Soil Flashcards
Humus
sticky, brown, insoluble residue from partially decomposed organisms
Topsoil
A horizon, mineral particles mixed with organic material, under surface litter
Subsoil
B horizon, accumulated clays and nutrients, sometimes develops hardpan layer
Sheet erosion
thin layer taken off land surface
Rill erosion
little rivulets of running water cut small channels in soil
Gully erosion
bigger channels of water that erode
Waterlogging
soil saturated with water, kills plants from lack of oxygen
Salinization
mineral salts accumulate in soil, saline irrigation
Soil fertility
capacity to supply nutrients (nitrogen, phosphorus, potassium) for plant growth
Soil porosity/infiltration
pore spaces filled with water=saturated, otherwise it is unsaturated
Infiltration
water through soil
Soil porosity
space between pores
Plasticity
high- soil likely to have excessively expand and contract on wetting and drying
Strength
ability of a soil to resist deformation
Cohesion
measure of the ability of soil particles to stick together
Friction
high in sand, strength of forcing particles together
Sensitivity
changes in soil strength resulting from disturbances such as vibrations or excavations
Compressibility
tendency to consolidate, decrease in volume, coarse- low comp
Erodibility
ease with which soil materials are removed by wind or water
Permeability
ease with which water moves through a material
Corrosion
slow weathering or chemical decomposition that proceeds from surface into ground
Ease of excavation
procedures required to remove soil during construction
Shrink-swell potential
tendency of soil to gain or lose water
