Compost matters

Fri, Mar 25, 2011

Climate Change, Soil and Composts


Why is Composting Important?

One of the simplest and most important things anyone can do is build their own compost to recycle bio-waste.

Every time you peel vegetables, or scrape away certain leftovers, you are limiting organic matter from impacting on climate change. By compacting waste, and then reusing it in our gardens, we are increasing the amount of carbon that is stored in the soil. Applying organic fertilizers also helps slow down greenhouse emissions in arable soil.

Other benefits of adding organic matter to the soil include better retention of water, improved workability and a reduction in the release of nitrous oxide. Organic fertilizers can also reverse the decline in soil organic matter. The mix of carbon, nitrogen, water and oxygen provides the essential environment for decomposition of organic waste, but for optimum results careful attention should be paid to the type of organic matter being composted.

What Makes Suitable Composting Matter?

Kitchen waste contains a variety of nutrients, which allow composting bacteria to produce sugar and heat, and to thrive. Vegetable, fruit trimmings and coffee grounds all have a high nitrogen content. Eggshells also provide a good source of soil nutrient, but do take a lot longer to decompose than fruit and vegetable matter.

Composting Methods

There are two methods of composting: one takes an active approach, which relies on composting at ideal conditions, whilst the other approach is more passive. Active (hot) composting requires that aerobic bacteria is allowed to thrive in temperatures exceeding 55C. The temperature for passive composting, on the other hand, never reaches 30C but is a much slower process.

Kitchen waste that is placed in a composting bin is then left untended and will start to produce a high water content. As this passive method provides no aeration the waste will soon emit a foul smell and significant greenhouse gases. Mixing in leaves, twigs or bark can however, reduce the unpleasant smell. Home composting however, can be successfully done using either approach, so ensuring your chosen method fits in with your lifestyle is worth considering before you begin.

Types of Composting Containers

Slatted sided or closed containers can both be used for composting. Where space is limited a cylindrical bin is recommended, although careful attention should be paid to aeration and carbon and nitrogen levels. In order to encourage recycling local authorities provide this type of composting container at a low cost price. The most important thing to get right however, is the correct mixture of carbon and nitrogenous materials and a good layering of rough and twiggy layers, as this improves the circulation of air.


Three essential garden friends – compost heap, water butt and watering can

Follow this step by step guide to building your own compost by Alan Titchmarsh:

For more info on getting the right balance in your compost mixture visit:

This post was written by:

- who has written 872 posts on My Climate Change Garden.

I am not an experienced gardener - more of an enthusiastic amateur who learns by trial and error and who is keen to "manage" the effects of shifting weather patterns on my garden. Writing this blog is my passion and it has evolved over 12 years to inspire engagement with climate change outside our back doors, in our personal gardens and green spaces. My mission is to fertilise and expand this platform to grow a community of global gardeners communicating about the effects of climate change on our plants and exploring how each individual can make small changes in our lives to become more sustainable. The future of our gardens and #OurPlanet is in our hands - please plant your own seeds for our collective sustainable future.

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