Life and thoughts from a small-scale organic farm . . . and its farmers

This is a blog that explores ideas around the growing of food and community at Glen Valley Organic Farm.

Monday, August 22, 2011

Compost Bin Update

Many readers, I assume, are waiting for an update on the new compost bin I built earlier this season. I wrote about it here in May.

The bin is working well, composting the tremendous amount of plant matter we generate as we clean and grade produce each week. In fact, I'm turning the bins weekly at this point and getting some great compost in the process.

In the photo above, I have the front off of the first bin, which I had just finished turning into the second bin in the middle.

Two days later, the temperature in the centre bin was at 130F/54C. At this temperature thermophilic bacteria is breaking down the compost and creating a significant amount of heat. This is made possible by oxygen having been added to the compost during the turning process, resulting in what we call "hot" composting. 

During hot composting, the temperature reaches levels that kill pathogens. This is particularly important when composting manure. In the case of veggie materials, we don't need to achieve hight temperatures, but the composting process goes faster with the heat. In the winter, hot composting can also help keep bacteria working, despite the cooler temperatures (although in very cold regions, your compost will still freeze up).

After cleaning out the first bin, having turned the contents into the second bin, we're ready to add more plant material.

Meanwhile, the third bin is ready to be cleaned out. The compost can be used immediately, although the best results will be achieved from curing the compost in a dry area. Curing is a process where worms and insect digest coarse materials such as sawdust, straw and harder bits of plant material.

You will get the best results in your compost if you add dry, carbon-containing materials to your food waste. This includes, straw, sawdust or dried leaves. 

By adding carbon or brown layers, you are allowing the compost to hold more oxygen, but also providing proper ratios of carbon the the nitrogen-rich food materials that form the basis of your compost. This layering also helps dry out your compost, helping to avoid the dread pile of slime that often happens to home composters. Finally, this layer also helps reduce odour and flies on the pile.

Compost should form the basis of your growing process. Not only is it the ideal way to return food and plant waste to a useable form, but it is also the ideal source of fertility for any garden. I find composting to be a very satisfying process. To do it well, you need adequate materials -- a proper system of bins plus carbon/brown layering additions.

1 comment:

  1. I am renting right now, but as soon as I have a house of my own I'm getting a giant compost bin. Right now I just toss a lot of my veggie scraps directly onto my garden. Not optimal, but still giving something back to the dirt.

    I tried worm composting once but could not keep the bin dry enough and they kept trying to climb out.