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