What does organic matter improve in soil?

• A. Structure, infiltration, and nutrient retention
• B. Only pH stabilization
• C. Only microbial diversity
• D. Only water-holding capacity

Answer: (A)

Organic matter helps soil particles stick together into stable aggregates, which improves soil structure.That better structure creates connected pore spaces, so water infiltrates more readily and the soil resists crusting, facilitating root growth and gas exchange.Organic matter also boosts nutrient retention by increasing the soil’s capacity to hold onto nutrients and by providing a reservoir of nutrients that are released as it decomposes, helping nutrients stay available rather than washing away.All these effects together—better structure, improved infiltration, and greater nutrient retention—capture the main ways organic matter benefits soil. (It can also influence pH buffering, microbial habitat, and water storage, but the most comprehensive description is these three aspects.)