soil conserving Flashcards
What Is the physical structure of soil
Parent Material and organic material
Soil consists of four main parts what are they and what percentage of soil do they make up
Air -25%
Mineral grains- 45%
Organic matter -5%
Water-25%
How is sand formed
As rock surfaces weather and erode, small particles of sand are formed
How is silt formed
When the particles enter the water system
How is clay formed
If the particles are transported to a moist climate
Plants need what around their roots in order to thrive
Air
What do the plants need that’s in the air
Carbon dioxide
What happens when carbon dioxide is dissolved in water
It creates carbonic acid
What does water do to soil
It dissolves the nutrients in the soil so that the roots can absorb them
What does soil do
- filters water
- decomposes waste
- stores heat
- exchanges gasses
Half the volume of soil is what
Pore space
What are the techniques recommended to conserve soil
1) lengthen crop rotations by adding high residue crops
2) use cover crops when possible
3) reduce tillage (continuous no till)
4) rotate livestock among pastures
5) use mulch anywhere you have bare soil
What is shelter Belts
Are 3 lines of trees that are planted around edges of a field to prevent wind from blowing soil away
What are some advantages of shelter belts
- very easy
- inexpensive
- basically one full step until process is completed
What are some disadvantages of shelter belts
No main disadvantages
What is zero tillage
When machines are not taken onto the fields unless absolutely necessary.
Advantages of no tillage
- soil isn’t pressed down
- save money on gas
Disadvantages of zero tillage
The stubble may stop seeds from directly into soil
What Is crop rotation
Putting different crops on your field each year so you don’t have the same field 2 Years in a row
Advantages of crop rotation
- nutrients can build back up
- makes soil last longer
Disadvantages of crop rotation
-not all crops are a high price so it hurts farmers profits
What is strip farming
Playing different crops in rows in the same field, all crops should be at right angle against the wind
Advantages of strip farming
- soil lasts longer
- by planting by the right angle to roots, it holds soil in the right place
Disadvantages of strip farming
Way more difficult to harvest the crops b/c you cannot mix them
What is irrigation
Watering plants with special sprayers so more food can be grown in drier places
advantages of irrigation
more food grows
disadvantages of irrigation
costs a lot
uses up fresh water
what is the technique of use of specialty farm equipment
the use of special farming equipment that don’t cause as much damage to the soil
advantages of specialty farming equipment
- cuts weeds and grass without disturbing soil
- soil doesn’t get as impacted
disadvantages of specialty farming equipment
tools are expensive
most cereal crops need at least how much topsoil
18cm
how much topsoil do vegetables need
25-30cm
T or F, soil renews itself
true
in areas with moderate temperatures and moderate precipitation, how many years does it take to build 2.5 cm of soil
500 years
in hot, dry places, how many years does it take to build soil
2000 years
if the parent material is iron what colour can we expect the soil to be
reddish
if the parent material is calcium what colour can we expect the soil to be
whitish
what are some of the problems in agriculture
mechanization aging population start-up costs erosion and soil damage urbanization
why is soil formed in layers
the particles that make up soil are deposited at different times and from different places.
what do we call these soil layers
horizons
what are the 5 horizons
O horizon A horizon B horizon C horizon D horizon
what is the o horizon
organic material that gathers on top of the soil layers
what is the A horizon also called
topsoil
ideally how deep is the A Horizon
18cm
what is the B horizon also called
Subsoil
what is the B horizon
an accumulation of finely weathered material that have washed down from the A horizon
what does the B horizon act as
a storehouse of nutrients for the A horizon
what is the C horizon also called
Regolith
what is the D horizon also called
bedrock
what is the D horizon
the solid foundation on which all the other layers sit.
what is salination (calcification)
the accumulation of soil salts in the topsoil as heat evaporates the moisture out of the soil
what is capillary action
as surface water evaporates it is replaced by water further down in the soil profile
-nutrients can move upward
what is leaching
the process by which mineral salts in the upper horizons are moved downwards
