What is soil organic matter and why is it important?

• A. Decomposed Plant and Animal Residues That Improve Soil Structure, Water-Holding Capacity, and Nutrient Supply
• B. A Mineral Component
• C. A Synthetic Fertilizer
• D. A Type of Soil

Answer: (A)

Soil organic matter is the portion of the soil made up of decomposed plant and animal residues, plus the stabilized material that remains (like humus) and the living microbes that thrive in it. It’s important because it helps push soil structure into stable aggregates, creating better spaces for air and water to move and be stored. It boosts the soil’s water-holding capacity, so plants have moisture between rains or irrigation. It also supplies nutrients as the material slowly decomposes, and it supports soil life that helps make nutrients available to plants. Additionally, organic matter improves the soil’s capacity to hold onto nutrients, buffers pH, stores carbon, and reduces erosion.