To understand the structure of the soil, I like to make a kind of comparison. Imagine a cake cut into many layers. But when it comes to serving, they all disassemble and end up mixing into your plate.
On planet Earth, the successive layers of stone, clay, sand, and organic matter occur according to the rocks that originate from the ground and the mineral components that exist in it. These layers are formed by thousands of years, by the decomposition of rocks and overlapping mineral waste, and also by the life that grew in each geological period of the Earth.
Therefore, on the same land, right there in your garden or backyard, you can find layers of various types of sediments. And they may have lost their original order of deposition, causing one piece of land to have stains of stony soil, others of pure clay, and yet, layers of mixed land.
These layers can be a few centimetres or many metres apart. Often, their side view can be exposed on roads, where there are cuts revealing rocks. The set of these vertical soil layers is technically called a profile.
When it comes to preparing the soil or potting pot in your home or apartment, the ideal is to reproduce a natural profile for each type of plant. First, use stone in the lower part to drain the excess water. Then, put some soil with fertilizer so that the seedling develops and soil without fertilizer to stay in contact with the roots during the adaptation period (about 30 days after planting), because they can burn when in direct contact with fertilizers.
Finally, add a layer of straw or stones to protect the soil from the impact of rain and sun rays and to maintain moisture (if the pot is in an open space).
This is the ideal structure of a pot for terrestrial plants. Already in a deeper ground, as in the garden of your house, the structure is hidden in the underground and to know how it is, you should study the ground. To do this, dig a hole about 50 cm deep and 50 cm wide to see if there are roots, rocks or river pebbles. And already see what is the type and color of the earth.
It is very important to take into account the relief, observe the marks of erosion, the accumulation of sand and clay soil and the existing plants to discover where the soil is more irrigated and fertile. Also observe the types of plants that exist in the place, because many of them reveal where the land is more fertile. In farms or sites, it is important to avoid areas where cars or cattle have passed because they cause the compaction of the land.
If you want to plant a deep-rooted, leafy tree such as Mahogany or Pine, it is better to have space in the subsoil for the roots to grow without the obstacle of finding a rock in the middle of the path or the compacted soil, so that the roots cannot develop (very common to happen in flowerbeds near the streets and roads).
Already if the desire is to cultivate a garden, the best is that it is in a well-drained soil, with greater depth to 50 cm so that this soil is turned from time to time, returning the lightness and permeability and providing rest and fertilization so important for the development of the roots.
To know about the granularity (texture) of the soil, it is necessary to take the soil in hand and rub or sift to see the size of the grains. A good test is to mix the soil with water in a glass to understand how that mineral is diluted and regrouped. If it is a sandy soil, it will settle underneath because it is heavier, and the clay will accumulate overneath because it is lighter and the organic matter will float on the surface. Then you can have a general idea of how these parts divide and the proportions that make up the soil on the ground where you intend to grow your garden or plant your tree.
Once the soil is prepared, the choice of cultivation becomes much simpler. Now what will it be? A beautiful tree to give enough fruit and shade for your home or tasty and aromatic herbs for your next dish in the kitchen?