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 active-stable flow.

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.

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