Garden soil is one of the most basic elements required in gardening. A gardener cannot do without soil, regardless of the type of plants he is planting. Good quality soil is essential to your plants’ health but have you ever thought what the humble garden soil is made of?
What is Soil Made of?
There are four main components of soil – mineral matter, organic matter (humus), water and air. Within the soil contains inorganic elements such as stones and gravel. These are the mineral matter and they make up to 40%-60% of the soil volume. Mineral matter originates from the bedrock that is under the soil.
Organic matter or humus is the decomposed remains and waste products of plants and animals. Soil nutrients or the chemical properties of the soil are largely affected by organic matter. In between the mineral matter and organic matter is the space occupied by water and air.
Purpose of Soil
The role of garden soil is much like the role played by parents. They provide support and help the plant to grow strong and healthy, just like the way our parents supported and provided for us when we were young. Soil is needed to support the plant by allowing its roots to grow through the soil and hold itself in place. With its ability to store nutrients and water, soil also plays a vital role in the biological support for the plant.
In addition to supporting plant life, garden soil also supports other life forms. Microorganisms and insects rely on soil to survive while contributing to the plant by decomposing organic material and adding structure to the soil. Microorganisms like fungi and bacteria that live in soil are used to produce antibiotics, which have benefited much to mankind. The soil is also used to support vegetation growth for mankind’s consumption to ensure survival. All life on earth is dependant on it either directly and indirectly.
Now, let’s explore further the different types of soil texture.
Different Types of Soil Texture
Soil texture is determined by the different mineral particles and its respective size distribution. These mineral particles are sand, silt and clay. Sand particles are 2 to 0.05 mm in diameter, silt particles are 0.05 to 0.002 mm in diameter and clay particles are less than 0.002 mm in diameter. These particles exhibit different properties and their combinations in different proportions will have favorable outcomes for certain plant life. Let’s take a look at the most common classes of soil texture:
As the term suggests, sandy soil feels gritty to the touch and contains a high percentage of sand particles. There is a lot of space in between the particles and therefore, it does not hold water well. Hence, essential plant nutrients also get washed away due to the free draining nature of sandy soil.
Clay soil has small size particles which make it clump together easily. What this means is, there is less room for air spaces and drainage capability is relatively poor. Besides, clay soil does not hold nutrients well, thus it’s not ideal garden soil. Clay soil is heavy, feels lumpy and becomes sticky when it’s wet, making it difficult to work with.
Contrary to clay soil, silty soil feels smooth to the touch. It contains a high percentage of silt particles and has good drainage capability due to the small size of the particles. Water is able to permeate through easily with silty soil. Silty soil holds nutrients better than clay soil and is easy to cultivate but it can be compacted quite easily.
Loamy soil has the best soil texture and is a gardener’s dream soil. It has a good proportion of clay, silt and sand particles thereby providing the perfect amount of drainage. Unlike sandy soil, it does not lose water excessively. Loamy soil is able to retain nutrients for your plants. Thanks to its good structure, loamy soil is also easy to cultivate.
Healthy soil provides the basis for healthy plants. In the second part of our Garden Soil series, we will look at what constitutes healthy soil and how to create healthy soil.