earth

Soil

Soil Introduction

Soil is all around us and shows up in different forms. Loamy soil is dark brown and nutrient dense -- often what you want in your garden! Clay soil is common in the southern United States and is known for its deep sediment. Gritty, sandy soil is best in dry climates for cacti and desert plants.

Where you live affects the soil you live on. An area's climate, landscape, lifeforms, and parent material all impact the type of soil you live on and the plants you can grow.

EXPLORATION

Go outside and inspect the soil

What is the texture like?
- Is it loamy, clay, or sandy?
Why do you think that is the soil in your region?

Soil Layers

Soil is comprised of five layers, stacked ontop of one another:

Organic: This uppermost level contains organic matter such as fallen dead leaves. Not all soils contain this level.
Topsoil: A mix of organic matter and small pieces of parent material. This is an ideal layer for organizims to live and plants to grow.
Eluviated: Often found in forest soils, this level contains a mix of clay, minerals and organic matter.
Subsoil: This layer is created from particles in the Topsoil and Eluviated sections that leached down.
Parent Material: This layer contains Earth's weathered bedrock.

Concerns for Soil

Pesticides

Organisms such as worms, beetles, and ants, help soil keep its structure by digging burrows and adding organic matter to the dirt. Despite their important role in keeping soil healthy, studies have found that these invertebrates are harmed by commercial pesticides. Unfortunately, pesticides are widely used within farms, landscapes, and home gardens across the nation. The United States alone uses more than 1 billion pounds of pesticides each year!

Plastics

As discarded plastic erodes and disintegrates, it breaks itself into smaller pieces known as microplastics and nanoplastics. Plastics are not biodegradable, meaning that they will last forever within our ecosystems.

The chemicals contained within these plastics have been found to cause various earthworm species to become sick. Similarly, new studies are finding that some plant roots might be taking in micro and nanoplastics as well, harming the crop and those who eat it.

Deforestation

Deforestation refers to the clearing of forested land whether it be accidental, natural, and purposefully cleared. Trees are critical to ensuring soil stays in place, as the root systems take in and reserve water and secure topsoil.

Without forests, top soil becomes eroded and extra water can flood large areas without the assistance of tree roots. Deforested areas are often used for agriculture due to the demand for large quantities of land.

Why Keep Soil Healthy?

Human and Animal Health:

Humans and many animals rely on healthy soil to grow our plants so that we can nourish our bodies. Across the Earth, we are able to grow a variety of different crops based on the soil’s composition. Below you can see what fruits and vegetables are most commonly grown within the United States. Notice that there are locations producing different crops within a single state!

Below is a list of some crops that grow in each region:

Northeast Region: Apples, Cranberries, Blueberries, Soybeans, Mushrooms, Rhubarb
Southeast Region: Citrus fruits, Peaches, Watermelon, Peanuts, Sweet potatoes, Kale, Pecans
Midwest Region: Corn, Soybeans, Wheat, Apples, Cherries, Cranberries, Blueberries, Pumpkins
Great Plains Region: Wheat, Corn, Sorghum, Soybeans
Southwest Region: Citrus fruits, Pecans, Melons, Grapes, Chickpeas, Chia, Sunflower, Beans, Pomegranate
West Region: Grapes, Almonds, Walnuts, Lettuce, Tomatoes
Pacific Northwest Region: Fruits: Apples, Cherries, Potatoes

Bugs and Microscopic Organisms:

Just as humans and other animals need healthy soil for plant production, bugs and other microscopic organisms need healthy soils to live. These organisms, mainly found in the topsoil, eat the layer’s organic materials. By breaking down these matters, they keep the soil rich and nourished.

Carbon Management:

Carbon Sinks refer to natural systems that absorb and sequester [store] carbon dioxide and other gases from the atmosphere. Soil is an important carbon sink. When we disrupt or destroy carbon sinks, not only do we stop them from providing this service, we also release the carbon they have previously stored.

How can we be a part of the solution?

Let's Find Out