Organic Fertilizer - one or many?

[emk]

So, I'm busy devouring Naka's first Techniques book and one thing he mentioned seemed somewhat dubious compared to other things I've read. On his section on fertilizer, he discusses how to make fertilizer "biscuits," and then suggests placing just one on the surface of the soil, in a corner or on the edge of the pot behind the trunk. Similarly, he suggests that if you use dust/powder rather than biscuits/cakes to make a large pile of in one spot on the soil.

For comparison, Koreshoff promotes placing multiple cakes (depending on the size of the bonsai) in different areas of the pot (e.g. one in each of the four corners).

Naka's fertilization method seems to imply that so long as any part of the root mass gets nutrients, the whole tree prospers. I know that junipers in particular exhibit a tendency to transfer water/food horizontally (thus their ease at being treated with severe shari techniques), but I didn't know that many other trees were like this. Koreshoff (and most other authors as well) doesn't seem to buy into this method, which further suggests something is amiss.

Now, since all of the other new ideas I found for the first time in Naka's book make good sense, I want to believe that I might just be ignorant on this point. When you water the tree, wouldn't the fertilizer only penetrate the soil in a conical region directly below the biscuit? If that's true, then wouldn't you have a disparity between the roots that were being fertilized (let's say about 1/3 at most) and those that weren't? Wouldn't that lead to uneven growth above as well, since the water and nutrients basically follow a direct vertical route from roots to branches & foliage? At least, that's how I understand the mechanics of tree biology, so if I'm way off here I'd rather be corrected now that have my trees suffer from my ignorance.

 

[Anonymous User]

Put a paper towel on your counter, add a few drops of water only at one point, observe what happens....


Water or the nutrients it contains does not go straight down and out the drainage holes, it is absorbed by the soil in an ever widening (think upside down cone) area as it soaks in.

As with your paper towel, where the couple drops of water spread out and wet an area far greater than the water originally touched, the fertilizer also spreads out in the soil.


This is not to say that you should only place one ball on the extreme outer edge of your pot, but that is is not necessary to cover every square inch of soil.



Some Other Resources for you. (Or you could check here, oops, you already did, sorry.)


Will

 

[agraham]

I'm not sure of Naka's reasoning for that recommendation.It seems odd.Especially with the coarser soils being used today,I doubt that the fertiliser would be spread very evenly in the soil/water solution if not evenly distributed over the soil(or in it).

andy

 

[emk]

Put a paper towel on your counter, add a few drops of water only at one point, observe what happens....


Water or the nutrients it contains does not go straight down and out the drainage holes, it is absorbed by the soil in an ever widening (think upside down cone) area as it soaks in.

As with your paper towel, where the couple drops of water spread out and wet an area far greater than the water originally touched, the fertilizer also spreads out in the soil.


This is not to say that you should only place one ball on the extreme outer edge of your pot, but that is is not necessary to cover every square inch of soil.

That's pretty much what I was getting at by saying "...wouldn't the fertilizer only penetrate the soil in a conical region directly below the biscuit?" In a deep pot (for cascades or training) or a grow box I could see that this area would be pretty large, but for shallower bonsai pots, I don't see how that area would be large enough. Maybe the network of fine roots makes the soil more like a paper towel than a pile of sand, so that would indeed help the distribution.

Some Other Resources for you. (Or you could check here, oops, you already did, sorry.)


Will

Thanks for the first link...we've already had a "discussion" about the second.

 

[Chris Johnston]

That's pretty much what I was getting at by saying "...wouldn't the fertilizer only penetrate the soil in a conical region directly below the biscuit?" In a deep pot (for cascades or training) or a grow box I could see that this area would be pretty large, but for shallower bonsai pots, I don't see how that area would be large enough. Maybe the network of fine roots makes the soil more like a paper towel than a pile of sand, so that would indeed help the distribution.



Thanks for the first link...we've already had a "discussion" about the second.

Some of what Naka taught has been superceded by better information as the years have gone by and more information and better soils have come into use.

This was perhaps a case of miscommunication in his book but it has contributed to the dearth of healthy trees among American bonsai enthusiasts for many years. Feed your tree. Make the cakes like he says, and if your tree is young or in development, feed the heck out of it. It's not necessary to cover every square inch of the soil, but sometimes that might be the appropriate amount. One fertilizer cake in one corner of your pot is insufficient even for the oldest, most completed tree.

One other thing: for a tree with a good mycorrhizal mantle can take advantage of nutrient sources far beyond the reach of the roots themselves.

 

[Chris Johnston]

I'm not sure of Naka's reasoning for that recommendation.It seems odd.Especially with the coarser soils being used today,I doubt that the fertiliser would be spread very evenly in the soil/water solution if not evenly distributed over the soil(or in it).

andy

Andy, part of his reasoning (judging by the teachings of those who only studied under him in the 70s) was to keep the tree from growing too much. As you already know, this is completely counterproductive to what we are trying to do as we bring trees along.

 

[Anonymous User]

One other thing: for a tree with a good mycorrhizal mantle can take advantage of nutrient sources far beyond the reach of the roots themselves.

While this is true, we must consider the environment, in our case this is a bonsai pot. Unless the tree is freshly potted or unhealthy, there is little area that is actually outside the reach of the roots.



Will

 

[Chris Johnston]

While this is true, we must consider the environment, in our case this is a bonsai pot. Unless the tree is freshly potted or unhealthy, there is little area that is actually outside the reach of the roots.
Will

Well that's obvious. It was just an observation. On many collected trees, it may be a while before the roots fully colonize the pot, but the mycorrhizae can do so much faster.

Either way, Naka's advice was often taken by his students to mean "be stingy with your fertilizer." I can't believe he really meant that. For our trees to be healthy and strong, developing trees need far more fertilizer than most of us are comfortable putting on our trees.

 

[emk]

Thanks for sharing your thoughts and insights guys!