10. Soil and change Flashcards
Soil degradation
the physical loss (erosion) and the reduction in quality of topsoil associated with nutrient decline and contamination.
Soil profile
the vertical variations that occur in the characteristics of a soil from the surface to the underlying rock.
Universal soil loss equation
a mathematical model used to describe soil erosion processes.
Deforestation
the process of destroying a forest and replacing it with something else, especially by an agricultural system.
Overgrazing
the grazing of natural pastures at stocking intensities above the livestock carrying capacity.
Acidification
the change in the chemical composition of soil, which may trigger the circulation of toxic metals.
Salinisation
the condition in which the salt content of soil accumulates over time to above normal levels; occurs in some parts of the world where water containing high salt concentration evaporates from fields irrigated with standing water.
Soil aggregates
soil particles that are closely bound together are called peds or aggregates.
Desertification
the gradual transformation of habitable land into desert.
Dust storms
a severe windstorm that sweeps clouds of dust across an extensive area, especially in an arid region.
Soil buffering capacity
the capacity of soil to absorb contaminants.
Carbon farming
involves using the plants grown on a farm to ‘harvest’ carbon form the atmosphere and return it to the soil.
Soil structure
the shape and arrangement of aggregates gives soils a characteristic structure, e.g. blocky, platy, crumb or prismatic.
Perennial crops
crops that do not die off once harvested (annual crops), existing for years before reseeding may be required.
Afforestation
planting seeds or trees to make a forest on land has not been a forest recently, or which has never been a forest.
