What is Compost?

When one walks attentively in a natural forest, one’s senses are inundated:  the sounds of the breeze through the leaves, the birds singing away, and the buzz of insects; the play of the sunlight through the branches, the infinite hues of green among the countless types of foliage; and the earthy smell.

There are incredible yellowwood forests in KwaZulu-Natal, South Africa. Click through the gallery above to experience a hike through one of these forests.

Earthy smell. What is that? Is it the forest soil?

Dead organic matter is a primary source of nutrients for growing plants. Plants are designed to feed from the soil surface.

That wonderfully, pungent, earthy smell that moistens your nostrils in a forest does not come from the soil alone. It comes from the precursor to that soil. It’s the smell of nature’s recycling system working. It is, in fact, the smell of death being transformed into life.

Dead organic matter is a primary source of nutrients for growing plants. But first, it needs to be changed — broken down, decomposed, transformed — into a form that plants can access. This transformation is accomplished by bacteria and fungi, without which there would be no life. Amazing!

The transformed organic matter is… compost.

A paintbrush lily thrives in the
decomposing blanket of organic matter
at the base of mighty yellowwood trees.

Under foot in the forest is a thick blanket of decomposing leaves, twigs, fruits, last year’s annual growth, and animal droppings. If you dig a little into this covering, you discover layers of organic material. The farther down you dig, the more advanced the decomposition, until you get to fully cured compost. The compost is soft, crumbly, and sweet-smelling. Pure fertility.

Plants and trees are designed to send their nutrient-gathering roots into the top levels of soil, where all the nutrients from the decomposing blanket are! Some of the world’s great forests are growing in terrible (infertile) soil and subsoil. How is that possible? It’s possible because the naturally occurring plants of the ecosystem are feeding at the top of the soil profile where the nutrients are. Amazing!

Natural decomposition in the forests happens gradually. It is the nutrient replenishment that the forest depends on. Nothing dies and is discarded. Instead death gives way to new life. It is the way God intended his natural ecosystems to exist and it is the way we ought to mimic when we step into the role of farmer, gardener or cultivator.

Keeping the Inundo soil blanketed with thick mulch is good food for the plants

How Can We Imitate What We See in Nature?

When we learn from God’s ways, we keep our soil blanketed with a thick mulch cover. That cover slowly breaks down, just like in a forest. We can care for the soil structure by never ploughing or inverting the hidden layers which hold together in a complex structure with amazing water holding capacity.

Adding 500ml of compost to
every maize planting station

We can also do even more to imitate God’s incredible ecosystems. We can make our own compost and give it back to the soil every season. In fact, we teach that you have to give generously to the soil to aid in its ability to give back to you. The role of a wise farmer or gardener is to make sure there is enough organic fertilizer for our crops. In that regard, we always add homemade compost.

Hot Composting Method

At the Inundo Model Farm, we teach hot composting. Hot composting has the added advantages of making more high-grade compost in less time, and we can add diseased material or weed seeds, because the seeds and pathogens are killed by the heat. The pile needs to be turned a number of times, though, because otherwise the pile gets too hot and burns up some of the nutrients we want in our compost, and the pile becomes anaerobic — which results in low quality compost (and a bad smell!).

One of our first tasks at the model farm in 2020 was to make our first compost pile. A compost practical was a great learning activity for the interns. There are 5 key ingredients for compost:


  • Dry and Brown Material
  • Dry material provides most of the carbon component
    • Dry grass and leaves
    • Dead weeds
  • Woody Material
  • Woody material gives height and structure to the compost pile. You need bulk to keep air flow throughout the pile. Woody material encourages fungal growth.
    • Sticks, bark
    • Maize cobs, and stalks
  • Greens
  • Green material provides plant sugars to encourage bacterial growth. Sugars exist in plants that are still green.
    • Freshly cut plants
    • Still green
    • Grass, pruning trimmings
    • Fresh Weeds
  • Manure
  • Manure is your nitrogen source and fuel for bacterial growth
    • From any animal source
    • The fresher the better
  • Water
    • Having a tap nearby with a hose is helpful
    • Lots of water is needed

We collected most of our materials from organic sources right on the property. Sticks and bark came from brush piles we had collected over a few months. Dry leaves were raked up from the lawn. All pruning discards were also collected and placed into piles. Greens were collected 48 hours ahead of making the pile. Invasive ferns became our greens along with avocado leaves. Our neighbour offered us her horse manure which was a fantastic gift.

Compost Ingredient Ratios

To get the ratios of the different materials correct, we build the pile in layers. The recipe for compost to be used in a vegetable garden (adding plenty of water as the pile is being built):

  • 5 cm layer woody material
  • 15 cm dry material
  • 20 cm green material
  • 2 50kg bags of well wetted manure
  • Repeat the layers until the pile is 2 metres high

It is essential that lots of water is added through out the entire process. Many compost piles will not activate properly without sufficient water. On our first compost turn, we had to add extra water because there wasn’t enough activity in the pile.

Scroll throw the gallery below and see our compost pile grow layer by layer… and you’ll see that it is also fun working together.

Once the pile is built, the temperature needs to be monitored – either with a compost thermometer, or a steel rod pushed into the pile (once you leave it in for a few minutes, if you can’t hold on to the rod, it’s time to turn!). When the pile reaches 65 degrees C, it’s time to turn. After 8 or 9 turns, it’s time to leave it to cure for 4 months. And then… black gold!

Compost Has So Many Benefits

When we teach Farming God’s Way, we teach learners not to worry about their potentially marginal soil. The best amendment for sandy soil? Compost. The best amendment for tight, clayey soil? Compost. Soil acidic? Wood ash (or bonemeal, or agricultural lime) is great for adjusting the soil ph. But for added, amazing ph buffering? Yep; compost.

Dan tests the moisture content of the compost.

The benefits go on and on. When we put quality compost in, or preferably on the soil, we are adding trillions of microbes that will get to work transforming elements in the soil into plant-available nutrients. Compost  increases water-holding capacity, increases water infiltration, provides a host of micronutrients, decreases water-logging due to better drainage… the list goes on. Compost is the best fertilizer you can use and it’s made from ingredients that can cost us nothing monetarily, if we look around our gardens and communities.

When we go into a community to do a training, one of the essential elements is making a compost pile — for reasons that are, by now, clear. If you are growing, or are wanting to grow anything, we hope we’ve convinced you to get composting!

Published by


Flourishing Land, Flourishing People, Flourishing Communities.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s