Soil properties Flashcards
What is water holding capacity?
The total amount of water soil can hold
What does water retention contribute to?
Land productivity and fertility of the soil
Water holding capacity varies with:
different soil types
What does the particle size and composition of each soil horizon affect?
The porosity, permeability, and fertility of soil.
Why is it important to test the chemical, physical, and biological proper sites of soil?
The results can aid in a variety of decisions such as irrigation and fertilizer requirements.
What is a soil texture triangle?
A diagram that allows for the identification and comparisons of soil types based on their percentage of clay, silt, and sand
What three particles is the geologic (rock) portion of soil made up of?
From biggest to smallest: sand, silt, clay
What is soil texture?
The percentage of sand, silt, and clay in soil. It always adds up to 100%.
What is porosity?
The amount of pore space soil has
How does more sand in a soil affect porosity?
More sand in a soil means it is more porous/has a higher porosity because it’s easier for water and air to enter. Because sand is bigger, it has bigger pores.
How does more clay in a soil affect porosity?
More clay in a soil means it is less porous/has a lower porosity because it’s harder for water and air to enter. Clay has smaller pores, so it’s harder for air and water to enter clay-heavy soils.
What are soil pores?
Empty spaces between particles
What determines soil texture?
The percentage of clay, sand, and silt
How should you use a soil texture chart?
- start at the bottom with sand percentage
- move out to the point where sand and silt meet
- go straight over to clay
- make sure it adds up to 100%
What is porosity?
The pore space within a soil (more sand = more porous)
What is permeability?
How easily water drains through a soil
What is the water holding capacity of a soil?
How well water is retained/held by a soil
There is an inverse relationship between:
and a positive relationship between:
- porosity/permeability and water holding capacity
- porosity and permeability
When porosity goes up, what happens to permeability and water carrying capacity?
When porosity goes up, permeability goes up, and water carrying capacity goes down.
Higher porosity =
higher permeability and lower water holding capacity
How do porosity, permeability, and water carrying capacity relate to each other?
inverse relationship between porosity/permeability and water carrying capacity
what happens to plants when soil is too sandy?
the soil is too permeable so water drains too quickly for roots and the soil dries out
what happens to plants when the soil has too much clay?
clay-heavy soil doesn’t et water drain to roots or it waterlogs the roots, suffocating them
what is the ideal soil for plant growth? why?
the ideal soil for most plant growth is loam which balances porosity (drainage) with water holding capacity
