First up, here’s what compost is not

Compost is probiotics for soil

When we make composts, we are really making an ideal environment for beneficial aerobic soil organisms to thrive.

Why does soil need compost

Just as we need beneficial microorganisms in our gut for overall health and well-being, soil needs microorganisms (and plants) to keep it healthy and thriving. Hans Jenny, the father of soil science, defines soil as:

At Project Black Gold, we like to call this whole soil, like whole food.

In Singapore, our soils are mostly heavy clay that is lacking in organic matter and aerobic organisms. Gardeners usually try to lighten the soil by adding sand, which is an equally heavy mineral. If we added compost instead, the texture and biology would be greatly improved

When soil is whole, it is able to

  • Support healthy plant life above the ground-by providing the right structure for root development, and a buffet of nutrients for plant growth.
  • Support vast and healthy ecosystems below the ground to ensure ongoing regeneration of the soil food web that is vital to life on earth.
  • Act as a sponge-by absorbing and retaining moisture, preventing ponding
  • Act as a filter for ground water so that our rivers and streams are cleaner
  • Function fully as the carbon sink Nature meant it to be-drawing down atmospheric carbon, and sequestering it for longer periods of time

In a nutshell, soil loves compost, plants love compost, and we most certainly love making compost.

At the two Project Black Gold neighbourhoods, we practice aerobic hot composting

The aerobic hot composting method can be used in an open pile or in an open container because the kinds of organisms that are beneficial to soil and plants are oxygen-loving, and become dormant or die in the absence of it.

The compost is constructed in a particular way with nitrogen and carbon materials to naturally kick-start microbial activity. We do not inoculate our compost piles with store-bought enzymes or microbes, but instead harness the microorganisms that are naturally present in the local environment.

How does the compost get hot? Well, it is definitely not dependent on the sun nor ambient temperatures. As the oxygen-loving microorganisms go through their life cycles of feeding on the compost materials and on each other, pooping and reproducing, they naturally generate heat. The more active the microbial party, the hotter the compost. As the oxygen gets used up, the party slows down, the compost loses heat. If fresh food and oxygen are not added, the party dies down eventually.

The benefits of aerobic hot composting

It is a faster way of making compost, compared to colder methods. The level of bio-activity means the pile can digest a vast assortment of materials that are available in Singapore – from hardy twigs, leaves, sawdust, cardboard to the more perishable fruit and vegetable scraps, and other food items. The diverse range of materials encourage a broader range of microorganisms, which ultimately makes a better compost.

What are the signs of a well-made ready-to-use aerobic hot compost

  • Dark chocolate brown
  • Except for some chunky pieces, the various materials that made up the compost are no longer distinguishable
  • Feels like a smushed up rich chocolate cake, forms and keeps to a shape, but breaks up easily at a touch
  • Cool to the touch
  • Smells like good earth

Look for signs of life:

  • Slightly moist-thanks to the exudates from the microorganisms
  • When kept in a container, there is slight condensation on the container walls-this is the transpiration of the microorganisms
  • Visible tiny white strands interspersed amongst the dark brown organic matter-these are fungal hyphae. They are highly beneficial to soil and plants alike.
  • There are compost-friendly organisms such as sow bugs, springtails, mites, millipedes, centipedes, snails and earthworms in the compost.