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David Johnson

David Johnson

Molecular biologist and co-inventor of the Johnson-Su composting bioreactor; retired from New Mexico State University's Institute for Sustainable Agricultural Research and adjunct professor at CSU Chico's Center for Regenerative Agriculture.

Jun 28, 2026

1:06
I have great tomatoes, I have great lettuce in the field." And they're wondering, okay, could it be better? Is the best thing to do, you gotta try it, or is there some sort of test? Can you see this under a microscope? Can you send a sample of soils somewhere to say, "Okay, what does my community look like?"
1:23
I...
1:24
From what I've observed as a microbiologist, I don't see a good test yet.
1:29
Uh, I see a lot of, you know, looking at fungal to bacterial ratio through microscopy, you can get such a varied results that you can't really make heads or tails of what's going on.
1:44
If it's blatantly obvious, yeah.
1:48
But I've sent compost samples, the same compost sample in, and had it analyzed three times, and I got three different results going from bacterial dominant to fungal dominant.
1:59
So that scares me away from...
4:44
What are your thoughts around percentage of organic matter in relation to soil health, and is there an upper limit where there could just be too much?
1:00
At its core, what are the base principles around the compost that you're
1:05
using? The method that we developed maintains four key factors on this.
1:12
It's aerobic.
1:13
It always has oxygen.
1:14
The way the bioreactor is designed with the columns up the middle, you're never more than 6 to 12 inches from ambient air.
1:22
So it's a completely aerobic process.
1:26
It's a process that operates at about 70% moisture content.
3:36
What are the big differences in johnson sue bioreactor compost versus traditional compost if you just drive to the landscape yard near you and they sell compost what are the differences in those methods well
1:34
On the other hand, you have people just piling compost on Do you think that an approach of just constantly putting on compost is it's working, but maybe you're working too hard or it's not really a means to an end? Is there some way that people can move from this, just dump it on to a more sparse application? Well,
1:58
yeah, that's what we're seeing.
1:59
I started out at 400 pounds per acre, which is a dusting.
2:03
So it's not a nutrient amendment the way We're developing this.
2:09
It's an inoculant of the microbiome.
2:12
We're down now to two pounds per acre and having success.
2:17
The farmer was $80 an acre more profitable by using the compost from this bioreactor and that research in Wilcox.
4:41
between you took really high quality compost that is a food source and an inoculant in one and you put more of it on a poor soil initially, you're going to get results that much faster?

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