Final answer:
Contrary to common assumptions, grassland soils generally have a higher organic matter content than forest soils due to the significant amount of roots and surface material they contribute to the soil, making grassland soils thicker and more fertile.
Step-by-step explanation:
Soils developed in forest settings tend to have lower organic matter content compared to those developed in grasslands. Forests add organic matter to the soil surface through the dropping of leaves and needles, creating a thin organic-rich layer over time. Grassland soils, on the other hand, have much thicker A horizons with high organic matter contents due to the considerable root and surface masses of grasses.
Soils are influenced greatly by the type of vegetation present. While forests do contribute leaf litter and other organic materials to the topsoil, forming an organic-rich A or O horizon, it is in grasslands where the soil tends to be richer in organic matter. This is because grasses contribute a considerable mass of roots and surface material that decomposes and enriches the soil. In grasslands, the A horizon is generally thicker and due to the substantial contribution from grass roots, it contains higher levels of organic matter, which leads to increased agricultural productivity. Furthermore, soil organisms crucial for nutrient cycling add to this organic compound richness, which benefits the soil structure and fertility. Climate also plays a significant role, with temperate climates supporting rich organic accumulation due to limited decomposition and reduced nutrient leaching.