Vegetable Root Development

[vicj]

[eeldip]

i feel like soil science in general is a practice that is constantly undergoing changes. lots of advice that people give just wastes time and energy.

i was just reading yesterday about a study that concluded that compost tea does less to stimulate soil microbes than synthetic fertilizer.

https://sharepoint.cahnrs.wsu.edu/blogs ... stuff.aspx

(the take-away being, add compost. forget the compost tea. if there is a nutrient problem, add fertilizer.)

[Lollykoko]

Thanks for the article, Eeldip. It's good to know that studies are still rigged to give the response that pays off in contributions from big ag.

They diluted the compost tea. The compost had less microbial life than standard, and the writer of the article thinks they dosage of commercial fertilizer was higher than normal.

[eeldip]

no, they used concentrated tea, diluted tea, and fertilizer in three different trials.

compost tea has not held up to study for a long time, this is one of many studies that support that.

[Lollykoko]

This is the section that led me to the conclusions I made. Lacking the empirical data from the study, this is all I have to go on.

Quote from article (my bold): “Aerated Compost tea appears INFERIOR [you read that right – inferior] compared to fertilizer in its ability to increase microbial biomass, microbial activity” and a few other things. Hmmm…I’d been told that microbes hated synthetic fertilizer. I guess not all microbes agree. In terms of the fertilizer used, it was a 30-10-7. I didn’t see it explicitly stated in the article, but I’d bet it was a synthetic fertilizer called Arbor Green Pro. It was applied at what I would consider a heavy dose.
Aerated compost tea, or at least the compost tea tested in this article, did contain a significant amount of nutrients.
On the up side for compost tea it was pointed out that compost tea treatments might help a poor soil retain more nitrogen. Maybe…but the authors also pointed out that “only the fertilizer treatment appeared to deliver enough available nitrogen to potentially meet tree needs in the Bt horizon soils” (in other words poorer soils). Interesting – but if we just added compost we’d have a better soil anyway, which brings us to the next point….
The compost tea tested contained only a small portion of the microorganisms that compost does. (end of quote)