When a Horizon Loses or Gains Material

Introduction

• Soil horizons are distinct layers in the soil profile, each with specific characteristics.
• Changes in these horizons occur due to processes like eluviation, illuviation, and waterlogging.

Eluviation

• Eluviation is the process of material being washed out or leached from a soil horizon.
• It often affects the upper horizons (A and E) and leads to the loss of nutrients and minerals.
• Rainwater or percolating water carries dissolved substances downward.

Illuviation

• Illuviation is the opposite of eluviation and involves the accumulation of material in lower horizons.
• It typically occurs in the B horizon, where leached substances from above accumulate.
• Illuviation enriches the soil with minerals and organic matter.

Impacts of Eluviation and Illuviation

• Eluviation can deplete the topsoil of essential nutrients, affecting plant growth.
• Illuviation can create nutrient-rich subsoil, which may benefit vegetation.

Waterlogging

• Waterlogging is the saturation of soil with water, causing it to become waterlogged.
• It reduces oxygen availability in the soil, leading to anaerobic conditions.
• Plant roots may suffocate and suffer from oxygen deficiency.

Effects of Waterlogging

• Waterlogging can lead to poor plant growth and even plant death.
• It can result in soil erosion and compaction.
• Nutrient availability can be affected, leading to nutrient imbalances.

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What Happens When a Horizon Loses or Gains Material?

Summary

• Eluviation is the loss of material from soil horizons, while illuviation is the accumulation of material in lower horizons.
• Eluviation can lead to nutrient depletion, while illuviation can enrich the soil.
• Waterlogging, on the other hand, causes oxygen deficiency, impacting plant growth and soil structure.