The correct answer is - biomass from the decomposing grasses.
The Midwest is a region known for its highly fertile soil. The reason for this is that the weathered bedrock combines with huge amounts of biomass. The biomass is almost entirely form the grasses. The grasses grow naturally in this region and they dominate the landscape. They grow and die out relatively quickly, as most of those grasses are one season grasses. They manage to create very large amounts of biomass every year, and also they decompose very quickly. The grasses also are high in nutrients, so once decomposed, they give the soil a lot of nutrients as well, which makes it very fertile and suitable for agriculture.
Boston, the biggest burg in New England, is located on a mountainous peninsula in Massachusetts Bay. The region had been inhabited since at least 2400 B.C. by the Massachusetts race of Native Americans, who assemble the peninsula Shawmut. Fearing more tension between Native Americans and settlers, England's King George III upshot the Proclamation of 1763, prohibiting residence westward of the Allegheny Mountains.
Because the earth is tilted on a axis and tilts differently to get the 4 different seasons
I don't believe that that is true due to the fact you can see soil even if there are no plants in it although im not 100% sure as soil and key components in it may be considered organic
