Soil Basics

Soil Basics

Photo by Gabriel Jimenez / Unsplash

What is Healthy Living Soil?                   

Healthy soil contains humus. Humus is partly broken down organic matter: compost, mulch, manure, plant roots and plant material. Humus provides food for soil biota, which then become food for plants. Humus also stores plant nutrients, helps to bind soil particles together, improves soil structure, and soaks and stores water in the soil Healthy soil means that the soil is alive! It contains millions of soil biota which turn organic matter and nutrients into plant food. Soil biota includes bacteria, microorganisms, ants, worms, and many other very small organisms.

It contains a balanced combination of clay and sand particles. The clay holds the minerals and the sand allows drainage / water channels It is composed of 50% clay, sand, humus and organic materials and 50% air pockets. The texture should be loose when pressed, not crumbly like sand or sticky like clay.                    

Air pockets are very important because:            

They provide space for the soil to hold a lot of water

The air provides the oxygen that is needed by plant roots to process nutrients

They allow easy, fast and deep root growth, so that the plants can soak up more water and nutrients, and the plants will become bigger and healthier

The soil can function as a ‘nutrient bank’, it stores nutrients that are ready for plant use, and those nutrients are then not lost from the soil

The soil will have a balanced pH level. This means that the soil is not too acidic and not too alkaline.


The Importance of Worms in the Soil        

Worms are your best friends in the soil!        

These worms are earthworms. This is a different type of worm than the ones that make animals and people sick. Many worms in your soil show that the soil is healthy. Earthworms eat the humus in the soil, and then change that humus into nutrients, this is very good for the soil.        

Earthworms will continuously:        

1. Change humus into nutrients that plants can use
2. Dig the soil so that air can enter the soil  
3. Improve soil structure and water drainage
4. Bring nutrients up from deep in the soil to supply food for plant roots     

All the worms need is mulch and compost! However, be careful with chemical pesticides, herbicides and some fertilizers, because they will kill the worms in the soil.       

Benefits of Healthy Living Soil

  • Plants are more drought resistant because the soil can store much more water and plants can send their roots much deeper into the soil to receive water and nutrients  
  • Plants are more disease and pest resistant because they are healthier. An unhealthy person will become sick more often, the same is true for plants  
  • The plants produced will contain more vitamins and minerals, which if consumed will improve the health of the whole family, especially children  
  • Reduces evaporation from the soil, so that the soil will hold and store much more water. This will reduce the need to water plants  or  
  • You have millions of workers in the soil that manage nutrient availability, store those nutrients, and increase the amount of air in the soil. Worms are hard workers!  
  • The soil becomes easier to dig and work with because it has a loose texture. This is very important because it will save a lot of time and human energy  
  • It can save a lot of money if most of the land management is organic. Soil needs very little expense if good techniques are used. Remember to compile and reuse all plant and animal wastes  
  • Water will not be stagnant in the soil during the wet season. Even though healthy soil can store more water, the good soil structure will also allow for drainage if there is too much heavy rain. Too much water can slow down plant growth, and even kill plants if their roots become drowned in water. In areas where the soil contains too much clay, stagnant water can become a big problem. Making raised garden plots will also greatly reduce this problem  

To improve soil, do:

  • Use organic compost, mulch and EM (Effective Microorganisms) regularly. This will provide a lot of nutrients, increase the amount soil biota, improve soil structure and they are inexpensive to make  
  • Use mulch to protect the soil from direct sunlight, conserve water and increase the amount of humus in the soil  
  • Recycle organic materials, such as left over plant and animal material, to return nutrients into the soil  
  • Use legumes. There are many different types of legumes that can be planted, from seasonal to perennial. Legume plants provide nitrogen for the soil, can be used for mulch, animal feed, food for people, serve as windbreaks, help to prevent erosion, and more  
  • Rotate crop production. Different types of plants need different types of nutrients. Crop rotation is useful for balancing nutrients in the soil. Crop integration will also help  To protect soil quality, don’t:
  • Compact the soil. Soil compaction reduces root growth, water storage and water drainage, as well as damages soil structure. It also means that a lot of energy is needed to dig the hard soil  
  • Leave the soil open, exposed to the sun. This will make the soil dry and more difficult to dig  
  • Use anything that will kill soil biota. Soil biota are your friends and helpers for building healthy and balanced soil. Using pesticides and herbicides will kill them  
  • Waste water. Water is a precious resource and should be stored in the ground. Water that is continually flowing can create erosion. Good water usage will reduce the risk of drought. The amount soil biota will also reduce if the soil is very dry, these biota need water too  


Stop erosion...

The first soil that is eroded is the topsoil. This is the most valuable layer of soil! The topsoil contains a lot of nutrients that could take years to replace. The soil will not be able to hold water, and plant roots will become exposed to the soil surface, the plants will then grow very slowly or even die.

Stop burning...

  • Burning destroys valuable materials, that can be made into compost, mulch, and nutrients for the soil  
  • Burning reduces the amount of soil biota  
  • Burning dries out the soil and reduces water volume  
  • Burning creates erosion and pollution  

Different Types of Soil

By doing a simple experiment, you can identify the types of soil that you have. This knowledge will help you in choosing the best method for improving your soil.

• First, take three or more soil samples and place them in clear jars or bottles • Fill the container 2/3 with soil, then add water until full
• Close the containers and shake them evenly
• Then, let the soil settle and you can see what type of soil you have

Simple soil identification experiment

Clay will always be at the top, with sand underneath, and very course sand at the bottom. This is a very simple experiment, so even kids can do it.

Clay soil holds nutrients well, but does not contain much air, so when heavy rains come the water can become stuck in the soil.

While sandy soil will soak up water quickly and contains a lot of air, it easily releases nutrients and can quickly become dry.

Improving Soil Quality For All Types of Soil

For all types of soil the best solution is to regularly use mulch, dry compost and liquid compost. This will:

• Improve soil structure and the amount of air in the soil • Increase the number of soil biota
• Increase the amount of available nutrients

• Increase water storage capacity

For Clay Soils

The following steps are useful for improving clay soils:

  • Reduce compaction, because once the soil becomes compacted it sticks together. This makes root growth difficult, as well as making it difficult for people to dig  
  • Add sand to improve soil structure  
  • Use green manure crops and crop rotation to help improve soil structure over time. See the section on legumes in this module for more information on techniques  
  • Planting trees will also help to improve the structure of clay soils. Trees provide mulch material and their roots will help to break up the clay soil. Trees can also be combined with other types of plants  
  • Gypsum can help to improve the drainage and structure of soil. This technique will improve clay soil structure quickly, but is expensive. This technique will not work well if the soil’s pH is too alkaline  

For Sandy Soils

The following steps are useful for improving sandy soils:

• Add 3 shovels of clay into liquid compost. The clay will bind nutrients, and when this mixture is used, the clay will stay in the sandy soil and hold nutrients within the soil

adding clay
to liquid compost

• Add 1/2 a shovel of clay to a large bucket of water, spray this mixture over the sandy soil. Using the liquid compost technique above is much better, but this method still adds valuable clay particles to the sandy soil

• Use green manure crops to add humus to the soil, this will improve the sandy soils structure

• Plant trees. In dry sandy areas, it is better to plant trees than to plant annual vegetable crops

Soil pH

The soils pH level is a measure of the acidity or alkalinity of the soil. For example, we can compare a soil’s pH level with your stomach. If your stomach is too acidic it will not work well. This will then cause problems for you stomach and the rest of your body. The same is true with soil. In good conditions, the soil’s pH level will be neutral, this will greatly improve the productivity of everything that is being grown in that soil.

pH Chart

If the soil is acidic, nutrients will easy leach out of the soil. Productivity will reduce and if the soil is very acidic, only a few types of plants can be grown.

If the soil is alkaline, there are many nutrients in the soil, but they are bound and not easily available for plants to use. Productivity will reduce and only a few types of plant can be grown.

By adding enough mulch, compost and other organic materials, the soil will contain more humus which will then neutralize the soils pH levels, as well as increasing the amount of nutrients in the soil.

Using chemical fertilizers when the soil is in acidic or alkaline condition will only be wasting money, because a lot of nutrients will be bound in the soil or leach out of the soil. Besides that, it will also create many more problems in the future.

Identification of Soil pH

Acid soils:

  • Are generally found in wetland, areas with higher rain fall, and in the mountains
  • Taste sour, like vinegar  Alkaline soils:
  • Are generally found in dry land, coastal areas, and areas with lots of limestone  
  • Taste sweet  

Testing Soil pH

Soil pH can be accurately identified using a pH tester. A pH tester shows a series of numbers, ranging from 1 to 12. Number 1 shows that the soil is most acidic, and number 12 shows that the soil is most alkaline. The ideal soil condition will have a pH of 6.5 or neutral; in this condition, the soil is neither acidic nor alkaline.

There are a few types of pH testers. Some agriculture workers and NGOs may have this type of tester. However, by identifying landforms (for example, swamps), rocks, and common tree types, you can identify the soil pH without needing this equipment.

Solutions for Balancing Soil pH

The best solution for acidic or alkaline soils is to increase the amount of humus in the soil. This can be done by regularly using mulch, compost, liquid fertilizer and other organic materials. Increasing the humus content in the soil will make the soil pH neutral, allowing more nutrients to stay in the soil and be available for plant use.

Other Solutions for Acidic Soils

  • Ash from wood fires (there must be no plastic content in the ash) can be spread over soil that is acidic. Don’t use more than 1 kg for every 30 square meters each year. Don’t burn grass and plant materials to make the ash; grass and plant materials are also very important for balancing soil pH  
  • For acidic soil in small areas, crushed seashells will provide lime to help balance soil pH  
  • For larger areas, dolomite can be used. Lime can also be used, but dolomite is better because it contains magnesium, and is safer for plant roots. These materials are expensive, and should only be used after the soil pH has been tested  

Spreading dolomite on acidic soil

Amount (kg) of dolomite needed to raise soil pH levels to 6.5, per 30 square meters:

Soil pH Sandy Soil Loam Soil Clay Soil

Other Solutions for Alkaline Soils

  • Use 6 kg of compost per square meter to lower soil pH by 1 point (for example, 8.5 pH to 7.5 pH). This does not need to be applied all at one time  
  • Use 2 kg of manure per square meter to lower soil pH by 1 point  
  • Iron sulfate (FeSO4) or other materials that contain sulfur can be used, but they are expensive. It is best to test the soil pH before using these materials  Amount (kg) of iron sulfate, or other materials that contain sulfur, needed to lower soil pH by one point per square meter:  Material Sandy / Loam Soil Clay Soil

Don't forget to Keep it simple,