Composting in the Subarctic: Operations

The Actium compost drums are used in a variety of climates. In the tropical and subtropical climates, the composter is used year-round. In temperate climates, the Actium Batch Compost Drum can be used year-round because the drum is insulated. However, the decaying process can be slowed where winter temperatures are below freezing for a prolonged period. There are two approaches to maintain hot composting temperatures when ambient temperatures are below freezing. One approach is to use an Actium Batch Compost Drum that includes a heating coil. The other approach is to place the composter in a sheltered area.

In subarctic or arctic climates, maintaining composting temperatures during the winter season can be challenging when outside temperatures are regularly below -15°C ( 5°F) – leaving limited options for (sub)arctic composting. One option is to have the Actium Batch Compost Drum in an insulated building to allow for year-round composting. The other option is not to compost during the winter season. In the subarctic community of Fort Albany First Nation (FAFN), Ontario, Canada, they chose only to compost from late May to early October. This article provides an overview of the composting operations applied in FAFN, and I discuss some alternative approaches. Many details in this article can be used to operate an Actium Batch Compost Drum in other climates

Spring (Late May)

By late-May, the Albany river is no longer covered in ice, and most of the snow has melted. At this time, the composter manager prepares the Actium Batch Compost Drum for another season of composting. In the upcoming 2021 season, we plan to start the compost earlier – in April – to increase the number of compost batches per growing season.

Checking if the composter is level

The first task is to ensure the Actium Batch Compost Drum is level. It is ideal to have the composter on a cement pad, though that was not an option in FAFN. Instead, the composter is located on a flat gravel area that can subside after freezing and thawing due to the region’s geomorphology. Filling an unlevel composter with organics can cause strain on the crank, chain, and supports. When the composter is not level, we lift the empty composter using a log as leverage (as a substitute, a forklift or tractor can be used) and repair the uneven side. The ideal placement of the Actium Batch Compost Drum would be on a level concrete pad.

Chain inspection

Next, we check that the chain is fitted snug to the crank, and we turn the crank both clockwise and counter-clockwise to make sure it is in working condition.

Adding Organics

Once the composter meets our spring inspection, we start to add organics. We add both green and brown materials in equal volume. This upcoming 2021 season, we plan to fill the compost drum 1/4 full of brown materials (i.e. sawdust, shredded paper and cardboard). Starting the composter with extra brown materials will help regulate moisture when wet green materials begin to decompose. As well, we plan to add a garden shovel full of soil to help accelerate the compost.

Summer – Early Fall (July – September)

Twice a week throughout the summer, the compost manager adds green and brown types of organic waste. When organics are added to the composter, the drum is fully rotated at least three times in a clockwise direction – to mix newly added organics with existing decomposing materials. The Actium Compost Drum can handle up to 50 lb (23 kg) of organic waste per day – giving a total allowance of 350 lb (159 kg) per week. We add approximately 60 to 200 lb (27 – 91 kg) per week depending on the organic amount supplied to us by the FAFN organizations participating in the compost program.

Monitoring temperature, moisture, and odours

Throughout the summer, we monitor temperature, moisture and odours. When one (or all) of these issues occur, we take measures to improve decomposition activity. Troubleshooting for these issues are discussed in previous posts: Regulating Compost Moisture during Hot Composting (January 17, 2020), Compost Temperatures (December 18, 2019), and Greens and Browns: Compost Input Management (March 3, 2020). We are happy with the compost produced in FAFN. However, closer monitoring of compost moisture and temperate would improve the decomposition rates and allow for an additional compost batch.

The drum approaching full

The Actium Compost Drum can hold a volume of 1.56 m3 ( 55 ft3 or 411 gal) and a mass up to 2000 lb (907 kg). When the composter is near full, we add organics less frequently. Organics will continue to decompose, and this will permit more space for new organic additions. In FAFN the composter usually approaches near full by the end of-August. Currently, we only do one compost batch per year, so we allow the organics to continue to decompose in the Actium Batch Drum into the late summer /early fall. In the late summer, we add more browns to control compost moisture and supply additional carbon to decomposer microbes. Additionally, we ensure that we turn the Actium Batch Compost Drum weekly – even when no new organics are added to the composter.

Alternative approaches

In a scenario where the compost was near full by July, we would have the ability to create two batches of compost within a growing season. In that case, we would empty the Actium Batch Compost Drum. This first compost batch would be placed in a resting area, and we would start a new batch in the composter. 

Fall (October)

In October, we dedicate approximately an hour to empty and winterize the Actium Batch Compost Drum. Emptying the Actium Batch Compost Drum in the fall allows for a quick start-up when the warm weather arrives in the following spring. 

Emptying the composter

Emptying the composter is easy. First, we turn the drum counter-clockwise a few times to loosen the compost. Secondly, the lid is removed. The drum is then rotated counter-clockwise until the drum opening is in the desired position to empty the composter. In previous years we allowed the compost to fall onto a tarp placed directly under the drum. More recently, we created a tarped ramp (shown in the picture) for the compost to be moved and piled beside the composter. Then we shovel the compost to a secondary resting location. 

Secondary resting location

In our first year with the Actium Batch Compost Drum, we covered the compost with a tarp. In recent years we opted to modify an intermediate bulk contain (IBC) to store the compost over winter (shown in picture). We cut off the top of the IBC to add compost with ease. When the IBC is filled with compost, we tightly cover the IBC with a tarp to prevent snow and rain from accumulating into the container.

Compost removed from the Actium Batch compost needs to rest before it is used to nourish plants. Decomposer microbes active in fresh compost can be harmful to growing plants. It is suggested that fresh compost rest for 2-3 weeks before being used on plants. In FAFN this resting period occurs when the compost is in the IBC during the winter season.

Winterizing the Actium Batch Compost Drum

Winterizing the Actium Batch Compost Drum is simple. We clean around the drum opening and reattach the drum lid.  We add grease to the crank chain to prevent rust – considering the composter will be in a stationary position from October to April.

Following Spring (April/ May)

When warmer weather arrives, the compost in the IBC is ready to distribute throughout the FAFN community – to the community garden, the school greenhouse, and those with gardens at their homes.