IB ESS Topic 5
soil - correct answer ✔✔a complex ecosystem made up of minerals, organic material, gases and liquids
which forms the habitat for many species of plant and animal
soil storages - correct answer ✔✔the energy and matter within soil - organic matter, organisms,
nutrients, minerals, air and water
soil transfers - correct answer ✔✔biological mixing, translocation, leaching
translocation - correct answer ✔✔movement of soil particles in suspension (liquid)
leaching - correct answer ✔✔minerals dissolved in water moving through the soil
soil inputs - correct answer ✔✔organic matter from leaf litter and dead or decaying organisms -
inorganic matter from parent material (rock), precipitation and energy
soil outputs - correct answer ✔✔uptake by plants (minerals and water)
soil erosion
soil transformation - correct answer ✔✔decomposition or organic material taking place
weathering causes large particles (rocks) to become smaller
nutrient cycling within soil
minerals - correct answer ✔✔metal atoms and compounds which make up rocks - dissolved in water to
become an inorganic storage in soils
humus - correct answer ✔✔plant and animal material in the process of decomposition - generally the
top layer of soil
, soil horizons - correct answer ✔✔the layers of soil in a cross-section which is modified over time as
organic material leaches downwards and mineral material moves upwards
O (soil horizon) - correct answer ✔✔leaf litter - newly added organic material
A (soil horizon) - correct answer ✔✔mineral horizon at the surface showing organic matter enrichment -
where humus forms
B (soil horizon) - correct answer ✔✔subsoil horizon showing enrichment of clay material, iron aluminum,
or organic compounds - where soluble minerals and organic matter tends to be deposited from the layer
above
C (soil horizon) - correct answer ✔✔horizons of loosened or unconsolidated material - mainly weathered
rock from which soil forms
soil structure - correct answer ✔✔the proportions of clay <0.002mm particles, silt 0.002 - 0.05mm
particles, and sand 0.05 - 2mm particles
sandy soils - correct answer ✔✔gritty and fall apart easily - good drainage and air supply to the roots,
however, leaching is rapid
clay soils - correct answer ✔✔good nutrient retention, however, heavy soils which are relatively
impermeable and have poor drainage
loam soils - correct answer ✔✔roughly 40 - 40 - 20 sand, silt, clay
ideal for agriculture due to sand's drainage and porosity, clay's nutrient retention and silt keeping the
other two together
porosity - correct answer ✔✔e.g. high in sand soils, low in clay
the amount of space between particles in soil
soil - correct answer ✔✔a complex ecosystem made up of minerals, organic material, gases and liquids
which forms the habitat for many species of plant and animal
soil storages - correct answer ✔✔the energy and matter within soil - organic matter, organisms,
nutrients, minerals, air and water
soil transfers - correct answer ✔✔biological mixing, translocation, leaching
translocation - correct answer ✔✔movement of soil particles in suspension (liquid)
leaching - correct answer ✔✔minerals dissolved in water moving through the soil
soil inputs - correct answer ✔✔organic matter from leaf litter and dead or decaying organisms -
inorganic matter from parent material (rock), precipitation and energy
soil outputs - correct answer ✔✔uptake by plants (minerals and water)
soil erosion
soil transformation - correct answer ✔✔decomposition or organic material taking place
weathering causes large particles (rocks) to become smaller
nutrient cycling within soil
minerals - correct answer ✔✔metal atoms and compounds which make up rocks - dissolved in water to
become an inorganic storage in soils
humus - correct answer ✔✔plant and animal material in the process of decomposition - generally the
top layer of soil
, soil horizons - correct answer ✔✔the layers of soil in a cross-section which is modified over time as
organic material leaches downwards and mineral material moves upwards
O (soil horizon) - correct answer ✔✔leaf litter - newly added organic material
A (soil horizon) - correct answer ✔✔mineral horizon at the surface showing organic matter enrichment -
where humus forms
B (soil horizon) - correct answer ✔✔subsoil horizon showing enrichment of clay material, iron aluminum,
or organic compounds - where soluble minerals and organic matter tends to be deposited from the layer
above
C (soil horizon) - correct answer ✔✔horizons of loosened or unconsolidated material - mainly weathered
rock from which soil forms
soil structure - correct answer ✔✔the proportions of clay <0.002mm particles, silt 0.002 - 0.05mm
particles, and sand 0.05 - 2mm particles
sandy soils - correct answer ✔✔gritty and fall apart easily - good drainage and air supply to the roots,
however, leaching is rapid
clay soils - correct answer ✔✔good nutrient retention, however, heavy soils which are relatively
impermeable and have poor drainage
loam soils - correct answer ✔✔roughly 40 - 40 - 20 sand, silt, clay
ideal for agriculture due to sand's drainage and porosity, clay's nutrient retention and silt keeping the
other two together
porosity - correct answer ✔✔e.g. high in sand soils, low in clay
the amount of space between particles in soil
