Amazon Soil and Their Characteristics.
Most Amazonian soils are poor in nutrients and have a low potential retention, especially in relation to calcium, potassium and phosphorus. However, on poor soil grows a dense vegetation, which has come to confuse many!! - because it is assumed "that beneath a forest fertile soils are very fertile." But the truth is quite the opposite.
Unlike other temperate regions, nutrients are not mostly on the ground but in the forest, that is, in the biomass. What happens is that the forest has a high ability to absorb nutrients from decaying organic matter and fall, and thus controls the loss of nutrients.
The low nutrient content is due to two causes: (i) at high temperatures and precipitation, and (ii) to the geological history of the region.
Deforestation-the-amazonasLa intense weathering and washing (leaching) over millions of years has removed nutrients from the minerals that form soil parent materials. The loss of nutrients by washing or erosion can not be replaced by subsurface weathering, as in temperate regions.
Amazonian soils also have a very low retention capacity of nutrients, which originate from the decay of organic matter.
This is due in part to the high concentrations of aluminum and hydrogen, which occupy the spaces in which the nutrients should be retained. Aluminum comprises a high percentage of soil minerals. The hydrogen coming from the organic acids formed in the organic matter of the topsoil.
Despite the low capacity of the soil to retain nutrients, forest survival is not threatened, because species of Amazon trees have adapted to highly weathered soils and washes. One of the most important adaptations is the concentration of roots in the ground surface, that capture the nutrients from the decomposition of organic matter and prevent loss by washing.
1. In the Amazon forest nutrients are mostly in biomass (plants and animals) and not on the floor.
Two. Arboreal plants have a high capacity to recapture the nutrients from the decomposition of organic matter for surface roots and involving fungi (Mycorrhizal). This system is highly efficient and allows conservation of nutrients in the ecosystem.
Three. Consequently, when you destroy the fo
rest (slash and burn) soils occur for a short period (2-3 years) and lose their fertility, because it interrupted the recycling of nutrients and there (ash and organic matter) are washed by heavy rains.
The only way to preserve and restore nutrients in the soil and maintain its fertility is achieved through three ways:
1. Let rise again in the forest replenish depleted soils and nutrient cycling through alternating practices and fallow crops (logging-crop-fallow-crop-fallow) practiced in the region.
2. Contents crops with greater forest cover possible (agroforestry) to maintain nutrient recycling as efficient as possible.
3. Continuously feed synthetic fertilizers, which is impractical in many areas by distance and high prices, and the lack of capital to purchase.