Our recipe for outcomes that matter to soil

Your garden is as healthy as your soil.

Reusing kitchen and garden wastes makes sense. You can turn these wastes into crumbly soil-like compost while helping to send less to landfill.

We gave it a go using established systems like the 3-bay method, compost bin and worm farm. We also tried compost activators and adding aeration pipes.

But a persistent lack of success prompted us to ask what went wrong and seek answers through scientific investigation. Now, we have a positive experience to share and an easy method to recreate it.

Begin with nutrition in balance

Compost microbes are our natural allies. They’ll speed up the return of nutrients in organic matter to our soil when fed wastes which as a whole, have nutrition in equilibrium. Instead of a haphazard mixture, get a good start with a composite of sorted wastes.

Balance in macronutrients

First, create a Waste Lasagne recipe with your usual wastes, sorted in layers. As is convention, one layer of waste should be carbon-rich, the other rich in nitrogen.

The macronutrients carbon and nitrogen dictate how quickly compost microbes use up the wastes. An excess of one macronutrient means the other is deficient.

There are telltale signs if there is too little of either one: low nitrogen levels means it takes longer to break down the extra carbon, but a carbon deficiency results in a quick use of available nitrogen and loss of excess nitrogen as a pungent gas.

Always start with the macronutrients, carbon and nitrogen, in balance. Here's an example with kitchen scraps.

Moisture is also essential

Another essential is water. Microbial activity wouldn’t begin if the wastes aren’t moist enough, so include water as an ingredient in a Waste Lasagne recipe involving lots of dry wastes.

The required level of wetness is around 50% water content, similar to a squeezed sponge.

With balanced nutrition and the right amount of moisture, the Waste Lasagne is in the sweet spot for compost microbes to do their work.

Size matters

Cut or break wastes into pieces less than 2.5 cm in size. This provides more surface area for microbial activities, and ensures each piece of waste matter breaks down quickly and evenly.

Match recipe to compost system

The thickness of the layers can vary - a traditional recipe is two parts of carbon waste to one of nitrogen waste. This works well for garden waste composites in compost bins and tumblers, but adapt the Waste Lasagne recipe to suit other kinds of waste or a different compost system.

A good recipe can help us prepare a delicious dish. Similarly, we can use a Waste Lasagne recipe which includes our compost system’s instructions, to turn wastes into plant food.

Follow the waste lasagne recipe

Compost microbes are tiny living organisms. They require oxygen and water to break down wastes and unlock all the goodness in your Waste Lasagne.

Some compost systems require oxygen to be provided by mixing or turning the wastes, and for them, regular aeration should be part of the compost cooking process.

Aerate to supply oxygen

Oxygen is typically provided through air pockets. Woody waste is included in a standard Waste Lasagne recipe because it bulks up the waste with lots of air pockets. The oxygen in air pockets is topped up with regular mixing, to prevent a slowdown in microbial activities.

Aerating by mixing is a taxing task but is a necessity for compost bins and tumblers. Oxygen can run low with poor or little mixing, producing faint smell which can attract rats, flies and other pests.

Interplay between air and water

Oxygen can run out when wastes get too wet, as excess water fills the air pockets and causes rotting. To remove the stench of rot, add dry matter to soak up the excess water, or mix the wastes often to bring up the oxygen level.

The opposite - hot dry air in summer can cause moisture loss through evaporation and halt waste breakdown. Water dry wastes to restart the process.

A well-ventilated alternative

While dryness is a no-no, excessive moisture isn’t really a problem in a well ventilated system. By using controlled airflow to aerate, Bioverter can turn high moisture into an advantage. Compost juice is created as another produce, as surplus liquid is gathered in a collection tray. Enriched with soluble nutrients and useful microbes, compost juice can be diluted right after harvest to water plants.

Good ventilation also remove the need to aerate by mixing.

Consistency in results

Stick to your Waste Lasagne recipe for consistent results. Where required, mix to aerate the wastes and check the moisture level. The demand on your time is minimised with Bioverter, which is designed for unattended operation.

Finish properly with a spell of rest

Cheeses taste better when aged, and wines are matured to enhance quality. So, is mature or aged compost the best kind to make? The answer - YES!

Hot-heap composting

This is the classic method for generating temperatures around 60C to destroy nasties like weed seeds and pathogens. A big pile of wastes (1000L or more) is kept hot for 1 month with frequent turning, then left to rest for 2 months. Ready-to-use (mature) compost is produced in 3 months, but this hot heap method is laborious and only for households with lots of wastes.

Small-scale composting

Small-scale composters like bins and tumblers can’t reach the same temperatures as a hot heap. Weeds and nasties found in pet faeces can survive in these systems, so we recommend excluding them.

Composting is slower at cool temperatures, so wastes take longer to break down in mainstream compost systems. Without regular mixing to keep the wastes aerated, it will take even more time.

Fresh wastes can be added as the current contents are processed, but this results in a blend of wastes at different stages of breakdown after mixing. Harvesting can’t be done until everything has finished maturing, so fresh wastes should go in a second unit. Unless, of course, you have a system that can separate them for you!

Flow-through, insulated section

Wastes are naturally sorted in a flow-through system like Bioverter. As the wastes travel from the point of entry to exit, they are broken down into tiny pieces by compost microbes. Bioverter has been designed and tested to ensure exiting materials are ready to be taken away to evolve into mature compost.

Bioverter is optimised to break down wastes faster and reaches higher temperatures than uninsulated systems like compost bins and tumblers. This also means it can handle wastes that tend to break down quickly like kitchen scraps.

Finishing step - slow but fruitful

The established hot heap method of leaving the compost pile untouched shows an important principle - that maturation occurs naturally when left undisturbed. The same can be done with wastes broken down inside compost systems - leave your harvest to mature properly in your garden to enjoy an increase in beneficial earthworm activities.

Ready-to-use compost

It takes two stages, breakdown and maturation, to turn wastes into ready-to-use compost.

For optimum results with small amounts, speed up waste breakdown in Bioverter, and let its output evolve into mature compost somewhere sheltered.

From organic waste to soil superfood

Organic wastes can be repurposed at home - not only as rich sources of plant nutrients, but also for enhancing the physical and biological qualities of your soil. A less appreciated benefit is soil enrichment from increased earthworm activity in gardens.

Turning waste into superfood for our plants and garden involves the following phases:

Recover all the goodness in wastes

Compost microbes help us recover the various nutrients and micronutrients in our wastes. They first break down the wastes to unlock all these goodies - a process which can be sped up with a compost system. How quick the breakdown is, and how much work is involved varies a lot depending on the system, ranging from slow with regular manual mixing to fast with no manual intervention.

Ensure availability to plants

The broken down waste matter is semi-processed. Often called immature compost, it wants to evolve into its stable form, and will compete with plants for nitrogen and oxygen if used near roots.

Unlocked goodies in broken down wastes are also unavailable to plants, and have to be transformed by a different group of microbes in the final or maturation stage of composting.

Maturation takes time and cannot be hurried, but returns huge rewards.

Allow time to mature

Compost maturation completes the process of turning organic waste into mature compost, which looks and smell like good soil. It occurs naturally when immature compost is left to rest in a sheltered spot.

Mature compost is ready to be blended with soil or potting mix. It is both nutrient-dense and function like a slow-release fertiliser. Its crumbly texture improves soil structure, and its retention of moisture reduces watering in summer.

Fresh homemade mature compost is full of beneficial microbes that can boost soil health.

Trying to improve your garden’s ecosystem with purchased compost is less likely to work, as it has been bagged and stored for a while.

Cultivate earthworms in parallel

Earthworms inhabit soil that is rich in organic matter. They burrow to create deep channels that aerate and irrigate the soil, and allow roots to grow. An abundance of them is very good for gardens.

Did you know you can cultivate earthworm with immature compost? Offer them a rich source of food by carrying out the maturation phase on garden soil. As they feast and multiply, these free-range wrigglers produce worm casts to enrich garden soil.

Natural superfood

Turn organic waste into mature compost to create a superfood that improves garden soil in many ways, including an increase in earthworms and worm casts.

Build soil health for plants to thrive

Healthy soil is a living ecosystem, with plenty of organic matter that most of the work of nurturing plants on its own.

Healthy plants grow strongly, look better and are less prone to pests and diseases. What we see shines brightly, but what goes unnoticed does all the work below ground.

Adding organic matter to soil, especially as compost, is the best way to build soil health.

More wondrous humus

Humus is dark, organic material that forms in soil when plant and animal matter decays. Fallen plants, leaves and twigs pile up as leaf litter. When animals die, big or small, their remains add to the litter. Over time, all this litter decomposes, breaking down into its most basic chemical elements. The thick brown or black substance which remains after most of the organic litter has decomposed is called humus.

Humus is important in many ways - it stimulates the good microbes, retains nutrients and water, and conditions the soil to enable easier movement of roots, water and air. It is the key to healthy soil.

We can produce this highly beneficial, carbon-rich humus from our organic wastes. Most of it is formed during the compost maturation stage.

More carbon in soil

Did you know that soil quality and productivity are tied to the stock of carbon, or the organic matter in it? Carbon-rich soil can sustain plant growth at optimum levels for maximum benefits.

It may seem paradoxical, but overusing conventional fertilisers can reduce soil productivity over time. Nitrogen in fertilisers boosts soil microbial activity but doesn’t provide the necessary carbon a balanced soil diet requires. With a supply of nitrogen but scarce carbon, plant growth will be affected once it runs out. Soil carbon needs restocking.

There is a natural way to restore and even increase soil carbon - with humus!

Restoring the environment

Reversing a decline in garden soil productivity can be achieved with humus made from our organic waste. As humus can hold on to its carbon for a long time, we can also use it to keep more carbon in soil and as a result, out of the atmosphere.

Homemade humus can help us do the right thing for the environment.

Rewarding outcomes

Humus-rich soil is healthy and productive. Watch your plants flourish with homemade humus. It will feel great that you are achieving a lot of good, not just diverting waste from landfill.

Success in transforming kitchen waste

Kitchen scraps are generated routinely. When deprived of oxygen, they rot quickly and emit both annoying smells and environment damaging gases.

Turning nutrient-rich kitchen scraps into superb plant nourishment requires a compost system with excellent aeration (amongst other considerations, of course).

A good start

Follow the textbook sorting of organic wastes as either rich in carbon or nitrogen. Use a Waste Lasagne recipe to layer the sorted wastes.

With the Sweet Spot diagram as a guide, vegetable and fruit scraps in a kitchen composite can be layered beneath a covering of carbon-rich waste like fresh leaves and paper. You can form balanced composites with different mix of wastes.

A waste composite in or near the Sweet Spot is just right for compost microbes to begin the breakdown process.

Faster when hotter

Temperature has a strong effect how quickly wastes break down. It rises significantly when insulation is used to retain the heat released as wastes are broken down by compost microbes.

Hotter temperatures in an insulated system like Bioverter, result in faster microbial activities and reduced time to break down the wastes.

Go with the flow

Put wastes IN at the top, and products come OUT at the bottom - simple as that! It is the essence of a flow-through system.

Designed with a controlled environment to optimise compost microbial activities, Bioverter’s flow-through design enables the continual breakdown of regular inputs of wastes (2 or more times a week). Pulled by gravity, everything flow downwards, and ending as compost in the collection area.

An easy-to-harvest setup complements the beauty of Bioverter’s flow-through design. All released goodies from the wastes are captured and separated into two slide-out collectors. One gathers compost juice, the other gathers compost solids.

Reap what you make

Compost juice is the liquid product, which after dilution, can be be used immediately to water plants.

Allow the harvested solids to mature into soil-like superfood afterwards to maximise the benefits.

Companion systems

You’ll produce richer plant nourishment from nutrient-rich kitchen scraps than from garden waste, but the task is also more demanding. Use Bioverter to make this process less daunting. You could use a compost bin as a companion system for woody garden waste and tough kitchen scraps like corncobs and avocado skins.

Go for black gold as well as earthworms

Depending on your compost system, organic waste is turned into nutrient-dense (immature) compost, worm castings, or mature compost which looks and feels like crumbly rich soil.

Mature compost contains humus, the ultimate enrichment product which is also called gardeners’ black gold. You really want humus in gardens, as it boosts soil health by improving its physical and biological state. One of the many benefits is an increase in beneficial organisms, which makes plants more resilient against pests and disease.

To get the utmost value out of composting and to do it conveniently, we found the best way involved:

1. Using microbes in a controlled environment to break down wastes into nutrient-dense compost - a process that can be sped up and made less taxing with science and engineering.
2. Resting harvested immature compost on garden soil. It is natural for compost to evolve into its mature form, and when done in the right setting, earthworms multiply and excrete casts (or droppings) to enrich the soil further. The garden benefits doubly from mature compost and earthworms.

Garden soil environment

How well compost enriches your soil depends on the nutritional value of what you put in. Kitchen scraps are richer in nutrients than garden waste, and accordingly, produce richer compost.

As kitchen scraps tend to break down fast, you have to take more care with them when using standard garden systems like compost bins and tumblers. An undemanding alternative is Bioverter, which has been designed to handle kitchen waste.

Using a compost system to turn waste into (immature) compost soil is just the first step to achieving your eventual reward - soil enrichment.

The final step - using your harvest - can be done in several ways. Our 3 preferred options have been trialed successfully with harvest from Bioverter. You can adapt them to suit the harvest from your system.

Worm pop-up

A worm pop-up serves to mature harvested compost and breed earthworms.

Leave your harvest to rest in a lidded container with holes or perforations in its base. Earthworms make their way to it via the holes, feast on your offer, multiply, and generate earthworm casts. This is a great way to produce mature compost and casts for growing flowers and vegetables.

You can use a garden pot (25cm or larger) or worm farm tray as the pop-up. Place your harvest in it, cover with a damp cloth, and put on the lid. Keep adding more harvest until full, then wait for about 2 months for the last addition to mature. Partially bury the pop-up to provide safe access for earthworms.

Compost pop-up

This pop-up succeeded in preparing areas for future planting, and for enriching the canopy area of young trees and shrubs. The compost harvest is spread as a top dressing inside the pop-up, and protected by a top layer of standard garden mulch. It becomes part of the soil eventually.

Create the pop-up walls with timber, bricks or recycled plastic strips (in our trials).

In-between plants

This option suits garden beds protected by nets, to stop birds from digging for earthworms. It allows harvested compost to mature in a shallow channel between plants, shielded from the sun with mulch.

Maximum value

Homemade compost offers the maximum benefits when it allowed to mature. Your rewards are enhanced by using the maturation process to boost the earthworm population in your garden.