SOIL SCIENCE EXAM REVISION
QUESTIONS AND 100% CORRECT
ANSWERS!!
what are the two kinds of nutrient cycles
nitrogen and mineral cycles
Nitrogen cycle
the nitrogen comes entirely from the atmosphere where it occurs as a gas, a form hat plants
cannot use. Soil organisms convert gaseous nitrogen to forms that plans can use. Some nitrogen
recycles as once-living material decays in he soil, while water carries some nitrogen deeper into
the ground. Some nitrogen returns to the air when other microbes change it back to its original
form.
Mineral cycle
nutrients are released from rocks within he earth's crust when the rocks are broken down by
weather, plants, and other factors. These nutrients are continuously reused by plants until some
return deep into the ground by leaching, get washed into the ocean, or are removed by cropping.
what are the four needs that an individual plant depends on soil for
Anchorage, water, oxygen, and nutrients
Anchorage
how plants are firmly supported in he soil so they can grow o reach for sunlight.
Water
soil supplies the water a plant uses, because the roots are a plant's water absorbing body.
Oxygen
The soil air has less oxygen and more carbon dioxide than the atmosphere because of cellular
respiration. The resulting concentration gradients between soil and atmosphere cause oxygen to
diffuse into he soil and carbon dioxide out.
, Soil aeration
a process that exchanges soil and atmospheric air to maintain adequate oxygen for plan roots.
How many of the 17 nutrients needed for plants are provided by the soil
14
soil solution
plant nutrients dissolved in soil water.
pore spaces
open spaces or voids that exist between solid particles in the soil.
soil matrix
The arrangement of solid particles and pore spaces. Typically about half is solid material and
about half is pore space.
macropores
large pores that are largely responsible for easy movement of air and water in the soil.
Micropores
Small pores that retain water for plant use.
What matters from a root's point of view
Pores, as roots grow into he soil, hey follow continuous pore spaces between solid particles,
absorbing water and nutrients from he soil solution.
What are two important engineering properties of soil
Shrink-swell potential and load-bearing capacity.
soil quality
is he capacity of a specific soil o provide needed functions for human or natural ecosystems over
he long term.
QUESTIONS AND 100% CORRECT
ANSWERS!!
what are the two kinds of nutrient cycles
nitrogen and mineral cycles
Nitrogen cycle
the nitrogen comes entirely from the atmosphere where it occurs as a gas, a form hat plants
cannot use. Soil organisms convert gaseous nitrogen to forms that plans can use. Some nitrogen
recycles as once-living material decays in he soil, while water carries some nitrogen deeper into
the ground. Some nitrogen returns to the air when other microbes change it back to its original
form.
Mineral cycle
nutrients are released from rocks within he earth's crust when the rocks are broken down by
weather, plants, and other factors. These nutrients are continuously reused by plants until some
return deep into the ground by leaching, get washed into the ocean, or are removed by cropping.
what are the four needs that an individual plant depends on soil for
Anchorage, water, oxygen, and nutrients
Anchorage
how plants are firmly supported in he soil so they can grow o reach for sunlight.
Water
soil supplies the water a plant uses, because the roots are a plant's water absorbing body.
Oxygen
The soil air has less oxygen and more carbon dioxide than the atmosphere because of cellular
respiration. The resulting concentration gradients between soil and atmosphere cause oxygen to
diffuse into he soil and carbon dioxide out.
, Soil aeration
a process that exchanges soil and atmospheric air to maintain adequate oxygen for plan roots.
How many of the 17 nutrients needed for plants are provided by the soil
14
soil solution
plant nutrients dissolved in soil water.
pore spaces
open spaces or voids that exist between solid particles in the soil.
soil matrix
The arrangement of solid particles and pore spaces. Typically about half is solid material and
about half is pore space.
macropores
large pores that are largely responsible for easy movement of air and water in the soil.
Micropores
Small pores that retain water for plant use.
What matters from a root's point of view
Pores, as roots grow into he soil, hey follow continuous pore spaces between solid particles,
absorbing water and nutrients from he soil solution.
What are two important engineering properties of soil
Shrink-swell potential and load-bearing capacity.
soil quality
is he capacity of a specific soil o provide needed functions for human or natural ecosystems over
he long term.
