“Despite its artistic pretensions, its sophistication, and its many accomplishments, humankind owes its existence to a six-inch layer of topsoil and the fact that it rains.” –Anonymous
Soil. Everything on Earth needs it. What is it? Where does it come from? How is it made? By the end of this ditty, you should have a few answers and if I’ve done my job well, will have created a moderate amount of concern on this relatively ignored earthly phenomenon.
Soil (not dirt) is made up of a variety of ingredients and where you are in the world determines what types of plants and hence, food, can be grown. Carrots, for example, are best grown in sandy soils and do very well in the drier parts of Western Canada. Clay is very mineral rich, but gets water logged, so not much can grow in it, unless it is mixed with other soil types.
The major components are: silt, clay and sand. All soil is made of a mixture of these three materials. Minerals, chemicals, additives and a slew of other things change the properties of soil. Iron makes soil reddish; decomposing plant matter makes humus and so on.
In its most basic form, soil is made of crushed rock. Worms also create soil with their castings (or, worm poo) and provide aeration and the cycling of nutrients from different layers. Engineers need to understand the properties of soil if they are to build on it and climate scientists have begun highlighting the importance of a healthy soil system by showing the effects of melting permafrost and “drunken trees”. Soil plays a bigger role than most people have anticipated and much of it is in danger, worldwide.
Soil is being degraded everywhere. Some of the major problems are desertification, salinization, acidification, erosion, contamination; anything that degrades the functioning and quality of the soil. The finger can be justifiably pointed at large-scale agriculture, which is the reason so much global forest land is cleared every year.
In tropical rain forests, the soil layer is very shallow. In humid environments, as opposed to cold climates where it freezes for half the year, decomposition never stops. Nothing has the opportunity to accumulate and all plant life has adapted to take advantage of this thin layer.
Strangler figs are a perfect example of an opportunistic root that takes what it needs from other trees rather than a nutrient-poor soil column. When a rain forest is clear-cut, the crops that are planted there, whether it be livestock, palm or soya bean, have a very short period of productivity because the soil is so poor and easily eroded.
Heartbreakingly, some of the world’s most productive agricultural land is being paved over in sacrifice to the condo fad. Our little corner of North America in Eastern Quebec is a very productive crop-growing zone, but it is being lost at an alarming rate, along with our connectedness to the land and knowledge of where our food comes from.
There are enough global dilemmas that it is a rare day when someone ponders the state of soil. A few news sources provide up to date information, such as Doctor Dirt, Soil Science Society of America and Science Daily. Some prominent scientists are also giving soil some public attention, such as Vandana Shiva who the book “Soil not Oil” in 2008, which connects soil erosion and climate change together through agriculture.
Wes Jackson of the Land Institute is another researcher who is spearheading soil as an issue that demands our attention. What holds the soil together are plant roots. The roots of different monocrops that have been exploited over the past century do not penetrate the soil column very deeply, leading to rapid erosion and poorer quality plants. Dr. Jackson is exploring the creation of different crop varieties that grow deeper root systems, increasing soil fertility and stability with perennial plants.
You can help increase soil fertility by supporting local organic agriculture. Find a farmer’s market and buy some of your weekly vegetables there. Avoid foods made by green-washers galore; ConAgra and others like it like the plague. Being aware that what our food grows in and what we live off of is at risk is a good first step to improving the future and our success on this planet.