Amend or just top dress.

[stonedSay10]

Hi,

Could anyone shed some light on the use of amended soil in organic growing?

How do plants utilize nutrients in the amended soil throughout the growing period? For instance, Gaia Green recommends amending new soil with 3 tablespoons per gallon of soil, whereas for top dressing, it's 1 tablespoon per gallon of soil on a monthly basis. Am I wrong to assume that based on this information, amending the soil should maintain the nutrients for approximately 3 months, potentially eliminating the need for top dressing altogether?

 

[Hog_M@Gundy]

Simple(ish) explanation:
Gaia Green and other dry amendments are not plant available as they are. When incorporated into soil, microbes (fungi and bactiera among others) essentially eat and break down the bits of rock dust and organic material then, when they die the nutrients contained in the amendments are released in plant available form.

As far as your other question, no I don't think it necessarily means that amending new soil will feeds for 3 months.
It all really depends on how much soil your plant is in and how big that plant is.
If you amend a 7 gallon pot and grow a medium sized autoflower that runs 84 days, you might be able to do water only and not topdress (though you'd definitely want some kind of microbial inoculated like rootwise or recharge)
But on a 3 gallon pot with the same plant, you would likely need to topdress monthly as recommended.
What genetics are you running and what size pot?

 

[stonedSay10]

My next grow I plan to use 5 gal pot with top layer light soil and bottom layer amended soil. I usually grow Mephisto, short size plants.

 

[HAWKMAN]

for top dressing in flower consider Build-a-Soil Top Dressing - works well OR just top dress with the soil you are using for the grow