a vertical section through a soil showing its succession of horizons and the underlying parent material
The layer of soil that differs in color and texture from the layers above or below it.
rocks material whose weathering and gradual breakdown is the source of mineral portion of soil
breaks down compounds into simpler products
cause by erosion and weathering (factors: climate, topography, parent material, biological activity, time, human impact)
the chemical and physical processes that break down rock at Earth's surface
the structure of a soil based on the relative proportion of particle sizes (sand, silt, and clay) present within it.
is the smallest of soil particles, tightly packed with tiny grains - it feels smooth when dry and sticky when wet
Rich, fertile soil that is made up of about equal parts of clay, sand, and silt.
a type of soil that doesn't hold water well because the large particles allow the water to drain quickly
material formed from decaying leaves and other organic matter
Process in which various chemicals in upper layers of soil are dissolved and carried to lower layers and, in some cases, to groundwater.
movement of air into and through the soil
the process in which soil bacteria convert ammonium (NH4+) to a form that can be used by plants; nitrate, or NO3.
process in which fixed nitrogen compounds are converted back into nitrogen gas and returned to the atmosphere
process in which bacteria convert nitrogen gas into nitrogen compounds plants can use to make proteins
an erect or climbing bean or pea plant of the family Leguminosae
symbiotic bacterium that lives in nodules on roots of specific legumes and fixes nitrogen gas from the air into a form of nitrogen plants require
substances such as the chemicals nitrogen and phosphorus that are required by plants and animals for energy, growth, development, repair, or maintenance
N, P, K, Ca, Mg, S
vitamins and minerals, plants need eight in small amounts: chlorine, iron, boron, manganese, zinc, copper, molybdenum, and nickel.
damage to soil--for example, as a result of deforestation or the removal of topsoil from bare land by water and wind erosion
the process of moving sediment from one place to another
The depletion of vegetation due to the continuous feeding of too many animals.
The clearing and destruction of forests to harvest wood for consumption, clear land for agricultural uses, and make way for expanding settlement frontiers.
Total removal of the crops after harvest, this leaves the soil open to erosion.
Chemical compounds which convert to more toxic forms in the soil and water.
the artificial application of water to land to assist in the production of crops
Process that occurs when soils in arid areas are brought under cultivation through irrigation. In arid climates, water evaporates quickly off the ground surface, leaving salty residues that render the soil infertile.
Methods used to reduce soil erosion, prevent depletion of soil nutrients, and restore nutrients already lost by erosion, leaching, and excessive crop harvesting.