Section 6: Soil, Other Growing Media, and Fertilizer

Glossary

Lesson 1: Types of Soil

Soil type usually refers to the different sizes of mineral particles contained in the soil.
Most soils are made up of a combination of three basic types of mineral particles. The texture of the soil  depends on the amount of mineral particles in that particular soil, as well as the presence of humus in it.

 
Image Source: Science Online by Heba Soffar CC 4.0
The three basic types of soil, are:
This soil consists of the biggest particles. The bigger the soil particles, the better the aeration and water drainage of the soil. Sandy soil is formed by the disintegration of rocks such as limestone, granite, quartz, and shale. It warms up fast in the spring, and it is good for plants since it lets water drain easily, which prevents root rot problems. However, it is imperative that you water it regularly during the summer months.
To check if soil is sandy, moisten a small sample of the soil and try to make a ball using the palms of your hands. If the soil is sandy, then no dirt balls will form and the soil will crumble and fall through your fingers.
Silty soil is considered to be one of the most fertile soils. It is composed of minerals like quartz and fine organic particles. It is granular like sandy soil, but it consists of smaller particles and has more nutrients. When dry, it has a smoother texture and looks like dark sand. To check if the soil is silty, take a small amount of moist soil and rub it between your fingers. Silty soil will feel slick and stick to your fingers. of soil can hold more moisture and is easier to work with when wet.

Clay soil consists of very fine grain material, with much less air space. Because of this, it is difficult to work with, and it becomes very heavy when wet. Hence, water logging can occur, which can harm the roots of a plant. Clay soil is formed by extreme rock disintegration and weathering, and thus it is rich in mineral content.

To identify if the soil is clay, take a soil sample and dampen it with water. Feel it between your palms. You'll find it to be sticky and to retain a good amount of water.

Soils can be even further classified into three sub-types, as follows:
This soil consists of sand, silt, and clay (each to some extent). It is considered to be the perfect soil for gardening. It's texture is gritty and it retains water very easily, yet the drainage is good. There are various kinds of loamy soil, ranging from fertile to very muddy. But out of all the different kinds of soil, it is the one that is ideal for cultivation.
This kind of soil contains much more organic matter than other soils. It is basically formed by the accumulation of dead and decayed organic matter in a wet climate, and is generally found in marshy areas. This soil is prone to water logging, and although it is rich in organic matter, it contains fewer nutrients than any other type of soil. If the soil is fertilized and appropriate drainage is monitored, it can actually be ideal for growing plants.
Unlike peaty soil, chalky soil consists of a large number of stones. The fertility of this kind of soil varies greatly, and it is prone to dryness during summers. Because of this, it is a poor choice for plantation, since plants would need more watering and fertilizing than in any other type of soil. Chalky soil also blocks a plant's absorption of nutritional elements such as iron and magnesium.
Every soil type has its own advantages and disadvantages.  Plants have different requirements and therefore suited to different soils.



 Clay soil, at left, is the dislike of many gardeners. It offers good nutrition, but it is hard to work with.
Source: http://suhow.info/sh-definition-of-clay-soil
 
 
 Loamy soil, at right, is the perfect soil. It has about 40% sand, 40% silt, and 20% clay.)
Source: www.ruralmuse.co.uk/
gardens/2008/10



  Digging Deeper


Soil test   

Watch this video, from Canadian gardener, Mark Cullen, as he talks about soil in simple terms.