Monday, September 03, 2012

A lot of rot - in a good way

One of the aspects of gardening that newcomers and young people in particular struggle with is the idea that any kind of cultivation depletes the soil of its natural nutriments, and that intensive gardening of any kind requires keen attention to soil fertility and structure.
For some kinds of landscape gardening the process of growing plants and allowing them to die naturally and return to the soil will keep things more or less in equilibrium – woodland gardens can be treated this way, and many native gardens will also function perfectly well in this manner.  But if we are constantly removing vegetation from the soil and not replacing it – as we do when we grow bedding plants in the same soil year after year, or in an even more pronounced way, when we establish vegetable beds – then we need to think long and hard about how we treat the soil.
One of the things we can think about is returning the spent vegetation from the garden back into the soil, by recycling it through a composting system.   Young people, used to the ‘garbage in, garbage out’ concept in computers (where bad data into the programme results in bad computing results) are always amazed that there is a natural system where ‘garbage in, brown gold out’ is the rule!
The value of well composted material is two-fold.  Compost returns valuable nutriment to the soil, in the natural forms of the valuable chemicals plants need to function – nitrogen, potassium and phosphate in particular.  It also functions as a valuable way of restoring humus to the soil, ensuring the soil structure is maintained or enhanced leading to a better fauna of microscopic animals that help break nutriment down, and also helps aerate the soil, meaning roots will develop better and more efficiently make use of the increased nutriment available.
Having decided upon a compost system, how does the tyro composter get underway?
Firstly, choose a receptacle for your compost.  There are many containers that will suit, including plastic bins, wooden crates, and even simple cages made from chicken wire.  The optimum size is probably about a metre square, and they should be placed away from the wind, sun and rain so you can control the moisture level in the bin.  Also make sure you place the container on soil rather than concrete – you are going to be relying on soil critters to make their way up into the bin to do the work for you.
Now you can think about what can be composted, and fortunately there is a wide range of suitable material – lawn clippings and leaves from the garden, as well as fruit and vegetable scraps, tea leaves, and coffee grounds are all useful.  You can also improve the way the system works by adding thin layers of animal manure or seaweed, and alternating with coarse layers of straw or the like.  You can also use sparing portions of wood ash.

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