Soil organic matter

Definition

Soil organic matter is the fraction of soil that is composed of plant and animal residues at various stages of decomposition, along with the microorganisms that feed on them. This component of soil plays a crucial role in enhancing soil fertility, improving structure, and supporting water retention, which are essential for agricultural adaptation and resilience in food systems.

5 Must Know Facts For Your Next Test

1. Soil organic matter can improve the physical properties of soil, such as aeration and drainage, which are vital for root development.
2. This organic component helps to sequester carbon in the soil, contributing to climate change mitigation efforts by reducing greenhouse gas emissions.
3. Healthy levels of soil organic matter can enhance biodiversity in the soil ecosystem, supporting a variety of organisms that promote nutrient cycling.
4. The presence of adequate soil organic matter is linked to improved resilience against drought and flooding, making it crucial for sustainable agriculture.
5. Regular practices like crop rotation and cover cropping can increase soil organic matter content over time, leading to more resilient food systems.

Review Questions

• How does soil organic matter contribute to the overall health of agricultural systems?
  • Soil organic matter contributes significantly to agricultural health by enhancing soil structure, fertility, and moisture retention. It provides essential nutrients for plant growth and supports microbial activity, which is vital for nutrient cycling. By improving these aspects, healthy soil organic matter leads to increased crop yields and greater resilience against environmental stressors.
• Evaluate the impact of increased soil organic matter on food system resilience in the face of climate change.
  • Increased soil organic matter directly enhances food system resilience by improving soil health and fertility, which allows crops to better withstand extreme weather events such as droughts or heavy rains. It also plays a key role in carbon sequestration, helping mitigate climate change effects. With healthier soils, farmers can adapt their practices more effectively, ensuring consistent food production despite changing climatic conditions.
• Assess how practices aimed at increasing soil organic matter could influence long-term agricultural sustainability and food security.
  • Practices that increase soil organic matter—like cover cropping, reduced tillage, and composting—can significantly enhance long-term agricultural sustainability by maintaining soil health and fertility over time. These methods lead to improved water retention, nutrient availability, and biodiversity within the soil ecosystem. Consequently, this bolsters food security by ensuring reliable crop yields even under adverse conditions, fostering a more stable food supply for communities.

Related terms

humus: Humus is the stable, well-decomposed organic matter found in soil that contributes to soil fertility and structure.

soil fertility: Soil fertility refers to the ability of soil to provide essential nutrients to plants, which is often influenced by the presence of organic matter.

composting: Composting is the process of decomposing organic matter, such as kitchen scraps and yard waste, into a nutrient-rich soil amendment known as compost.