The History of Soil Episode 2 in the Garden Soil Series

Todays episode we are going to continue the exploration of our garden soil series. If you have missed any episodes in this series click here to view the playlist.

In order to get a complete understanding of the relationship between our garden soil and plants we need to step back in time. It is important to understand what is forming earths soils.
Horizon shot with little or no detail of the land itself
Lets step back 400 million years in Earths History.

Soil formation or paedogenesis is driven by physical, chemical, biological and anthropogenic or in other words human cause interactions with organic and inorganic mediums.

Soil formation began some 400 million years ago in the Devonian period. Before that time there was very little oxygen in the atmosphere and no organic material on land. Around that time oxygen began to appear in significant quantities as a result of the development of Photosynthetic processes in organisms. Around the same time there is evidence to suggest land was being colonized by its first organisms.

Fast forward 400 million years and we have an amazingly complex terrestrial ecosystems including our gardens. As far back as there are human records people have been studying soil science. This is because for the most part our civilizations depend heavily on food from farming or foraging.
For the last 400 million years soils have been formed largely by the Parent Material, Climate — Temperature and water changes, Topography, and Time

The Parent Material is the unconsolidated material that forms the base for soils. Typically weathered from solid types of rock by either physical or chemical processes. This material is either the material that the soil sits on or has been transported in by wind, water glaciers or gravity. Interestingly because of the diversity of parent materials that are transported in they are commonly more fertile then there in place counterparts.

Climate is usually the biggest factor in soil formation. Changes in temperature and water regimes drive both physical and chemical weathering of parent materials and soils.

Temperature influences soils by the change caused by daily and seasonal fluctuations. Large shifts in temperature change the soils water regime either stimulating biological activity or inhibiting it. Water is involved in most reactions in soil and as it moves through, interacts with and leaves the soil it has lasting effects. Most notably leaching minerals water in solution away from the soil.

Topography is the shape of the land itself and plays a key role. It influences not only the location of soil formation but the radiant energy and water regimes that shape and change the soil.

Organisms or the biota play an important role in soil formation and are made up of vegetation, animals, bacteria and fungi. Plants for instance make up most of the organic material found in the soil and can influence the weathering process.

Finally we get to time which ultimately allows all of the earlier mentioned factors time to work.

All of these factors combine to form the basics that plant life needs to grow. The soils holds organic material, water and gasses allowing the plants to have a medium to grow in that provides water, minerals and nutrients to allow for the photosynthetic growth.
Next time we are going to talk about the Nitrogen Cycle and how much of a key role it takes.

I would like to send a special thanks to COAL Photography. Click here to subscribe to his channel.

About Stephen

The Alberta Urban Garden Channel hopes to promote organic gardening that is simple, sustainable and does not have to cost a lot. We do this by investigating the Science behind gardening, methods, practices and products to make sure that you will have the best chance of successfully growing your own food at home.