View Full Version : Synthetic ferts might encourage disease, do organic ferts as well?

08-20-2008, 08:57 PM
I think so...

I think Compost Tea, and Compost are really the only nutrient inputs that would not encourage disease growth. (Due to the good microbes that come with them)

What do you think?

Also, there have been studies how CT's reduce diseases, but are there studies showing that organic ferts do the same?

08-20-2008, 10:17 PM
It seems to me that the diseases are caused by adding fert when it is not needed. For the most part synthetic ferts are put down as a feed now and when it rains... wording may not be exact so hold the tomatoes, organic ferts are broken down as the plants require them? so they aren't fed more than they need therefore not causing more stress on top.

Right now here there is a MAJOR watering issue, I have swapped ALL my customers to a organic fert of 4-2-3? Something like that, with 50% OM. The thought here is that the plant still receives the nutrients, and at the same time I am getting a little OM down to help hold nutrients, whether it be synthetic or organic, in the future, again, to help prevent over feeding to the plants causing more stress.

Am I wrong? I wouldn't be surprised if I am. It has been a long day in the sun.

08-20-2008, 11:32 PM
I have a hard time believing that organic ferts are broken down as the plants require them. IMO they are broken down as quickly as the environment allows microbes to consume them.

But IMO in some cases where nutrients are not readily avaiable the plant can make the envornment more appropriate for more microbes and hence what OM is there is more quickly consumed and available as a result...

08-20-2008, 11:34 PM
don't the plants tell the microbes what it needs therefore breaking them down to get the needed nutrients?

08-20-2008, 11:40 PM
I understand it more like the plant makes it easier for the microbes to metabolize and reproduce. I don't think the plant actually says hey I need 2,400 more moles of potassium, and the microbes start up production.

But perhaps plants do use something like quorum sensing with microbes.. that is all speculation for now... The known is that plants can excrete food which helps microbes metabolize (which helps them digest more SOM) which indirectly makes more mineral nutrients avaiable to the plants.

Kiril might need to step in, but that is my current understanding.

But with that understanding that is why I think organic ferts can encourage disease just as much as synthetic ferts... I don't think the bad fungi care what form the food is in... if the food is there and they have an opportunity to reproduce, they will.

08-21-2008, 12:23 AM
I don't think the question is between synthetic vs. organic (or "natural). It is a question between quick-release vs slow-release. Quick-release is best utilized as a spoon feeding. The problem arises when too much quick ' is applied at the wrong time, promoting surge growth in expense of root growth. This puts the grass in an "exhausted" and stressful state, making it more susceptible to disease pressure.

IMO, synthetic-organic slow-release sources (Urea formaldehyde, methylene urea, urea triazone, et. al.) can be utilized in a responsible matter just like natural fertilizers can, efficiently and without excess. I agree that the addition of beneficial microbes is important, and can reduce disease pressure in either program, but is not exclusive.

08-21-2008, 01:10 AM
More food ..... more microbes. Growing plants provide food.

It may be possible that some plants are capable of "stimulating" microbial activity (even specific microbes) in the rhizosphere by releasing certain compounds, which results in more nutrients available for uptake. That said, I do not believe the science is anywhere near making that determination with absolute certainty, especially given the complexity of studying rhizosphere relationships. Perhaps Tim has some pdf's quickly available that address this, I know it is one of his interests. I will search my archive when I get a chance.

08-21-2008, 01:14 AM
ok, I see where not to make an assumption until better understhood. Thanks Kiril.