NS SOIL Flashcards
what is the center of the earth called
molten (melted rock into liquid)
what is the other layer of the earth called
crust (= rocks and soil)
how thick is the crust?
between 4-8 km
what are the remains of animals and dead plants called that we find inside rock
fossils
what is humus
dead plant and animal material
what are the substances called that help plants and animal grow and are found in soil
nutrients
what is the rich soil filled with nutrients called?
topsoil
what is the land made up from?
rocks, topsoil and subsoil
what is soil
rock that has been broken down into small particles
what supports life on earth?
water, rock, soil, air
explain how all living things depend on soil
why do we say that soil supports life on earth
All living things needs plants to make food. Plants need soil to grow
name 2 purposes of soil
source of nutrients and hold the plants in place
what is subsoil
the layer of soil below topsoil
what does weathered mean
been broken down into small particles
what is soil made up off?
weathered rock (broken down pieces), humus (remains of dead plants and animals), air, water
name some living things in soil
plants, worms, small insects
true or false: the more humus (dead plant parts) soil has, the more fertile
true
why is topsoil darker?
it contains more humus
what is topsoil made up off?
living and dead plant and animal matter, minerals, nutrients, air and water
how can farmers know if the soil is fertile?
they can feel the soils quality and they can smell
what will the smell say?
if it has a strong smell, there are more nutrients (from dead plants and animals)
what are some characteristics of top soil?
darker, easily washed away by water, between 5 cm-20 cm thick, contains nutrients
what is soil erosion
when topsoil is lost
how can topsoil be lost? (how does erosion happen?)
when wind blows it away or water washes it away
why should we take care of topsoil?
it takes long to form
where does the topsoil come from?
from rocks broken down into tiny particles over a long period of time, mixed with dead plant parts
what 3 main soil types are there?
sand, clay, loam
say something about sandy soil
loose, coarse big particles, rough. cannot be rolled into a ball. light in color. lets water through
say something about clayey soil
small, fine particles, smooth, thick texture. easy rolled into a ball. Does not let water through, very dark brown
say something about loam
mixture of sand, clay and other particles so mixes sizes, let some water through, medium dark brown,
allowing water to pass through
drainage
do page 209 with mom
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do page 215 with mom
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Do page 216 with mom
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How can you increase humus in soil and make it more fertile
spread animal poo or dead plant material onto the soil
what is the word for the process when the body/plant breaks down into smaller parts?
decompose
Study page 14 on worksheet (name soils)
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What do you call it when we use resources carefully so they last?
conserve
