A clarification here. When I stated the retention is minimal I meant the unwanted insoluble salts, not the ferts.
I have quite an aggressive feeding schedule from early March to late November there is no break during summer as some books profess. Other literature states to continue feeding right through summer with the exception of when trees are actually in bloom. The latter is found in many circles to include but not limited to orchids. Therefore when a tree starts to bloom I withhold feeding and resume soon thereafter. That being said the composition of ferts used varies with the seasons and species in general. e.g the NPK for flowering and non-flowering species etc...
My take on feeding in the Western world is that feeding hasn't kept with the times of substrate composition. The Japanese on the other hand always had a free flowing substrate. In many books we can still find substrate compositions to include loam etc...
I hope this helped clarify matters. SFII is a maintenance program. SFI is a aggressive building program.
The whole secret to the superfeeding regimen was not the amount of fertilizer that was used. It was the Roots 2 and the Roots 2 liquid with iron.
Roots 2 is not manufactured anymore. Roots 2 was a
humas enriched fertilizer like Gro Power that I have been useing for 4 years now. Roots 2 was 10 percent humic acid and Gro Power is 14 percent humic acid. A superfeeding regimen is not superfeeding without the addition of humic acid to deliver to the roots all that is being offered to the plant to utilize. Organic fertilizers take massive amounts of bacteria to break down organics into useable compounds. Humic acid has been shown to build bacteria quickly to break down fertilizer compound as well as build michoyrizza(sp.) quickly.
Free flowing bonsai soils like we use now have poor CEC's like akadama. Most clay products have poor CEC. The addtion of the humic acid changes the polarity of the soil components to attract and capture the fertilizer ions and make them available to the plant. Without the addtion of humic acid or a fertilizer enriched with humic acid like Roots 2 or Gro Power the fertilizer will wash straight thru. It is impossible to superfeed useing Michael Persiano's formula with out the addition of the humic based fertlizer.
Ironically, the issue of Bonsai Today ( issue 46 )that introduced the world to Michael's superfeeding plan failed to mention that Roots 2 was a product that contained humic acid. For many years I am sure that many people made fertilizer cakes with the formula ommitting the Roots 2 due to availibility or cost. Had there been more of a focus on what actually was making the whole thing work could have changed bonsai as we know it 12 years ago.
As an aside, since I have been doing extensive research on humic based fertilizers for years, I have found this.
http://www.cababstractsplus.org/abstracts/Abstract.aspx?AcNo=20053112688
There are far too many to list so you can check them out yourself if needed. Over 12 years ago I found akadama to be a magical soil. When the issue of Bonsai Today ( issue 6 ) came out telling of akadama's poor CEC I was wondering what made the red clay soil work so well. I think that the volcanic clay soil from Japan may have additional humates already in the soil as retrieved and so fertilizers work well with akadama.
Humic acid is the new frontier in bonsai. Many organic based fertilizers are already containing small percentages of humic acid in their formula. The entire
Kellogs line of fertlizers contains humic acid and many other organic based fertilzers are adding humates with names like " soil conditioning, soil enhancers, soil activators, etc. etc.
Tried not to steal this thread but humates are a very important part of the superfeeding regimen and the real hero was never talked about....untill now!
The photo's show pure humic acid as leonardite, Gropower granuals, gropower tablets, and some organic based kellogs fertlizer all containing humic acid. Not in picture is a humic acid solution I buy that can be diluted and just poured over the soil as a drench, which is basically the same stuff Michael used later in his fertlizer cakes as the Liquid Roots2 with iron.
Thanks, Al