Modern composting techniques have developed from the pioneering work of Sir Albert Howard (1873 -1947) one of the fathers of the organic movement. Sir Albert’s books “An Agricultural Testament” and especially “The Waste Products of Agriculture” demonstrated the value of composting.
Sir Albert developed the Indore method named after the Indian State in which he perfected his practice. This method remains the basis for most aerobic composting.
The Indore method is a “batch” composting method, that is, the compost pile is made at one time from materials gathered together for the occasion. It is made of layers of rough organic matter – that is coarse material ( these days often called the brown material) followed by a layer of fresh green stuff such as grass, weeds or leaves and topping this a layer of manure, soil urine and wood ash or lime.
The layers are not too thick and are repeated until the compost pile is complete. One suggestion is that the layers should be about 4 inches (100 mm) for the bottom, 3 inches (75 mm) for the middle and 2 inches (50 mm) for the third.
The Indore Compost Pile had urine soaked soil as a manure but also suggested thin layers of local field soil to help develop the army of microorganisms that would do the work. Practice has found that layers of soil are not vital.
This type of compost is aerobic – air works through it – and becomes very hot. The heat helps kill pathogens and facilitate the first stage of breaking down the hard fibrous parts of plant material. Because of the need for oxygen, turning the pile was advocated.
Many compost makers suggest using a special drum that can be turned or having a three-bin system so that the compost is turned from one into the next and then into its final resting place.
By using some coarse material, oxygen is trapped within the pile allowing the heating up process making turning unnecessary. Recent experiments have shown that turning is not important in the household style compost as there should be plenty of air trapped within to allow the heating process. In fact, heat may be lost during the turning process. What is necessary, is to thrust a pole or crowbar down into the compost a few times during the building to create three holes through the compost. These should be enough to permit air to the pile.
Something nitrogenous is needed to supply initial food for the army of mycorrhiza and bacteria that will work the compost. Howard used urine soaked soil scraped from the floor of cowsheds. Most of us will not have that. Human urine can be used as can horse, cow or fowl manure. These, too, may be difficult to obtain in a suburban environment in which case dried pelleted manure or blood and bone from the store will be fine. If using these do not be overly concerned about the thickness of the manure layer.
Some authorities maintain lime is necessary to reduce acidity. Others believe that compost is generally quite satisfactory without it. It is not usually worth making a special effort to purchase lime and it can be omitted. Similarly if one has wood ash it can be a valuable addition but it is not necessary.
When using leaves or fresh grass clippings take care not to allow them to form a dense impenetrable layer but tease them out and mix with coarser material to allow air to circulate.
Compost making seems difficult but with little effort and expense a perfect organic growing medium is produced.