Turning Units – rotating
The use of turning-units speeds up the rate of decomposition by the addition of extra oxygen.
Turning-Units are those in which your ingredients are turned regularly in order to oxygenate your mix, thus raising the heat necessary for hot-composting. There are two main types;
which are attached to a frame with a turning mechanism. Includes barrel composters.
which consists of a series of bins, placed side-by-side in which your compost is forked or turned by hand.
The latter system is especially suited to larger gardens and an abundance of raw materials. You also need to be reasonably fit!
Here, Let’s Look at Tumbler or Rotating Turning-Units
If you want to try hot composting, but do not wish to be tossing everything around on the end of a fork to provide aeration and if you do not have a huge garden or lots of ingredients, you could try purchasing one of the rotating-composters. These types of turning-units are suitable for hot-composting and are filled using theBatch Composting method.
They can be built, with some effort, at home, but there are several different types on the market that will answer most requirements although they can be quite expensive.
There seem to be quite a lot of advantages to using mechanical turning-units, but there is some dissension among composters (the human ones) regarding the worth of these devices in light of the cost. Even ‘Which?’ cannot seem to get the story straight, saying on one hand that they would appear to be an unnecessary expense, slower at producing the finished product than a basic static bin, while on the other, they state that a tumbler will give the fastest results. I have never used one of these turning-units, so can offer no personal experiences, but I must say, that after the reading I have done, if the circumstances were ‘right’ I would be very tempted to invest in one.
Right then, what is different about rotating-composters? Well, they differ from static turning-units in that they are held up off the ground on a frame, they are completely sealed and they can be rotated, thus mixing your waste materials where they lie. The inside of rotating-composters should be fitted with baffles to aid mixing and they are more effective if the sides are flattened off, allowing free movement of the materials. Some units are vertical and are rotated from end-to-end while others are set horizontally and rotate around the axle.
Advantages of Rotating-Composters?
-Well firstly, more frequent (and some say easier) turning, results in hotter temperatures, making for quicker compost! Some advertisements say in as little as three weeks, although that would seem to be debatable even under perfect conditions.
-Second, the sealed unit and more robust plastic offers insulation and prevents drying out.
-Third, there is no opportunity for predators to gain access.
-Fourth, the heat generated will be enough to kill seeds, plant diseases, fly larvae and animal pathogens.
-Finally, rotating-composters provide a neat and tidy way to do hot-composting on a small scale – probably better suited to a small garden than a 3-bin static system which is considered by some to be the best method of all for hot-composting.
-Well, there are some who would dispute the ease of turning, particularly with a bigger turning-unit that is full of materials. This seems to vary from make to make. Many would argue that these containers can be very heavy and awkward to turn, particularly if you are elderly or, for example, have a ‘bad’ back. You can of course, use a smaller option and only partially fill it.
-The length of time taken to compost is also in dispute, but so much depends on the management of the mix that it is difficult to be precise. In any event, hot-composting is much quicker than cold composting and if your tumbler is used according to directions the chances are that it will be very speedy indeed.
-The size of the bin can be limiting if you have a large amount of compostable waste.
-Because your bin is not placed directly on the ground, you will not have the advantage of microbes, worms, etc migrating into your bin. They will have to be introduced with a small amount of soil in each batch.
I think if I had a small garden with limited materials and wanted to carry out hot-composting, I would probably go for one of these bins notwithstanding the apparent down-side.