Soil formation factors

We know that soils are not the same everywhere. In terms of classification, there are hundreds or even thousands of different types, depending on the criteria used in their analysis. But why do soils have different shapes, chemical compositions, colors and even fertility levels? This is because each of them was exposed to the different combinations between the soil formation factors, which are: the matrix rock, the climate, O relief, living organisms and time.

Next, we will understand in more detail how each of these factors interfere in the pedogenesis process.

Soil formation - matrix rock

Matrix rock: If we consider rocks from their genesis, they can be classified into intrusive igneous, extrusive igneous, metamorphic and sedimentary. Therefore, depending on the type of rock that gives rise to the soil in its training process, different chemical and mineral compositions this soil will present.

See too: The Soil Formation Process

For example: the Brazilian relief, in a geologically distant past, suffered from many spills volcanic rocks in its south-central region, constituting a specific rock called basalt, among other types similar. This rock later gave rise to a type of very fertile reddish soil, called purple soil. In a different situation, a sedimentary rock with a low concentration of limestone (CaCO3) would give rise to a sandy and chemically poor soil.

Soil formation - Climate

Climate: the interference of climatic factors on soil formation happens from the regulation of some elements, such as humidity, winds and, mainly, the rainfall regime, which affects to a greater or lesser extent the weathering of the matrix rock. The trend is that the hotter and more humid the atmospheric environment is – something common in regions with tropical climates and equatorial - faster and more intense will be the rock decomposition process, since the physical and chemical weathering will be accelerated.

Soil formation - Relief

Relief: in regions where landforms are more accentuated, the presence of slopes is more common. In these places, the soils tend to be shallow and less developed, since in steep areas The water from the rain tends to drain and not infiltrate, which reduces the incidence of weathering. Flatter regions, on the other hand, tend to favor the action of exogenous agents of transformation of the environment, which contributes to accelerate pedogenesis.

Soil formation - living organisms

Living organisms: the presence of living organisms will also condition the soil formation process, since many of them act in what we call biological or chemical-biological weathering through the release of different substances. With that, the more organic material and living beings exist in that soil, the more intensified its constitution process will be. In addition, they will interfere in other instances, such as the degree of fertility and chemical composition.

Soil formation - Time

Time: refers to the quantitative period in which the matrix rock was exposed to environmental conditions. Therefore, regions with young soils tend to have less depth compared to geologically older regions. Most of the Brazilian territory is considered ancient, which, combined with the presence of humidity and heat in most of the country, means that we have many soils with a better developed profile.