Bet365 app download The official website of Oregon University recently published a message，Research team of Lucas Silva, a professor of environmental science at the school, discovered，The fertile black soil in the Amazon area northwestern Brazil is not the result of farming cultivation，but naturally formed。

For a long time，Some bet365 best casino games scholars think，The ancestors of the residents of Amazon's natives carried out plant domestication for a long time and fixed burn in some areas，The plant ash formed increased fertility，So the well -known high acidity、Amazon soil with lack of nutrition has become a fertile black soil that is suitable for farming。

Silva's research team analyzes the black soil samples collected by the Solimoes and Negro River in northwestern Brazil and the Solimoes and Negro Rivers.。They found，Calcium in the soil here、Phosphorus bet365 live casino games and other nutrients from the upper reaches of the river。These nutrients may be formed after the fire in the upstream areas encountered a fire，It was wrapped in the downstream because of the flooding of the river。Through the age measurement of the soil，Researchers discovered，The formation of these nutrients was later than 8000 years ago。After a long drought period from 8000 years ago to 4000 years ago，Climate change drives the river changes.，The flood of river water brings these nutrients Bet365 lotto review to the gathering of two rivers。

Silva and other researchers discovered，The nutritional component of the land around the ancient resident settings is much higher than the nearby area，This shows that these ancient residents chose fertile land to engage in agricultural activities，instead of their farming make the land here fertile。

　(Yan Yong/Compilation)