"Essentially, all life depends upon the soil ... There can be no life without the soil and no soil without life; they have evolved together."
Charles E Kellogg, USDA Yearbook of Agriculture, 1938
"The creation of soil has taken millions of years, but for us to truly understand it, we must first look to its origins and find out exactly how it was formed.
"Fundamentally, soil is derived from bedrock and it's the weathering and eroding of this bedrock that starts the process of soil formation. Over time, bare rock like these are exposed to the elements with weather like wind and rain, heat and freeze thawing, helping to break up the surface of the bedrock, fracturing it into many smaller pieces. Eventually, these pieces are broken up further and form the physical component of soil.
"As you might imagine, almost nothing could grow on a pile of fractured rock like this. There are minerals present in the rock, but they aren't available to the plants. And there's almost nothing to hold water, which is essential for life. This is where microscopic life comes in. Microbes and algae are able to utilize the minerals held in the rocks and start to grow in the little nooks and crevices.
"Most importantly, these tiny organisms fix nitrogen and carbon dioxide from the atmosphere, leading to a buildup in organic material. And this process paves the way for another key group of organisms that are instrumental in the process of soil formation. These are the lichens.
"Lichen gets most of what it needs to survive from the atmosphere, hence its remarkable ability to survive in extreme locations. Lichen is formed from an incredible symbiotic relationship between algae and fungi and its these bizarre organisms that would have been the first to take advantage of the organic material left over by the microbes and algae.
"Not only can lichen survive without soil, but through the secretion of acid, it also chemically erodes the rock that it grows on which frees up a wealth of beneficial nutrients.
"When the lichen dies, a small deposit of organic matter is left and gets trapped inside crevices within the rock. As more and more lichen grows and dies, this layer of organic matter, rich in nitrogen and essential minerals, builds up, allowing routine plants a foothold in an otherwise unhospitable environment.
"This process is long and slow, typically taking 500 years for just one centimeter of topsoil to form.
"This old quarry is a great place to see soil formation in action as it mimics the natural evolution of the soil. Originally, there would have been a lot of bare rock like this. But, over time, as the organic matter built up and up, it has led to the succession of larger and larger plants. As these die, they feed into the formation of more soil and allow a diverse range of plants to grow ...
"By truly understanding how soil interconnects with both the physical and biological worlds, we can start to work with the soil, in harmony and manage it responsibly for both wildlife and future generations."
CLICK | to learn where soil begins (5:27min) - also linked above