Organic phosphorus mineralization in wetland soils
The soil organic phosphorus (P) fraction in wetlands is derived from both internal (detrital matter from vegetation) and external (particulate matter loading) sources. Accumulation of the organic P fraction is directly linked to organic matter accumulation in wetlands. Organic P accounts for 30 to 90% of the total P in wetland soils, with lower values found in wetlands dominated by mineral soils and high values in wetlands dominated by organic soils. The methods used to determine organic P pools and their mineralization rates are in the developmental stage. This chapter provides an overview of the methods most commonly used by researchers. These include: (i) organic P fractionation to determine various pools including labile organic P, microbial biomass P, fulvic acid bound P, humic acid bound P, and residual P; (ii) laboratory methods to determine potential organic P mineralization rates; and (iii) field methods to determine organic P mineralization. The laboratory and field methods currently used by various researchers are operationally defined, have limitations, and the reader is cautioned to use these methods in that context; however, these methods do provide information on the behavior of organic P in wetland environments and are adequate for routine monitoring and assessment.