Tag Archives: nematode

The Microbes Version of the Thermal Compost

March 13, 2020

The Essence of A Thermal Compost
as told by the microbes, in community

Material Variety

Amy Amoeba begins the compost story, “Wow. I just got thrown onto a big pile with critters I have never seen before.”

“Yes indeed”, echos Belinda Bacteria ecstatically, “Look at all the nitrogen choices: one bucket beer mash – very hot commodity, and three buckets of finely chopped fresh plants, coffee grounds and seeds. Yum. Yum.”

“As for me”, responded Henry (fungal) Hyphae, “I prefer the six buckets of carbon a la carte: sieved wood chips, hardwood bark and brown leaves. Plenty of carbon here for me to put away in the soil. I can break down lignin and even plastic!”

Belinda again. “I just got a text from my cousin Armando Bacteria. He’s in a pile with only manure and straw.

“Oh no!,” the microbes chanted, “Borrring. With so little diversity, that compost might not have enough nitrogen-metabolizing bacteria. And will it be the best pathogen suppressant?”

Sun, Mar 15, 2-4, Work Party
Mon, Mar 30, 6:30-8:30pm, Fig Pruning Class
Mon, Apr 6, 6-8pm, Work Party
Sun, Apr 19, 2-4, Work Party

The Mesophilic Stage

“It’s getting cozy now.” Pretina (predatory) Nematode was delighted. “At 125F, and with 50% moisture, we can feast without worrying about whether we’ll use up the oxygen or water.”

But Henry sounded the alarm. “Well let’s not spoil it Pretty Pretina. Let’s just keep the temperature right where it is. Slow down. Chew each bite 20 times.”

Amy Amoeba, transformed in her naked form, moved closer. “But wait Henry. We won’t get rid of those nasty plant pathogens until it feels like an oven in here.”

The Thermophilic Stage

“Whoa”, cried Nemar, the young bacterial-feeding nematode. “We have been pigging out, using the moisture and oxygen. We may end up in a dray sauna! I think I will lay an egg and then get outta here.”

“Belinda Bacteria choked out a few words. ” I am only so mobile and I can’t get to that bamboo pole with air holes in it. I’m writing my will.”

“Oh no you’re not,” exhorted Amy, “I insist that you encyst! If the temperature is above 131F, we only have to hang on for three days or, at 150F – just two days and, if we can handle 165F – just one day. Those times and temperatures will take care of the pathogens. Look over there. Silly Ciliate is spinning into a dormant cyst right now. Maybe we will get through this. It’s necessary that everybody take a turn in the hot center.”

“Well now”, slurred Baxter the nasty (pathogenic) bacteria. “150F this morning. Pretty hot but I found a completely dry pocket in some oversized chips. I can weather the storm tucked in here. Feng Farmer better do a thorough job of watering and turning if he wants to eliminate me and my weed seed pals.

“Oh my. What is going on?” Baxter’s adrenaline soared. “Someone just tossed me from the middle of the pile to the outside and the outside of the pile is going into the middle. And a splash of water everywhere. This farmer knows how to rid the compost of pathogens.”

“Oh. Yes. Feng is a pro!” Pretina confirmed, “I have been on this farm for years and I know they turn and water the pile. But they only turn as many times as needed to ensure all parts roast for the required amount of time, per Amy’s outline above.”

The Cooling Stage (Second Mesophilic Stage)

The alarm clock of Nemar’s protected egg sounded and he broke out from his dormant state. “Hello everyone.” He panned the abundant new microbial mix, searching nervously for any hyphae that might be constructing nematode-trapping loops. He twisted toward an unknown amoeba. “Can you tell me where the nearest Starbucks is? I just woke up.”

The amoeba responded kindly. “There may still be some remnants of the coffee grounds but most of us drink compost tea. It’s cheap.”

The young nematode sipped some tea and observed how fast the numbers and types of microbes were increasing. They were coming out of dormancy, hatching from eggs,  joining from the surrounding soil, or being dispersed by a larger organism. It seemed they were falling from the sky. So many different microbes! Tens of thousands per gram of soil. “Time to eat!”

The Maturation Stage

In six month’s time Nemar’s nematode egg grew to be a reproductive adult. She knew the compost had been stable enough for the garden for a couple of months; microbial respiration had slowed and the pile had reached ambient temperature. She also knew, however, that the diversity of the pile kept increasing for about six months and right now the compost was mature for one of its main uses – as a pathogen suppressant. The proof, of course, will be in the pudding: the successful seed germination and hearty plant growth.

“We are in the zone!” She shouted to the others. “The volume of fungal hyphae have finally caught up and we now have a fungal to bacteria ratio of 4:1, perfect for the apple trees. The color of our pile is dark brown and doesn’t smell like rotten eggs. I hope Feng is not thinking to wait until we look like soil because at that point, we won’t be compost anymore. Feng! Liberate us. Use us or lose us!”

“Feng is so smart. Here he comes with his wheelbarrow”, smiled the amoeba. “We can keep the soil food web going.  Those of you who aren’t coming along in this ride, you’ll be comfortable because Feng will maintain the pile at about 35% moisture.”

Feng looks closely into the pile. Belinda Bacteria has the energy and divides. But here comes the nematode to snarf up her new sister. A clever fungal hyphae squeezes Nemar’s offspring, and it’s not love. Then Amy Amoeba sits and sucks on the hyphae, but then soon becomes lunch for a Springtail (Collembola).

I acknowledge Dr. Elaine Ingham, with Soil Food Web, who makes science very accessible. And to Seattle’s Sound Bio Lab, a non-profit science lab that turns no one away.

The photos are from my microscope, sent to ClipppingPathIndia where they make line drawings from photos.

Watch the freewayestates.org calendar for a thermal compost class in May.

© 2020 Ruth Callard

Soil Camp

May 27, 2018

Last week I attended a five-day soil science class with research scientist Dr. Elaine Ingham, just outside of Oroville, CA, where they say Ahmonds when referring to Almonds.

Seven of us hovered over microscopes much of the time, counting nematodes, protozoa, and bacteria. Near the end of each day, it was hard to differentiate the floaters in our eyes from the Oomycetes we were trying to measure.

By Thursday I accomplish something very special – how to correctly place the cover slip on the slide. Seriously, this is an important step. By the time you are done measuring the volume of an organism per gram of soil, by taking five counts from each of five sections of each slide, you hope your standard deviation is at an acceptable level. A way to increase the reliability of your data is to master the art of the cover slip.

On Tuesday, I ask Elaine, who never refuses anyone’s questions, if I can watch her put the cover slip on the slide. Instantly I hear chairs screech as the other students dart over to watch.

Elaine, with the grace that comes from 40 years of doing anything, places the edge of the cover slip on the slide and we watch the drop of water disperse along the edge of the slip. Then she sweeps back and forth, back and forth and drops the slip.

I take a breath and try it again myself. As soon as I start my slide I realize I have missed some step. I drop the cover slip and there is an air bubble and all of the visible organic matter is under 20% of the cover slip!

On Wednesday I tell myself not to be proud and again I ask, “Dr. Elaine, would you mind if I watch you put the cover slip on again.” She graciously gets out of her chair and, once again, the other students position themselves to see the show. She places the edge of the slip to the left of the drop. The drop, hugs the right side of the slip. She leaves the slip in contact with the slide and sweeps to the RIGHT, then left, then right, then drops it. Aha…

By Thursday, I am preparing more uniform samples. (Look soon on our Library page for the soil test results of the thermal compost I made last November. (Thanks immensely to Jennifer Micheli, Elaine’s employee, for enhancing Dr. Ingham’s soil biology test result spreadsheet.)

By Friday, we have completed everything on the agenda (white board photo) and have bathed in the knowledge of Dr. Ingham for a whole week (except for half a day when a film crew from Johns Hopkins was visiting the farm). I am certain it was the most worthwhile and enjoyable investment in education I have made.

Ruth

Good Soil Biology – The Perfect Recipe For Plants

December 19, 2017sm-171119-big-nema-400x-worm-bin-tc_7

It’s time to honor our important volunteers who live in the soil – the nematodes, protozoa, microarthropods, fungi and bacteria. All these fellows work tirelessly underground, decomposing organic matter and pooping out the nutrients in the form that plants can use.

In fact, organic matter is the only food we have supplied for the orchard trees and shrubs over the last six years. And, now that we are using the thermal compost process (see Nov. 2017 blog), we will be regularly cooking up tasty treats our plants enjoy.

rc-plant-succession-slide-elaine-ingham-life-in-the-soil-oxford-keynote-2014Plants put out sugars in their root zones to attract the critters they most desire. Early succession plants, like weeds, desire soil with more bacteria (see Ingham slide). Late succession plants, such as deciduous and conifer trees, prefer fungal dominated soils.

When we make our compost, the types of inputs we use will determine whether the compost will also be bacterial or fungal dominated.

How do we test the characteristics of our compost? We can put the finished product under the microscope and actually count how many bacteria, fungi, protozoa and nematodes we have and then convert the counts to biomass.

Sun, Dec 31, 2-4, Roof Work Party
Sun, Jan 21, 2-4, Work Party
Sat, Feb 17, 1-3, Pruning Class

Dr Elaine Ingham offers very accessible online classes in soil biology, making compost, compost tea the-soil-food-web-nrcs142p2_049822and using microscopes to test soil life. She discounts classes at various times of the year. If you take these classes, you will learn how to be a good land steward (see Ingham’s soil food web slide).

You won’t remember but, when seed plants arrived over 360 million years ago, good soil biology was already in place. Plants know what they need from the soil and how to get it. We can all play a part to improve soil quality by minimizing soil compaction and avoiding use of inorganic fertilizers. The importance of soil is the subject of this recent article from the New York Times.

Ruth