Agriculture Reference
In-Depth Information
Peat Moss and Coir
Peat is organic matter — plants, microbes and even insects and other animals — that has
been broken down in wet, anaerobic conditions, generally in marshy areas. In fact, peat
bogs can preserve animals extremely well, and were used for human sacrifices back in the
Iron Age.
There are different kinds of peat moss. While it's often thought of as a sterile medium,
this isn't always the case. Some peat is low in microbes and some of it is extremely high in
microbes. Some of it is 90% organic matter and some closer to 30%. While some is high in
minerals and some is low, all peat has a high CEC and water-holding capacity. Sphagnum
peat is the most common variety. It's very acidic, low in nutrients, and high in oils that re-
pel water. Though it holds a lot of water, once it dries out, it needs to be soaked to wet it
again. It's not useful to us a mulch, nor as a soil amendment.
More importantly, peat bogs are unique, vitally important ecosystems for this planet.
When they are harvested for their peat unsustainably or to create farmland, these ecosys-
tems are gone, species go extinct, and a huge amount of greenhouse gases are emitted. The
bogs are supposed to be restored after harvest, but many aren't, and some scientists propose
that it's impossible to restore them properly. Shipping peat across the country or the planet
isn't environmentally sustainable. One could argue the same thing for any fertilizer, but
peat is very heavy for the surface area it covers, and for the lack of real benefits it provides.
Coir is ground coconut fibre husk, a by-product of the coconut industry. It doesn't have
the high CEC of peat, but it also doesn't have the water and pH problems. There are sus-
tainability issues with coir, too — do you have coconuts growing where you live? Is the
coir coming from them? Most of the coir you see in your garden center is coming from far
away. I see no need for shipping this stuff around the world when we have organic matter
locally.
