Stop Burning Brush!

Burning brush piles is a terribly wasteful practice.

Burning is the most common way to remove prunings from an orchard: it guarantees that any diseases overwintering in the pruned wood will be eliminated. But along with disease organisms, burning also removes large stores of carbon and mineral nutrients from the orchard.

There’s a better way!

Instead of burning, we recommend:

1. laying prunings in the drive lanes
2. shredding them in place (e.g. with a flail mower)
3. [optional] applying BioDigester™, a Tainio Biologicals product composed of a blend of microorganisms that excel at digesting cellulose.

The shredded prunings will break down in the orchard, eliminating the habitat for disease organisms and breaking their life cycle. BioDigester greatly speeds up the decomposition process, which can be helpful if you’re worried about disease.

This method has 3 main advantages over burning:

1. Retains carbon in the orchard.

Your trees have been working incredibly hard to capture carbon from the atmosphere. Burning their branches sends an awful lot of carbon back into the atmosphere; composting them sends it into the earth. Which do you think is a better way to build healthy soil?

2. Retains nutrients in the orchard

Prunings are generally comprised of young, small-radius wood. As we mentioned last week, smaller radius wood has more buds than thicker wood. It also has a higher ratio of cambium to cellulose. Buds and cambium are both veritable treasure troves of minerals, so burning wood also removes those minerals from your orchard. By contrast, composting the wood puts them right back into the soil, already in plant-available form.

Michael Phillips rhapsodized on the benefits of such “ramial chipped wood” in his books—if you’re looking for elegant paeans to its benefits, we’d recommend you check those out.

3. It’s cheaper

Let’s compare the costs of the two methods:

• Shredding requires a pass or two with the tractor (plus an additional one if you’re applying BioDigester).
• Burning requires much more labor and tractor time to gather prunings and tend burn piles.
• (Biodigester costs between $20-$36 per acre depending on the quantity you buy. In these instances, if you’re just applying it in drive lanes, it wouldn’t cover the whole acre, and would be correspondingly cheaper—for these purposes, let’s say half, so $10-$18 per acre.)

You should be able to use your own labor costs to roughly calculate the cost of each method for your operation.

A key part of regenerative agriculture is employing natural processes to your benefit. In this case, promoting the rapid decomposition of prunings can be a great boon to restoring soil health.

*** Burning can be useful in certain circumstances:

• If you’re paranoid about disease. While composting prunings in place can break the disease cycle, burning tends to soothe the anxious mind. However, improving plant health by adding carbon and nutrients to the soil is a much better way to get on top of disease in the long run.
• If you’ve removed tons of wood and have more to dispose of than you can reasonably shred.