not fully understood. NASA’s page seems to imply that it is large, while Mich U seem to suggest its minimal.

 

[Bnana]

Of course does lightning create NOx but looking at the bigger picture it's obvious that concentrations of NOx in the air are mostly related to burning fossil fuel.
Just look at this map:

NASA CSI: On the Trail of a Hazy Global Killer - NASA

For more than three decades NASA has focused its space-faring skills and science chops CSI-like on an elusive global killer. Later this month, that pursuit

www.nasa.gov

The red spots are industrialised areas, not areas with a lot of lightning.

In Singapore most NOx will be from ships, traffic and industry with a negligible input from lightning.