Grim’s Guide to dirt
After reading a recent article in the National Geographic Magazine, I began to speculate about dirt. Well, soil to be more precise. After a long read about soil quality, erosion, compaction, and toxicity around the world, it became evident that there is more to good ol’ dirt than we originally expected.
My family has composted for as long as I can remember. At the time I didn’t think much of it, but here we are many years later, when I realize that just like so many other things taken for granted, soil plays an essential role in this world. As it stands, the world food supply is in the most severe danger. In the effort to feed so many people, with as little effort, for as much profit possible, we have nearly exhausted the soil. In short, the dirt is tired.
Soil is comprised of many things, a mixture of dead and dying plant matter, sand, fine rocks and minerals, and most importantly, zillions upon zillions of microorganisms. These tiny bugs work day and night to convert plain soil into an organic buffet for plants. However, these bugs are finding it hard to work in the conditions of our ignorance. Not only do they have to worry about chemical pesticides and herbicides, they need to cope with chemical fertilizers loaded with good and bad ingredients. In addition to chemicals, these amazing micro organisms have trouble getting around in dirt compacted by increasingly heavy machinery.
From what I have read so far, between the National Geographic, Wikipedia, and my mother’s guide to gardening, we are killing our soil faster than we can replenish it. Now, for most of us, improving soil quality is as simple as going to the supermarket and buying some nitrogen rich potting soil. For over two thirds of the world however, things are not so simple.
Anyway, now that we know that things are crap and getting worse, let’s yet again embark on a Quest for Informational Enlightenment and see what can be done.
I did some preliminary Questing on this subject and found several methods for improving soil quality. Some were as simple as placing some rocks on the ground, others were much more labour intensive. One method really caught my attention due to its self propagating nature and ease of implementation.
Terra Preta is a soil found in areas of the Amazon rain forest, which has shown some rather amazing properties. What amazed me most was the fact that this soil was being used for open crops. At first this may seem normal, but from all that I have read on soil<insert exhaustive sigh here>, is that the loamy rich soil of rain forests is extremely delicate. Rain forests are incredibly complicated ecosystems and the soil suffers greatly after deforestation. Areas of logging turn to barren dessert in a very short time and will support almost no growth. The difference between regular tropical soil and Terra Preta, is that Terra Preta will remain fertile after centuries of sun and rain.
One of the key components of Terra Preta is charcoal. Charcoal is basically a form of carbon made by smoldering bio-mass such as wood, animal waste,etc, at low temperatures with a minimal amount of oxygen. Charcoal is a very porous material which helps retain water, nutrients and most importantly, provides an excellent home for micro organisms. A large quantity of charcoal in the soil allows crops to thrive in even tropical sun exposure. It would seem that many hundreds of years ago, some ancient cultures in the Amazon would mix charcoal as well as broken pottery into the soil. We can’t be sure of their intentions at the time; however the result was the development of a soil that could very well be the blueprint for soil restoration around the world.
At first glance, it would seem rather energy intensive to me to turn organic matter into charcoal, only to throw it into the ground again. Even more so when you consider that you must first saturate the charcoal with nutrient rich liquids such as urine. As our fortunes would have it however, there are modern technologies which actually produce more energy than is used in the production of biochar, which is essentially, fine charcoal made from biomass.
The more efficient of these practices of making biochar utilizes a process called Pyrolysis. This system allows one to take dried biomass such as human and animal wastes, woody materials, and produce biochar in addition to syngas and bio-oil. The total energy output from some of these operations can sometimes be as high as 7 times the energy invested.
So now we conclude that charcoal + pee + soil = good. The carbon from charcoal has many other uses to be explored in another quest. We hope to post again on the benefits of charcoal and how you might produce some top quality soil, right at home.