05 • Land Flashcards
(22 cards)
What are the four basic components of soil systems?
- Minerals
- Organic Matter
- Air
- Water
Each component plays a vital role in the soil’s ability to support life and facilitate plant growth.
What are the three essential minerals for plant nutrition?
- Phosphorus
- Nitrogen
- Potassium
These minerals are crucial for soil fertility and plant health.
What is organic matter in soil derived from?
Living or once-living organisms in the biosphere
This includes materials like leaf litter, manure, and dead animal biomass.
What gases are found in soil air that are essential for plant growth?
- Oxygen
- Carbon Dioxide
- Nitrogen
These gases diffuse into the soil’s pores and impact its chemical composition.
How does water influence soil?
It affects soil’s texture, structure, and ability to support life by influencing nutrient availability
Water enters soil through precipitation, humidity, or surface water.
What are the various functions of soil?
- Medium for Plant Growth
- Habitat for Organisms
- Store of Water
- Medium for Gas Exchange
These functions are essential for ecological balance and human agriculture.
What type of organic inputs are found in the soil system?
- Organic Material (plant litter, dead animals, manure)
These inputs break down to release nutrients essential for plant growth.
What inorganic inputs contribute to soil composition?
- Weathering and Deposition
- Precipitation and Air
Weathering releases minerals, while rainwater brings dissolved minerals into the soil.
What human activities can enhance soil productivity?
- Adding compost
- Using fertilizers
- Irrigation
However, these practices can lead to issues like salinization.
What are the natural outputs of the soil system?
- Erosion
- Leaching
- Mineral Uptake
- Evaporation & Gas Diffusion
These outputs can affect soil fertility and health.
What is leaching in the context of soil systems?
The process where water dissolves and carries away essential nutrients
This can deplete soil fertility, especially in areas with heavy rainfall.
What is infiltration?
The process by which water enters the soil from the surface
This provides moisture for plants and recharges groundwater.
What is percolation?
The downward movement of water through soil, carrying nutrients
Excessive percolation can lead to nutrient loss through leaching.
What is the role of biological mixing in soil?
Organisms like earthworms and insects mix organic matter and minerals
This enhances soil fertility and structure by distributing nutrients evenly.
What are the two types of weathering that contribute to soil formation?
- Physical Weathering
- Chemical Weathering
Physical weathering involves mechanical breakdown, while chemical weathering involves reactions with water and gases.
What is nutrient cycling?
The movement of nutrients through the soil, plants, and organisms
It involves the release of nutrients from decomposed organic matter.
What are the distinct layers of soil known as?
Horizons
The combination of these horizons forms a soil profile.
What is the O Horizon in soil?
The organic layer rich in decaying plant and animal matter
It is the topmost layer of the soil profile.
What is the A Horizon also known as?
Topsoil
This layer is fertile and nutrient-rich, where most plant roots grow.
What does the B Horizon contain?
Minerals leached from above but fewer nutrients
This layer is often referred to as subsoil.
What is the C Horizon made up of?
Partially weathered rock that forms the upper soil layers over time
It serves as the parent material for soil development.
What does the R Horizon consist of?
Unweathered rock that serves as a foundation for the soil layers above
It is the deepest layer in the soil profile.
