What is topsoil?

 What is topsoil?

Topsoil is the top most layer of soil. Depending on the natural conditions, it takes anywhere from 100 to 1,000 years to build up just ONE INCH of this precious substrate.

Topsoil is made up of organic matter and mineral particles, and it's usually the darkest layer of soil due to its high organic matter content. It's an important part of the overall soil structure because it holds water and air, which encourage biological activity. Topsoil is primarily composed of a mixture of sand, silt, clay, and humus. Humus is decaying plant and animal debris from the surface layer of the earth, making it the most nutrient-rich soil layer.

Topsoil is home to a diverse range of living organisms including bacteria, fungi, protozoa, nematodes, earthworms, insects like ants and beetles, mites, centipedes, and larger animals like moles, voles, and gophers, all contributing to the breakdown of organic matter and nutrient cycling for plants.

Bacteria and fungi are the most abundant life forms in topsoil, playing a crucial role in decomposing organic matter and releasing nutrients for plants. Creatures like earthworms, springtails, mites, and nematodes are also vital for aerating the soil and breaking down organic material. Burrowing animals like moles, gophers, and some rodents also live in topsoil, helping to mix and aerate the soil.

The world is losing topsoil at a rate that's 10 to 40 times faster than it can be naturally replenished. This loss is largely due to human activities such as conventional farming practices, which strip the soil of carbon and nutrients. The consequences of losing topsoil are significant. The world grows 95% of its food in the top layer of soil, so losing topsoil threatens food security.

Humans have moved a significant amount of soil on the surface of our planet. Scientists estimate that at this time, we have moved more soil around than any other natural geological processes in earth. In the last 150 years, half of the world's topsoil has been lost. This is because the rate of soil erosion from human activities has exceeded the rate of new soil formation.

So how do we protect our topsoil and prevent further loss? There are several steps you can take to protect your topsoil and help to build it up. For more info, check out my posts on "mulch," "green mulch," and "matrix planting." 

Shared from Perfectly Imperfect Gardens