Soil Composition and Types in Ireland

Soil Composition

• Soil is composed of mineral matter, humus, water, air, and living organisms.
• Mineral matter is the largest component, derived from weathered bedrock. Examples include stones, sand, clay, and silt.
• Humus is a dark, jelly-like substance rich in nutrients, created by decaying plant and leaf matter. Humification is the process.
• Air fills the spaces between soil particles, essential for plant growth and providing oxygen for living organisms.
• Water dissolves minerals and nutrients, aiding plant absorption through roots.
• Living organisms such as earthworms, bacteria, and fungi contribute to soil mixing, nutrient cycling, and humus formation.

Soil Types in Ireland

• Ireland has four main soil types: Peat, Gley, Brown Earths, and Podzols.
• Peat soil: Found in bogs, black in colour, limited plant litter, high rainfall leading to waterlogging, and poor fertility.
• Gley soil: Blue-grey in colour, high rainfall and waterlogging, impermeable bedrock, and infertile.
• Brown Earths: Dark brown colour, found in the Midlands, South, and East of Ireland, plentiful plant litter, fertile, and good for arable farming.
• Podzols: Grey or light grey colour, coniferous forest areas, cold and wet, acidic, infertile, and best suited for forestry or grazing.

Soil Formation

• Soil formation factors include Bedrock, Relief, Climate, and Human Activity.
• Bedrock: Source of mineral matter. Some rocks weather quickly while others take longer, affecting the characteristics and time taken to form soil.
• Relief: Upland areas (higher) tend to be wetter and have less plant life, while lowland areas (lower) typically have well-drained soils with more humus.
• Climate: Rainfall and temperature influence weathering rates and soil depth. Cold regions have thin, slow-forming soils, while hot regions develop deep soils from rapid weathering,
• Human activity: Impacts soil composition; farming practices, irrigation, and deforestation can make soil more fertile or reduce its fertility impacting nutrients or leading to erosion and mass movement.

Soil Texture and Soil Acidity

• Clay soils are heavy, sticky, difficult to plough, and commonly used for dairy farming.
• Silt soils drain well but can get waterlogged with rainfall.
• Sand soils drain easily.
• Soil acidity, measured using the pH scale, affects plant growth. Optimal plant growth mostly occurs in a pH of 6.5.

Soil Processes and Exploitation

• Leaching: Process where water washes minerals and nutrients into lower layers or out of the soil. Excess leaching can lead to infertile soil.
• Overgrazing: Too many animals grazing in a limited area removes plant cover, exposing soil to wind and rain, causing erosion and reduced vegetation, potentially leading to landslides and further losses.
• Soil erosion: The removal of top soil, resulting from factors such as over grazing, deforestation, overcropping and climate change.
• Overcropping: Repeated farming of the same crop on the same land depletes nutrients and reduces soil quality.
• Deforestation: Removal of trees exposes the soil to the elements and reduces soil fertility

How Soil and Vegetation are Interconnected

• Soil is part of an ecosystem or biome.
• Ecosystems involve the interaction of plants, animals, and their environment.
• Soil and plants interact through the nutrient cycle.
• This cycle involves the continuous movement of elements like nitrogen, carbon, and iron between the soil and plants.

Case Studies

• Case studies of overgrazing in Ireland and human activity in Brazil illustrate the impacts of these practices on soil quality, fertility, and environmental consequences.
• Climate change-induced drought and desertification lead to famine, erosion of land, and migration.