Function describing exponential decline from a defined starting value, with a decreasing rate constant.

The form given here differs slightly from the original reference by Gustafson
and Holden (1990). The parameter `beta`

corresponds to 1/beta in the
original equation.

1 |

`t` |
Time. |

`parent.0` |
Starting value for the response variable at time zero. |

`alpha` |
Shape parameter determined by coefficient of variation of rate constant values. |

`beta` |
Location parameter. |

The value of the response variable at time `t`

.

The FOMC kinetic model reduces to the `SFO`

kinetic model for
large values of `alpha`

and `beta`

with
*k = beta/alpha*.

Johannes Ranke

FOCUS (2006) “Guidance Document on Estimating Persistence and Degradation Kinetics from Environmental Fate Studies on Pesticides in EU Registration” Report of the FOCUS Work Group on Degradation Kinetics, EC Document Reference Sanco/10058/2005 version 2.0, 434 pp, http://focus.jrc.ec.europa.eu/dk

Gustafson DI and Holden LR (1990) Nonlinear pesticide dissipation in soil: A
new model based on spatial variability. *Environmental Science and
Technology* **24**, 1032-1038

1 | ```
## Not run: plot(function(x) FOMC(x, 100, 10, 2), 0, 2)
``` |

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