Understanding the Importance of Soil Sterilization

What Is Soil Sterilization

The reason we plant is to grow healthy crops for food or plants to beautify our environments. It can be very disheartening when your plants keep getting destroyed by pests, fungus, and harmful microbes that make the soil their abode. To get rid of these anti-plant-growth organisms, you should sterilize the soil.

Soil sterilization is a farming process that employs the application of chemicals and other methods to eradicate pests and diseases, viruses, fungus, pathogens, and harmful mixes from the soil. The process always clears out the weeds, insects, and all they become fertilizer for your soil. When you farm on soil repeatedly without treating the soil or allowing it to replenish itself, it is essential to sterilize it from time to time. A soil left unattended leads to the buildup of weeds, fungus spores, and other harmful pathogens.

How to Sterilize Your Soil

There is a mix of opinions concerning the sterilization of soils as to whether it is a healthy practice or a soil damaging activity. It is because of the methods employed in its application. The methods applied in the sterilization of the soil can also destroy good bacteria and microorganisms. Such concerns are a result of misapplication of chemicals and non-proper sterilization. That is why it is essential to know how to sterilize soil, not to mess it up. The decision on what method to apply is dependent on the type of soil and surface area.

Types of Soil Sterilization

There are three methods of sterilizing soils. There could be more, but the most common methods include:

  1. Chemical sterilization
  2. Heat sterilization
  3. Solarization

Chemical Sterilization

Chemical sterilization involves the use of chemicals in sterilizing the soil. These chemicals, when diluted and administered, give off-gas fumes that penetrate the soil and kill all forms of bacteria, anti-plant growth organisms. This method is perfect for commercial purposes because it is more economical for large-scale farming as it requires less effort and helps achieve more with less time. However, many feel the gas fumes may be harmful to other plants and the humans applying them. Some chemicals include hydrogen peroxide and formalin.

It is essential to follow instructions when applying chemicals to the soil as you do not want to kill your plants. It is also essential to test the soil before planting so your seeds don’t die from the chemical residue. You can do this by taking a bowl of soil and planting seeds in it. If it germinates, you are good. But before testing, leave the soil for a while so the chemicals can degrade fully.

Heat Sterilization

Heat Sterilization involves raising the temperature of the soil through steam or dry heat to make it impossible for harmful organisms to survive. This method was invented due to the concerns generated from the use of chemicals. The soil is heated to about 180 degrees for as long as thirty minutes before allowing it to cool. Heat sterilization is said to be more effective in most cases. That is because many harmful organisms, pests, and diseases cannot survive under an extreme amount of heat.

However, too much heat can burn up the soil increasing the phytotoxicity due to soluble salts and toxic organic compounds. In plain words, manure in the soil under excess heat can become toxic for plants. Soil heating methods include boiling water or steaming, microwave, oven heating, and natural sunlight.


This method involves the use of sunlight energy to generate steam that heats the soil. This method is applied when you intend to heat a large surface area like a garden or more. This method takes longer (usually 2 to 6 weeks) because of the amount of heat required to achieve the goal. This method also serves as an alternative for chemical sterilization when dealing with a large surface area.

Here you cover the fields or surface area with plastic to trap the energy from the sun. Some materials can retain heat more than others. In this case, a transparent plastic would work perfectly. Remember to wet the soil before covering it up.

Benefits of Soil Sterilization

Sterilization is focused on treating the soil and preparing it for planting. It provides quick relief for the soil from substances and organisms that are harmful. It kills the weeds and leads to a significant increase in crop yield. For soils that have been in use without treatment, it helps to revitalize the soil with the activation of chemical-biological reactions.

Sterilization should be carried out before you begin planting. Whatever methods you choose to employ in sterilizing the soil, make sure to get some professional advice.