thumb|Humus has a characteristic black or dark brown color and is an accumulation of Soil carbon|organic carbon. Besides the three major [[soil horizons of (A) surface/topsoil, (B) subsoil, and (C) substratum, most soils have an organic horizon (O) on the very surface. Hard bedrock (R) is not in a strict sense soil.]]
Humus is a dark-colored layer of organic material that accumulates on or near the soil's surface, formed from decomposed organic carbon. It matters because it represents a crucial organic component of soil that sits above the three main soil layers and contributes to soil structure and fertility.
AI-generated from the Wikipedia summary — may contain errors.
thumb|Humus has a characteristic black or dark brown color and is an accumulation of Soil carbon|organic carbon. Besides the three major [[soil horizons of (A) surface/topsoil, (B) subsoil, and (C) substratum, most soils have an organic horizon (O) on the very surface. Hard bedrock (R) is not in a strict sense soil.]]
Humus is the organic matter above the topsoil and below leaf litter which is finely divided having a high surface area. It is derived from decomposition of plant and animal substances. Humus, which ranges in colour from brown to black, is largely composed of Carbon, and contains high amounts of Nitrogen, and smaller amounts of Phosphorus and Sulfur. Humus retains moisture in the topsoil, in particular in soils with a coarse texture (e.g. sand). Humus is the Latin word for "earth" or "ground".
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).