The Compost Conversation – Nutrient cycling: everyone’s doing it!

Over the past few weeks we have been celebrating the impressive skills of the bacteria and fungi in our compost piles. We watched how they each resolve their specific and very different dietary preferences, absorbing the nutrients they have access to into their microscopic bodies.

How do our plants get access to all these delicious nutrients?

Now it’s time to introduce some other members of the soil food web, or in the words of Caesar Flickerman, ‘let the Hunger Games begin’…

Protozoa are single-celled organisms like bacteria, but while they are still microscopic, they are much, much larger. It’s quite entertaining to watch these little critters under the microscope: observing the blobby, naked amoeba slowly oozing its way, or marveling at the beautiful testate amoeba that build intricate protective shells around them from the minerals in the soil . Or watch cute little flagellates bubble by as ciliates zoom by, so fast they are known as the race cars of the Earth. Importantly, each of these protozoa eats approximately 10,000 bacteria per day!

Other essential players are the microscopic worms called nematodes. Some species of nematodes eat bacteria, others prefer fungi, some eat other nematodes! A few nematodes nibble on roots which have given these little critters a bad name, but most are very useful, which is probably why they are the most numerous multicellular organisms on Earth!
So what do they all have in common?

They eat and they poop. And when they poop, they release all the excess nutrients stored in those juicy little bacteria. Now these nutrients are in a form available to plants, a form that plants can easily absorb and use. But it doesn’t stop there; something bigger comes along, like a water bear or a springtail, and eats them!

It is this process of nutrient cycling, eating, being eaten and pooping out excess nutrients that makes our compost so nutritious for our vegetables and our fruit trees. As a composter we are also part of this process. We recycle nutrients from our kitchen and our garden and give them to our microbes to continue this process at the microscopic level, all in our humble backyard compost piles.

So, as you can see, it’s a nematode-eat-nematode world down there, all for the benefit of us and our plants. If you would like to see some of these microbes under the microscope, captured on video of some of our YIMBY* compost, visit our website: yimbycompost.com

And remember: all these microbes need water to survive. The weather has certainly warmed up in recent weeks, so make sure your compost stays nice and moist.

Next week we’ll look at that ashy white stuff we sometimes see when we dig in our compost. What is it and what does it tell us?

– Mikaela Beckley has partnered with Yes In My Back Yard (YIMBY*), a community-scale composting initiative in Castlemaine and the surrounding area. Send questions or comments to [email protected]