Glossary
Aeration
The process by which air, water, and nutrients are able to penetrate and move through the soil. Good aeration is crucial for root respiration and microbial activity.
Example:
Compacted lawns often suffer from poor aeration, leading to shallow root systems and unhealthy grass, which can be improved by core aerating.
Cation Exchange Capacity (CEC)
The soil's ability to hold onto positively charged ions (cations), which are essential plant nutrients. Higher CEC indicates better nutrient retention and stable pH.
Example:
Soils rich in clay and organic matter typically have a high cation exchange capacity, meaning they can store more vital nutrients like calcium and potassium for plants.
Fertility
The soil's ability to provide essential nutrients (like nitrogen, phosphorus, and potassium) and other conditions necessary to support plant growth.
Example:
Crop rotation and the addition of organic fertilizers are common practices used by farmers to maintain or improve soil fertility over time.
Loam
A type of soil considered ideal for agriculture due to its balanced mixture of sand, silt, and clay particles, which provides optimal water retention and drainage.
Example:
Gardeners often seek out loam for their vegetable beds because its balanced texture supports robust plant growth and nutrient availability.
Permeability
The rate at which water and dissolved nutrients can move through the soil. It is higher in soils with larger, more connected pore spaces.
Example:
A soil with high permeability might be good for a rain garden, as it allows stormwater to quickly infiltrate rather than run off.
Porosity
The amount of empty space, or pore space, within the soil. It is higher in soils with larger particles.
Example:
Gravel has very high porosity, allowing water to drain through it almost instantly, unlike clay.
Soil Compaction
The process where soil particles are pressed together, reducing pore space and increasing soil density. This decreases porosity, permeability, and aeration.
Example:
Heavy machinery used in construction can cause severe soil compaction, making it difficult for new plants to establish roots and for water to infiltrate.
Soil Texture Triangle
A graphical tool used to classify soil types based on the relative percentages of sand, silt, and clay particles present in a soil sample.
Example:
Using the soil texture triangle, a scientist determined that a sample containing 40% sand, 40% silt, and 20% clay was a 'loam' soil.
Water-holding capacity
The amount of water that soil can retain against the force of gravity. It is influenced by particle size and organic matter content.
Example:
A farmer chose to add compost to their sandy fields to increase the soil's water-holding capacity, ensuring crops have enough moisture during dry spells.
pH (Soil pH)
A measure of the acidity or alkalinity of the soil, expressed on a scale from 0 to 14. It significantly influences nutrient availability and the types of plants that can thrive.
Example:
Blueberries prefer acidic soil, so a gardener might add sulfur to lower the pH of their garden bed to suit these plants.