What do the soils consist of? Sandy soils. Acidic soils

What is the greatest wealth of our planet? Of course, this is water and air, but one should not forget about something else. On the soil. It is the fertile substrate that provides millions of diverse species of animals and plants, thanks to it, there is a large part of the biosphere. Do you know what the soils consist of? If you are interested, you can read our article!

What is the soil?

Many people assume that the ground under their feet is a common dirt, but no one will think about its composition at all. Meanwhile, soil is an extremely complex natural formation. Conditionally it is divided into solid and liquid parts, gaseous fraction and living component. The composition of the solid component includes many minerals, as well as some dead organic matter. The liquid fraction is water and microelements dissolved in it.

Accordingly, air and other gases, which are formed in the ground as a result of natural biological processes flowing there, belong to the gaseous part. The living phase is millions and billions of fungi, molds, microorganisms, spores and other biomass. This is what the soils consist of.

Characteristics of the solid fraction

Particles of solid mineral elements form the basis of a solid fraction. It is generally believed that they form sand and clay. Sand refers to elements from 1 to 0.01 mm in diameter, and everything that is smaller than 0.01 mm forms clay. All particles more than one centimeter in diameter form a rocky skeleton of soil.

Why do we need to know all this? The fact is that the percentage of all these elements depends on the type of soil. Here is the definition of the soil, which in its works is brought about by virtually all eminent agronomists:

• Loose sandy, which contains not more than 5% clay.
• Sandy connected, in which there are 5-10% clay particles.
• Sandy loam, in which the proportion of clay reaches 20%.
• Light loam. The content of the clay fraction is 20-30%.
• Medium loamy soils. Contain 30-45% of clay.
• Heavy loam, in which physical clay has 45-60%.
• Clay.

Knowing the name of the soil, you can determine what the soil consists of.

Some characteristics

Of course, the mechanical composition has a predetermining effect on the agrarian qualities of the soil, its fertility and the amount of biomass in it. So, in practice, sandy loams and sands are often called light soils, as they take a little energy and resources to process them. Accordingly, almost all medium sandy loam and clays themselves can be attributed to heavy ground, since for their plowing and cultivation it is necessary to spend extremely much fuel. Other characteristics of soils also largely depend on their mechanical composition.

So, light soils are very loose, and therefore easily pass deeper into moisture and air. In the spring they warm up the fastest. But only they get water they do not hold, and all the organic remains that predetermine fertility from the light soil are extremely easily washed away. Clay soils are poorly heated, disgustingly pass moisture and air. But their humidity is always about the same. And the content of nutrients is much higher, if you compare these indicators with sandy soils.

Structural elements

All mineral elements of the soil can aggregate, forming larger structures. If such a phenomenon is not observed, the soil belongs to a variety of structureless. Such a soil can not be a suitable substrate for plant growth, since it does not properly fix the root system.

Sandy soils

An ideal example is sandy soils. So called the soil, which contains from 0 to 5% of clay particles. Soils of this type are extremely light, they lack any structure. Of these, nutrients are almost immediately washed out , and the water evaporates quickly.

To get at least some sort of crop in such conditions, you often have to put a lot of fertilizers, and also make the soil structural, bringing in clay, peat and rotted sawdust. It should be noted that the sandy soils in this case are extremely expensive, as they have to spend a lot of time, resources and money to improve them.

Recently, science has tried not to fight on its own with the lack of structure in the sand, but to select such plants that could create it independently. In particular, there are varieties of cultivated plants, derived specifically for desert conditions.

They develop a fruited root system, in which several grass bunches are able to firmly adhere to each other, forming a strong "canopy". Under it, the accumulation of useful substances is gradually proceeding, as water and air are no longer able to blur and blow them out. If you sow a semi-desert area with such crops, then in a few years there is formed a soil quite acceptable for growing crops.

Which soils are good for agriculture?

Scientists-agronomists believe that the most optimal soil is with a particle size of 10 to 0.25 mm. It is quite porous and well resists erosion. In addition, such a soil is excellent for water, but its evaporation is relatively slow.

The main advantage is the fact that on the surface of this kind of soil there is hardly any dense cake that prevents growth and development of cultivated agricultural plants. Even in strong winds, the structure of the soil remains intact, the fertile layer is not blown out of it. Thus, structural soil, other things being equal, will allow us to gather a much richer crop.

Of course, you can get such a result on an unstructured ground, but for this you will need to spend a lot of time and money trying to somehow neutralize its negative characteristics.

Humus

Along with various mineral particles, the solid fraction also includes particles of humus. Recall that the so-called remains of animals and plants, processed by soil microflora. In general, in an ordinary soil contains a huge amount of nutrients, but most of them are not available for plants.

Only thanks to saprophyte microorganisms that process such organic matter, plants get nutrients available for absorption. Upper soil horizon contains up to 15% humus. The more it is, the better the most important properties of the soil - its fertility and ease of processing.

Water and gases

It is no exaggeration to say that all soil processes can go only if there is moisture in the soil. In any case, without it, plants will not grow and develop, and the microflora will die. All ground water and salts of microelements, which are dissolved in it, together form a soil solution. From it, vegetation extracts necessary for life and development of mineral elements.

All gaps between the particles, which are normally not occupied by water, are filled with air. However, in some cases, its place may be occupied by methane, hydrogen sulphide or pure carbon dioxide (forest soils in low places). By the way, soil air is just the same and has a higher content of carbon monoxide. In order for plants to feel good, and saprophyte microorganisms actively carry out their activities for processing the substrate, in the ground should be at least 15% of the air.

Live faction

As we already said, the live fraction includes bacteria, algae and fungi. Bacteria are incredibly important for the soil, as they turn minerals into forms that are available to plants. In addition, leguminous plants enter into a symbiotic relationship with microorganisms that have the ability to fix nitrogen of air and transfer it to an easily digestible form.

Important! If the soil has a low pH (acid soil), then there are very few bacteria in it. The work on the decomposition of organic residues in this case is completely performed by fungi. Of course, in the ground there is also a large number of multicellular invertebrates and even vertebrates (moles, mole rats) of animals.

Now you know what the soil consists of.

Acidic soil

Since we mentioned one characteristic feature of acidic soils, let's talk about this kind of soil a little more. What is this?

The most important factor in determining the quality of soils is their acidity. This indicator is neutral if the pH is 7. If it is greater, the soil is alkaline. Less is sour soils. This factor is affected not only by the microflora, but also by the amount of mineral and nutrients dissolved in the soil. Most of the cultivated plants are in great need of neutral or slightly alkaline soil, but there are also species that need an acidic environment. For example, rye, which alone can significantly acidify the soil.

Determine pH independently

This requires a bulb and a solution indicator (phenolphthalein, for example), which can change color depending on the characteristics of the environment. A small amount of soil is added to the vessel with it, and then everything is shaken well, so that everything is properly mixed. After this, you need to wait until the suspension settles and the solution changes color. Using the instructions to the preparation, we determine the acidity of the soil. This is how the characterization of the soil is determined.

Attention! Contrary to popular belief, pH is not constant. It can be different even in neighboring areas of the garden, and therefore the research should be done several times, taking soil samples from at least three to four places. After each application of fertilizers (especially mineral fertilizers), it is also necessary to check the acidity level.

What should I do to change the indicator?

If the soil is too acidic, then it must be deoxidized. For this, limestone, chalk and some buffer mixtures, which are specifically produced by the agricultural industry, are used. In the case when acidity just needs to be increased, peat or ordinary manure is used. Yes, yes, acid soils are often obtained from those gardeners who use this natural fertilizer in large quantities.