What is Compost?

At Green For You we implement circular economy principles by converting food waste into compost. Compost is a form of organic matter that when applied to soil improves its health.

Compost is a type of organic matter:

Organic matter refers to the decomposed remains of plants, animals and microorganisms found in the soil. Organic matter is present in various forms, it includes perished plant roots, leaves, branches, tree trunks, sawdust, feathers, beetles, earthworms, grubs, bugs, bacteria, fungi, actinomycetes, spores, enzymes, amino-acids and finally humus.

As organic matter breaks down it undergoes a series of chemical and biological processes that releases nutrients and forms complex organic compounds. The remaining organic matter from these processes is called Humus. Humus is dark coloured and composed of large organic molecules containing mainly carbon, hydrogen and oxygen. Nitrogen and sulphur are also present in humus, in smaller quantities, as well as other trace elements.

When organic matter is not completely composted, there is a large presence of phytotoxic compounds. Phytotoxic refers to something that is toxic or harmful to plants. Phytotoxic compounds negatively affect plant growth, development and health. Due to the presence of these complex organic compounds, it is essential that organic matter is composted before it is applied to your soil. When organic matter is composted, these complex compounds break down even further into stable and nutrient available forms.

Compost:

Compost is a dark, nutrient rich and crumbly material that is created through the process of composting. Composting is the controlled decomposition of organic matter. Composting harnesses the natural process of decay and transforms organic waste into a valuable soil regenerator. This rich and raw earthy material can be used as a soil enricher, soil amendment, potting mix component, mulch and even during seed germination.

Here are some key benefits of using compost:

1.     Nutrient cycling: Compost can serve as a source of essential nutrients for plants. Compost releases nutrients such as nitrogen, phosphorus, potassium, macro and micronutrients into forms that are easily absorbed by plants. Compost increases soil fertility and supports healthy plant growth.

2.     Soil structure: Compost plays a crucial role in soil structure. It creates aggregates which improves a soils ability to hold and store water, enhances drainage, and prevents erosion. Compost prevents soil compaction, improves soil porosity and root penetration.

3.     Water retention: Compost plays an important role in increasing water retention by increasing the surface area within the soil profile. This characteristic prevents excessive runoff, increases drainage and minimises the fluctuation of water out of the soil.

4.     Soil biological activity: Compost provides a habitat for organisms such as, fungi, earthworms, bacteria and insects. These organisms play a vital role in the natural cycle acting as decomposers, soil structure improvers and disease suppressors. These organisms increase the diversity of the soil and thus contribute to the overall health of the ecosystem.

5.     Carbon sequestration: Compost is a major initiator of carbon sequestration in the soil acting as a carbon reservoir. Increasing the overall organic matter content helps sequester carbon from the atmosphere and mitigate climate change. It also helps feed mycelium populations residing in the soil.

By increasing the biological activity within our soils, we are able to produce more humus and organic compounds that bind mineral particles together into crumbs or aggregates. When humus content increases and the structure of your soil improves this means more air and water are available to the roots of your plants.

What happens during the composting process?

When compost is being created, a complex and fascinating biological process known as decomposition takes place. Decomposition is driven by various microorganisms, including bacteria, fungi, and other soil-dwelling organisms. These microorganisms break down organic materials into simpler substances, ultimately transforming them into nutrient-rich compost.

The composting process involves three main stages:

Mesophilic Stage: The process begins with the mesophilic stage, where mesophilic microorganisms (bacteria and fungi) are most active. These microorganisms thrive in moderate temperatures, around 20-40°C. During this stage, they start breaking down easily accessible materials like sugars, starches, and simple proteins, generating heat as a by product. The temperature inside the compost pile rises, creating a warm and hospitable environment for further decomposition.

Thermophilic Stage: As the temperature continues to rise, the thermophilic stage commences. Thermophilic microorganisms (heat-loving bacteria and actinomycetes) become dominant, operating in higher temperatures, around 40-70°C. These microorganisms are highly efficient decomposers, capable of breaking down complex organic compounds like cellulose, lignin, and fats. The intense heat generated during this stage further accelerates decomposition, sterilizing the compost pile by killing potential pathogens and weed seeds.

Curing or Maturation Stage: After the thermophilic stage, the compost gradually cools down, entering the curing or maturation stage. The maturation stage allows mesophilic microorganisms to return, breaking down any remaining organic matter. The compost continues to stabilize and mature over several weeks to several months, during which it develops a dark, crumbly texture, resembling rich, fertile soil. The final compost product is teeming with beneficial microorganisms and nutrients.

Throughout the composting process, the microorganisms feed on the organic materials, converting them into simpler compounds like carbon dioxide, water, and humus. The humus, a stable form of organic matter, enriches the soil with essential nutrients and improves its structure, increasing its water-holding capacity and promoting better plant growth. Additionally, composting reduces the volume of organic waste, diverting it from landfills and reducing greenhouse gas emissions.

Ways to compost at home:

For families looking to compost there are several convenient methods which are available:

Backyard Composting: This traditional method involves creating a compost pile in the backyard using a mix of kitchen scraps and yard waste. It's suitable for families with a small outdoor space.

Compost Bins: Compact compost bins can be placed on a balcony, patio, or small backyard. They control odour and pests while speeding up composting.

Vermicomposting / Worm Farm: Ideal for small spaces, vermicomposting uses worms to break down kitchen scraps into nutrient-rich vermicompost. Worm bins can be kept indoors or on a balcony.

Bokashi Composting: Bokashi bins are great for small apartments. This method uses beneficial microorganisms to ferment food waste quickly and without odour.

Community Composting: Some urban areas have community composting facilities where families can drop off their food scraps for composting. It's a great option if space is limited.

Each method offers a sustainable way for urban families to reduce waste and create valuable compost for their plants or community gardens.

Composting for beginners:

As a beginner with no composting experience, starting composting may seem overwhelming, but it's easier than you think! Getting into contact with your local council about the possibility of sourcing some composting accessories such as a food waste caddy or subsidised worm farm is an excellent way to start. Follow the next steps to help you get going.

Here are some simple steps to help you begin your composting journey: 

Choose the Right Composting Method: Consider your available space, lifestyle, and the amount of organic waste you generate. For beginners, a small compost bin or vermicomposting (using worms) are excellent choices. Both options work well in small spaces like balconies or indoor areas.

Gather Compostable Materials: Collect kitchen scraps like fruit and vegetable peels, coffee grounds, tea bags, and eggshells. Also, gather yard waste such as grass clippings, leaves, and small twigs. Avoid adding meat, dairy, oily foods, or pet waste, as these can attract pests or slow down the composting process. 

Choose a Compost Bin or Location: If you're using a compost bin, place it in a sunny spot with good drainage. If you opt for vermicomposting, choose a worm bin suitable for your space. Alternatively, consider starting a small outdoor compost pile in a corner of your yard.

Layer Your Compost: Add a layer of browns (dry leaves or shredded paper) followed by a layer of greens (kitchen scraps). Continue to layer them until you have a good mix. Make sure the pile is moist but not soaked.

Turn and Mix: If you have a compost bin, give it a gentle turn or mix the contents every week to aerate and speed up the decomposition process. If using a worm bin, occasionally mix the bedding to ensure even composting.

Be Patient: Composting takes time, and it's normal to see results gradually. It may take a few weeks to a few months, depending on the method and conditions. As you continue to add organic waste, your compost will transform into rich, dark soil-like material.

Monitor and Adjust: Keep an eye on your compost pile or bin. Adjust the moisture levels if needed, ensuring it remains damp. If the compost is too wet or smelly, add more dry materials. If it's too dry, sprinkle some water. 

Use Your Compost: Once your compost is dark, crumbly, and has a pleasant earthy smell, it's ready to use! Incorporate it into your garden soil to improve soil health, moisture retention, and plant growth.

Remember, composting is a learning process, and mistakes are part of the journey. Don't be discouraged by challenges; instead, learn from them and keep composting. Before you know it, you'll be well on your way to creating nutrient-rich compost for your plants and reducing your waste footprint. Happy composting!

For tips on how to work with different soil types, refer to the how to treat our soil learning section.