4-6 Flashcards
What is irrigation?
Irrigation is a technique that farmers use to make sure
that moisture gets into the soil for crop growth. It is
often a problem in grassland areas, where the moisture
evaporates quickly.
Irrigation systems (using natural waterways and
irrigation canals) can often be the life or death of a
crop and must be maintained to ensure adequate an
supply of water is available when it is needed.
How do foresters harvest trees?
Foresters explore a potential tree cutting area thoroughly
before any work begins. They map the area indicating
which trees to be cut and what special features should be
noted.
They also decide
how to cut the trees,
either clear cut
(removing all the trees)
or selective harvesting
(removing only selected
trees)
How do foresters reforest areas?
Foresters try to improve the
conditions (light, temperature, water,
and nutrients) within the forest. ,
leftover branches must be disposed
of. They are chopped (shredded),
spread over the forest floor, and
some smaller piles are burned.
Replanting is always done by hand.
When the trees begin to grow
again, if too many of a particular
kind compete, they must be removed
by thinning or pruning
Fertilizer is dropped from a
helicopter to improve the level of
nutrients for the young trees.
Forest fires are a natural
development of forests, but
foresters try to ensure that they
burn in a controlled fashion (as
much as possible)
What is desertification?
a process in which desert has
taken over much of the agricultural land
Which 5 factors determine how soil develops?
1) Parent Material – is the mineral
(non-organic) matter (rocks, soil,
clay) from which the soil developed
2) Climate – determines the kinds of
plants, and how fast they will
decompose. Warmth and moisture
are required for soil organisms to
break down plant and animal matter
and change it to a rich, dark soil
called humus. Humus holds nutrients
and water for plants
3) Vegetation – the vegetation
growing in the area determines the
amount and type of organic matter
in and on the soil. It also protects
the soil from erosion
4) Water – brings new soil and
nutrients. In healthy soil, spaces
between the particles hold water
and air for roots. If soil is saturated
with water, less oxygen is available
5) Time – all of these processes
happen over long periods of time
What are the 4 main types of decomposers?
Bacteria: actively break down
dead plant and animal tissue;
they are the most diverse and
numerous of all soil
organisms
Fungi: including mushrooms
and moulds, fungi make
nutrients available to the
plants and receive
carbohydrates in return
Microscopic Actinomycetes: are a
special type of bacteria that also
plat a vital role in decomposing
organic matter and forming
humus
Earthworms: eat the soil, grind,
digest, and mix it. They leave the
soil richer in nutrients than when
they took it in. Tunnels move air
and water through the soil, and
the mucus that the worms add
help soil particles stick together
What 6 basic nutrients do plants require from the soil?
Nitrogen
Phosphorus
Potassium
Sulfur
Calcium
Magnesium
What do the first, second, and third numbers on fertilizer mean?
The first number in a fertilizer formula is
the amount of nitrogen in the fertilizer –
which is used by plants for producing leaf
growth and greener leaves
The second number is the amount of
phosphorus – which is used by plants to
increase fruit development and to
produce a strong root system
The third number is the amount of
potassium – which is used by plants for
flower colours and size. It also helps
strengthen the plant
What is salinization?
The white ring around a body of water is salt, which has
run off the land into the water. This condition is called
salinization, and can have the same effect as a drought.
Which factors lead to increased salinization?
Not enough vegetation (water will enter the soil
because there is no vegetation roots to absorb it)
Ground water will evaporate and leave the minerals,
and the salts, behind
Too much water (added water just aids to the above
problem, depositing more minerals with no plant
absorption)
What is zero-tillage?
Farmers use special seeding equipment,
called seed drills, which push seed right through
the stubble (cut off) of previous crop as to not
disturb the soil or cause erosion.
What are the benefits and disadvantages of zero-tillage?
Benefits are: lower tillage costs, improved soil
structure, and more soil moisture for the next
crop
Disadvantages are: weeds and disease causing
organisms can only be killed with pesticide, rather
than with cultivation
What are shelterbelts?
When farmers plant
rows of trees along the edges of
fields, in order to modify waterways,
and help with crop rotation
What is hydroponics?
Hydroponics is a technique for growing plants without
soil.
Plants are usually grown in a non-organic growing
medium, such as gravel or ‘rock-wool’ (rock that has
been heated and spun) and nutrients are added to the
water.
In Canada, hydroponics is used
in greenhouses
