Soil Phosphorus Mobilisation: Challenges and Opportunities

Mobilisation describes the release of phosphorus for onward transport, either into the plant or for wider transfers, out of the soil system. As well as the obvious importance of mobilisation for plant availability and uptake, wider topics are explored, including mobilisation of legacy phosphorus, mobilisation to water, and mobilisation in context with climate change, especially Arctic soils and riparian soils along river corridors. We also consider challenges of modelling phosphorus mobilisation and global inequalities in the use of fertiliser. This paper is a reminder that phosphorus mobilisation from soil to the plant is a strangely inefficient process, with many challenges remaining to make best use of phosphorus in local soil conditions. Despite this, understanding the role of mobilisation is increasingly relevant, as many soils, having received decades of legacy phosphorus in fertiliser, are starting to release phosphorus into the wider system, and changing climate may contribute to increased mobilisation over the longer term. Here we provide a contemporary global and long-term perspective on the controls, challenges and opportunities over phosphorus mobilisation from soil.