Here's a breakdown of why:
* O: Stands for organic matter.
* Horizon: A distinct layer of soil with specific characteristics.
The O horizon is composed of:
* Litter: Dead leaves, twigs, and other plant material.
* Humus: Decomposed organic matter, rich in nutrients.
* Living organisms: Microorganisms like bacteria and fungi that break down organic matter.
This layer is crucial for:
* Nutrient cycling: Decomposing organic matter releases nutrients that plants can absorb.
* Water retention: The O horizon helps to hold water, preventing erosion and drought.
* Soil structure: It provides structure and stability to the soil.
Remember that not all soils have a distinct O horizon. It is most common in forest soils, where leaf litter accumulates.
