Soil and Infiltration Flashcards
What is regolith?
A region of loose unconsolidated rock and dust that sits atop a layer of bedrock
What is the vadose zone?
The unsaturated soil space between the land surface and the water table
What is parent material?
The base geologic material of soil
What is organic matter
Living and dad microorganisms as well as decaying plants and animal materal
What is a horizon
each layer of soil
What is a soil profile?
The cross-section of soil as a whole
What is top soil?
Inorganic and organic material most nutritive for plants
What is leaching?
Dissolved particles moving through horizons
What is litter?
Surface deposits of leaves, branches, mosses, animal waste
What is the O horizon composed of?
Organic material
What is the A horizon composed of?
Mainly mineral
What is the E horizon composed of?
Fine particles move down, water leaches the more soluble minerals
What is the B horizon composed of?
Accumulation zone for fine-grained particles
What is the R horizon composed of
Unweathered bedrock
What is fertilizer?
Substances that contain essential nutrients, but over-application can damage soils
What are inorganic fertilizers?
Mined or synthetically manufactured mineral supplements
What are organic fertilizers
The remains or wastes of organics
What is compost?
Produced when decomposers break down organic material
What is weathering?
The physical, chemical or biological processes that break down rocks to form soils
What is physical weathering?
Wind, rain, no chemical change in parent material
What is chemical weathering?
Substance chemically interact with parent material
What is biological weathering?
Organisms break down parent material
What is humus?
A dark, spongy, crumbly mass of material formed by partially decompostion
What is erosion
The dislodging and movement of soils by wind or water
What does soil colour indicate?
Its composition, water content and fertility
What does black or dark brown soil indicate?
Rich in organic matter, higher water content
What does pale gray or white soil indicate?
Leaching, less water content
Soil texture
the size of particles
What is the order of soil texture (smallest to largest)
clay, slit, sand, gravel
Porosity
Measure of the relative volume of spaces within the material
Permeability
Measure of interconnectedness of space and the ease with which fluids can move through the material
Does clay have a high or lower porosity?
Highest porosity
Does clay have a high or low permeability
Low permeability
What is loam?
Soil with an even mixture of clay, slit and sand
What is soil structure?
A measure of soil’s “clumpiness”
What is plowpan
A hard layer resulting from repeated plowing that resists water infiltration and root penetration
What is soil pH
Influences a soil’s ability to support plant growth
What is liquid limit?
Upper limit of water content for the soil to exhibit plastic behaviour
What is plastic limit
Lower limit of water content for the soil to exhibit plastic behaviour
Shrinkage limit
the transition from plastic to soil behaviour; not volume change with further drying
Plasticity
The ability of a soil to undergo unrecoverable deformation at constant volume without cracking or crumbing
