Is the Amazon basin soil fertile?

Answer 1

Soil in the tropical rainforest's is very nutrient poor. The topsoil is only one to two inches (2.5 to 5 centimeters) deep. The only reason plant life is so lush is because the plants store the nutrients in themselves rather than getting them from the soil. When plants decay, other growing plants tap the nutrients from the dead matter and reuse nutrients left over from that plant. This is why farmers can only use the rainforest's soil for one or two years after they clear cut it, before all nutrients are stripped from the soil. The reason the soil so infertile is because it is more than 100 million years old, and has taken a beating from the elements. After time, rain washes minerals out of the soil, leaving it more acidic and nutrient poor. Soil exposed to the heat and condensed sunlight turns it into red clay. Other soils just cannot deal with minerals, and turn it into compounds useless to plants. There are some fertile patches of soil in the rainforest's, but they are scattered throughout the thick vegetation.