The Problem with Peat

Peat Moss by Doug Becker CC BY-SA
Peat Moss by Doug Becker CC BY-SA

I’ve been vocal about wanting to choose as sustainably as I can for my tiny home, and part of that is that I plan to use a composting system for my toilet, rather than install a black water tank.  I’ve commented enough times about my preference for Coco Coir over Peat, that a friend who is writing about compost toilets, asked me to provide him with info on it to include in his blog post. (which I will link when it is written.)

In starting to write about peat to him, I quickly realised that it would be hidden in a private message, when it’s probably a good post for everyone interested to read, and knowing that he wasn’t going to simply copy and paste my words for everyone, I figured it would be better for me to put them here, and then he can access them for his blog, but anyone else interested would have access to them too.

So here’s the gist on peat:

Okay, there’s a few things about peat… I’m going to give you a technical page and you can read the info yourself. Even if there wasn’t a sustainability issue, the properties of the peat itself make it sometimes a poor medium. It’s a great cover material when it’s fresh, but you can’t really always know how long it’s been sitting, and once it dries out, it’s irreversible and useless even as a soil amendment. I believe that for this reason alone it’s a poor choice.
Peat when dry, is hydrophobic, and you cannot rewet it to the point of being absorptive again. When you get it, you’re asked to rewet it first, and then squeeze out all the water, right? That’s because it is very absorptive before this point, hydrophilic, then it dries and becomes hydrophobic, here’s a very technical page to demonstrate this.
 Second, peat grows incredibly slowly, and while there are now some harvesting (mining) facilities that try to harvest lightly, the fact remains that more peat is harvested every year than what is replenished naturally.


Tourbière/ Peat bog by peupleloup CC BY-SA
Tourbière/ Peat bog by peupleloup CC BY-SA
There’s contention here too though, as a lot of peat is harvested from wetland ecosystems, and the harvesters feel that they are acting as conservation stewards. This could be partially true in countries like Canada, but by supporting the demand for peat moss, which as I mentioned already isn’t necessarily the best medium unless you’re certain of the quality of what you’re purchasing, you’re also supporting the harvesting practices that are less sustainable.
Most of the peat bog wetlands in Europe have disappeared due to overharvesting, yet in Canada, they are very careful to harvest slowly, sad truth though is, that they harvest too slowly for the demand, and have higher overhead, environmental costs, labour costs etc, so a large amount of peat is harvested in other countries where such care and stewardship is not taken. Any argument that peat is a sustainable ecofriendly activity needs to be seen in context of where that could be true, and if it’s true enough in one area to supply all of the demand that’s fine, but the fact remains that unless they wish to overharvest, someone else will do it for them.
Canada is really very good at mining the peat moss slower than it replenishes. They use this fact as evidence that they are good stewards, and in fact, they provide 60% of the peat to the North American market, but, the other 40% is not so sustainable, and if you’re only using how fast the peat replenishes, as this article uses, then you’re only getting half the story, because the peat bog itself doesn’t quickly re-establish itself.

Why does that matter?  Like all precious wetlands, peat-bogs purify fresh air and provide habitat for many species of butterflies, dragonflies, birds, frogs, and highly specialised species of native plants which may be endangered, and only found in the peat bog. These bogs also sequester carbon, which is released into the atmosphere when it is mined. Peat bog harvesters suggest figures that a peat bog will fully replenish itself within 5 years of harvest, and within 25 years, 95% of the original fauna will return, but managed bogs lack the biodiversity of the original bog.  Here’s a great article which details how important and delicate our peat bogs are, and a direct download link to a pdf written by Linda Chalker-Scott, Ph.D., Extension Urban Horticulturist and Associate Professor at Washington State University titled “The Myth of Permanent Peatlands” that details how the peat bogs never revert to their original state.  A quote from the article:

Peatlands degraded by mining activity do not revert to their former functionality; changes in hydrology and physical structure are hostile to Sphagnum re-establishment. Recently, degraded peatlands have been restored through the blockage of drainage ditches, seeding with Sphagnum, and application of a mulch layer to reduce water loss. When degraded peatlands are restored, the ability to hold water is improved but CO2 continues to be released by high levels of bacterial respiration, which represents the decomposition of mulch and other organic matter. It takes a number of years for the photosynthetic rate of new peatland plants to outpace the respiratory rate: until this happens, even restored peatlands represent a net loss of carbon to the atmosphere and thus contribute to greenhouse gas production.

So where peat gets really ugly, is in the areas where it isn’t mined in any way sustainably, and with no thought to the harm it does to the environment and endangered species it threatens. Peat isn’t only used for gardening and compost, in some areas of the world, it’s burned for fuel.  China’s peat industry supplies fuel for power plants, and mining the peat in peat swamps there has contributed to habitat loss for countless species, as well as degrading pastureland for their own animals. In Indonesia, peat rainforests occupy valuable land for plantation owners who wish to harvest palm oil.  The peat is drained, the forest is cut down and most often the peat is burned, making Indonesia the 3 largest producer of carbon emmissions in the world after China and the US. In areas where the peat is deep, it is mined and sold for profit.  This rainforest destruction, and the peat fires, is the number one threat to endangered species in the area, including orangutans. While peat harvesting is a very small part of the Palm Oil deforestation issue, ecosystems that contain peat remain very precious around the world.

Whooping Crane with transmitter by Don Faulkner CC BY-SA
Whooping Crane with transmitter by Don Faulkner CC BY-SA

The Whooping Crane nests in North American peat wetlands.  Siberian Cranes nest in West Siberian peatland. The Black Necked Crane is an icon of peat wetlands in China. There’s endangered fish (the Betta Persephone native to Malaysia and suffering due to peat swamp habitat destruction) native plants threatened, and serious damage done that isn’t reversible in practice, both to biodiversity and to the carbon in the atmosphere. All for an inferior quality product that sometimes is beyond use.

Sawdust toilet by Eli Duke CC BY-SA
Sawdust toilet by Eli Duke CC BY-SA

For a better alternative, you can use locally produced and milled sawdust as a byproduct of a wood milling or furniture building industry.  Choose a wood species that isn’t going to impede growth of plants once you compost it. Walnut contains a compound called juglone, (info here) that is a toxic poison to many other plants, especially tomatoes.  While you can compost the walnut to the point of destroying the compound, it’s best to test your compost by trying to plant tomato seedlings in it before you decide to put it in your garden. The longer you compost this cover material the better, lest you cause all your plants to wilt and die. Cedar is another wood that has toxicity issues with other plants, (info here )it contains phenolics which impedes growth of seedlings.  It makes an excellent mulch in areas where you wish to prevent weed growth, but because of its high Carbon to Nitrogen ratio, it is very slow to decompose. Be certain to add a lot of nitrogen to this compost pile, and even to the garden itself if you haven’t fully composted the wood shavings before use. (good thing our toilets will provide much of this)

20090728-145925 by StretchyBill CC BY-SA
20090728-145925 by StretchyBill CC BY-SA

Coconut Coir is very useful, if you don’t have a local source of wood sawdust. When coconuts are harvested, long fibers from the husk are removed and used in manufacture of things like rope, brushes, doormats, plant pots, even as upholstery stuffing.  What is left, is unusable small pieces of husk, which is taken and milled to a uniform consistency and used as a soil amendment in place of peat, but it also makes an excellent cover for a compost toilet. It’s a renewable product, as a byproduct of another industry, and using it solves a waste issue in the countries where it is produced. It absorbs moisture better than peat (which sometimes doesn’t at all, as noted in the first link above) and it withstands compacting better, you’ll find it is highly compressed when you purchase it. If you are composting with worms, coconut coir is the very good bedding for them, because it can retain moisture while allowing air to pass through, preventing the worm bin from becoming anaerobic. (plus the worms eat it for grit so you won’t need to add any) Coir pH runs 6-6.7 so it won’t alter the soil pH of a neutral garden, peat moss runs acidic, so ornamental plants may benefit from it, but coir is still a very good soil amendment.

There are ethical concerns surrounding the manufacture of the coir pith as well that you should be aware of. The production of the coir takes water, and in countries where water availability is limited, using water for industry can be seen as a negative. While a lot of places are now aware of this, and collecting and reusing the water, there is room for improvement.  There is also the question of poor labour practices, and while you can get fair trade and ethical coir, sometimes it’s difficult to determine as brands are not always clearly marked. Working conditions not only can be low wages, but there’s also a safety issue with regard to the small particles. Here’s a very in depth analysis of the sustainability and supply chain issues surrounding it, (direct download)

I still see the use of coir as the superior option due to the environmental issues surrounding the use of peat.  While one can work towards better industrial standards for water use and labour practices (Sri Lanka and India, two major manufacturers are deemed to have “adequate” labour practices, but there is always room for improvement) it’s difficult, and likely impossible to restore peat bogs to their natural state.

I can research the company I choose to purchase coir from, and find one that suits my ethics.  I cannot say the same for peat.  I also can choose to use a byproduct of a local industry via wood sawdust, likely for a very small cost (if any at all).  The cost to the environment by using peat, is far more than I’m willing to pay.


creative commons licence for the above photos

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