The Dirt on Soil Conservation

What does life on earth need to survive? You probably think of food, sunlight, and water, right? These things are important, but I bet you’d never think to say soil. It’s easy to forget that soil plays a very important role in supporting all life on Earth!

What is soil?

Soil makes up the top layer of the Earth’s surface. The layer that contains soil, where soil-forming processes happen, is called the pedosphere. Soil is made of minerals, water, air, and broken down organic material. This organic material can be things like leaves, roots, twigs, and bugs.

What living things depend on soil?

You probably know that plants grow in soil and get water and nutrients from it. But you may not know that soil is home to an ecosystem of its own. 

Soil is filled with organic and inorganic nutrients that are used by plants and microorganisms like bacteria and fungi. These microorganisms are a food source for other animals, like insects. Insects are then eaten by larger animals like mice and birds, which are eaten by other animals, like hawks or foxes. 

Soil is the foundation of every terrestrial (land-based) food chain on Earth. Without soil, it would be very difficult for plants and microorganisms at the bottom of these food chains to grow. So, the health and conservation of soil are very important.

How can soil be damaged?

Soil can be damaged when something harmful is added to it, or when nutrients are taken away from it. Land pollution is when solid waste, liquid waste, or pesticides are added to soil on purpose or by accident. Land pollution is a major contributor to soil contamination. 

Solid waste, like the garbage in landfills, takes up land and can get mixed up in the soil. This can make it difficult for plants to grow because there isn’t enough space on land or underground for their roots. 

Liquid waste from landfills, factories, and farms can contaminate soil. This happens when chemicals leak into the soil and make it poisonous or remove its nutrients. If soil is contaminated, plants and microorganisms are not able to live in it. 

Pesticides are chemicals that people spray on farms or in gardens. These chemicals protect the plants we are growing by killing unwanted insects, fungi or competing plants such as weeds. But if too many pesticides are used, they can build up in the soil and kill important microorganisms, along with the insects. People can choose to use pesticides that break down easily, and do not build up over time. Or they can use pesticides made of natural materials, such as soap, that get rid of the insects with little to no environmental impact. 

Soil can also be damaged when nutrients or water is lost from it. This can happen through irresponsible ways of farming, or through erosion. 

Tillage is the process of digging and turning over soil to remove the weeds that compete with crop plants. But if the farmland is on a hill, tillage can move nutrient-rich soil down the hill, leaving the higher soil without nutrients.

Desertification is when soil loses so much water that nothing can grow in it. This soil becomes a type of land called drylands. Drylands now cover over 40% of Earth’s land, and many organisms have a difficult time living in or on it.

Erosion from wind or water can cause nutritious topsoil to be removed from an area. This can happen slowly or very quickly. Water erosion often happens when there is a lot of rainfall. It can also happen when snow melts and the ground thaws in the spring, causing water runoff. Wind erosion happens when the wind moves small particles of soil long distances or moves larger particles of soil around. This affects the way nutrients are spread through the soil, making it hard for organisms to survive in it. 

Did you know?

Due to poor farming methods, fertile soil (soil where plants and organisms can grow) is being lost at a rate of about 24 billion tonnes per year. This is one-third of the Earth’s total soil.

What is soil conservation?

Soil conservation includes many ways to reduce soil damage. It is often used in forestry and farming. 

Farmers can choose to use composted manure to fertilize their plants, instead of chemical fertilizers that can damage soil. Farmers can also use crop rotation, switching up the kinds of crops that are planted in a certain area. This way, the soil will not lose as many nutrients as it would if it only contained one crop for a long time. Conservation tillage describes a number of ways farmers can till while protecting the soil. For example, changing the time of year that they till, and changing the way they till, can help the soil keep its nutrients. 

To prevent wind and water erosion, farmers can leave a layer of mulch over their crops. This is called mulching. Buffer strips, or conservation buffers, can also be used to prevent wind and water erosion. These are barriers such as trees, alfalfa crops, or waterways that block the wind or provide water with a route to pass through farmland without removing the soil.

When you consider the importance of the dirt beneath your feet and support biodiversity and life on Earth, you can’t help but want to protect it!