Garden with Insight v1.0 Help: Soil daily P cycling group
P as fresh organic in flat residue mineralized today by layer: Amount of fresh organic phosphorus mineralized by
microbes. Depends on soil water, temperature, and C:N and C:P ratios
in flat residue. 80% of mineralized fresh organic P goes into labile P;
20% returns to humus P in dead microbial biomass.
P as organic in humus mineralized today by layer: Amount of organic phosphorus mineralized to
labile phosphorus (by soil microbes). Depends on the same factors as does active humus nitrogen
mineralization -- uses the same equation.
P flow from labile to active mineral today by layer:
Equilibrium flow today from labile to active mineral phosphorus. If negative, flow is from active mineral
to labile P. Based on 'P sorption ratio', the fraction of labile P expected to
enter the active mineral state soon after labile P application.
P flow from active to stable mineral today by layer: Equilibrium flow today from active (loosely bound) to stable (tightly bound)
mineral phosphorus. If negative, flow is from stable to active mineral P. Based on maintaining ratio of 1:4 active to stable mineral P.
P mineral flow coefficient today by layer: Proportion of excess active mineral phosphorus that
moves into stable mineral P each day. Determined by the P sorption
coefficient, which is the equilibrium ratio of labile to mineral P. The higher the labile P ratio, the slower the
P sorption coefficient today by layer: The equilibrium ratio of
labile to mineral P, or the fraction of labile P expected to enter the active mineral state soon after labile P
application. Determined by soil texture (sand/silt/clay) and soil weathering.