Soil production function

Soil production function refers to the rate of

bedrock In geology, bedrock is solid rock that lies under loose material ( regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of be ...

weathering Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs '' in situ'' (on site, with little or no movemen ...

into

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

as a function of soil thickness. A general model suggested that the rate of physical

of bedrock (de/dt) can be represented as an exponential decline with soil thickness:

de/dt = P_0 \exp

where ''h'' is soil thickness ''P₀'' m/yearis the potential (or maximum) weathering rate of bedrock and ''k'' ⁻¹is an empirical constant. The reduction of weathering rate with thickening of soil is related to the exponential decrease of

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied on ...

amplitude with increasing depth below the soil surface, and also the exponential decrease in average water penetration (for freely-drained soils). Parameters ''P₀'' and ''k'' are related to the

climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologica ...

and type of parent materials. found the value of ''P₀'' ranges from 0.08 to 2.0 mm/yr for sites in