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Background: The dynamics of phosphorus (P) in the environment is important for regulating nutrient cycles in natural and managed ecosystems and an integral part in assessing biological resilience against environmental change. Organic P (Po) compounds play key roles in biological and ecosystems function in the terrestrial environment being critical to cell function, growth and reproduction. Scope: We asked a group of experts to consider the global issues associated with Po in the terrestrial environment, methodological strengths and weaknesses, benefits to be gained from understanding the Po cycle, and to set priorities for Po research. Conclusions: We identified seven key opportunities for Po research including: the need for integrated, quality controlled and functionally based methodologies; assessment of stoichiometry with other elements in organic matter; understanding the dynamics of Po in natural and managed systems; the role of microorganisms in controlling Po cycles; the implications of nanoparticles in the environment and the need for better modelling and communication of the research. Each priority is discussed and a statement of intent for the Po research community is made that highlights there are key contributions to be made toward understanding biogeochemical cycles, dynamics and function of natural ecosystems and the management of agricultural systems

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Partitioning of 109Cd and 65Zn fractions in an alum shale soil as affected by time, temperature, and organic matter was investigated. The soil was extracted sequentially by H20 (F1), 1 M NH4OAc at pH 7 (F2), 1 M NH4OAc at pH 5 (F3), 0.04 M NH2OH HCl (F4), 30% H2O2 (F5), and finally by 7 M HNO3 (F6). Sequential extraction of metals was performed on soil samples collected at time intervals ranging from 0.5 to 8760 h (1 yr) after spiking the soil with 109Cd and 65Zn. The soil was placed incipiently in temperature controlled climate chambers at 9, 15, and 21°C. Before spiking, the soil was treated with 0 or 4% organic matter. Adsorption of 109Cd and 65Zn was rapid, but a subsequent slow diffusion of the metals toward chemisorbed fractions was also evident since the 109Cd and 65Zn concentrations decreased in the three mobile fractions (F1–F3) and increased in the inert fractions (F4, F5, F6 and F7) with time. Temperature elevation resulted in decreased concentrations of 109Cd and 65Zn in the F2 and F3 fractions, whereas the concentrations of these metals increased in the inert fractions. In the organic matter‐treated soil, 109Cd and 65Zn were increased significantly in the mobile fractions, with a corresponding reduction of 109Cd and 65Zn in the inert fractions. The effect of organic matter was more pronounced at 9°C than at 21°C. The results thus indicate that increasing time and temperature reduce the organic matter‐induced mobilization of 109Cd and 65Zn in soil.

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